Download Conservation of Vegetation in Africa South of the Sahara

ACTA PHYTOGEQGRAPHICA SUECICA 54
EDIDIT
SVENSKA VAXTGEOGRAFISKA SALLSKAPET
Conservation of Vegetation
in Africa
South of the Sahara
Proceedings of a symposium held at the
6th Plenary meeting of the "Association pour
l'Etude Taxonomique de la Flore d'Afrique Tropicale" (A.E.T.F.A.T.)
in Uppsala, Sept. 12th-16th, 1966
Edited by lnga and Olov Hedberg
ALMQVIST
&
UPPSALA 1968
WIKSBLLS BOKTRYCKBRI AB
C O N S E RV AT I O N O F V E G ETAT I O N I N AF R I CA
S O U T H O F T H E SAHARA
At the fringes of the grassy plains the trees suffer continually from the repeated fires, and gradually all tree growth disappears.
Tanzania, near Mbeya, Photo P. R. 0. Bally, 1956.
ACTA PHYTOGEOGRAPHICA SUECICA 54
Conservation of Vegetation
in Africa
South of the Sahara
Proceedings of a symposium held at the
6th Plenary meeting of the "Association pour
l'Etude Taxonomique de ]a Flore d'Afrique Tropicale" (A.E.T.F.A.T.)
in Uppsala, Sept. 12th-16th, 1966
Edited by Inga and Olov Hedberg
UPPSALA 1968
Illustrations printed with
contribution
from Langmanska Kulturfonden
Printed in Sweden by
Almqvist
& Wiksells Boktryckeri AB
Uppsala 1968
CON T E NT S
Foreword, 0. Hedberg
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INTRODUCTION
Why conserve natural vegetation, B. Verdcourt
Soil resource·s ·and land use in Tropical Africa,
W. Allan
The influence of fire in Trans-Saharan Africa,
J. F. V. Phillips . . . . . . . . . . . . . . . . . . . . . . .
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Congo-Brazzaville, C. Farron
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C�meroun, R. Letouzey .
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Congo-Kinshasa, R. Germain
Rwanda, P . Deuse
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Burundi, J. Lewalle
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Fernando Po, E. Guinea
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Principe, S. Tome and Annobon, A .
Synthes·e regionale, A . A ubreville . .
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Nature conservation and forest clearance in
Africa with special reference to some eco­
logical impJications of Tsetse control, R.
Goodier . . . . . . .. . . . . . . . . . . . . . . . . . . . . . .
Zoological aspects on the conservation of vegeta­
tion in Tropical Africa, K. Curry-Lindahl . . . .
La conservation des habitats: Problemes. de definitions et de choix, Th. Monad . . . . . . . .
Les Pares N ationaux comme archives de re­
cherches et de documentation de !'evolution
des especes, K. Curry-Lindahl . . . .. . . :
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Education towards conservation of nature in
Tropical Afri'ca, M. Steentoft . . . . . . . . . . .
The IBP J CT Survey of areas of significance to
conservation, G. Peterken . . . . . . . . . . . . . . .
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WEST TROPICAL AFRICA
Senegal, J. G. A dam . . . . . . . . . . . . . . . . . .
Guinee, R. Schnell . . . . . . . . . . . . . . . . . . . .
Sierra Leone, J. K. Morton . . . . . . . . . . .
Liberia, A. G . Voorhoeve . . . . . . . . . . . . .
La Cote d'Ivoire, E. A djanohoun, L. A ke
& J. L. G uillaumet
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Ghana, G. W . Lawson . . . . . . . . . . . . . . . .
L e Dahomey, E . A djanohoun . . . . . . . . .
Nigeria, J . R. Charter . . . . . . . . . . . . . . . . .
L'archipel du Cap-Vert, L . A . Grandvaux
hosa
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Regional synthesis, F. N. Hepper . . . . . . .
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CENTRAL AFRICA
Repub1ique Centrafricaine, G. G uigonis .
Gabon, F. Halle & A . Le Thomas . .. .
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Ethiopia, E. W. Beals . . . . . . . . . . . . . . . . .
French Somaliland, B. Verdcourt . . . . . . .
Somali Republic, North, C. F. Hemming
Somali Republic, South, P . R . 0. Bally
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Uganda, H. A . Osmaston . . . . . . . . . . . . .
Kenya, G. Ll. Lucas . . . . . . . . . . . . . . . . . .
Tanzania, R. Polhill
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Socotra, M. D. Gwynne
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Regional synthesis, B. Verdcourt . . . . . . .
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SOUTH TROPICAL AFRICA
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Angola, J. Brito Teixeira . . . . . . . . . . . . .
Bechuanaland protectorate, H. Wild
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Rhodesia, H. Wild
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Zambia, F. White
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Marawi, J. D. Chapman
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Moc;ambique, L. A . Grandvaux Barbosa
Regional syn�hesis, H. Wild ..
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EAST AFRICA
ZONE SAHELIENNE
La Mauritanie, J. G. Adam
Mali, P. Jaeger . . . . . . . . . . . . . . . . . . . . . . . . .
Tchad et Sahel tchadien, H. Gillet . . . . . . . . .
Sudan, E. A. Bari . . . . . . . . . . . . . . . . . . . . .. .
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SOUTH AFRICA
Cape Province, H. B. Rycrojt . . .
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Transvaal, J. B. Killick
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Natal, A. W. Bayer, R. C. Bigalke & R . S. Crass
The Orange Free State, B. R. Roberts . . .
South West Africa, W. Giess & K. L. Tinley
Lesotho, A . Jacot-Guillarmod . . .. . . . . . .
Swaziland, R. H. Compton
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Regional synthesis, L. E. Codd .. . . . . .
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MADAGASCAR AND THE MASCARENES
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Madagas·car, M. Keraudren
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Mauritius and Rodriguez, R . E . Vaughan
La Reunion, P. Rivals . . . . . . . . . . . . . . . .
Seychelles, C. Jeffrey . . . . . . .
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Synthese regionale, M. Keraudren . . . . .
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VI
APPENDIX
PROGRESS IN THE PREPARATION OF
AFRICAN FLORAS
Especes de souche africaine n!cemment decou­
verr t es au Sahara, P. Quezel . . . . .. . . . . . . . .
Gabon, Cameroun : Progres accomplis par le
Laboratoire de Phanerogamie du Museum de
Pari s, A. Le Thomas . . . . . . .. . . . .. . . . . .
West Tropical Africa, F. N. Hepper . . . . . . . .
Nigeria, D. P. Stanfield . . . . . . . . . . . . . . ... . ..
Congo, Rwanda & BLtrundi, J. Leonard . .. . ..
Ethiopia: Adumbratio Florae Aethiorpicae, R .
E . G . Pichi Sermolli . . . .. . . . . . . . . . . . .. . .
Ethiopia: Enumeratio Plantarum Aethiopiae, G .
Cufodontis . . . . . . .. . . . . . .. . . . . . . . . . . . . .
Tropical East Africa, E. Milne-Redhead . . . . . .
Kenya uplarids, A . D. Q. A gnew . . . . . . . . . . . .
Angola, A . F ernandes .. . . .. . . . . . . . . . . .. . .
Bechuanaland, Rhodesia, Zambia,. Malawi & Mo�ambique: Flora Zambesiaca, A . W. Exell . .
South Afri>ca, Lesotho, Swaziland & South West
Africa: Flora of Southern Afri·ca, L. E. Codd
South West Africa, H. Merxmuller .. . . . . . . ..
Madagascar et les Comores, M. Keraudren . .
Sur un eventuel Genera Plantarum Africanarurn
(Revision de "Genera" de Thonner), Th. Manod
297
Statistiques des progres accomplis en 13 ans
dans la connaissance de la flore phaneroga­
rnique africaine et malgache (1 953-1 965),
J. Leonard . . . . . . . . . . .. . . .. . . . . . . . . . . . . 297
Flores ou Monographies. Discussion . . . . . . . 299
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PROGRESS IN THE MA PPIN G OF THE
AFRICAN FLORA
The new A.E.T.F.A.T. map of the vegetation of
Africa , F. White . . . .. . . . . . . . . . . . . . . . . . . .
Different standard outline maps of Africa . . . .
A proposed atlas of ecologically important plant
species in Africa, F. White . . . .. . . . . . . . . .
Repartition des especes vegetales Ouest A.fricaines, J. G. Adam . . . . .. .. . . . . . . . . . .. . . .
Progress in the preparation of a vegetation map
of the Fl·ora Zambesiaca area, H. Wild . . ... .
Progress i n the mapping o f the vegetation of
South Afr'ica, D. J. B. Killick . . . . . . . . . .. ..
La ·carte de vegetation d e Madagas·car, M . Keraudren
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3 1 :3
VII
Map showing the location of the territories treated in this book. A number of the islands which are likewise treated do not appear
on the map, viz. Cape Verde Islands, Socotra, the Seychelles, Reunion, Mauritius, and Rodriguez.
A F R I C AN S I T E S O F S C I E N T I F I C I NT E R E S T I N U R G E N T
N E E D O F P R OT E C T I O N
Cape Verde Is. : Pico da Antonia (on Santiago)
Mauritania: Atar region, maintenance of fenced
areas
Senegal: Diantem-Guibourtia forest
Mali: Kita-Toukoto-relict forests of Gilbertioden­
dron glandulosum
Guinea: Mt. Gangan
Sierra Leone: Loma and Tingi Mountains-upland
savanna, montane forest, tropical rain forest
Liberia: the present National Forest of Vai and Sapo
(or Krahn-Bassa) to be designated protected areas
Ivory Coast, Tonkoui Mountains
Ghana: W. Accra Plains-thickets in coastal savanna
Togo Republic: sites at Palime-thick humid rain
forest
Dahomey: Savalou-Dassa, site of Encephalartos
N. Nigeria: M ambila Plateau
E. Nigeria: Oban Forest Reserve
Cameroun: Cameroun Mountain-montane grassland
and forest
Sao Tome: Pico-montane forest
Principe: Papageio Peak-summit forest
Annobon: summits of Santa Mina, Quioveo and Pico
do Fogo
Congo-Kinshasa: Lukaya River, Kimuenza
Rwanda: effective protection of Kibira Forest
Burundi: part of lakes of mid Nyabarongo with savanna woodland
Sudan Republic: Jebel Marra
Ethiopia: High Simien
French Somaliland: Dai Forest
Somaliland Republic: Proposed Cordeauxia reserve
Socotra: area to the E. of Hadibo
Uganda: Lake Nabugabo-swamp
Kenya: Kakamega Forest-most easterly point of the
Western type forest
Tanzania: Usambara Mts.-range of types from moist
lowland to dry montane forest
Mozambique: Chipenhe, Gaza dist.-sacred forest of
Chirindzeni
Malawi: Malawi Hills-lowland rain forest
Rhodesia: a site of A ndrostachys johnsonii
Botswana: Central Kalahari Reserve
Zambia: establishment of a reserve at Matonchi farm,
M�inilunga dist.-floristically rich savanna wood­
l and
Angola: maintenance of existing reserves
Madagascar: maintenance .of existing res·erves and
protection of endemic families Didiereaceae and
Sarcolaenaceae etc.
Seychelles: Central Mahe with its outlier Mount
Sebert
Rep. of S. Africa: L. Bangwazi, N. Natal-swamp
forest
LI S T O F C O N T R I B U T O R S
J. G. Adam, 24 rue de Juvisy, F 9 1 Athis Mons,
France.
E. Adjanohoun, B . P. 8090, Abidjan, Cote d'lvoire.
A. D. Q. Agnew, Botany Dept., University College
Nairobi, P.O. Box 3 0 1 97, Nairobi, Kenya.
L. Ake Assi, Laboratoire de Botanique, Universite,
B.P. 4322, Abidjan, Cote d'Ivoire.
W. A llan, "Reduit", Le Yariouf Forest, Guernsey,
Channel Islands, England.
A. A ubreville, Laboratoire de Phanerogamie, Mu­
seum National d'Histoire Naturelle, 1 6 rue de Buf­
fon, Paris ye, France.
P. R. 0. Rally, Conservatoire Botanique de l'Uni­
versite, 1 92 Route de Lausanne, Geneve, Suisse.
P. Bamps, 127 Avenue G. E. Lebon, Bruxelles 1 6,
Belgique.
L. A . Grandvaux Barbosa, Institute de Investigacao
Cientifica de Angola, Estudos Gerais Universitarios
de Angola, C.P. 3244, Luanda, Angola.
Ekhlas Bari, Mrs, Eva Smith House, 1 6 Grange
Road, Cambridge, England.
A . W. Bayer, 14 Greenacre Place, Kloot, Natal.
E. W. Beals, Botany Dept., University of Wisconsin,
Madison, Wisconsin 53706, U.S.A.
R. C. Bigalke, Natal Parks, Game & Fish Preserva­
tion Board, Pietermaritzburg, Natal.
J. D. Chapman, c j o Tilhill Forestry (Scotland) Ltd.,
High Birkby Nab, Ripon, Yorkshire, England.
J. R. Charter, Federal Dept. of Forest Research,
Ibadan, Nigeria.
L. E. Codd, Chief of Botanical Research Institute,
P.O. Box 994, Pretoria, South Africa.
R. H. Compton, Botanical Survey of Swaziland,
Mbabane, Swaziland.
R. S. Crass, Natal Parks, Game & Fish Preservation
Board, Pietermaritzburg, Natal.
G. Cufodontis, Reisnerstrasse 15 J 5, Wien 3 , Austria.
K. Curry-Lindahl, Zoological Dept., Nordiska Museet
and Skans·en, Stockholm, Sweden.
P. Deuse, Institut National de Recherche Scientifique,
B.P. 80, Butare, Rep. Rwandaise.
A . W. Exell, Commonwealth Forestry Institute, Ox­
ford, England.
C. Farron, Centre ORSTOM, Brazzaville. Actuelle­
ment: Botanisches Institut der UniversiUit, Schon­
beinstrasse 6, CH 4056 Basel, Suisse.
A. Fernandes, Institut Botanique de l'Universite de
Coimbra, Coimbra, Portugal.
R. Germain, Laboratoire d'Ecologie Yegetale, He­
verle-Louvain, Belgique.
W. Giess, Dept. of Agriculture, Windhoek, S.-W.
Africa.
H. Gillet, Museum National d'Histoire N aturelle,
Agronomie tropica·le, 57 rue Cuvier, Paris ye, France.
R. Goodier, The Nature Conservancy, Bangor, North
Wales, Gr·eat Britain.
G. Guigonis, Le Conservateur des Eaux, Forets et
Chasses de la Republique Centrafricaine, B.P. 830,
Bangui, Rep. Centrafricaine.
J. L. G uillaumet, ORSTOM, Institut d'Adiopodoume,
B.P. 20, Abidjan, Cote d'Ivoire.
E. Guinea, Jardin Botanico, Plaza de Murillo n° 2,
Madrid, Spain.
M. D. Gwynne, E.A.A.F.R.O., Muguga, P.O. Box
301 48, Nairobi, Kenya.
N. Halle, Laboratoire de Phanerogamie, Museum
National d'Histoire Naturelle, 1 6 rue Buffon, Paris Ye,
France.
C. F. Hemming, 8, Guards Club Road, Maidenhead,
Berkshire, England.
F. N. Hepper, The Herbarium, Royal Botanic
Gardens, Kew, Richmond, Surrey, England.
A. Jacot Guillarmod, Mrs, Botany Dept. , Rhodes
University, Grahamstown, C.P., South Africa.
P. Jaeger, Faculte de Pharmacie, 2 rue St. Georges,
Strasbourg, France.
C. Jeffrey, The Herbarium, Royal Botanic Gardens,
Kew, Richmond, Surrey, England.
M. Keraudren, Mlle, Museum National d'Histoire
Naturelle, Laboratoire de Phanerogamie, 1 6 rue de
Buffon, Paris ye, France.
D. J. B. Killick, Botanical Research Institute, P.O.
Box 994, Pretoria, S. Africa.
G. W. Lawson, Botany Dept., University of Ghana,
Legon, Ghana.
J. Leonard, 19 rue de Decembre, Bruxelles 1 5, Bel­
gique.
A . Le Thomas, Mme, Laboratoire de Phanerogamie,
Museum National d'Histoire Naturelle, 1 6 rue Buf­
fon, Paris ye, France.
R. Letouzey, Laboratoire de Phanerogamie, Museum
X
National d'Histoire Naturelle, 1 6 rue Buffon, Paris
France.
ye,
J.
Lewalle, Dept. de Botanique, Universite Officielle
de Bujumbura, B .P. 1550, Bujumbura, Burundi.
L. Liben, 1 2 Av. Capitaine Piret, Bruxelles 15, Bel­
gique.
G. Ll. Lucas, The Herbarium, Royal Botanic
Gardens, Kew, Richmond, Surrey, England.
H.
Merxmiiller, Botanische Staatssammlung, Men­
zinger Str. 67, D 8000 Miinchen 1 9, Germany.
E.
Milne-Redhead, The Herbarium, Royal Botanic
Gardens, Kew, Richmond, Surrey, England.
A . 0. D. Mogg, Dept. of Botany, University of
Witwatersrand, P.O. B ox 1 1 76, Johannesburg, Rep.
of S. Africa.
Th. Monad, Laboratoire des Peches Outre-Mer,
Museum National d'Histoire Naturelle, 57 rue Cu­
vier, Paris ye, France.
J. K. Morton, Dept. of Biology, University of Water­
loo, Waterloo, Ontario, Canada.
H. A . Osmaston, Dept. of Geography, The Uni­
versity, Bristol 8, England.
G. F. Peterken, Biological Records Centre, Monks
Wood Experimental Station, Abbots Ripton, Hunt­
ingdon, U.K., formerly Scientific Co-ordinator
IBP J CT.
E. Petit, Rijksplantentuin, Koningstraat 236, Bruxel­
les, Belgique.
J. F. V. Phillips, P.O. Box 375, Pietermaritzburg,
S. Africa.
R. E. G. Pichi Sermolli, Js.tituto Botanico "Hanbury"
dell'Universidt, Corso Dogali 1 'c , Genova, Italy.
R. M. Polhill, The Herbarium, Royal Botanic Gar­
dens, Kew, Richmond, Surrey, England.
P. Quezel, Faculte des Sciences de St. Jerome, Bo­
tanique, Traverse de la Barasse, 1 3 Marseille, France.
P. Rivals, Le Caussetier, Portet-sur-Garonne, France.
B. R. Roberts, University of the Orange Free· Stat�,
Bloemfontein, Orange Free State.
ll. B. Rycroft, National Botanic Garden, Kirsten­
bosch, Newlands, C.P., South Africa.
R. Schnell, Laboratoire de Botanique tropicale, Fa­
culte des Sciences de Paris, 4 Cite Cardinal Lemoine,
Paris ye, France.
D. P. Stanfield, Department of Botany, University of
Ibadan, lbadan, Nigeria.
M. Steentoft, Mrs, Institute of Biology, Royal Danish
College of Education, Copenhagen, Denmark.
J,. Brito Teixeira, Agronomical Research Institute of
Angola, C. Postal 406, Nova Lis boa, Angola.
K. L. Tinley, Dept. of Nature Conservation and
Tourism, Okaukuejo, S.-W. Africa.
R. E. Vaughan, The Herbarium, Mauritius Sugar
Industry Research Institute, Reduit, Mauritius.
B. Verdcourt, The Herbarium, Royal Botanic
Gardens, Kew, Richmond, Surrey, England.
A . G. Voorhoeve, P.O. Box 436, Paramaribo, Suri­
name.
F. White, Dept. of Forestry, Commonwealth Forestry
Institute, South Parks Road, Oxford, England.
H. Wild, Dept. of Plant Science, University College
of Rhodesia, P.B. 167 H, Salisbury, Rhodesia.
Editors:
I. and 0. Hedberg, Institute of Systematic Botany,
P.O. Box 123 , S-75 104 Uppsala, Sweden.
F O R EW O RD
In recent years the intensified exploitation of tropical
and subtropical countries necessitated by the popula­
tion explosion has led to wholesale destruction of
nature over vast areas-to the extent that several
natural ecosystems are on the verge of extinction.
The seriousness of this development was first realized
by zoologists, and already long ago steps were taken
to save some of those animal species that were
particularly menaced. Botanists and ecologists were
slower to react, but today it is being realized by an
increasing number of people and national institutions,
as well as by international bodies like UNESCO and
FAO, that urgent measures are required if we want
to save representative samples of most tropical eco­
systems before it is too late.
When, in the capacity of general secretary of the
"Association pour l'Etude Taxonomique de la Flore
d'Afrique Tropicale", I was to organize a scientific
symposium for this or,ganization in Uppsala in Sep­
tember 1 966 I therefore decided, on the suggestion
of several members and with moral support from the
International Union for the Conservation of Nature
(IUCN) and of representatives of UNESCO and the
International Biological Program (IBP), to devote
the main part of that symposium to the theme "The
Conservation of Vegetation and of its constituent
Species in Africa South of the Sahara". The other
two themes treated at the same symposium, "Progress
in the study of the tropical African Flora", and
"Progress in the mapping of the African Flora" also
have direct bearing on the conservation of African
vegetation.
The present volume contains the papers read at
this symposium and summaries of the discussions.
Each contribution is printed in the language in which
it was read, whi,ch matches as a rule the language
used by government departments and scientific in­
stitutes in the relevant country. In order to promote
informed discussions at the symposium the bulk of
the contributions were circulated as preprints before
the meeting. The discussions have been summarized
as far as possible from the abstracts submitted by
participants and from the notes of the secretariate.
Passages quoted from abstracts submitted by the
participants are indicated by a colon following the
speaker's name; the remaining parts of the sum­
maries have been formulated by the editor.
The organization of the symposium concerned and
the preparation of this book would not have been
possible without the wholehearted collaboration of a
large number of specialists within the framework of
AETFAT. Financial support for the symposium and
towards the printing of this book has been given by
the Wenner-Green Foundation, the Swedish Natural
Science Research Council, the Department of Educa­
tion of the Swedish Government, the Swedish Inter­
national Development Authority, "Uingmanska Kul­
turfonden", the Special Committee for the Interna­
tional Biological Program (SCIBP), the United States
IBP Committee, Mr. Harold K. Hochschild and the
Natural Area Council, New York, and the University
of Uppsala.
A substantial part of the preparations for the sym­
posium was made by my wife, Dr. Inga Hedberg,
who also took over the tedious task of editing this
book.
Olov Hedberg
Introduction
W H Y C O N S E RV E N A T URA L V E G ETATI O N?
B. Verdcourt
You will shortly hear a great deal about the prospects
of conservation of vegetation in Africa, poor in some
areas, more encouraging in others, but although we
as botanists are united in wanting habitats and vege­
tation preserved, our enthusiasm may blind us to
the fact that most other people do not agre� with us,
although I hope the majority would b e concerned at
the vision of a world totally covered with concrete.
Before we get involved in detail I want us to con­
sider exactly what it is we want and whether we are
j ustified in forcing public opinion to agree it is
needed. Our one hope is that opinion can be forced.
Most of the world's population see no point in col­
lecting works of art 'in museums and think the money
spent is wasted, but such institutions are clearly now
a fixed part of the culture of most countries. The
minority has got its way by actively caring. This con­
feren ce can best help by showing as many as possible
that we care about natural treasures. Within the past
ten to fifteen years there has been an ever increasing
awareness of the danger facing the world's species
pool and a large number of conservation groups
(sometimes seemingly none too well affiliated) have
come into being, mainly concerned with groups of
more popular interest. Naturally it is easier to whip
up concern over the possible extinction of a large
mammal or attractive orchid than it is about a min­
ute, unattractive insect or small annual plant. It may
well be philosophically wrong to pretend that all
species are of equal value since conservation means
nothing save in terms of the human mind.
Let us make no mistake-farmers, the majority of
agricultural scientists and most ordinary people can
see no point in saving any habitat to preserve un­
economic plants. Foresters will talk of low grade un­
economic forest and always there is a move to drain
all swamps and bogs. In Kenya it proved difficult
to preserve a small piece of natural vegetation on
a long range research organisation-it will obviously
be much more difficult to preserve patches of forest
adjacent to African farms and it is unlikely that
1 - 6 8 1 557 Hedberg
any patch not in a reserve will survive for more than
a few years unless it is made financially attractive
to the surrounding people. Poor people in need of
fuel cannot ce expected to see beauty in trees to the
extent that they will buy other fuel.
From the title of our conference we can assume
that we as botanists are interested in the conserva­
tion of vegetation in its natural state over as much
of the globe as possible-perhaps a selfish aim if
most other men do not share it. We would not be
satisfied with the perpetuation in botanic gardens
alone of all the component species, although this
would be preferable to extinction. Why should we
not exhaust an area of its scientific information and
then destroy it? ICI offered to pay for such ex­
tensive research in Teesdale in England ; even if it
were possible to obtain all the information (and
clearly it is not because new scientific methods will
yield new facts), this is not what we want because
we would still resist the destruction of the area. We
are told we must be strictly scientific else no one will
listen, but there is a danger that we will not make
it clear what we really want. I feel that in the end
the cultural and aesthetic reasons will be the most
important because modern science and technology
will totally alter the economic arguments for con­
servation. We want habitats preserved with all their
components. Can we justify this? Shortly I will ex­
amine the reasons for wanting to conserve any plants
as honestly as possible. Any naturalist who has stood
in an area of tropical rain forest and been staggered
at the abundance and diversity of its life, where
the same species of tree is often not duplicated in
a kilometre walk, and where there are myriads of
associated insects and birds, can understand the feel­
ing of his fellows when they wish to preserve such
an area for all time. It is less easy to put this idea
of conservation over to those people who would.
probably wish to be described as hard-headed busi­
ness folk and probably see. nothing but potential tea
plantations. I am both a pessimist and a cynic where
Acta Phytogeogr Suec 54
2 B. Verdcourt
human behaviour is concerned-a truly honest sur­
vey of the history of mankind is scarcely conducive
to any other frame of mind.
The tremendous increase in the world's population
is the crux of the problem. Despite so much pub­
licity the facts will bear repeating. By the year 2000
the world's population will be 6 x 1 09 assuming that
science can produce the necessary methods to main­
tain an increase in food production. The population
at the beginning of this era (0 AD) is usually es­
timated to be 2 . 5 x 1 os. The vastly increased annual
rate of increase is due as much to a fall in the
death rate as an increase in the birth rate. Cities like
Calcutta will probably have populations of 6 X 1 07 by
the end of this century, and it is already possible
to travel through 200 miles (3 30 km) of urban de­
velopment from New York to Washington ; in fact
it is estimated that two acres (0. 8 hectares) of the
United States is used every minute for housing or
other developments. In Africa it is estimated that
the 1 960 population of 2. 7 3 X 1 os will have increased
to 8.6X 1 0s by the end of this century. This all seems
inevitable and obviously the clash between man and
nature will grow more and more insistent. This po­
pulation explosion is a vast social problem in its
own right apart from any incidental effects on na­
ture. More will be said later about possible solutions,
but it is up to conservationists to be sure they keep
their eyes on proposed developments of a revolu­
tionary nature so that they can be in on the ground
floor.
The main danger to natural vegetation does not
lie in the increase in the space occupied by humans
and their expanding agriculture but in the fantastic
development of science and technology. Many argu­
ments for conservation were very much stronger be­
fore this development reached its present level. When
the population reaches limiting numbers, assuming
no check is made, food will have to be produced
artificially, and the abandonment of normal agri­
cultural methods will free all agricultural land for
tbuilding. Work on such food production is underway
in laboratories. With the great increase in our knowl­
edge in the actual way chromosomes work, the
mechanics of n:J.Orphogens, and the nature of the
genetic code, it seems likely that spe·cies will be ·pro­
duced to order in the distant future. I feel some
reference must be made to modern methods of war­
fare where whole areas of forest are destroyed and
burnt. The application of some of these methods for
jungle clearance has been contemplated, e.g. the
proposed use of atomic explosives to build a new
canal in Central America. The indiscriminate use of
weed controllers and insecticides which destroy polActa Phytogeogr Suec 54
linators have all contributed to the rarity of some
species. Even some areas of dry bush which might
be thought to be safe (in our sense!) could be totally
ait ered by clearance followed by pasture improve­
ment or large scale irrigation. In truth we may as­
sume that no area is safe from possible exploitation,
since existing land use is certainly no guide to po­
tentialities in these days of modern agricultural
science. Experimental irrigation with sea water with­
out desalinification has met with some success.
SURVEY OF REASONS FOR CONSERVING
VEGETATION
Direct Uses of Plants Themselves
Plants supply us with a vast array of foods, drugs,
building and other raw materials, fuels, fibres and
ornamentals for beautifying our surroundings. It
might be thought that we have enough species in
cultivation to supply all our diverse needs and that
that part ·o f the gene pool consisting of hundreds
of thousands of species not used by us could well
be dispensed with. To the ordinary man these are
weeds, scrub, uneconomic forest, weed trees and all
the other unpleasant words used by farmers and for­
esters. Science must surely have made it clear by
now that it is very dangerous td pronounce any or­
ganism (and, for that matter, any abstruse fields of
knowledge) as valueless to man. If various moulds
had been up for judgement fifty years ago and it had
been feasible to render them extinct, anyone attempt­
ing to save them would have been considered mad,
the importance of modern antibiotics being then un­
foreseen. No plant can be considered useless even if
it has been the subject of thorough study, since it
may have value in a quite unknown field in the
future. As an example, a recent visitor to Kew
wanted to know if there was a tiny annual legume
with nodules which could be used in experiments
involving air containing an expensive nitrogen iso­
tope. The work would have been impracticable if
large amounts had to be used. Thus the tiny A nto­
petitia immediately became useful. The minute duck­
weeds (Lemna) are now being used in numerous ex­
periments where much larger plants would at one
time have been employed. Some plants are partic­
ularly suitable for genetical work. The contribution
that the fruit fly Drosophila has made to our knowl­
edge of genetics is a prime example of how easy it
is to underestimate the value of an organism.
It is true that there are a number of products
still obtained from the wilds including drugs, spices,
resins and excellent but now luxury hardwoods, but
all drugs are synthesised in time and woods are now
Why conserve natural vegetation?
obtained from plantations of fewer species or totally
replaced by new synthetic materials. Even though
drugs are synthesised, biological screening of large
numbers of plants frequently brings structures to the
notice of chemists which might not have been dis­
covered after generations of blind empirical grop­
ing in the laboratory. There are untold biochemical
mechanisms awaiting discovery. A tropical forest is
a vast biological storehouse of knowledge and though
doubtless human life could go on without it, it would
be an act of folly to destroy it all when so little
is known. Certain plants will no doubt be developed
into new food plants and new ornamentals; others
possessing valuable attributes can be used for im­
proving known foodplants of the same genus by
means of crossing, as has been done with Solanum
and Manihot and, in the past, with wheats. Even
in such well-known ornamentals as the roses (per­
haps more investigated than any other genus), horti­
culturalists have as yet barely begun to tap all the
possible means of producing new varieties. Certain
plants which are not cultivated but which yield val­
uable foodstuffs, e.g. Butyrospermum and Corde­
auxia are in need of preservation.
In the present state of the world there are un­
doubtedly many areas where the ground has been
cleared of vegetation potentially more valuable than
the miserable crops produced afterwards (here I in­
clude domestic stock), which in any case quickly
ruin the soil. In marginal areas on arid ground the
biomass of the climax flora and faunil vastly ex­
ceeds that produced by the same areas when cleared
and planted. In many areas where people are hungry
more could have been obtained from the land by
sensible cropping over the years than has been ob­
tained by traditional pastoralism or peasant farming,
and the habitat would not have been turned into an
eroded dust bowl. In the past the North American
Indians sensibly utilized their resources by cropping
the buffalo rather than domesticating it, their skilled
horsemanship rendering this easy though they burned
forest to extend the habitat.
It will not, however, cut much ice with non-bo­
tanists to say that vast areas of natural vegetation
on good farming land must be left in case something
of value turns up. They suspect, rightly, that con­
servationists frequently say such things with tongues
in their cheeks hoping to blind with science-we
would still hope to preserve an area even if nothing
of value were there. We must be truthful about our
reasons.
Indirect Value of Vegetation
Conservation for scenic purposes. This is such an
obvious reason that it scarcely needs comment.
3
There are very many picturesque places that owe
their beauty largely to the vegetation, e.g. the Cali­
fornian redwood groves, the alpine regions of Africa,
or any expanse of natural forest. Where the income
from the tourist trade is high conservation may not
be difficult, particularly where no rival interests are
at stake. Alpine regions are usually conserved since
they are wasteland to farmers ; in East Africa several
mountain tops are National Parks and tourists visit
them at least partly to see the strange flora that
has developed on them. Countries with a developed
tourist industry preserve vegetation to provide suit­
able habitats for game. In East Africa this is clearly
understood but many foresters still emphasise that
the problem of damage by game is serious. Game
populations have been squeezed by the increasing
human population. The forester still looks on a for­
est as something to be managed (i.e. reafforestation
with soft woods) so as to give a maximum return
consistent with protection of soil and water supplies.
The return from timber sales or tea plantations is
usually far in excess of game receipts in a given
forest. Actually only a fairly small proportion of
animals occurs solely in forests and it seems unlikely
that forests will be preserved for their scenic value
alone; a very few may be preserved as habitats for
rare animals.
r
Effect of vegetation on climate. Forest lovers have
long maintained that extensive forests have a marked
effect on the rainfall of the surrounding area which,
if true, would be a telling argument for conserva­
tion. Unfortunately this is now widely accepted to
be much exaggerated, the effect being negligible or
very small save in special circumstances. In a recent
book Molchanov concluded that the increase in pre­
cipitation due to forests was positive but slight. Here
again it is dangerous to expect results mostly ob­
tained in temperate areas to equally pertain to the
tropics. No really definite results seem to have been
obtained in Russia, Western Europe or North Amer­
ica but the situation in the tropics is clearly funda­
mentally different if only because all the factors
such as insolation and evaporation are much greater.
Undoubtedly clouds tend to persist over forested
areas and to evaporate over savanna and grassland.
Extreme radiation from barren ground can evaporate
rain before it strikes the ground. In some Pacific
islands where the forest has been totally destroyed
by introduced rabbits, pigs or goats, the rainfall has
been altered due to this reason. In areas subject to
'
low cloud vegetation undou�tedly causes quantities
of water to be withdrawn from the atmosphere, more
or less proportionally to the surface. A single tree
Acta Phytogeogr Suec 54
4 B. Verdcourt
will do this. This occult precipitation is important
in that any water that remains on the vegetation
may be considered as a net gain in precipitation,
since the energy used in its evaporation from the
leaf surfaces when clouds have cleared would have
been used in transpiring an equal amount of soil
moisture available to the plant. Hydrologists in East
Africa are prepared to believe that forests could af­
fect rainfall to some extent. Forested lands generally
provide an evergreen transpiring cover during the
dry season, and there is a marked alteration in the
diurnal heat balance over a forest as compared with
other forms of land use. Heat flux over forest is
half that over subsistence crops and goat pasture.
When forest covers areas of high ground the com­
bination of cooling due to the topography and trans­
piration may well result in heavier rainfall over the
area in general, and it could be that removal of the
forest would reduce the amount of rainfall. It is
considered that the replacement of forest by a com­
plete cover of continuously transpiring perennial
crops would be unlikely to cause any appreciable
difference in local climate.
It appears to me that desert conditions now pre­
vail in many places such as Mesopotamia densely
populated only a few thousand years ago, and if
there is any chance that human interference with
forests has had something to do with it then further
evidence is badly needed. Arguments that these cli­
matic changes are due to other reasons do not always
sound convincing.
Conserva·tion of vegetation for maintenance of
water supplies and prevention of soil erosion. A great
deal has been said about the effect of forest felling
on water supplies and, whenever water is scarce in
East Africa, Forest Departments are often strongly
criticised for not conserving enough forest. In recent
years 1 000 acres (405 hectares) of bamboo per year
on the catchment from which Nairobi obtains its
water has been, and is being, felled and replanted
with softwoods, and an alarming dwindling of
streams on nearby farms resulted in vigorous criti­
cism. This dwindling happened, however, to be
merely the expression of particularly poor rainfall in
general and proved nothing. Criticism without true
appraisal of the facts can do the idea of conserva­
tion more harm than good. In recent years extensive
sophisticated hydrological research1 has been carried
1 Studies
of the disposal and use of rainwater as run-off
and streamflow, its interception by, evaporation from, and
percolation into the soil, storage and subsequent use of
water by plants, and percebtion beyond the reach of plants
are all urgently needed and directly related to practical
farming.
Acta Phytogeogr Suec 54
out at the East African Agriculture and Forestry
Research Organisation, Muguga, Kenya, under the
direction of Dr. H. C. Pereira with a view to eliciting
some real factual evidence on which to base future
land use, since in tropical Africa available water is
usually the dominant factor determining crop yield.
At any one place the factors are soil, topography,
climate, rainfall and vegetation, and the latter is the
easiest to vary, at least at present. It is important
to emphasise that results and practices based on re­
search or experience in other parts of the world are
not always applicable in the tropics. In Great Britain
for example, .water can be obtained .for storage by
utilizing the run-off from heavily overgrazed sheep
pasture, but in the tropics this would result in ruin­
ous soil erosion in a very few years. Undoubtedly
the best method of water collection is to make sure
that there is no infiltration at all, e.g. to destroy all
the vegetation on a catchment and cover it with
concrete-as has been done at Gibraltar and in areas
in East Africa where rainfall is small and every drop
is needed. At Seronera such methods are in use and
natural examples of pools at the base of large rock
slopes are not uncommon. This method is, however,
extremely expensive and even the most unsympa­
thetic would agree, very unsightly. It is obviously
better to use the properties of deep soils which pro­
vide a n atural reservoir of water. Catchment area ex­
periments in East Africa have proved what has al­
ways been evident to field workers, that natural tall
montane fo�est, bamboo or a well-managed planta­
tion forest is unsurpassed for maximum infiltration
of water and natural control of stormflow or surface
run-off. These powers of regulation are unexpectedly
high, very severe storms being absorbed even by soil
already wetted by previous rain. In undisturbed for­
est the soil is very porous due to deep forest litter
or thick ground cover; the canopy protects it from
erosion due to the heavy and intense tropical rain
(it is this intensity that is the main reason for the
differences which exist between tropical and tem­
perate conditions). So long as no disturbance occurs
the topsoil is generally both rich and very perme­
able to water. Despite the rich vegetation which
mostly has roots penetrating to 25 ft (7. 5 m) or more,
the soil in high rainfall areas is usually too leached
for ordinary· agricultural development. Most fertile
soils tend to be found in areas where the rainfall
is 40-50" ( 1 020-1 270 mm), and above this figure
progressive leaching of the soil nutrients reduces the
agricultural potential. The moment the soil is dis­
turbed, e.g. by the ingress of native cattle from the
arid plains below in search of dry weather grazing,
the permeability is altered. Even one cow per twenty
Why consen:e natural vegetation?
four acres (8.9 hectares) can greatly increase the
storm run-off from a forested catchment and too
frequent use of fire by such pastoralists in an at­
tempt to improve the grazing can seriously reduce
rainfall acceptance. Wild animals do not damage the
habitat unless in abnormally large populations.
Where the soil is undisturbed and all rain passes
through it and is stored in the soil, a steady supply
of absolutely clean water is obtained in the form of
rivers, streams and springs. I saw a clear example
of this on Mt. Kulal, an isolated mountain covered
with forest in northern Kenya, surrounded by near
desert conditions. The nomadic pastoral Rendille
drove their cattle up the mountain for water and
grazing and burnt the forest to increase the grass
cover. Clearly in time another bare mountainside
would result with a total cessation of all water sup­
plies. By piping water from the top of the forest to
the bottom and prohibiting the entry of cattle into
the forest the latter has been conserved, the water
supply protected and browsing increased at the base.
Forest does, however, exact payment for this re­
gulation of water supply due to the high evapotran­
spiration rates which obtain in the tropics. During
the dry season the forest will use up all the available
soil water within its rooting zone even up to the
equivalent bf 3 0" (760 mm) of rain. Hence it is only
in the higher rainfall areas that there will be much
likelihood of a substantial water yield.! In East Af­
rica, for example, only about 4% of the country re­
ceives more than 50" ( 1 270 mm) of rain four years
out of five, so that all reliable water supplies origin­
ate in the high altitude catchments this 4% represents.
55 % of the ·country is unlikely to receive 30" (760
mm) in four years out of five and in this large area
perennial rivers from the 4% area are the life blood.
It has been truly stated that water is the most valu­
able crop yielded by forest. As annual rainfall decre­
ases, and since transpiration varies little from year
to year, the water yield from forested catchments de­
creases. "Where the rainfall falls below the potential
transpiration the indigenous forest cover is mostly
adapted to use aU the available water. Where the rain­
fall is 40-50" ( 1 020- 1 270 mm) no substantial water
yield can be expected, and where the rainfall is less
than 40" ( 1 020 mm) there is unlikely to be more
than sporadic streamflow. The ratio of peak flow to
minimum flow may be as high as twenty to one even
where the soils are deep and permeable, this being
a reflection of the very high rainfalls during the
1 In bamboo- forest, for example, in areas of 80--90" (2040-2280 mm) rainfall the evapotranspiration rate is 50" (1 270
mm) and the annual yield of clean water will be 3 0--40"
(760-1020 mm).
5
rainy season. Even in spate, however, the surface
run-off contribution to flood flow is very small,
amounting to only 1 . 5% of the incident rainfall and
the quality of the water remains high. Needless to
say these conditions mentioned obtaining under na­
tural forest are now to be found in very few areas.
Some modifications have been made to practically
all forests. Hydrologists recommend that all steep
land with ruling slopes of the order of 25-30% should
be retained under natural or plantation forests with
no grazing allowed, regardless of rainfall (often po­
litically difficult). Cultivation and grazing on small
contained pockets of flat soil within or above such
areas is also to be prohibited. Sloping land in a high
or medium rainfall area may be suitable for high
value plantation and other crops where expensive,
elaborate conservation works may be justified.
Ground water supplies should not be unduly affected
by replacement of the indigenous forest though the
danger of flooding is increased. Vigorous volunteer
cover is likely to colonise any bare soil so that infil­
tration and soil moisture holding capacity will be
maintained. Sloping land in areas receiving less than
40" ( 1 020 mm) of rain can still be highly productive
agriculturally though not hydrologically. Optimum
land use depends on maximum water acceptance by
the soil for use on the spot by the vegetation cover,
since little water yield can be expected. Given ade­
quate soil conservation measures, removal of forest
and replacement by arable crops is likely to give an
increase in ground water supplies because of the re­
duction in transpiration. Inadequate soil conserva­
tion measures w9uld result in serious flooding. The
agricultural scientist sees his problem to be the de­
velopment of methods of land use which will - give
a living to the maximum number of people and yet
will not cause much deterioration in the water sup­
plies.
Misuse of forest resources can spell disaster even
to the extent that in high rainfall areas of up to
90" (2280 mm) a year there can be serious water
shortages in the dry season, the streams and ground
water having dried up. Jeffrey ( 1 962) has mentioned
such a case in the Seychelles. To have water prob­
lems in a high rainfall area is absurd. The establish­
ment of tea gardens on very steep, cleared ground
without adequate soil conservation measures in one
part of Tanzania resulted in the loss of the total
top soil by erosion in a very few years. Unless mas­
sive applications of fertiliser are made annually such
a loss will take centuries to replace and the soil­
moisture storage capacity is considerably reduced.
The work carried out at Muguga was aimed at
determining the exact water usage of various crops
Acta Phytogeogr Suec 54
6
B. Verdcourt
and it was shown that although it is clear that some
cover is needed to ensure water penetration and re­
duction of evaporation loss, this cover does not have
to be natural vegetation. By having detailed figures
available land use can be planned more sensibly. For­
est uses more water than any other type of vege­
tation and it seems reasonable to suppose that to re­
place it with something more useful using less water
will help to conserve water. Unless great care is
taken, however, much damage results from soil ero­
sion and loss of soil fertility due to water run-off.
Forest exploitation with rotational clearing and re­
establishment of plantation crops may not seriously
affect soil structure and fertility provided that rea­
sonable land conservation measures are adopted.
Even complete forest clearance and replanting with
tea in Kericho resulted in an increase of run-off
equivalent to about 1 % of the total rainfall but re­
presenting 1 00% increase over the run-off from the
original forest. Replacement of indigenous bamboo
forest by productive cypress plantation in the Aber­
dares has, so far, had no harmful effect on Nairobi's
.
water supplies or their quality. A dense, matted grass
such as Cynodon or Pennisetum clandestinum uses
almost as much water as forest and none is stored,
but fallow land protected by heavy sowings of shal­
lowrooted grasses retains stored water. Indigenous
weeds use more water than do good crops of maize
and Sorghum. Obviously in areas which are marginal
for reliable water supply these facts may be utilised
by rotational felling of timber trees over an area, or
by replacement of perennial cover by agricultural
crops of greater economic importance, coupled with
stringent soil conservation methods. More and more
land · considered unsuitable for agriculture at present
will be utilised in the future, but care must be taken
as an experiment at Mbeya, Tanzania, has shown.
Comparison of two very similar catchment areas dur­
ing a six year period-one cleared and put under na­
tive crops and the other under natural forest was
made. During the rainy season the former flourished
but was dormant during the dry season ; the forest,
however, transpires all the time and, as a result, at
the end of the dry season the soil moisture deficit is
1 0" (254 mm) in the crop catchment and 3 0" (760
mm) in the forest catchment. These deficits must be
made good before any increase in streamflow can
occur. Rather naturally the resultant flow from the
former was on average 1 8" (475 mm) greater than
that from the latter. Almost immediately, however,
suspended sediment in water from the crop catch­
ment increased and doubled in two years. Although
no obvious erosion was visible to an ordinary ob­
server continuous arable cropping on steep slopes is
Acta Phytogeogr Suec 54
dangerous. In East Africa authorities have been far­
sighted in not taking irreversible decisions until ex­
perimental hydrological work had at least yielded in­
terim results. In Tanzania the Germans established
forest reserves to protect catchments at the turn of
the century and much progress has been made since.
I have gone into some detail in these matters since
conservationists frequently use very woolly hydrologi­
cal statements as evidence·. They should not be made
without adequate knowledge else it may do us more
harm than good. I might add that in the distant
future abundant desalinified water will doubtless be
available from oceans.
Indications of future land use. Another far-reach­
ing practical use of vegetation conservation, at least
temporarily, is its value for making overall plans for
land use in a large territory. The vegetation com­
position is a good measure of complicated mixtures
of factors all the details of which are not brought
out by normal methods of climate and soil analysis.
Land supporting identical vegetation types will have
the same crop potential.
Conservation of soil fertility. Almost any m1ssmg
element in the soil can now be replaced chemically
but forest and vegetation of other types can have
a direct result on soil fertility. Over much of the
earth exploitation of marginal land in particular has
led to bad erosion resulting in near desert condi­
tions. Clearly something has gone wrong when we
remember that these areas in the natural state would
carry a very diversified flora and support a wealth
of animal life, without any damage to the habitat.
Viewed in the long term, it is certain that more
could have been obtained from the land by cropping
the natural products as primitive man did, than has
been obtained by thoughtless over-exploitation.
Much has been said about the preservation of for­
est in connection with water supplies, but another
reason for leaving hill top forests undisturbed is that
they act as reservoirs of soil fertility; the continual
production of forest litter and humus ensures that
soil nutrients are passed down to the lower regions.
In natural forest the soil is preserved intact and ero­
sion does not occur but the soils themselves may
be inherently of low fertility. The early German set­
tlers in Tanzania on seeing the magnificent rain for­
est covering the East Usambara Mountains thought
the soils supporting it must be extremely fertile;
when cleared and planted with plantation crops the
opposite was found and the experiments were a fail­
ure. Plant nutrients were retained in circulation only
so long as the forests were undisturbed; the native
Why conserve natural vegetation?
species could produce a much greater weight of ma­
terial than could crop plants not adapted ecologi­
cally. This low soil fertility in such a high rainfall
forest is due to the progressive leaching of the soil
nutrients. It was found that Cinchona would grow
well if interplanted with the introduced Grevillea
which is extensively used for shade in coffee plan­
tations. Specialised research has shown many other
ways in which natural vegetation conservation can
aid soil fertility in surrounding areas. Two instances
only will be mentioned here. It has long been known
that crops can suffer from a deficiency of available
sulphur in the soil, e.g. the tea yellows disease in
Malawi and S. Tanzania. Various lake waters are
also short of sulphur possibly due to a shortage in
surrounding soils. Analyses of forest soils have
shown that although sulphates are normally absent
in the top soil, they are present in considerable
amounts at a depth of two feet (0.6 m) or more
whereas organic sulphur is present throughout the
profile. Most forest soils, therefore, represent an
ideal system of sulphur conservation. The humus­
containing top soils contain large amounts of organic
sulphur which is converted into sulphates and travels
to the subsoils by leaching action, but the loss of the
element to the lowest soils is prevented since it is
taken up by the tree roots which penetrate to the
subsoil. Doubtless this pattern is repeated for many
other elements. There are other ways in which the
removal of vegetation capable of evaporating large
quantities of water from the upper part of a slope
may alter the land use on the lower slopes. Progres­
sive encroachment of saline conditions in some sisal
estates in Tanzania was linked to a marked rise in
the dry season water table due to the clearing of
woody vegetation from the escarpment foot some
distance away.
It is perhaps unnecessary to mention that many
leguminous plants fix nitrogen and it is suspected
that some of the desert Zygophyllaceae may also
do this. A surprisingly large number of African le­
gumes in very diverse tribes possess nodules but little
experimental work has yet been carried out. I suspect
that in the future very detailed knowledge will enable
entirely chemical means of fertility replenishment to
be used. Whilst most of the world's farmers are of
the peasant type they cannot afford such means and
they must not squander the natural means by
thoughtless destruction.
Conservation
is considerable
recipients and
ment of white
of energy. Energy storage by forests
and they are the principle organic
storers of solar energy. The incre­
pine produced in one year by one
7
acre is equivalent in heating power to 3325 pounds
( 1 500 kg) of coal. When other forms of concen­
trated solar energy fossil fuel (coal, oil and gas) are
exhausted, the only significant storage of solar
energy may well be in forests. This seems unim­
portant, however, now that atomic power is easily
tapped; moreover, methods of directly using solar
energy are now practicable.
Therapeutic value of natural vegetation. The di­
rect value of the sight of unspoiled vegetation to
the human mind is unquestionably high but difficult
to assess and varies greatly with the human con­
cerned. There is a growing belief that constant over­
crowding of any animal in unnatural conditions can
have marked effects on the animal's psychology. Re­
cent work on rats has shown that it leads to out­
breaks of savage and merciless attacks by members
of the population on each other. There have been
too many instances of the paranoid tendencies in
human beings, witness the vindictiveness and sadism
during wars, to doubt that there is an element of
truth in the fear that man might suffer a fate at the
hands of the environment he has built up and be­
lieves he controls. Dominant species are slow to
adapt and on numerous occasions have perished.
Botany as a hobby is widespread if the sale of
popular books in England is any witness. Much of
the interest is the finding of something unexpected,
that element of surprise which is so apparent in a
natural, relatively undisturbed habitat. Parks and
gardens are often sterile from a naturalist's point of
view. The increase in this popular interest is an im­
portant element in our hopes for conservation.
One difficulty with purely practically minded peo­
ple is that such things as cultural amenities, mental
relaxation, and enjoyment of beauty never appear
in any credit columns and, because no monetary
value has been assigned to them, they are considered
to be valueless. Priceless things are difficult to value.
PHILOSOPHICAL CONSIDERATIONS
A major reason why scientists wish to conserve hab­
itats is that a great deal remains to be found out
about the flora and fauna in most parts of the world
but particularly in the tropics. Not only are many
unknown species awaiting discovery but detailed bio­
logical investigations have been made on only very
few tropical species. As Brenan (1 949) has pointed
out, about hardly any tropical African plant could
an account similar to those prepared for the Biologi­
cal Flora of the British Isles be written. It is indeed
possible that some species have become extinct withActa Phytogeogr Suec 54
8
B. Verdcourt
out being discovered by man. Certain areas are much
richer than others and if development of these is
unavoidable, then at least exhaustive collecting ex­
peditions should be organised first, similar to those
visiting islands chosen for atomic weapons tests.
A ttitude of religions. It may seem out of place to
discuss this but it is important. One's attitude to con­
servation is bound to be tempered by one's philo­
sophy of life if one is sufficiently free from the
struggle for life to be capable of any contemplation.
The Christian Church has always taught that all
other species are for man's use and no hints of their
possible right to exist apart from this seem to be
in its teaching. The Church would not support the
conservation of an area in Africa where there is
shortage of food and it could be ploughed up for
crops. In Oriental religions some element of the pre­
servation of other life does enter into the daily philo­
sophy, particularly when it is considered that the
spirit returns to earth in a different form. A Bud­
dhist will avoid killing an animal,-a J ain will even
attempt to avoid swallowing a fly. Schweitzer's phi­
losophy of reverence for life is appealing to a na­
turalist and, I feel, a good basis for conservation
if only partially attainable. It is at least a philosophy
that includes a standard of conduct to the rest of
life.
Conservation of individual species. Most systema­
tists probably feel that we are morally bound to
preserve all species from extinction, even those which
seem to be nothing but injurious; as much of the
total gene pool from which evolution will take place
must be kept as possible; it is impossible to assess
the loss to mankind caused by the removal of part
of the total gene pool. I personally feel that it may
well ultimately prove impossible to save even a large
percentage. Philosophical arguments here are diffi­
cult since species have come and gone; extinction has
always been part of evolution. Many of those now
declining would perhaps have gone anyway. All we
can say is that we condemn the unnecessary ex­
tinction of a species when, with a little care, it could
have been preserved. The blue whale is a clear ex­
ample in point-here an animal of great value to
mankind is in jeopardy because of lack of agreement
and the attitude of "let's make as much money
while we can"; here continuous cropping is quite
feasible. How much more difficult it will be to save
a species which is a nuisance to man. In Africa it
is very difficult to list species needing immediate
conservation since so little is known about their dis­
tribution. At this juncture I would rather press for
Acta Phytogeogr Suec 54
the preservation of as many varied habitats as pos­
sible. In certain circumstances, however, it is easier
to get action to preserve one species in particular
danger than it is to get a general plan accepted.
POSSIBLE SOLUTIONS
The immediate solutions to the problem are, of
course, to set up more reserves; above all to improve
education on conservation so that even those who
do not think about it come to realise that it is some­
thing necessary, much as a host of other institutions
are basically minority decisions. There are more far­
reaching decisions which will have to be faced how­
ever. Population increase must be reduced by birth
control methods and probably also the taxing of
those who produce too many children (not, as in
some countries, giving them extra allowances). New
methods of building cities have been suggested that
will l:ouse enormous numbers of people and take
up little space. Those who love the countryside
will have to give up wanting their own little bit with
a house in the middle-nothing is more wasteful
of countryside. This may sound very unpalatable
but the future is clear. We can only hope that these
solutions are not employed to house an ever ex­
panding population. The resulting alternative of con­
tinuous steel and concrete over the entire world is
a possibility which is too unpleasant to contemplate
and almost any measures to prevent it will probably
ultimately be taken. We must not, however, deceive
ourselves that man could not live and adapt himself
to a large concrete rat warren-we can only hope
that most would rebel at the thought. Even now
a fair proportion of the world's city dwellers can
and do live out their whole lives in the city. We may
. say they are missing something and are culturally
incomplete, but they often seem to be perfectly satis­
fied and healthy.
Some brief comments on the cost of conservation
must be made. At present very little is spent. Britain
spends less than two pence a head per year on her
national parks but this figure is greatly increased
if one considers the public subscriptions and dona­
tions to such bodies as the National Trust, the suc­
cess of which I always find most encouraging. As
Elspeth Huxley has recently pointed out in a news­
paper article, to claim that conservation cannot be
afforded is nonsense. We can afford bigger bombs,
space research, free medicine, colour television, air­
craft travelling at ridiculous speeds; in the past mag­
nificent cathedrals and palaces were built and every
age has found the money for its needs. Money is
available, one merely has to choose how it is spent.
Soil resources and land use in Tropical Africa
The million pounds paid out for a painting would
serve to protect some area for perpetuity. The choice
ultimately rests on the desires of people and these
can be modified by education. Whether we have a
philosophical right to assume our desires are more
important is pointless to discuss.
FINAL THOUGHTS
Whatever interim proposals are made, in the final
outcome it is the human species versus most of the
rest. A few thousand useful and ornamental species
of plants and animals will survive. I do not suppose
any of you here would have to think at all about
choosing between the preservation of a piece of for­
est or a herd of animals and the death of a hundred
humans; the problem will ultimately become this
simple unless drastic solutions are found to deal with
the population pressure. Actually thjs is not such
a different choice as is being made every day. The
cost of an art museum in one place would save
thousands of starving folk elsewhere. We have all
made some purchase this week we did not really
need which would have prolonged life in a famine
area. The attitude to life of various religions is a: cru­
cial factor in this whole conservation problem and it
is riddled with paradoxes. Any mission worker feels
that money spent on the conservation of wild life
and vegetation for its own sake is wrong when so
many people are desperately poor and hungry.
Plough it up and plant crops. If this argument is
taken to its limit, however, then all money spent
on cultural matters and entertainment would be
better spent on hospitals and food. The natural world
and its study is part of culture and culture has slowly
developed as man has evolved; it is now as basically
necessary as the so-called essentials even if this is
not consciously recognised by all. The consequences
9
of ignoring this real place of other species in our
world may lead to disaster.
REFERENCES
Allan, W., 1 965. The African Husbandman. - Edinburgh.
Dyson, W. G. et al., 1 965. Silviculture (symposium) - E.
Afr. agric. for. J. 3 1 , 42-122.
East African High Commission; East African Agriculture and
Forestry Research Organisation, Director's Summary Re­
port for 1955 in the East African Agricultural and
Fisheries Research Council Report for 1954-5 5 .
East African Agriculture a n d Forestry Research Organiza­
tion ( 1 965). Record of Research and Annual Report for
1 964.
Huxley, E., 1 966. Saving the countryside. - Article in the
Observer Weekend Review for April 17.
Jeffrey, C., 1 962. The Botany of the Seychelles. - Report of
the visiting botanist of the Seychelles Botanical Survey,
196 1-62.
Jones, T. (ed'.), 1 965 . East African Contributions to the
Eighth British Commonwealth Forestry Conference. - E .
Afr. agric. for. J. 30, 35 1-397 (see pa·rticularly 'Hydro­
logical Aspects of Protection Forestry in East Africa'
by McCulloch, J. S. G. and Dagg, M. on pp. 390-393).
Milne, G. & Calton, W. E., 1 944. Soil salinity related to
the clearing of natural vegetation. - E. Afr. agric. for.
J. 1 0, 7-1 1 .
Molchanov, A. A., 1 960. The hydrological role o f forests. Moscow. (Translation Jerusalem, 1 963.)
Pereira, H. C. (ed.), 1 962. Hydrological effects of changes
in land use in some East African catchment areas. - E.
afr. agric. for. J. vol 27 , special hydrological issue, pp.
131.
Puri, G . S . , 1 966. Fundamentals and methods o f teaching
of the course-Nature conservation and the problems of
conservation, wise use and rehabilitation of natural re­
sources-at universities and other higher schools. IUCN Commission on Education. IX General Assembly,
Lucerne, June, 1 966.
Russell, E . W. (ed.), 1 962. The natural resources of East
Africa. - Nairobi.
Thomas, W. L. (ed.), 1 956. Man's role in changing the face
of the earth. - Chicago.
United States Dept. Agric., 1965. Technical Bulletin 1 344.
Radiant energy in relation to forest.
S O I L R E S O U RC E S A N D LA N D U S E I N T R O P I C A L A F R I C A
W. A llan
THE SOILS
Continental Africa has an area of about 30 million
square kilimetres. Of this area, some twenty million
square kilometres has a soil cover, in the sense of
a surface layer which carries, or could carry vege­
tation of some sort. The rest is stony desert, bare
rock, broken rock material, open water, and at very
high altitudes even glacial ice and perpetual snow.
In this discussion we will ignore the third of the
continent which is almost wholly barren and con­
fine our attention to the twenty million square kilo­
metres of soil mantle.
Acta Phytogeogr Suec 54
10
W. Allan
Much of this is poor. In tropical Africa, exuber­
ant growth of natural vegetation and rapid regenera­
tion of bush or forest following clearing tend to
conceal the intrinsic soil poverty. Over a large part
of the continent rainfall is so low or erratic as to
make cultivation and even herding hazardous, or so
intense as to cause leaching and loss of soil structure.
This basic soil poverty is due mainly to poor parent
materials. The greater part of the soil mantle derives
from old, acid parent rocks poor in calcium and
nutrients, and the average organic content of Mri­
can soils is only 0.2% to 0.5% compared to 2.0% for
the cultivated soils of Europe.
Weakly developed soils.1 About 30% of the area of
soil mantle, some six million square kilometers, is
occupied by weakly developed soils which show only
very slight differentiation of horizons and evolution
of profiles. The most extensive groups in this mis­
cellaneous collection are the lithosols (3 .5 million
square kilometres) and sub-desert soils (2.0 million
square kilometres). It includes also young soils on
river and lake alluvium (0.4 million square kilomet­
res) and a small remnant comprising tidal mangrove
soils of the tropical coasts, and wind-blown sands.
Only a small fraction of this six million square kilo­
metres is now cultivable and the proportion cannot
be greatly increased. Pockets of stable soils occur
in the lithosol complex but it is largely uncultivable.
The sub-desert soils, on the other hand, are poten­
tially fertile over large areas and can give good yields
if irrigated. Here the limiting factor is water. Most
of the deposits on river and lake alluvium are hydro­
morphic, with high water tables which limit or pro­
hibit cultivation but there are alluvial plains of lim­
ited extent which may be counted among the most
fertile of the cultivated soils.
Soils of arid and sub-arid regions. Bordering the
deserts and separating them from the Mediterranean
zone in the north and the Equatorial zone in the
south are very extensive areas occupied by Brown
and Reddish soils of arid and sub-arid regions. They
cover in the aggregate some 2.6 million square kilo­
metres, or 1 2 % of the area of soil mantle. Here too
water is the factor which limits, or more generally
prohibits, cultivation. They are used mainly for ex­
tensive grazing.
The
1 The
Ferrallitic Soils.
The
nomenclatures
and
used
are from J. L. D'Hoore.
Commission
Ferrallitic
the
areas
of
soils
soil
1 964.
Acta Phytogevgr Suec 54
The Ferruginous Tropical Soils. The next most
extensive group (3 . 1 million square kilometres) com­
prises the Ferruginous Tropical Soils originating
from crystalline rocks of the basement complex.
They are widely distributed north and south of the
Equator. Their high content of iron compounds re­
sults in the frequent occurrence of ironstone crusts
at shallow depth and they are very vulnerable to
erosion, except for the most permeable variants. Al­
though the mineral reserve is often appreciable, they
are generally of low to mediocre intrinsic fertility
and durability under cultivation. High responses to
fertilisers have been observed, but under normal con­
ditions these soils can sustain only short periods of
cultivation followed by much longer periods of fal­
low.
The Ferrisols. A much less extensive group, the
Ferrisols (0.9 million square kilometres), show pro­
files similar to the Ferrallitic soils but differ in hav­
ing a higher content of exchangeable elements, better
structure and markedly higher intrinsic fertility.
They may be regarded as a transitional group in
process of evolution under warm and humid con­
ditions.
of
types
La Carte Des Sols D'Afrique
de Cooperation Technique en Afrique,
D'Hoore's classification occupy the largest area of
any single group (5 .3 million square kilometres or
27% of the soil mantle). They occur mainly in inter­
tropical Africa as residual soils of the ancient pla­
teaux. Typically, they are so highly leached and al­
tered that only the least mobile mineral constituents
remain. This group includes the vast area of the
Kalahari Sands and much of the high forest land
of the Congo Basin. In spite of their intrinsic pov­
erty, these soils carry high forest and savanna under
humid conditions, but most of the mineral reserve
is concentrated in the vegetation and the decompos­
ing plant material of the surface soil. Some tropical
tree crops can be fitted into this closed cycle but
under arable cultivation without amendments most
of these soils are exhausted after two or three years
and they require a very long period of fallow for
restoration of fertility. There are however some fer­
tile and durable variants, notably the Red Ferrallitic
soils on rocks rich in ferromagnesian minerals and
some humic soils of high organic content, but they
are a small fraction of the whole (0. 1 5 million square
kilometers).
-
Lagos
Eutrophic Brown Soils. The Eutrophic Brown
Soils of the tropics have a very small total extent
(0. 1 5 million square kilometres) but are remarkable
for their high agricultural value. These are relatively
Soil resources and land use in Tropical Africa
land use. They are difficult and costly to reclaim
by the most sophisticated techniques and almost
wholly unuseable by African techniques.
young or rejuvenated soils developed on volcanic
material, basic crystalline rocks or alluvial deposits
under warm humid conditions which favour rapid
soil formation. They are rich in mineral nutrients
and often in organic matter, and they have excellent
structure and permeability. Such soils on volcanic
ash are cultivated intensively to bananas and coffee
in the humid and semihumid tropics while similar
soils on mineral rich rocks are excellent for cocoa
in suitable climates.
The Vertisols. Vertisols are soils of prismatic
structure with a calcareous horizon. They also have
a dark AI horizon, although their organic content
is low. In general, their mineral reserve is high but
permeability and external drainage are almost invari­
ably poor. Two main groups may be recognised:
Lithomorphic Vertisols from rocks rich in ferromag­
nesian minerals and Vertisols of Topographic De­
pressions.
Lithomorphic Vertisols in association with Humic
.
Ferrisols cover much of the Ethiopian massif in
north-east Africa. Where the water table can be re­
gulated they may be counted among the best of the
agricultural soils. They are also the most inade­
quately used.
The Vertisols of Topographic Depressions cover
an area two and a half times as great as the Litho­
morphic Vertisols. The Sudanese depression, which
receives drainage from the Ethiopian massif, has,
probably, the world's greatest extent of these soils.
They are also important elements in the soils com­
plexes of the Victoria Lake Basin and the Rift Val­
ley. Difficult external drainage combined with poor
internal drainage limits or prohibits their use for
agriculture.
Vertisols of all types cover approximately a mil­
lion square kilometres of Africa.
Hydromorphic and Halomorphic Soils. Hydro­
morphs and Halomorphs, which are associated with
high water-table conditions, cover less than a million
square kilometres. They are permanently or season­
ally waterlogged. Many of the Mineral Hydromor­
phic Soils have a relatively high agricultural value
where waterlogging is seasonal. Organic Hydro­
morphs occur mainly in sub-humid to semi-arid re­
gions where they carry a swamp vegetation of Papy­
rus or Phragmites. Their reclamation, like that of
coastal mangrove swamps, has presented unexpected
difficulties. Halomorphic Soils are characterised by
the presence in the profile of soluble salts and ex­
changeable cations, mainly sodium. All present the
same drainage problems and extreme difficulties of
11
SYSTEMS OF LAND USE
·
In this complex and generally unfavourable environ­
ment of soil and climate the African peoples ev.alved
an enormous range of land use systems which are
often remarkably ingenious adaptations to environ­
ment.1 Some remain, unaltered or little altered; many
have degenerated and passed beyond recognition un­
der the impact of explosive population growth, cash
cropping, loss of land, social disruption, labour mi­
gration and other changes brought about by the Eu­
ropean intervention. The nature of these systems,
and of the social syst�ms with which they were
bound, was rarely understood or even perceived by
the suzerain peoples. In their original forms, they
vary from what may justly be called shifting cultiva­
tion to highly developed systems embracing most of
the principles known to the agricultural science of
Europe.
Shifting Cultivation
The term "shifting cultivation" is frequently used
and rarely if ever defined. It appears to signify
haphazard movements of cultivating communities
from one site to another at a considerable distance
when the fertility of the first site becomes exhausted
-a sort of agricultural nomadism. In this sense,
shifting cultivation is rare in Africa. It occurs where
land is so abundant, in relation to population and
its requirements, that a man need not ·think of re­
turning within the foreseeable future to land he has
cultivated. In these circumstances-which obtain, for
example, over part of the Congo Basin and much
of the Kalahari Sands-communities are free to
move unhampered by the strict requirements of the
cycle of cultivation and land regeneration, but within
limits imposed by the distribution of land among
the sections of the tribe. In other cases periodic
movement is necessitated by large local concentra­
tions of population , formerly for defence.
Land Rotation Systems
The most common systems are better described as
"Land Rotation Cultivation". They are typical of
the vast intertropical areas of Ferrallitic and Ferru­
ginous Tropical Soils which require more or less long
periods of rest for the restoration of fertility after
cultivation. They were soil-selection systems based
1
See Allan, W. The African Husbandman,
1 965.
Boyd, Edinburgh and London
Ollver and
Acta Phytogeogr Suec 54
12
W. A llan
on an intimate knowledge of environment, and par­
ticularly of vegetation. The character of a soil-its
initial fertility and "staying-power"-was assessed
by the vegetation it carried and by physical char­
acteristics. The indicator of initial fertility was the
climax vegetation and the index of returning fer­
tility was the vegetation phases following cultiva­
tion. Cultivation periods commonly varied from two
to six years and rest periods from six to thirty years,
in various combinations. Many of these systems have
complex features but the most usual cycle was a
simple alternation of cropping and fallow. Fallow
land was not abandoned land. Generally, it remained
part of the cultivator's "farm", and the period of
fallow was no longer than the time required for the
restoration of fertility to a satisfactory level.
These were, and are where they have not been
disrupted, stable systems which maintained the fer­
tility of the soil and protected it from erosion. They
also allowed of permanent habitations. It is true that
villages moved, and still move from time to time
but these are very short moves for social and sanitary
reasons unconnected with agriculture.
Permanent and Semi-pr::r manent Systems
In well-watered areas of strong and fertile soils which
could be maintained in cultivation with £allows
shorter or little longer than the period of cultiva­
tion, Africans used land in the same way as other
people do. The family holding aproximated closely
to what we understand as a permanent farm.
Among the Chagga on the Eutrophic Brown Soils
of Kilimanjaro the homestead was surrounded by an
intensely cultivated grove of bananas of many varie­
ties, for cooking, for table fruit and for beer-making.
Beyo:1d this lay irrigated fields of finger millet, the
staple crop, which were rotated with a short grass
fallow on which cattle grazed, or which was cut to
p:-ovide feed for them. This pattern has changed,
under stress of population pressure and the new eco­
nomic necessities, to a mixture of bananas, plantains
and coffee, as it has in almost all similar environ­
ments.
On similar Eutrophic Brown Soils and Humic Fer­
risols but in a different climatic environment the
Kikuyu evolved a more complex system of intensive
or semi-intensive land use which included the pro­
duction of fodder crops for livestock. With the in­
tense overcrowding of the Kikuyu Reserves, all trace
of this system has long since disappeared.
In both of these systems, as in most permanent
systems� animal manure and household refuse were
carefully conserved and used on the land.
Acta Phytogeogr Suec 54
In a totally different environment, the Lozi of the
great flood plain of the upper Zambesi evolved a
highly complex and sophisticated system which uti­
lised a wide range of young soils on riverine and
lacustrine alluvium, mineral hydromorphic soils of
the plain and ferrallitic soils of the Kalahari Sands.
Exploitation of the hydromorphic soils depended on
an elaborate and very extensive drainage system
which was maintained by communal effort. Two
causes brought about the decay of this system. The
first was the discontinuation by the British Admini­
stration of what they looked upon as "forced la­
bour" for the upkeep of the main drains. The second
was labour migration and the withdrawal of most of
the younger men from a highly labour intensive eco­
nomy which included cattle herding and fishing as
activities almost as important as agriculture.
Highly Developed Systems
The evolution of intensive and soil-conserving sys­
tems which did not depend wholly on intrinsic soil
qualities seems to have been characteristic of refuge
areas. In these areas the growing pressure of grow­
ing populations confined to strictly limited land gene­
rated this response even on soils of relatively low
intrinsic fertility.
These systems include elaborate anti-erosion meas­
ures such as the very effective and original pit system
of the Matengo in southern Tanzania and the ad­
mirable dry-stone terracing of the Hill Pagans of the
Mandura Mountains in the Cameroons. Soil fertility
was maintained and enhanced by composting grass,
weeds and crop and household refuse, by the use of
manure where livestock were available and the bedd­
ing of animals to make more manure, and by crop
rotations and other "advanced" practices. Nothing
was wasted or left undone that could add to the
fertility of the soil. They were highly intensive sys­
tems, and highly laborious.
One of the best examples is to be found on the
little island of Ukara in the south-eastern sector of
Lake Victoria. Here, on rather weak soils of no great
intrinsic fertility the Kara people evolved an inten­
sive system of mixed farming in which use is made
of devices commonly associated only with the more
"advanced" farming practices.
The Kara seem to have invented green manuring
for themselves. They use an indigenous legume,
Crotalaria striata or, less commonly, Tephrosia erecta.
On the main arable lands a regular three-year ro­
tation is followed during which two dressings of
farmyard manure are given. In the intervening year,
between the two manure applications, the green man-
The influence offire in Trans-Saharan Africa
ure crop is dug in. Three grain crops and one of
ground beans are taken in these three years and
cropping is continuous. The land is never rested.
In addition to the green manure, large quantities of
animal manure are required to maintain yields under
such intensity of cropping. The Kara are very con­
scious of this and of the value of their cattle as
manure machines. Their biggest problem is feed, for
there is little grassland on the island and it is in the
form of small terraced fields on steep slopes. To
augment the feed supply they have selected grasses
which they cultivate under irrigation or on moist
sites on the lake shore. They also plant fodder trees
and lop them to feed the cattle. Everything that can
be used for bedding is used and high yields of man­
ure are obtained. Laborious and skilful soil conserva­
tion is also a feature of Kara land use. Many meth­
ods are used, including tie-ridging, banks and ridges,
live washstops, terracing with and without stone walls
and control of drainage by streamside banking. To
all this they have added a well-developed system of
rice cultivation, with transplanting from seedbeds.
This complex and otherwise admirable system has
two weaknesses. One is the vulnerability of the ter­
raced grassland fields. The other is the great and
almost continuous labour demand. The enormous
care given to the arable lands did not extend to the
grasslands. This is hardly surprising. It was not until
the 1 92 0's that the farmers of Western Europe
adopted a positive attitude to pastures. The first sign
of decay of the Kara system appeared in the grass­
lands. Their carrying capacity diminished. Reduc­
tion of livestock numbers and of the manure supply
was reflected in falling crop yields. At the same
time the young men left the island for an easier
life on the mainland or disappeared on long fishing
expeditions when heavy work was required. Erosion
started in the grasslands, then gulleys formed and
broke through the neglected terrace walls.
·
13
When they were last reported on, the remaining
Kara appeared to be fighting a gallant rearguard
action.
THE OLD AND THE NEW
The indigenous systems of African Land-use were,
in general, ingenious and often admirable adapta­
tions to environment. They were also adaptations to
the social, demographic and economic patterns of the
old Africa, and so interwoven with them that social
and economic changes inevitably reacted on the sys­
tems of land-use. The Land Rotation Systems are
particularly vulnerable. Production can be readily in­
creased, for a time, by utilising "idle" fallow land
to meet cash crop demands and the needs of grow­
ing population. But sooner or later the price must
be paid in land deterioration and falling yields. N a­
ture is an inexorable creditor.
The old inputs were few. There was seed and
there was labour, the labour of the family and their
kin and neighbours. There was also time, the time
needed for the restoration of fertility. These did not
cost money, they had no part in the cash economy.
New cash-cost inputs must replace the old ; inputs
such as fertilisers, mechanical power, improved seed
and other planting materials, pesticides, weedicides,
water and the rest. New skills must supersede the old.
A whole new institutional structure must be created.
As yet no one knows how these things are to be
done, where the inputs are to come from or how
they can be applied to many of the African soils
so as to produce stable and economic farming sys­
tems. Our knowledge is woefully inadequate. It is
only on some limited soils and under special condi­
tions that European-type farming in inter-tropical
Africa, by white men or black, has succeeded.
There is one ominous sign. In the urge for devel­
opment, soil exploitation has acquired a veneer or
economic respectability.
T H E I N F LU E N C E O F F I RE I N T RA N S - S A H A RA N A F RI CA
1.
F. V. Phillips
INTRODUCTION
Although the influence of fire upon vegetation, as­
sociated feral and domesticated animals, man and
the environment has been discussed for many years,
it is true that our knowledge is still fragmentary
and largely based upon general observations, im-
pressions, word-of-mouth passed down the genera­
tions and, at best, upon local field experimentation
not always sufficiently critical.
This does not deny that there is a steadily growing
mass of published information: for example, the in­
complete bibliography by the lamented Bartlett
Acta Phytogeogr Suec 54
14
J. F. V. Phi/lips
(1955, 1 9 56, 1 957, 1 9 6 1 ) includes many references
to Africa, while Aubreville ( 1 949 and other papers),
West ( 1 965), various other students and I myself
·
(Phillips 1 930, 1 93 6 , 1 965) have recorded a number
of the more important titles. My emphasis is rather
upon attention being focused more upon precise ex­
perimentation aimed at gaining information about
the significant phenomena in selected ecosystems­
plants, animals, men and their environment.
The detailed study of the responses of selected
plants and animals to fire is also imperative-that
is the physiological, morphological and anatomical
responses of the plant and the physiological and eco­
logical responses of the individual animal. Further­
more, we should endeavour to obtain, before time
makes this impossible, a fuller and better co-ordi­
nated record of the history, usage of and the lore
regarding fire possessed by the older generations of
Africans-the younger people certainly do not pos­
sess as much information nor show intuition of the
same depth and scope.
As I have so recently covered a wide field in my
paper (Phillips 1 9 65) upon the role of fire-as mas­
ter and servant-in the bioclimatic regions of Trans­
Saharan Africa, I confine my comments here to sum­
marizing my working impression regarding the in­
fluence of fire upon the grand ecosystems existing
within some of the bioclimatic regions. Although the
paper to which I refer is fuller than this present
communication, it is itself no more than a preamble
to deeper investigations required.
Background
Although its use by man in Trans-Saharan Africa
may not be as old as that in North Eastern Asia
and Europe, fire is thought to have been used toward
the very end of the Earlier Stone Age (Clark 1 9 5 1).
This comparatively late occurrence might be due,
as Clark himself suggests, to the wealth of sunshine
in Africa. It is, of course, true that long before
man learned to make fire, it was caused in some
regions, by lightning and in others through the fall
of rock. I myself have seen many examples of the
first in Southern African Wooded Savanna and one
of the second in September 1 9 3 8 in the Magaliesberg
Range in the Transvaal, South Africa (in Protea
Open Woodland; Phillips 1 965, p. 1 0). Fire has long
been associated with the environment in Trans-Saha­
ran Africa, especially in the subhumid to subdesert
regions. Man has used and misused this element
intensively as well as casually-before the Bantu en­
tered Eastern and Southern Africa it is likely that
the Bushman group of peoples-great hunters as they
were-used fire in the chase. In Southern and Eastern
Acta Phytogeogr Suec 54
Africa the European, learning from the indigenous
people, went �ven further in the misuse of fire, be­
cause he has misused it more intensively and effec­
tively.
Why Should We Be Concerned with a Study of Fire
in Trans-Saharan Africa?
Observation down the years has repeatedly demon­
strated to the interested observer that fire, wickedly
destructive as it is when running "wild", may be
used as a valuable tool for the management of vege­
tation: what is called today in wild life and land­
scape architecture circles in the United States, "ma­
nipulating" the environment!
My boyhood experiences in South Africa, followed
by more precise studies later, led me to publish my
impressions of this dual role of fire after examining
conditions in East Africa (Phillips 1 930), while op­
portunities for conducting scientific investigations in
the Highveld grassland of the Transvaal later led me
to dub fire a bad master, a good servant and a na­
tional problem (Phillips 1 9 36). Opportunities for
study in parts of the United States, Latin America,
South East Asia and, more especially, in Trans-Sa­
haran Africa have since been mine-and accordingly
I am all the more convinced about the dual role of
fire (Phillips 1 9 59, 1 9 6 1 , 1964, 1 965, 1 966). What
is required by the forester, the agriculturist, the con­
servationist and manager of water resources, veld
(range) and pasture and wild life management and,
of course, the landscape architect, is knowledge and
experience permitting the very much more effective
use of this "tool" in conserving and improving the
environment, indeed the local ecosystem itself.
It is also desirable-both because of its inherent
historical interest and its possible to definite scien­
tific, technical and managerial significance-to know
the ecological status of vegetation and wherever pos­
sible, of biotic communities: are these much as they
always have been? Are these climax, or subclimax,
proclimax, postclimax? How does such knowledge
bear upon the existing or the projected conservation,
alteration and management of these communities?
A Resume of Working Impressions of the Role of
Fire in Selected Bioclimatic Regions in TransSaharan Africa
Because the bioclimatic regions provide a convenient
approach to a condensed review of the significance
of fire in Trans-Saharan Africa, I refer to my ten­
tative classifications of these regions (Phillips 1 959,
1 96 1 , 1 965, 1 966). For the present purpose I define
the bioclima·tic region thus:
The influence offire in Trans-Saharan Africa
A unit embracing a certain interplay of climatic factors
and biotic phenomena, integrated to permit the development
of natural vegetation to a stage where it is ultimately in
dynamic equilibrium with the climate . . . influenced to a
greater or a lesser degree by the prime edaphic factors.
The ultimate stage is the climax but, actually, excluding
the forest, certain restricted high montane and subdesert
grassland and extensive subdesert and desert bioclimates,
this is still either imperfectly known or rarely in existence
because of various disturbing influences and controls. Where
the development toward a climax is either retarded or pre�
vented by some influence-often man�induced-the prevailing
temporary bioclimatic unit remains at a point either a stage
or several stages below the climax: the subclimax or pro�
climax respectively (Clements 1 936). An example of a non�
climax-either a subclimax or a proclimax-is wooded sa�
vanna in Trans-Saharan Africa (Phillips 1 959, p. · 48 ; 1 961,
p. 62).
The terms forest, derived savanna, wooded savanna, scrub,
macchia, open grassland and variants of these are defined
elsewhere and their distribution is shown grossly on maps
(Phillips 1 959, 1961, 1 965, 1 966).
Obviously, the role of fire in wooded savanna,
macchia and open grassland has influenced the corn�
position, structure and successional history of these
communities.
THE ROLE OF FIRE IN THE PRINCIPAL
BIOCLIMATIC REGIONS
Table 1 contains a condensed description of the main
feature of the bioclimatic regions to which I draw
attention in respect of the role of fire.
My conclusions as regards some of the more im�
portant influences of fire upon the vegetation, wild
animals, and the soil, are summarized in Table 2.
EFFECT OF FIRE UPON GROWTH FORM OF ,
WOODY PLANTS IN THE WOODED
SAVANNA AND IN OPEN GRASSLAND
I have outlined the views of various observers (vide
Phillips 1 965, pp. 57-59) regarding the suspected in�
fluence of fire upon plants subjected to annual or
other frequent burning. The principal forms to
which attention has been drawn include the follow�
ing:
(I) Grotesque orchard-like small trees and large
woody shrubs, for example, Commiphora fischeri,
Lannea humilis, Dichrostachys glomera·ta, Dalbergia
melanoxylon. These have been termed the Obst�
gartentypus (Meyer) and the Zwetschenbaumtypus
(Busse).
(II) The relatively succulent-and-woody small
trees and small woody shrubs represented by the
genus Commiphora.
15
(Ill) The stunted, gnarled, relatively thin-barked
woody shrubs of various genera frequently showing
either extensive root-systems or else very large, thick­
barked semi-subterranean stems.
(IV) The relatively thick-barked trees and woody
shrubs of various genera.
(V) The coppice-like large woody shrubs, for ex­
ample species of Grewia, Combretum, and Bussea
massaiensis which produce many stems from a
single-root stock and, among the larger trees, Jul­
bernardia, Isoberlinia, and Brachystegia.
The interesting fact that apical bud behaviour dif­
fers widely among species of grass in South Africa
and bears upon the influences of burning and graz­
ing has been brought out by Scott et al. (1956; vide
Phillips 1 965, pp. 56-57).
Studies of the morphology and anatomy of woody
and other plants as influenced by fire could provide
information of great interest.
GENERAL CONCLUSION
From the greatly condensed outline presented in
Table 2, it is obvious that fire plays a highly signi­
ficant role in the life of biotic communities, especi­
ally in those in the wooded savanna, open grassland,
and macchia and that considerable changes have
been wrought in the forest ecosystems by this ele­
ment.
Detailed investigations-morphological, anatom­
ical, ecological, physiological, and economic-still
are required before our knowledge could be much
refined.
REFERENCES
A:ubreville, A., 1949 . Climats, Forets et Desertification de
l'Afrique Tropicale. - Soc. d'Edit. Geogr., Marit. et
Colon. Paris.
Bartlett, H. H., 1 956. Hre, primitive agriculture, and grazing
in the tropics. - In W. L. Thomas (ed.) : Man's role in
changing the face olf the earth, pp. 692-720. Chicago.
- 1 955. "Fire in relation to primitive agriculture and
grazing in the tropics." - Annotated mbliogmphy, Ann
Arbor, Miohigan: University of Michigan, Bot. Gardens:
Vol. I (out of print) .
- 1957. Vol. 11. ibid.
- 1961. Vol. Ill. ibid.
Vol. IV, V: not prepared, owing to death of author.
Clark, J. D., 1 9 5 1 . The Prehistory of Southern Africa. Penguin Books. London.
Phillips, J., 1930. Fire: Its influence on biotic communities
and physical factors in South and East Africa. - S. Af­
rican J. Sci. 27, 352-367.
- 1936. Fire in vegetation: A bad master, a good servant
and 'a national problem. - J. S. African Botany, I, 36-45.
- 1 959. Agriculture and Ecology in Africa. - Faber, Lon­
don; Praeger, New York.
Acta Phytogeogr Suec 54
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Table 1 . A f!.(meral comparison of aerial factors conditioning the major bioclimatic regions of Trans-Saharan Africa (Phi/lips 1959, 1961, 1966).
1 Radiation: heat-light complex. Megatherm : above mean of 74°F (23°C) ; mesotherm: mean of 68-74°F (20-23°C).
2 Humidity: Very high, above 27 mb ; high, 20-27 mb ; moderate, 1 3-20 mb ; slight, below 1 3 mb.
.
3 Rain : Excessi�e, ab ove 98 inches (may attain over 200) ; very high, 7 1 -98 in. ; high, 5 5-7 1 in. ; moderate, 39-5
5 in . ; slight, 24-39 in. ; very slight, 1 6-24 in. ; very, very slight, 8- 1 6 in. ;
·
trace, 4-8 in. ; negligible, below 4 in.
4 Drought: ecologically dry months (EDM's) (1 inch and less); negligible, below one mont h ; very short, 1 -2 months; short, 3 months ; moderate, 4-5 months; fairly long, 6 months; long,
7 months; very long, 8-9 months; excessive, 1 0- 1 2 months. ( ) indicates occasional, not usual.
Saturation deficit
dry seasons
�
�
�
�
�
c.,
in
Evaporation
Bioclimatic region
Radiation1
Humidity2
Rain3
Drought4
Highly humid forest,
low and medium
elevations N. and S.
of Equator, mainly N.
Megatherm, range very
slight; monotonous­
ly uniform through­
out year
Uniformly high, range
very slight
Very high to high, re­
liable, locally exces­
sive
Nil to very slight;
EDM : 0-(1-2)
Negligible
Negligible to slight un­
der canopy, moderate
(to high) on extensive
exposed areas; less
than rain
Humid forest, low and
medium elevations N.
and S. of Equator,
mainly N.
Megatherm, but above
2500-3000 ft mega­
mesotherm; range
very slight through­
out year
Uniformly high, with
slight decrease in dri­
est months and on
drier days only
Very high to high, nor­
mally reliable
Short and mild, but
locally may be longer
and more severe;
ED M : 1-2-3 (4),
rarely more
Slight to very slight to
negligible
Slight under canopy,
moderate (to high) on
extensive exposed
areas; less than rain
Humid montane forest
(with a less humid
variant:
Humid-sub-humid
montane forest),
4000- 1 0,000 ft. N .
and S. of Equator,
mainly N.
Mesotherm, range
moderate (rarely high)
High , but in driest
coolest months mod­
erate
Moderate to high, lo­
cally moderate; reli­
able
Short to moderate;
ED M : 3-4 (5) but
locally less: 1 -2
Slight to moderate
Slight under canopy,
moderate under full
exposure (temporarily
high when wind
strong) ; almost equal
to rain
Derived wooded sa­
vanna, derived from
Highly Humid but
more often from Hu­
mid Forest and Hu­
mid Montane Forest,
N. and S. of Equator,
mainly N., in places
converted to open
grassland
Megatherm where de­
rived from H ighly
Humid and Humid
Forest; mesotherm
where derived from
Humid Montane For­
est; generally appre­
ciably higher because
of more open cano­
As for forest biocli­
mate in which it has
been derived, with re­
duction in humidity
when radiation is ex­
cessive
Normally as for the
forest biocl imate in
which derived; im­
pact of rain on soi l
severe a s canopy
much less dense and
even "open" in many
parts
Much as for the forest
bioclimate in which
derived, but higher
because of greater
exposure to sun, wind
and higher evapora­
tion
Much as for the forest
bioclimate in which
derived, but may be
more severe because
of greater exposure to
sun, wind and higher
evaporation
More severe than for
the forest bioclimate
in which the commu­
nity has been derived
because of greater ex­
posure to sun and
wind ; greater than
rain where vegetation
is woodland, open
woodland and grass­
land
Subhumid wooded sa­
vanna, low, medium
and upland elevations
N. and S. of Equator
Megatherm, but at
higher elevations
(3000 ft upward)
mega-mesotherm;
range moderate to
great according to
rainy and dry seasons
High in rains, mode­
rate in dry seasons
Moderate to high ; re­
l i able to fairly so to
unreliable
Moduate to fairly
long and fairly severe
to mild; EDM: (3)4-5
Moderate to high
(Moderate) to high in
dry season, moderate
in rains; greater than
rain
PY
0'1
�
I
0)
00
......
Ot
Ot
-.1
�
0'
�
Subarid wooded sa­
vanna, low, medium
and upland elevations
N. and S. of Equator
Megatherm, with vari­
ations as in S HWS,
but range greater
High in rains, mode­
rate in dry season
Slight to moderate ac­
cording to l ocality
and year, unreliable
Moderate to fairly
long to (long) and
fairly severe; EDM :
(5-)7
High
High in dry season,
moderate in rains,
greater than rain
Arid wooded savanna,
low, medium, and
upland elevations N.
and S. of Equator
Megatherm, with vari­
ations as in SHWS,
but range much grea­
ter
Moderate to high i n
rains, slight in dry
season
Very slight to slight,
unreliable
(Fairly long) to long
and fairly severe to
severe; ED M: 6-8
High to (very high)
High to (very high) in
dry seasons, moder­
ate i n rainy ; greater
than rain
Subdesert wooded sa­
vanna, low, medium
and upland elevations
(littoral variants may
be more humid, but
rain is negligible) N.
and S. of Equator,
mainly N.
Megatherm with varia­
tions as in SHWS, but
range great to very
great in dry season
Moderate to high i n
rains, slight in dry
season, drier than
AWS
Very, very slight to
very slight, very unre­
liable
Long to very long, se­
vere to very severe;
ED M : 7- 1 0
High to very high
Very high to (excessive
locally)-in dry sea­
son but (moderate) to
high in rains, much
greater than rain
Open grassland, low,
medium and upland
elevations, almost
wholly subclimax and
proclimax; mainly
subtropical, S. Africa
Mesotherm, rarely me­
ga-mesotherm; in
cold, dry season (Ap­
ril-Sept.) micro-me­
sotherm, when frost
moderate to severe
for a variable period
High to moderate dur­
ing rainy season, mod­
erate to slight dur­
ing dry
Varying with latitude
and elevation : 1 5 to
40 inches, over a sea­
son of 3 to 6 months
Slight t o moderate to
severe during rains,
varying with sub­
region
Moderate to high ac­
cording to subregion
Slight to moderate dur­
ing rains, moderate
to high during hotter
periods in late dry
season; greater than
rain
Macchia (Maquis ; S.
African Fynbos), Sub­
tropical, S. Africa;
successional to For­
est or climax in cer­
tain montane and
other subregions
Mesotherm; frost rare
except at high eleva­
tions in montane sub­
regions where climax;
more severe during
warm, dry season
(October-March)
High to moderate dur­
ing rainy season
(usually in "cool"
season, April-Sep­
tember) ; moderate to
slight during dry sea­
son in climax subre­
gions
During "co ol" season
where climax, but
fairly well distributed
where successional to
Forest; 20-.SO plus in­
ches
Where subclimax to
Forest, slight to mod­
erate, but where
climax may be mod­
erate to severe
Where subclimax to
Forest, slight to mod­
erate, but where cli­
max may be moderate
to high during warm,
dry season
Slight to moderate dur­
ing "cool", rainy sea­
son; usually greater
than rain during
rainy season
�
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�
�
�
�
�
s·
�
(")
�
"1:1
�
<:;)
�Cl
�
....
V:l
::::
1"1>
(")
V.
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§
1'
�
::s-o
�
§
.;;
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-...]
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Table 2. The gross influence offire upon great bioclimatic ecosystems in Trans-Saharan Africa.
00
Explanations. of symbols: Inflammability : VH, very high ; H, high ; MH, moderately high ; M, moderate; SI, Slight ; N, negligible; NA, not applicable. Reduction in area: VS, very severe;
S, severe; MS, moderately severe; M, moderate; Sl, slight; N, neglible; NA, not applicable. Influence on soil, crop production, pasture and browse, forestry potential, associated wild animals,
aesthetics and landscap J: symbols for severity as above.
Symbols for nutrients (soil only ; line b) : N, nitrogen; S, sulphur; P, phosphorus; K, potassium; Ca, calcium; Mg, magnesium.
Brackets indicate occasional not usual.
�
Highly humid
forest, low and
medium elevations
N and S of Equator,
mainly N
Inflammability
N
to
SI
to
(M)
�
Reduction
in area
Soil
(a) Historic
(b) Continuing
(c) Conversion
to open
grassland
(a) Organic
matter
(b) Nutrients
(c) Physical
conditions
(a) M
(b) M
(c) M
(a) MS loss
(b) N, S loss,
P, K, Ca, M g
gain
(c) N-Sl3
(a) MS
(b) M
(c) M
(a) M S-S loss
(b) N, S loss
P, K, Ca, Mg
gain
(c) N-Sl-(M)3
M
Humid montane
forest, 4-10,000
ft. , N and S of
Equator, mainly N
M
to
MH
(a) S
(b) MS
(c) M S
(a) S-VS loss
(b) N, S loss,
P , K , C a gain
(c) Sl-M3
MH1
(a) M
(b) M
(c) M S
(a) Loss M
(b) As above
b u t less in
amount
(c) Sl-M3
(a) M
(b) M
(c) M2
(a) Loss SI
to M
(b) Less than
in DWS
(c) SI-M
locally S3
Subhumid wooded
savanna, low,
medium, and
upland elevations N and S
of Equator
MH
to
(H)l
�
-.
::::::
Humid forest,
low and medium
elevations, N
and S of Equator,
mainly N
Derived wooded
savanna, derived
from H ighly Humid
but more often
Humid Forest and
Humid Montane Forest,
N and S of Equator,
mainly N
::::
�·
Influence of fire upon:
Bioclimatic
regions
�
Crop
production
Pasture and
browse
Forestry
potential
Associated
wild animals
Aesthetics and
Landscape
SI-M
helpful
N to
helpful
in dry
spells
N
N to SI
Harm : N to SI,
rarely M
Introduces an
attractive
scenic contrast
N
N to SI
As above
N to SI
to (MS)
locally to
antelope
H arm :
M to MS
(long duration)
An attractive scenic
contrast but danger of
deterioration of soil
Harmful to
young
antelope :
M
Harm :
M to MS
(temporary)
Scenic contrast
slight
Harmful to
young
antelope:
M
As above
SI-M
helpful
SI-M
helpful
SI-M
helpful
SI-M
helpful
SI to
helpful
in dry
spells
Sl to
helpful
in dry
spells
Early Dry
Season
M S-S
Mid-Dry Season
helpful
Early Rains
M S-S
E.D.S.
M S-S
M . D.S.
helpful
to N-Sl
Early Rains
M S-S
M
M
to
MS
SI
S to VS
SI to M
Subarid wooded
savanna, low,
medium, and upland elevations
N and S of Equator
Arid wooded
savanna, low,
medium, and upland elevations,
N and S of Equator
Subdesert wooded
savanna, low,
medium and upland
elevations, N and
S of Equator
Open grassland,
low, medium,
and upland
elevations,
almost wholly
climax and proclimax;
mainly S of
Equator and
Subtropical
�
("')
�
�
'<:
C)
�
�.....
�
;::
�
("')
.....
�
Macchia (Maquis,
S. African Fynbos),
Subtropical,
S. Africa;
either successional to Forest
or climax in
certain
localities
Hl
H
to
VH1
H
to
VH1
H
to
VH1
(a) MS
(b) M
(c) MS2
(a) MS
(b) MS
(c) M2
(a) NA
(b) NA
(c) NN
(a) Increase
in area
(b) Slow
increase
(c) NA
(a) Loss N to
Sl
(b) Less than
SHWS
(c) S I-Mlocally S
(a) N
(b) Less than
in SAWS
(c) Sl-M
locally S
(a) N
(b) Less than
above
(c) S
(a) N-SI
(b) P, K, Ca,
Mg gain
more than
above
(c) SI-M
SI to
M
helpful
Crops
rare except in
wetter
periods,
SI-M
helpful
NA
SI-M
helpful
E.D.S.
M S-S
M.D.S.
N-Sl
helpful
Early Rains
MS-S (rare)
E.D.S.
M S-S
M.D.S.
N-Sl
helpful
Early Rains
MS-S (rare)
E.D.S.
M-MS
M . D.S.
N-Sl
(helpful)
Early Rains
MS-S (rare)
E.D.S.
M S-S
M.D.S.
helpful4
Early Rains
helpful4
S l to M
S l to VS
Harmful to
young
antelope:
M to MS
Harm:
M to MS
(temporary)
MS-S (rare)
SI to M
S to VS
Harmful to
young
antelope:
M to MS
Harm :
M to MS
(temporary)
Rarely
harmful
unless
thicket
refuges
are
fired: SI-M
Harm :
N, locally
where grass
is abundant
M to S
harmful
(temporary)
Harmful to
young
antelope and
ground-nesting
birds
M to MS
Harm :
M to MS
(evanescent)
Stimulates
flowering
aspects
Sl to M
N
N
N
NA
NA
NA
�
n:.
�
;::
MH
to
H
to
(VH)1
(a) Increase
(b) Increase
(c) NN
(a) Sl-M(S)
dependent
on date of
last known
(b) N, S loss
P, K, Ca, Mg
gain more
than above
(c) M to S
Sl to M
helpful
E. D.S.
M-MS
M.D.S.
S-VS
Early Rains
helpful
n:.
�
r')
n:.
NA
NA
NA
Harmful to
young buck
and to birds:
M to MS
Stimulates
production
of flowers
in some
genera; may
be S to VS
locally
1 Dependent upon volume and dryness of grass and other growth and the precise season of the year.
2 Time to convert to open grassland dependent upon time of year and condition of grass and woody elements, usually many years.
3 Dependent upon nature of vegetation, season and corresponding severity of the burn ; severe burns indurate the surface, moderate burns have negligible to slight effect.
4 Influence of seasonal burning upon specific and economic nature of pasturage in South African open grassland dependent upon the precise ecological subregion: for example: in
parts of the Transvaal burning before the first rains of the new season does no harm, whereas in Natal, it is imperative to burn after the first rains.
�
�
n:.
s·
�
�
�
7
�
�
�
§
�
...,
;:;·
�
-
\0
20
R. Goodier
Phillips, J., 1 96 1 . The Development of Agriculture and Forestry
in the Tropics. Faber, London; Praeger, New York.
- 1 964. Shifting cultiv.ation. - Proc. and Pprs. of IUCN
9th Tech. Meeting, Nairobi, Sept.: IUCN pub. new series
4-1964: Part Ill: The Impact of Man on the Tropical
Environment.
- 1965. Fire-as Master and Servant: Its influence in the
Bioclimatic Regions of Trans-Saharan Africa. - Proc.
4th annual Tall Timbers Fire Ecology Conference, Talla­
hassee, Florida, 7-1 1 0.
- 1966. The Development of Agriculture and Fo·restry in
the Tropics. - Faber, London; Praeger, New York. 2nd
ed.
Scott, J. D., 1 956. The study of primordial buds and the
reaction of roots to defoliation as the basis of grass­
land and management. - Proc. 7th. Int. Grassland Con­
gress, Wellington, N. Z. (Scott and his students have taken
this study a good deal further; those interested should
contact Prof. J. D. Scott. University of Natal, Pieter­
maritzburg, S. Africa.)
Thomas, W. L. (ed.), 1956. Man's Role in Changing the
Face of the Earth. - Univ. Chicago Press.
West, 0., 1 966. Fire in vegetation and its use in pasture
management, with special reference to tropical and sub­
tropical Alfrica. - Commwlth . Agr. Bureaux, Mimeo No.
1 / 1965 (references to West's work 1 943-1 964 therein).
N A T U R E C O N S E RVATI O N A N D F O RE S T C LE A RA N C E
I N A F RI CA W I T H S P E C IA L R E F E RE N C E T O
S O M E E C O LO G I CA L I M P L I C A T I O N S
O F T S E T S E C O NT R 'O L
R.
Goodier
INTRODUCTION
For the conservationist one of the most disturbing
of present day trends is the increasing rapidity with
which natural forests and woodlands are being re­
duced within the tropics. With the growth of popula­
tion and technological development much of the re­
maining forest is perhaps inevitably doomed to ex­
tinction but one may still be dissatisfied with the
haphazard way in which this reduction is being un­
dertaken with little thought for the resources of these
unique communities or even for the preservation of
small areas for biological research.
In his fascinating account of the clearing of the
woodland in Europe Darby ( 1 956) has shown that
even in the relatively highly developed western Eu­
ropean countries the extent to which total woodland
clearance proceeded varied greatly and in many
countries a considerable proportion of woodland
cover remains, though of course this is by no means
all "natural" woodland in the sense that the prime­
val ecosystem has remained undisturbed. While great
inroads are made into forests for the production of
timber it is probably true to say that in most cases
this type of exploitation is followed by fairly rapid
regeneration of forest cover which, although it may
not closely resemble the original forest, ensures the
continuity of many important forest habitats. How­
ever, in practice, timber removal is frequently folActa Phytogeogr Suec 54
lowed by exploitation for pasturage and conversion
to arable.
For obvious historical and sociological reasons the
process of de-forestation has proceeded rather dif­
ferently in Africa though many parallels can be ob­
served. Over relatively few parts of Africa south of
the Sahara has the population reached the order of
density necessary to maintain extensive completely
de-forested areas so that, except for the deserts, most
of the area remains under some kind of tree cover.
However the widespread practice of shifting cultiva­
tion has ensured that much of this tree cover has
been more or less modified from a primeval state
and has resulted in a complex pattern of develop­
ment stages to confuse the phytosociologist. Com­
plete removal of the natural vegetation and its per­
manent substitution by pasturage or arable or exotic
trees is a relatively recent development in tropical
Africa and in its early stages has resulted in some
outstanding examples of ecological mismanagement
(Brown 1964).
In this paper I am not concerned with the usual
causes of de-forestation but wish to direct attention
to a rather specialised type of forest clearance, na­
mely that connected with the biological control of
insect vectors of disease. Although clearance of for­
est for this reason is on a much smaller scale than
for the more usual reasons it has, I maintain, par­
ticular significance for conservation, particularly in
Nature conservation andforest clearance in Africa
relation to vegetation clearance as a measure against
tsetse flies (Glossina spp.).
The attack on tsetse in Africa over the last fifty
years represents one of the most massive applica­
tions of sdentific manpower seen in the continent
and though, if one reviews the battlefield the defeats
are at least as prominent as the successes, yet this
effort has yielded what must be, for the ecologist,
one of the most fascinating of scientific literatures.
I draw my examples in this paper from this field
as I believe that within it are to be found many
features of interest and of direct relation to the con­
servation of African vegetation.
VEGETATION CLEARANCE AGAINST
TSETSE
Buxton ( 1 955) concludes his introduction to the prin­
ciples of vegetation clearing against tsetse by com­
menting that: " . . . all species of tsetse are closely
associated with forest, trees or bush, at least as breed­
ing places: to a considerable extent, therefore, the
struggle against tsetse cannot fail to be an effort to
replace woody vegetation by grass. There is, there­
fore, an essential conflict between the control of
tsetse and the preservation of forest."
It has been estimated that approximately 1 0 mil­
lion square kilometres of Mrica lie within the limits
of infestation by the various species of the genus
Glossina. The true figure is undoubtedly less than
this but because of the fragmentation of tsetse belts
and the difficulty of establishing boundaries in the
case of species that infect large areas at low densities
it is very difficult to arrive at an accurate estimate.
Certainly human and animal trypanosomiases result­
ing from transmission by tsetse is an important eco­
nomic and social factor within a very substantial
proportion of the continent.
Within this huge area tsetse may occur anywhere
from sea level up to nearly 6000 feet near to equator
or 4000 feet in Rhodesia and, depending on the
.
species concerned, in a wide range of climatic con­
ditions. High temperatures are only very locally · lim­
iting on tsetse distribution but generally a mean an­
nual temperature below 20 ° C is inimical to most
species of tsetse as is also the regular widespread
occurrence of frost (Nash 1 9 37, Jack 1 927) .
Thus almost the whole range o f tropical Mrican
woody vegetation below the montane zone is liable
to infestation by tsetse and the genus has evolved
the capability of exploiting almost the whole range
of the ecological potential.
Although the relation of tsetse to vegetation is
21
complex the general association of the species or
species groups of tsetse with the main physiognomic
groupings of vegetation can be attempted (c.f. Bux­
ton 1 955, Phillips 1 959) and is summarized in Table
1.
The general situation i s made more complex by
the fact that most if not all species of tsetse appear
to require more than one type of vegetation within
their range. Thus the breeding place is often in rela­
tively dense vegetation while the feeding place may
be in open woodland or even in treeless grassy areas.
Nevertheless, it has often, though by no means al­
ways, been possible to distinguish an "essential hab­
itat" in the form of a recognisable vegetation com­
munity within the local range of the particular tsetse
species that is necessary for its survival. This recog­
nition of the relationship of the various species of
tsetse to recognisable vegetation types and to "es­
sential habitats" within these types is the basis of
all tsetse control methods based on the modification
of the vegetation cover.
The efficacy of "bush clearing" against tsetse
has been recognised for a long time and riverside
clearing against G. palpalis in W. Africa was made
as early as 1 909. Since then there have been very
many clearing campaigns too numerous to list in­
divid� ally. A selection of some of the most interest­
ing and important ones, chosen to illustrate the vari­
ous types of scheme and their scale of effect on vege­
tation, are shown in Table 2.
This is not the occasion to discuss the degree
of success of these schemes in the control of tsetse
though of course this has a bearing on the future
use of the method. In general clearing schemes have
proved quite successful when applied with ecological
insight and effective follow up action. Buxton ( 1 9 55)
has made the point that such schemes are likely to
be most effective when applied in areas close to the
environmental limits of tsetse and some evidence for
this was found in a certain part of Rhodesia where
the cold season temperatures were reduced by river­
ine clearing to a level that could be harmful to tsetse
(Goodier 1 9 5 8).
It has on occasion been suggested (Stebbing 1 93 8)
that bush clearing has a direct detrimental effect by
promoting soil erosion but in practice this is seldom
the case as the removal of woody vegetation and
consequent disturbance of the topsoil usually leads
to a profuse grass cover which may sometime lead to
better soil stability than before (Glasgow 1 9 60).
Thus on the Sabi river in the south east of Rhodesia
the clearance of A cacia heteracantha and Colophos­
permum mopane communities on riverine alluvium
led to a rich growth of the perennial Panicum maxiActa Phytogeogr Suec 54
22
R. Goodier
Table 1 . Relation between the most important species of tsetse and vegetation.
Species of
Glossina
Buxton
( 1 9 55)
Phillips
(1 959)
G. swynnertoni
G. longipennis
Thorn bush
Thornbush
V AWS
V AWS
G. morsitans
Miombo
V AWS
V AWS
V AWS
G. morsitans
submorsitans
G. pal/idipes
Thicket
AWS
G. /ongipalpis
Intermediate
S HWS
G. palpalis
Fringing
woodland
G. tachinoides
Fringing
woodland
G. brevipalpis
Thicket
G. austeni
Thicket
}
A.E.T. F.A.T.
classification
} Open
woodlands
Woodland
and open
woodland
with some
thicket
Thicket with open
woodland
Subhumid
woodland
and open
woodland
with
riverine
forest
Evergreen
thicket
and riverine
and fringing
forest
}
IX, A. l ( 1 ) ; V A
IX, A . l (a)
Ill A. l
11 A . 1
I I A. 1
Ill A, 1 and 2
Ill A, 1 and 2
I l l A,
G. fusca
Forest?
G. medicorum,
tabaniformis
etc.
Forest
HF
HF
G. caliginea
Forest
(mangrove)
XI Mangrove
?
Tmpkal
equatorial
forest
mum, Digitaria sp. and Urochloa sp. However, a de­
finite danger of erosion exists if cattle are allowed
too rapid ingress to the cleared areas-this also in­
creases the rapidity of scrub encroachment into the
cleared areas and hence increases the danger of their
being reinvaded by tsetse.
·
While still considering the secondary effects of
bush clearing it is perhaps worth mentioning the
promotion of the growth of exotic species due to
removal of the natural vegetation cover. This is dis­
advantageous both from the point of view of the
conservation of the natural vegetation cover and also
from the viewpoint of tsetse control because the in­
vasive exotics are sometimes much more difficult
to eliminate than the original native vegetation and
while probably not providing ideal habitats for tsetse
may nevertheless provide cover through which the
tsetse may invade more favourable habitats. A good
example of this problem is seen on the Eastern bor­
der barrier clearing of Rhodesia where much effort
has to be expended each year cutting back regrowth
Acta Phytogeogr Suec 54
IX A. 1
IX A. 1
I.A. 1
which contains much Lantana camara (Cockbill
1 96 1 ).
From Table 2 we see the wide range of vegetation
that has been attacked in the course of tsetse control
operations from the thorn scrub savannah habitats of
G. swynnertoni to the evergreen forest habitats of
G. brevipalpis. The distinction is sometimes made
between total clearing of woody vegetation and dis­
criminative and selective clearing. Discriminative
clearing entails the removal of only certain com­
munities within the local vegetation ecosystem while
selective clearing removes only certain species of
woody vegetation. Both from the aspects of cost and
conservation discriminative or selective clearing is
to be favoured, where effective, but can still lead to
very marked alteration of the ecosystem even though
as little as 2-4% of the tree cover may be removed.
DISCUSSION
When one considers the intensity of arguments
centered on the destruction of game animals as a
Nature conservation and forest clearance in Africa
23
Table 2. Some major vegetation clearing schemes against Tsetse.
Date
Locality
Tsetse
Vegetation type
and area cleared
Reference
1 9251 929
N. Nigeria
(GadauSherifuri area)
G. tachinoides
Riverine Fringe
Forest clearing,
I 8,000 hectares
LLOYD et a/. (1933)
1 9521 953
N. Nigeria
(AnchauBanke area)
G . morsitans
Riverine Fringe
Forest, 534 linear
kilometres.
Barrier clearing
3 500 hectares
WILSON (1 958)
1 9351 948
N. Nigeria
(Anchau scheme)
G. palpalis
Riverine Fringe
Forest clearing,
869 linear kilometers
NASH ( 1 948)
1 9321 934
Tanzania
(Huru-Huru etc.)
G . swynnertoni
Barrier clearing
and selective
clearing in
Acacia drepanolobium "thornbush"
complex?
> 65,000 hectares
SWYNNERTON ( 1 9 3 6)
1 9 331 962
Rhodesia
(Eastern Border)
G. brevipalpis
Barrier clearing
BrachystegiaUapaca woodland
with some evergreen forest.
> 20,000 hectares
1 9421 949
Zululand
G . pallidipes
Barrier clearing
49,000 hectares
1 9451 950
Zambia
(Abercorn area)
G. morsitans
Discriminative
clearing i n
Brachystegia
woodland "ecotone",
4600 hectares
1 9561 961
Rhodesia
(S. E.)
G. morsitans
G . pallidipes
Selective clearing
to create "Barrier".
Riverine Fringe,
Androstachys
johnsonii forest,
Brachystegia
tamarindoides woodland, etc. > 1 0,260
hectares
FORD (1 960)
GOODIER ( 1 9 6 1 )
1 952
Mozambique
G. austeni
Selective clearing of
? Fringing forest,
c. 1 7,000 hectares
TRAVASSOS
SANTOS D IAS ( 1 9 54)
G. morsitans
submorsitans
submorsitans
G. tachinoides
method of tsetse control it is, perhaps, a little sur­
prising that so little attention has been paid to the
significance for conservation of vegetation clearance
for the same purpose. Evidently for most people it
is relatively easy to adjust to the fact that the de­
velopment of Africa will necessitate a great reduc­
tion of areas of natural vegetation while the im­
plications of this same process for game animals
are seldom faced objectively and the relation between
this same vegetation and the fauna is even less fre­
quently considered. Perhaps one of the most regret­
table aspects of tsetse control measures, be they game
destruction, bush clearing or the more recent wide-
Du TOIT (1 954)
spread application of insecticides, is that the organi­
sations which have undertaken them have never had
the resources to investigate their wider ecological
implications. Thus in the case of vegetation clear­
ance against tsetse there has always been the ten­
dency to consider the effect as being unimportant
on a continental scale and, therefore, of little con­
servation significance.
Two most important considerations that arise in
relation to tsetse control clearings are that the opera­
tions often involve the clearance of vegetation that
is, firstly, of particular ecological interest and, sec­
ondly, of a type that would often not be destroyed
Acta Phytogeogr Suec 54
24
R. Goodier
for any other purpose. While the term "particular
ecological interest" is perhaps incapable of close de­
finition there is no doubt that many of the types
of habitat removed in the course of anti-tsetse clear­
ance have this quality, which may be a function of
high biological produc'tivity and biological diversity.
This would undoubtedly apply to the riverine forest
habitats of Glossina palpalis, to the forest and thicket
habitats of G. brevipalpis and G. austeni and prob­
ably even to the "essential habitats" of such species
as G. pallidipes and G. morsitans. Indeed when the
habitats are sufficiently clearly defined as to allow
discriminative clearing to be undertaken it is incon­
ceivable that they do not have an ecological sig­
nificance far beyond that in relation to tsetse. The
significance for tsetse of the natural interzone or
"ecotone" between vegetation communities within
the overall tsetse "habitat" is often stressed and
the destruction or modification of these ecotones re­
commended but it is frequently these "edge" habi­
tats that are of particular importance for a wide
range of animals and plants.
Vegetation clearing operations against tsetse are
often carried out in remote areas where there is little
chance of clearing for agricultural development and
thus in areas that might well merit selection as con­
servation areas for both plant and animal communi­
ties. Conversely many of the remaining areas of re­
latively undisturbed plant and animal communities
in Africa are in areas that are at present tsetse in­
fested and may in future be subject to tsetse control
operations. Thus we encounter the well known para­
dox that the tsetse infestations which may have been
instrumental in preserving large parts of Africa
against overstocking by cattle etc. may eventually
make it more difficult to preserve even part of these
areas inviolate. A recent example of this type of
dilemma is seen in the Gona-re-Zhou Reserve be­
tween the Sabi and Limpopo Rivers in the S.E. of
Rhodesia where much interesting vegetation, includ­
ing patches of A ndrostachys johnsonii forest, has had
to be destroyed (Goodier 1 9 6 1 ) and, more recently,
game exterminated and insecticides applied (Cock­
bill 1 965) in a remote, sparsely inhabited area, in
an attempt to prevent a large spread of tsetse in­
festation from Mozambique.
Africa is changing rapidly and there is no reason
to believe that as technical resources grow the cam­
paign against tsetse will not be pursued on an in­
creasing scale and that the clearance of vegetation
will not continue to be an important weapon in the
armoury of the applied entomologist. It would, I
think, be unrealistic to expect the aims of this cam­
paign to be greatly diverted by considerations reActa Phytogeogr Suec 54
lating to the conservation of natural communities.
Nevertheless, there is great need for these considera­
tions to be brought clearly to the attention of those
responsible for the planning of tsetse control meas­
ures. With this aim in mind the conservationist must
define his requirements precisely so that irreparable
damage will not be caused in ignorance. Clearly the
present conference can provide a most necessary be­
ginning to this process of definition.
SUMMARY
The relationship between the species of tsetse and particular
types of vegetation is outlined and the use made of vegeta­
tion clearance in the control of tsetse reviewed.
Vegetation clearance against tsetse has particular signifi­
cance in relation to the conservation of the natural en­
vironment firstly because of the particular ecological sig­
nificance of the vegetation types cleared and, secondly, be­
cause the clearing operations often take place in remote
areas that would in all probability be conserved if it were
not for the necessity to control tsetse.
The importance of the need for conservationists to define
their requirements so that due account can be taken of the
need to conserve examples of the natural environment is
stressed.
REFERENCES
Brown, L. H., 1964. An assessment of some development
schemes in Africa in the light of human needs and the
environment. - I.U.C.N. 9th Technical Meeting. Nairobi
1 963.
Buxton, P. A., 1955. The Natural History of Tsetse Flies. London.
Cockbill, G. F., 1 96 1 . Preliminary investigations on the use
of a chemical brush killer in cont,rolling regrowth on
the Eastern Border Clearing-Chipinga District. - Rhod.
Agric. J. 5 8, 1 73-177.
- 1 965. Control of Tsetse by 'Game' Extermination. I.U.C.N. Bulletin 1 4, p. 7 .
Darby, H. C . , 1 956. The Clearing of the Woodland in Eu­
rope, in Thomas, W. L. (ed.): Man's Role in Changing
the Face of the Earth. - Chicago.
Du Toit, R., 1954. Trypanosomiasis in Zululand and the
control of tsetse flies by chemical means. - Onderste­
poort Journal of Veterinary Research 26, ·3 1 7-389.
Ford, J., 1 960. The Advance of Glossina morsitans and
Glossina pallidipes into the Sabi and Lundi River Basins,
Southern Rhodesia. - I.S.C.T.R. 8th Meeting Jos, Nigeria
C.C.T.A. Publication No. 4 1 .
1 965. Control o f tsetse-fly by 'game' extermination. I.U.C.N. BuJletin 1 5, p. 7.
Glasgow, J. P., 1960. Ecological effects of tsetse-fly control
in particular on a consequence of bush clearing. I.U.C.N. 8th Technical Meeting. Warsaw, pp. 85-92.
Goodier, R., 1 95 8. Some effects of bush clearing in Southern
Rhodesia. - I.S.C.T.R. 7th Meeting. Bruxe11es, pp. 241 245.
- 196 1 . Discriminative bush-clearing against tsetse in the
Zoological aspects on the conservation of vegetation
south-east of Southern Rhodesia. - Rhod. Agric. J. 58,
262-266.
Jack, R. W., 1 927. Some environmental factors relating to
the distribution of Glossina morsitans. Westw. in South­
ern Rhodesia. - S. Afr. J. Sci. 24, 357-75 .
Lloyd, Ll. et al., 1 9 3 3 . Experiments i n the control of tsetse
fly. - Bull. ent. Res. 24, 2 33-57.
Nash, T. A. M., 1937. Climate, the vital factor in the ecology
of Glossina. - Bull. ent. Res. 8, 75-127.
- 1948. The Anchau Rural development and settlement
scheme. - London. H. M. Stationery Office.
Phillips, J., 1959. Agriculture and Ecology in Africa. - Lon­
don.
25
Stebbing, E. P., 1 93 8 . The man-made desert in Africa.
- Journal of the Royal African Society. XXJVII,
CXLVI, Supplement.
Swynnerton, C. F. M., 1 93 6. The tsetse flies of East Africa
- Trans. R. ent. Soc. Lond., 84, 1-579.
Travassos Santos Dias, J. A., 1 954. Some considerations
about the control of Glossina austeni. Newst. based on the
knowledge of its ecology. - I.S.C.T.R.
5th Meeting,
·
Pretoria, pp. 1 48- 1 5 5 .
Wilson, S. G., 1958. Recent Advances of Glossina morsitans
submorsitans in Northern Nigeria. - I .S.C.T.R. 7th Meet­
ing. Bruxelles, pp. 367-3 89.
Z O O L O G I CA L A S P E CT S O N T H E C O N S E RVATI O N O F
V E G E T A T I O N I N T R O P I C A L A F R I CA
K. Curry-Lindahl
The fact that the most remarkable mammalian fauna
of the world has evolved in tropical Africa may be
explained by an interplay of many past factors, but
obviously the most important one was the vegetation.
The diversity and vast range of habitats in tropical
Africa from deserts to rain forests include a large
number of vegetation types, of which several are
transitional. Changes in climatic pattern released
physiognomic landscape changements, which led to
temporary or permanent dislocations in the distribu­
tion of plants and animals. This, in turn, favoured
the evolution of animal species in various directions.
Though it is a truism to say that the existence of
animal species and animal communities are depend­
ing on the vegetation, it is nevertheless true that
oldfashioned conservation regarded the protection of
certain animals, threatened by extinction, as a prob­
lem unrelated to the animal's habitat. The close
interrelationship between plants and animals belong­
ing to the same biocommunity was not recognized
or understood in the past. The consequences of such
an unrealistic view are still found in the legislation
of many countries, where certain mammals and birds
are entirely or partly protected by law without any
regard whatsoever to their habitats, which in a legal
way may be totally destroyed.
Fortunately for the animals and for man himself,
modern, scientific conservation of nature is aware
of the necessity to protect habitats, in some cases
even entire ecosystems, to save single species of either
plants or animals. Ecologically, the processes of
building up a habitat in constant evolution or main·
taining it in a climax community depends on a con­
version cycle, in which every plant and animal or­
ganism plays a role. In general, natural selection
brings the conversion cycle at the highest degree of
biological productivity of which the biotope is ca­
pable, if it is left undisturbed. This may be called
an ecological law that emphasizes the intimate re­
lationship between plant and animal organisms.
Hence, there are many reasons for ecologists and
conservationists working for the preservation of the
fauna of tropical Africa to be deeply interested also
in the conservation of the vegetation. In fact, this
is vital. However, it is only in the last 1 5 years that
this view has been fully realized. Before the 1 950's
very few biologists working in tropical Africa were
concerned about the relations between plants and
animals and even less between plant associations and
animal communities. The effects of animal popula­
tions on the vegetation or vice versa were neglected.
Animal species or populations were often looked
upon as isolated phenomena and not as being just
a part of the habitat.
The results of studies on animal ecology in vari­
ous parts of tropical Africa, chiefly in the Congo,
Uganda, Kenya, Tanzania, Zambia and Rhodesia,
soon provided a basis for wildlife management and
a sound utilization of animal populations as a valu­
able natural resource. They helped to understand
how the tropical landscape was functioning. This
led further to a better understanding of the long­
termed productivity of various habitats in tropical
Africa in comparison with areas exploited by agriActa Phytogeogr Suec 54
26
K. Curry-Lindahl
culture and pastoralism. It also gave useful indica­
tions about the background and ecology of human
malnutrition in tropical Mrica. The ecological ap­
proach to conservation problems in Africa, particu­
larly the preservation of mammals, has yielded con­
vincing · data showing the long term benefit to a
country and its people of utilizing the natural vege­
tation and the animal populations it sustains as a
renewable natural resource.
Thus, it is obvious that the conservation of vege­
tation is essential for the conservation of animals.
However, in many cases the reverse may be true.
Even if most plants in an evolutionary sense have
preceded the present terrestrial vertebrates, many
plant associations existing today are without doubt
the results of not only climatic and edaphic factors
but also of zoological ones. The multitude of animals
living in a savanna community, for example, inevit­
ably influences the vegetation greatly. Large quanti­
ties of vegetable matter are utilized in a tremend­
ous scale and in various ways by herbivorous animals
showing a very wide spectrum of structures and hab­
its, from termites to elephants. All strata of vegeta­
tion are used by the animals from the roots in the
soil to the leaves and twigs in the trees. The animals
constitute an important part of the energy flux
within a habitat. Some animal species greatly modify
the vegetation, virtually changing it from one type
of habitat to another. Elephants do so. In the long
run the interaction between plants and animals must
have evolutionary consequences for both groups of
organisms. Thus it is also of a botanic interest to
preserve animal species and populations if one wants
to conserve present habitats and plant associations.
In the following I will try to give some examples
of vertebrates living in tropical Mrica, which are
endangered by extermination· through destruction of
the vegetation. They are to be found in various hab­
itats and in each case conservationists have fought
strongly to preserve at least fragments of the natural
environment so as to be able to save the endangered
animal species in question. I deal with these animal
species ecologically in a broad sense dividing them
in the different natural regions of tropical Mrica,
and include in this brief survey wellknown examples
of habitat modifications made by wild mammals.
DESERTS
Today deserts, subdeserts and arid scrub cover
about 43 p�r cent of Africa. Only a minor part of
these dry areas are situated within the tropics. The
N ubian, Danakil and Somali deserts belong to this
Acta Phytogeogr Suec 54
latter category. The man-made deserts of Kenya and
Tanzania should also be mentioned.
The vegetation of the deserts is seldom modified
by man simply because the environment is in itself
so poor. However, grazing by goats causes a serious
deterioration of the land and this is the case in many
deserts of the African tropics. It has affected wild
species like the N ubian and Somali wild asses
(Equus asinus africanus and E. a. somalicus), but
their serious decline in number is primarily due to
direct persecution by man.
SAVANNA
What we here call savannas is a wide variety of
tropical Africa's plain environments. It includes vari­
ous types of grasslands as savannas, steppes, arid
plains and subdeserts. Some of these plains have be­
come deserts or are becoming deserts through human
misuse; others are still fertile grass or wooded sa­
vannas.
Practically all savannas in tropical Mrica are sub­
ject to frequent grass fires. Many workers (Bartlett
1 956, Stewart 1 956, Rattray 1 960, Talbot 1 960,
1 9 64) consider the fire to be a principal factor in
maintaining existing savannas and in creating new
ones throughout the tropics. Today most fires on
savannas are man-made. Beside fires grazing is an
important factor in the maintenance of a savanna
ecosystem. Also browsing may contribute to the for­
mation and maintenance of a savanna habitat.
In arid habitats, where acacias and bushes domi­
nate while shallow-rooted grasses are scarce, brows­
ing animals are commoner than grazing species.
Browsers from the tall giraffes (Giraffa camelopar­
dalis) to the tiny dikdiks (several genera) utilize aca­
cias and bushes from the top to the ground level.
Elephants (Loxodonta africana) are both browsers
and grazers. Except for man there is no other ani­
mal in Africa that is able to alter a habitat so dras­
tically as does the elephant. There are examples of
this process in areas where the elephants are pro­
tected, increasing and unable to emigrate, because
adjacent areas are occupied by human beings. The
Murchison Falls National Park in Uganda, the
Tsavo National Park in Kenya and the Albert N a­
tional Park in the Congo are such reserves where
elephants have modified the habitats.
In the Murchison Falls National Park elephants
and fire have almost destroyed the tree growth over
large areas. There luxuriant wooded grasslands, Ter­
minalia woodlands, Cynometra rainforests and gal­
lery forest are since several years in the process of
conversion into treeless, tall grassland. Under the
Zoological aspects on the conservation of vegetation
present conditions 30 to 40 fire-resistant species of
trees are unable to attain maturity (Buechner and
Dawkins 1 96 1 ). Of course, the destruction of ar­
boreal vegetation by elephants opens the way to fire.
However, it must be emphasized that the effect of
both browsers and grazers on the vegetation is
positive rather than competitive or destructive. Nor­
mally, no species of wild animal subjects the vege­
tation to too heavy a use. Unfortunately, one can­
not say the same about cattle, goats and sheep, which
by grazing and trampling damage natural grasslands
to such an extent that they are irreversibly destroyed
by erosion.
Only a century or two ago, the mighty savannas
of Africa provided scenes we today find difficult
to visualize. Numerous species of large and small
antelopes, mixed with giraffes, buffaloes (Syncerus
caffer), rhinoceroses (two species) and elephants,
lived on the various kinds of savannas. These great
plains were regions in biological equilibrium, highly
productive climax areas, created by nature herself
through countless ages.
In this highly specialized ecological system, each
organism was a necessary element in the perpetua­
tion of the region. The various species of hoofed
animals grazed together, choosing different kinds of
grass, twigs and leaves as food. Selection has eli­
minated competition, and in this way the effect of
grazing was evenly distributed. With a few excep­
tions such as the impala (Aepyceros melampus), the
gerenuk (Litocranius walleri) and the Thomson ga­
zelle (Gazella thomsoni), the herds congregated on
the savanna regions around lakes, rivers, springs and
small water-holes, for not many savanna species can
live for long periods without water. During dry peri­
ods, most of these hoofed animals moved to other
regions which had recently had rain, and where the
grass was plentiful and green. And so it went, all
the year round. The hoofed animals followed the
rains, changing pastures regularly, and as a conse­
quence the grazing never destroyed the vegetation,
which after the next rainy period was as fresh and
green as ever.
The African savanna could support huge numbers·
of large, meat-producing animals, which in turn were
kept under control by beasts of prey. Although the
wild hoofed animals a century or two ago were far
more numerous than the tame cattle on the plains
today, they did not destroy the land even in the
course of hundreds of thousands of years. But in
two hundred years, man, along with his goats and
cows, has managed to transform large parts of the
flourishing African savanna ir�.to a desert, a shadow
of its former splendor and wealth.
27
It is true that tame cattle have existed in tropical
Africa for five to six hundred years, and in some
coastal regions even longer, but it is only during
recent centuries that the destruction of land by man
and his domestic animals has had such terrible con­
sequences.
What has been said above about the fertility of the
African savannas and the incredible number of wild
animals on them may seem like a figment of the
imagination, but it is not. Europeans visiting both
the tropical African savannas and the South African
veld have left eye-witness accounts of these. And
the national parks and nature reserves remain as
oases, rich in wildlife, in various parts of the savan­
nas. Beside this, savanna fauna can still be found
in some regions not yet destroyed by domestic ani­
mals owing to the fact that the African sleeping­
sickness, spread by tsetse flies, has prevented the
breeding of tame cattle in those areas.
Vast parts of tropical Africa are covered by thorn
thickets, the so-called nyika in swahili. This thorn­
bush country is one of the many habitats inhabited
by elephants. Probably there are no other biotopes
which are affected by elephants to such an extent
as the acacia thornbush. One can distinguish a cycle
of major events. Simplified, the pattern is as follows.
Elephants feeding in thornbush break and smash
trees to pieces, eating branches and leaves. Other
browsers help them in denuding the fallen trunks
from bark and twigs. Where the tree canopy no
longer shadows the soil, the grass grows tall, partly
hiding the tree skeletons. Fires sweep in, consuming
both grass and tree or bush remains. The grass re­
conquers the burned area and is now more or less
alone on the scene. Grazing animals of various spe­
cies move in. They make the grassland less vulner­
able to natural fires and in this way help seedlings
of acacia to grow. The thorny young trees are not
browsed by the grazers, so they become taller and
gradually shade and suppress the grass. Finally, the
dense thornbush has taken over again and the ele­
phants come back.
The interaction of five main factors-climate, soil,
vegetation, animals and fire-has produced a com­
plex savanna . ecosystem with an extremely high bio­
logical productivity. The plants and the animals are
intimately adapted to each other as well as to the
other main factors involved. If one component of
this ecological pyramid is removed or changed, the
whole ecosystem may collapse.
On these African savannas the ungulates are more
varied and numerous than on any other continent.
However, as has been pointed out, the immense herds
of only a century ago are gone. Savannas of tropical
Acta Phytogeogr Suec 54
28
K. Curry-Lindahl
Africa, more or less untouched by man, support the
highest productivity of hoofed mammals without
showing any signs of vegetal or soil deterioration.
On these tremendously rich lands comes clumsy man,
assuming in his unbelievable self-assurance that he
can do it much better. Despite many great fiascos,
man continues to produce failures and destroy lands
in Africa, chiefly because he does not listen to those
who understand the African landscape, the complex­
ity of its energy-flow and the metabolic rate of its
organic matter.
The tremendous variety of species and number
of animals in the large national parks and reserves
show the way. Areas like the Gorongoza National
_
Park in Mo9ambique, the Wankie National Park
in Rhodesia, the Kafue National Park in Zambia,
the Serengeti National Park in Tanzania, the Masai
Mara Game Reserve in Kenya, the Queen Elizabeth
National Park in Uganda and the Albert and Ga­
ramba National Parks in the Congo are overwhelm­
ing examples of the productivity in areas more or less
undisturbed by man and his livestock.
The main factor behind the decimation of wild
animals on the savannas is the intense exploitation
of the land for agriculture and pastoralism. This has
led to a serious deterioration in grass cover and soils.
Most open lands of tropical Africa are not suitable
for farming and will probably never be so in spite
of enormous investments and ambitious development
schemes. The main menace to wild animals is man's
devastation of marginal lands through livestock graz­
ing.
The distribution ranges of several animal species
have been greatly reduced due to habitat destruc­
tions and alterations. Several of these species have
been strongly decimated also by direct persecution
by man for various reasons, so it is not the changes
in vegetation alone which are the cause of decline of
the black rhinoceros (Diceros bicornis), the square­
lipped rhinoceros (Ceratotherium simum) and the di­
batag (Ammodorcas clarkei), which at present are
the most endangered savanna mammals of tropical
Africa. Also the cheetah (Acinonyx jubatus) has de­
creased all over its range, apparently due to the
transformation of savannas and subdeserts in com­
bination with the disappearance of its prey.
WOODLANDS
Large parts of the woodlands in tropical Africa are
located within the tsetse belt. Several species of these
flies are vectors of animal and human trypanosomi­
asis (nagana and sleeping sickness). This makes
many woodlands and savannas unsuitable for cattle
Acta Phytogeogr Suec 54
raising, which in its turn explains why so much of the
woodlands contains a rich wildlife. These woodlands,
occupied by tsetse flies and a great diversity of large
herbivores, belong to what is called "marginal
lands" ; they are marginal in terms of cultivation be­
cause cattle cannot adapt to the environment. But
as far as the meat of wild ungulates is concerned,
these lands are highly productive. Therefore, the
woodlands of tropical Africa must be considered a
very efficient producer of protein and a most valu­
able natural resource. Unfortunately, many African
woodlands have been changed so drastically by hu­
man interference that they are no longer either
woodlands or savannas. In all of these woodlands
the destructive role of fire is evident, even where
man does not cultivate.
The vertebrate fauna of the African woodlands
is essentially the same as that of the savannas; many
species frequent both habitats. Of those animals
found only in the woodlands, none is at the moment
among endangered species, but we must remember
that many of the threatened savanna mammals and
almost all of them that are browsers have found
their last refuge in woodlands and savannas pro­
tected by tsetse flies. Moreover, for several mammals
the mosaic patches of woodlands surrounded by sa­
vannas are essential. That is why the African wood­
lands are so important for wildlife.
LOWLAND RAIN FORESTS
As a result of the damage done by man the rain
forests of Africa today cover only one third of their
former area. Nevertheless one third of all the tropical
rain forest in the world is in Africa.
All strata of the forest provide shelter for many
animals. They live under and on the ground and in
the trunks and crowns of trees, creating an immense
continuous habitat. Among vertebrates, not only do
bats, monkeys, hyraxes, squirrels, mice and birds oc­
cur in the highest storey of the trees, but also a
large number of snakes, lizards, amphibians, frogs
and toads, and, of course, insects. And down in the
earth, with its several layers of decomposed vege­
table matter, live an astonishing number of mam­
mals, reptiles and batrachians, and even some birds,
side by side with millions of tiny forms of life. Each
storey has its own microclimate and even within each
storey the conditions vary enormously.
Every year the lowland rain forests in Africa are
reduced by development schemes and shifting cul­
tivation practises. Only a few animals are, however,
in immediate danger of extermination.
The animals of West Africa have been decimated
Zoological aspects on the conservation of vegetation
by the destruction of much rain forest and by a ter­
rific hunting pressure. Once rich in game there is
today not much left in the strip of high forests in
Sierra Leone, Liberia and the Ivory Coast. Two
mammalian species with restricted distribution occur
in this region. The most famous, the pygmy hippo­
potamus (Choeropsis liberiensis), is very rare and
has perhaps always been so. However, it is diminish­
ing alarmingly.
Even more rare than the pygmy hippo is a small
forest antelope, Jentink's duiker (Cephalophus jen­
tinki), known only from a few areas in Liberia.
Another rare forest dweller is the banded duiker
(C. zebra) occurring in Sierra Leone and Liberia,
where forested habitats diminish quickly menacing
its animal inhabitants.
Except perhaps for elephants and buffaloes, there
is no more spectacular mammal of the lowland rain
forests of Africa than the gorilla. There are two
subspecies, the lowland gorilla (Gorilla gorilla go­
rilla), which occurs in coastland forests from Nigeria
in the west across Cameroon, Spanish Guinea, Ga­
bon, Congo (Brazzaville) to the Mayombe high forest
of the former Belgian Congo, and the mountain go­
rilla (G . g. beringei) in the eastern Congo, northern
Rwanda and western Uganda. In general, the low­
land gorilla is not considered to be in danger of exter­
mination but its scarcity, limited distribution and
its dependence on dense forests make its future un­
certain. Another primate from West Africa which
is threatened by extermination is the green colobus
(Colobus verus) from Ghana and Togo. The golden
potto (Arctocebus calabarensis) from Nigeria, Came­
roan and Rio Muni and the needle-clawed galago
(Euoticus elegantulus) from the coastal rain forests
of the Gulf of Guinea and Fernando Po have re­
stricted ranges and are very rare. Both are on the
list of endangered species. There are also two palm
squirrels on the verge of extinction: the African palm
squirrel (Epixerus ebii) from Guinea and Wilson's
palm squirrel (E. wilsoni) from Gabon.
29
There are three rare monkeys which have been
narrowly restricted to such river forests. One is the
Tana River mangabey (Cercoceb us galeritus gale­
ritus), which was formerly distributed in the gallery
forests of the lower Tana River in Kenya. Cultiva­
tion in this region eliminated the forests and forced
the Tana River mangabey to withdraw to small
patches of forests several miles from the right bank
of the Tana River. Here they have been subjected
to intensive trapping. Several recent expeditions have
searched in vain for them along the main river. Ob­
viously this monkey (the nominate race of a species
distributed in the Congo forests) is in immediate
danger of extinction.
Much the same fate faces the Tan a River red
colobus (Colobus badius rufomitratus). This subspe­
cies is not so uncommon in its few refuges as the
mangabey, but its very restricted distribution makes
it vulnerable. About twenty or thirty individuals were
seen in 1 963 by the Los Angeles County Museum
expedition to the Tana River. The subspecies enjoys
full protection, but again it is the destruction of its
ha�b itats that is the problem. Another endangered sub­
species of the red colobus is the Uhehe red colobus
(C. b. gordonorum), which lives in high forests on
the lower slopes of the Uzungwe Mountains in Tan­
zania. Very little is known about this monkey, which
is seldom observed. It is confined to a small area
of forest that has been heavily reduced for settle­
ment and cultivation.
·
GALLERY FORESTS
Gallery forests, which grow around rivers and some­
times extend far from the banks, form characteris­
tic, zoologically important habitats in many parts of
Africa and most of all in tropical areas. In such
areas the gallery forests along rivers often develop
into tall, luxuriant forests with their own peculiar
flora and fauna. Because of heavy forest destruction
the gallery forests have often become isolated from
surrounding woodlands or forests, trapping, so to
speak, several forest animals in them.
MONTANE FORESTS
Human activities are a serious menace to mountain
rain forests in Africa, the most productive habitat
of tropical mountains. Every year more and more
montane forests are destroyed, causing the whole
ecosystem to break down not only on the mountain
slope itself but also in the valleys and plains at the
foot of the mountain.
The mountain gorilla (Gorilia gorilla berengei),
a close relative of the lowland gorilla, is one of the
most interesting mammals. In a remote past the two
subspecies were presumably united by a continuous
distribution across the Congo equatorial rain forest.
Paradoxically, about 75 per cent of the mountain
gorillas live in the lowland rain forests of the eastern
Congo, in about the same environment as their rela­
tives in West Africa. The name "mountain gorilla"
is, however, not entirely misleading, for probably
the greatest concentration, 400 and 500 individuals,
live on the Virunga volcanoes, most of them at an
altitude of 1 0,000 to 1 1 ,000 feet.
It is interesting to observe that mountain gorillas
Acta Phytogeogr Suec 54
30
K. Curry-Lindah/
in the lowlands of Kivu about 2500 feet above sea
level prefer to live in secondary forests, rich in
ground vegetation, around roads and village3, instead
of in the dense forests where the closed canopy ex­
cludes light, allowing only a meagre understory. Like
the okapi, the gorilla lives on juicy plants, stalks and
leaves. He also finds these in the primeval mountain
rain forests, where light always penetrates to the
ground and the ground vegetation therefore is highly
developed. Of the different belts of vegetation on
the volcanoes, it is the broad-leaved woods of Hage­
nia abyssinica with their dense undergrowth which
are the favourite haunts of gorillas. Nowhere in Vi­
runga are these forests so richly developed as on the
slopes of the extinct volcanoes Karisimbi and Mi­
keno. These are the headquarters of the gorillas.
The mountain gorillas are not in immediate
danger of extermination. But man and his cattle are
advancing up toward the montane forests. Trees are
being felled and the ground grazed and trampled
bare. If this is not stopped in time, the mountain
gorillas on the Virunga volcanoes are doomed. The
threat comes from Rwanda and Uganda to the east.
In the west, the Congo respects the fact that the
gorilla's domain is in Africa's oldest reserve, the Al­
bert National Park. The authorities in Kinshasa and
in Kivu have promised to do the utmost to preserve
the living space of the gorillas.
In the higher mountains of southern Ethiopia
south and east of the Rift V alley lives the mountain
nyala (Trage/aphus buxtoni), an antelope found now­
where else. It occurs here in such mountain ranges
as the Chilalo, Gugu, Sahatu and Mendebo. It is
found chiefly above 9500 feet, ranging vertically
from high cedar forests (Juniperus procera) up to the
belts of giant heath (Erica arborea) and St. John's
wort (Hypericum).
The nyala population in the Mendebo Mountains
alone is estimated at from 1 500 to 2000. It is
thought that the whole population still numbers be­
tween 3000 and 4000 animals. This is not much for
a species, but it happens to be living in habitats
that at the moment are not too much disturbed by
man.
Unfortunately, one cannot be so optimistic about
another of Ethiopia's animal treasures, the walia
ibex (Capra walie). This is the southernmost of all
latter-day ibexes and, as a palearctic element in Af­
rica, of great zoogeographic interest. As far as zoo­
logists know, the walia ibex has always had a re­
stricted range in Ethiopia, but it must in the very
remote past have been in touch with other ibexes
living to the north, where its nearest neighbour is
the nubian ibex (C. nubiana).
Acta Phytogeogr Suec 54
All reports of the walia ibex originate from the
Semien Mountains in northern Ethiopia, where there
are about 1 50 or 200, a dangerously low number.
In the rain forest region of tropical West Africa
there are several mountains separated from one an­
other by lowland forests and savannas. One of the
most interesting of these equatorial mountain massifs
is Mount Nimba, situated on the border between
Liberia, Guinea and the Ivory Coast. It lies some
1 70 miles from the Atlantic coast and its greatest
elevation is 1 752 m.
The isolated situation of Mount Nimba gives it
the character of a great inselberg, differing in types
of habitats from the surrounding lowland forests and
savannas. This biogeographical isolation has pro­
duced an astonishingly high number of endemic ani­
mal species-about two hundred. Whether this re­
markable number of local species is due to the fact
that the massif served as a refuge for animals that
during previous pluvial periods had a wider distri­
bution, or to the fact that these animals through
isolation have evolved from ancestral forms, this.
massif is very important for speciation studies and
may be regarded as a key area for research in evolu­
tion.
The origin of the savannas of Mount Nimba has
heen much discussed. Many consider them the rem­
nants of man's burning and clearing and the grazing
of livestock. But the visitor gets another impression.
Various features of these grasslands, made up
mainly of A ndropogon and Loudetia, indicate that
many of them are an ancient type of natural sa­
vannas probably corresponding to a vegetational cli­
max in this area. They have produced a great num­
ber of unique animal species including the only ver­
tebrate endemic species of Nimba, the toad Necto-.
phryno¥des occidentalis. This toad seems to be adap­
ted exclusively to the high savannas of Nimba
(but not . above 3 500 feet), for it has not been found.
in the adjacent woods or on the savannas at the
foot of the mountain. This little batrachian is not.
any ordinary toad. Its nearest relatives, found on
the mountains of East Africa, live in trees. Besides
this, the female of the species, after a period of
gestation lasting eight to nine months, gives birth.
to living young; they do not pass through a larval
stage in water, which is of course very useful in
these mountain savannas. From the evolutionary as-.
pect, the little Nimba toad is exceedingly interesting,
for many phases of its reproduction are reminiscent
of those of mammals. Here we have an amphibian
whose evolution has followed other paths than those
taken by its kin.
Parts
of Nectophryno¥des' restricted range on.
Zoological aspects on the conservation of vegetation 3 1
Mount Nimba is menaced by mining exploitations
altering the vegetation.
SWAMPS, LAKES AND RIVERS
Several aquatic vertebrates of tropical Africa are
threatened by extinction but none due to destruction
of aquatic vegetation.
However, a grazing mammal, the hippopotamus
(Hippopotamus amphibius) has been accused of over­
grazing heavily the shores and plains surrounding
Lake Edward, which is said to make way for erosion.
This is certainly true on the Mweya Peninsula in
the Queen Elizabeth National Park in Uganda, where
hippos have been protected since the 1 950's, but in
the adjacent Albert National Park in the Congo,
where the species has been protected since more than
thirty years and where it has the densest population
in Africa, it is doubtful if overgrazing occurs. Pani­
cum repens is the staple food of the hippos on the
Congo side of Lake Edward. This grass seems to
withstand · the grazing by hippos remarkably well
(Curry-Lindahl 1 957, 1 96 1 , Bourliere and Ver­
schuren 1 960). On the Mweya Peninsula the hippos
chiefly feed on other species which may explain the
damage.
COASTS AND ISLANDS
On the island of Zanzibar lives an interesting local
race of the red colobus monkey (Colobus badius
kirkii), whose population is thought to number only
about two hundred. Since not much high forest exists
any more on Zanzibar, the red colobus frequents the
low and thin waste bush, but it also occurs in the
Jozani Forest Reserve. Apparently it was already rare
in 1 868 when it was investigated by its discoverer,
Sir John Kirk. It is belived that the replacement of
natural forest by plantations has contributed to the
animal's decline. It is protected by law, but the con­
trol does not seem effective.
MADAGASCAR
Zoologically Madagascar is almost as peculiar as Au­
stralia. Ecologically Madagascar is a diverse island
with such habitats as subdesert brush, open savannas,
dry forests and rain forests. Many of the endemic
species there are very specialized and adapted to
certain habitats. Therefore, the ravaging of the
countryside by "development schemes" and other
exploitation has had deplorable results. About 70
per cent of Madagascar's natural vegetation has been
destroyed by man. Forest habitats in particular are
vanishing rapidly, and with them many unique and
rare animal species.
A large number of Madagascar's mammals is now
threatened by extinction, including many found no­
where else. There are four families (one of tenrecs,
three of lemurs) that are peculiar to Madagascar.
Of other recent vertebrates on Madagascar no class
is represented by endemic families, but they do show
many peculiarities. The bird fauna is also very dis­
tinct. No endemic family exists on Madagascar alone,
but considering the whole Malagasy area (which in­
cludes Madagascar, the Comoros, Mauritius, Reun­
ion, the Seychelles and other neighbouring islands)
as a faunal region there are not less than seven
recent families and two extinct ones peculiar to this
region. Among the reptiles there are about forty spe­
cies of chameleons, a greater number than in any
other region. Many of the reptile genera are ende­
mic. This is also true of the amphibians, including
about 1 50 endemic frogs.
Madagascar is extraordinarily rich in small pri­
mates and almost all of them are in danger of ex­
tinction. Not less than 29 species or subspecies are
endangered.
CONCLUSIONS
All habitats are results of continuously working dy­
namic interrelationships. No plant associations are
static, but if botanists want to maintain the present
plant associations of tropical Africa or rather to let
them evolve in a natural way, it will be necessary
in many cases to preserve the grazing mammals and
their predators as well. This is particularly true for
habitats as savannas and woodlands, less for rain
forests, Hagenia forests and the montane ericaceous
belt and probably not at all for the afro-alpine as­
sociations. The latter very specialized habitats con­
stitute a climax, that comes very close to stability,
because they evolve with an extreme slowness. The
biocommunities of these levels have apparently not
changed very much during the quaternary, although
they have altered their vertical ranges in relation
to the pluvial and dry climatic periods. Probably
these habitats represent a biocoenosis that belongs to
one of the oldest on our earth.
What would happen if the wild grazing and I or
browsing ungulates should be removed from the sa­
vannas? Undergrazing may allow shrubs and woody
growths to convert the grassland into bushes or even
woodlands. The succession would be altered and the
conditions for survival of many species of plants and
animals (other than ungulates) would be violently
·
changed. The productivity of the new habitats would
Acta Phytogeogr Suec 54
32
Th. Monad
presumably be much inferior to those of which wild
ungulates are a part. But the worst of all for most
savanna ecosystems in tropical Africa and their bio­
logical productivity would be if livestock replaces
wild mammals. In most areas a ruined landscape
would be the result and the Africans deprived of
a living natural resource of high value.
REFERENCES
Bartlett, H. H. 1956. Fire, primitive agriculture, and grazing
in the tropics. - In W. L. Thomas (ed.): Man's role in
changing the face of the earth, pp. 692-720. Chicago.
Bourliere, F. and Verschuren, J. 1 960. Introduction a
l'ecologie des ongules du Pare National Albert. 1-11.
- Exploration du Pare National Albert. Mission F. Bour­
liere et J. Verschuren ( 1 957- 1 95 9). 1 5 8 pp. + 49 plates.
Bruxelles.
Buechner, H. K. and Dawkins, H. C. 1 9 6 1 . Vegetation
change induced by elephants and fire in Murchison Falls
National Park, Uganda. - Ecology, 42, pp. 752-766.
Curry-Lindahl, K. 1957. The grazing effect of the hippo­
potamus in the Albert National Park, Congo. - Mem­
orandum to the International Union for Conservation of
Nature and Natural Resources (IUCN). (Mimeographed).
- 1961 . Contribution a l'etude des vertebres terrestres en
Afrique tropicale. I. - Exploration du Pare National Al­
bert et du Pare National d'e la Kagera. Mission K. Curry­
Lindahl ( 1 9 5 1-1 952, 1 958-1959). 3 3 3· pp. + 22 plates.
Bruxelles.
Rattray, J. M. 1 960. The grass cover of Africa. - FAO Agri­
cultural Studies, 49, pp. 1 - 1 68.
Stewart, 0. C. 1956. Fire as the first great force employed
by man. - In W. L. Thomas (ed.): Man's role in chang­
ing the face of the earth, pp. 1 1 5-1 33. Chicago.
Talbot, L. M. 1 960. Land use survey of Narok District,
Kenya. (Mimeographed).
- 1964. The biological productivity of the tropical savanna
ecosystem. - In The Ecology of Man in the Tropical En­
vironment. IUCN Publications new series. 4, pp. 88-97.
LA C O N S E RV AT I O N D E S H AB I T A T S : P R O B LE M E S D E
D E F I N I.T I O N S E T D E C H O IX
Th. Monad
La necessite d'assurer une protection definitive a u n
echantillonnage adequat des habitats naturels n'est pas
discutable et se voit d'ailleurs deja largement reconnue
puisqu'une Section toute entiere du Programme Biolo­
gique International, « Conservation des communautes
biologiques terrestres », oriente precisement dans ce
sens son activite.
Le probleme est, bien entendu, planetaire et devra
recevoir sa solution a l'echelle du globe : sans oublier
que nous sommes ici pour nous occuper specifiquement
de 1' Afrique, et meme de 1' Afrique dite « tropicale »,
force me sera done d'envisager parfois des points qui
tout en s'appliquant naturellement a 1' Afrique pourront
avoir des incidences plus vastes encore. Je ne sais trop
si je do is m'en excuser : ne serait-il pas au contraire bon
qu'en un domaine neuf, ou tout, ou presque, est a faire
et ou i1 faut construire ab ovo, l'A.E.T.F.A.T. fit figure
de pionnier et prit, pour 1' Afrique, des initiatives suscep­
tibles d'application generale, justifiant de la sorte, une
fois de plus, le vieux proverbe : ex Africa semper aliquid
no vi?
Peut-etre n'est-il pas inutile d'insister ici sur le fait que
1' « habitat » n'est pas synonyme de formation vegetale
puisqu'il comprend aussi la faune, et meme le sol. 11
s 'agit done d'une notion largement synthetique et de­
passant le cadre de la seule biologie vegetale. Bien sur, il
est commode de designer les biomes et les autres subActa Phytogeogr Suec 54
divisions ecosystematiques sous des noms empruntes a
la composition de la vegetation, mais le botaniste ne
devra jamais oublier qu'en disant « foret de montagne
a Podocarpus », « mangrove a Rhizophora-Avicennia­
Laguncularia » ou « steppe a Acacia-Panicum », i1 s'agit
autant d'une faune que d'une flore, et que pour certains
districts de !'Empty Quarter ouest-saharien, !'expres­
sion « steppe a Aristida pungens » ou « steppe a Addax
nasomaculatus » sont synomynes. L'unite qui nous in­
teresse, meme s'il demeure commode et meme necessaire
de la designer du nom d'une formation vegetale, n'est
pas seulement un phyto-type . . .
LA NOTION D'HABITAT-TYPE
A vec les developpements recents de l'ecologie, avec la
substitution du concept « protection d'un milieu global »
a celui de « protection d'une espece », avec !'importance
desormais reconnue a !'etude des biocenoses et des eco­
systemes, le souci devrait se manifester de parvenir a
soustraire aux bouleversements et aux destructions an­
thropiques un certain nombre de temoins so it de milieux
veritablement intacts - dans la mesure ou il en subsiste
et qui sera faible, meme en Afrique - soit de milieux
au moins aussi peu transformes que possible par l'acti­
vite humaine.
La conservation des habitats: problemes de definitions et de choix
De U t a la notion d'habitat-type - que l'on pourrait
peut-etre provisoirement appeler « biotype »1 - il n'y
avait qu'un pas. Encore qu'il soit illusoire de vouloir
fixer une origine a une date, a une idee, celle qui
nous interesse ici semble avoir cristallise, gnlce a
quelques zoologistes, au cours du Symposium « Con­
servation de la Nature et ressources naturelles dans
les Etats africains modernes » tenu a Arusha, Tangan­
yika en 1 96 1 ; la recommendation n° 6 de cette reunion
'
intitulee « Preservatio� of typical habitats in Africa »
debute ainsi : « Recognizing the need to create through �
out Africa a type collection of natural habitats assured
of definite protection and constituting a representative
sample of as many varied environments as possible . . . »
La notion de « biotype » est-elle nee en Afrique? Ce
n'est pas impossible, mais ce qui importe avant tout
c'est qu'elle s'y voit, au plus tot, system atiquement re­
connue et appliquee. Mais comme une « biotypologie »
africaine ne saurait etre qu'un aspect et qu'une section
d'une « biotypologie » mondiale, ce que I'Afrique peut
utilement tenter des m:1intenant, c'est d'etudier une sorte
de codification generate du « biotype », de sa definition
.
de son statut, de son « mode d'emploi ».
Si les botanistes africains acceptent d'envisager un
semblable projet et d'y collaborer, ils ser v iraient les in­
terets de la science et de la conservation nori seulement
en Afrique mais aussi a l'echelle de la planete, rejoignant
ainsi divers efforts deja entrepris, par exemple pour les
milieux humides la « Liste des zones humides d'irnpor­
tance internationale en Europe et dans le Maghreb »
(Projet MAR, IUCN Publ., n.s., N° 5, 1 965), pour les eaux
douces la liste preparee par le Prof. H. E. Luther (Asso­
ciation Limnologique Internationale et Section Producti­
vite des eaux douces du P.B.I.) ; enfin le travail entrepris
pour les « aires P . B . I . » et leur definition par la Section
Conservation des Communautes biologiques terrestres
du P.B.I.2 .
1 Sur le modele « biosphere », « biomasse », etc. ; je n'ignore
pas que semantiquement le mot « biotype » pechera par defaut
puisque !'aspect localisation topograp h ique ne s'y trouve pas
suffisamment explicite : a cet egard « biotopo type » ou « b io­
chorotype » seraient plus adequats, mais le mot devient peut­
etre un peu long, en particulier pour pouvoir accepter de pretixe
(holo-, para-, etc.). Le mot « biotype » a cependant deja ete
uti lise dans des sens differents (cf. R. Bouillenne, « Man, the
destroying biotype », Science, 1 3 5, March 2, 1 962, No 3 505, p.
706-7 1 2) et, a ce titre, peut-il etre util ise ici? S'il ne convenait
pas, « chorotype » serait peut-etre un substitut possible.
2 Qui vise a la preparation d'un « Worldwide List of habitats
based on their broad ecological characteristics and their interes
to biology and conservation » (E. M. Nicholson, Definition of
I BP Areas, 1 966). Cf. G. F. Peterken, Guide to the Check Sheet
for IBP Areas, i ncluding a Classification of Vegetation for general
Purposes by F. R. Fosberg, !BP Handbook N o . 4, London, 1 9 67,
1 3 3 p., 2 figs, 1 1 tabl.
�
3 - 6 8 1 557 Hedberg
33
LE STATUT SYSTE MATIQUE DU BIOTYPE
Les sciences naturelles , pour assurer a la nomenclature
systematique la possibilite d'un recours a des termes de
reference permanents, devaient insister sur la valeur des
echantillons « types » ; zoologistes, botanistes et paleon­
tologistes pratiquent ainsi a juste titre une veritable
religion du type que, pour des raisons diverses, n'ont
d'ailleurs pas toujours observee au meme degre les
descripteurs de roches, tandis que les geologues, aux
prises avec des objets non depla9ables, definisent au­
jourd'hui avec une rigueur toujours accrue leurs strata­
types .
Le « biotype », tout en participant du stratotype par
le fait qu'il ne peut etre objet de collection, devrait sans
doute, comme les types d'especes animales et vegetates,
pouvoir etre pris tour a tour dans des acceptions di­
verses.
Prenons le « biotype » « mangrove a Rhizophora ». La
surface officiellement choisie pour typifier cet habitat
sera un « holobiotype », qui pourra se voir designe de
plus ou moins nombreux « parabiotypes »; et le jour
ou les exigences de l'economie et de la technique auront
provoque la destruction de « I'holobiotype », l'un des
« parabiotypes » deviendra un « neobiotype ».
Bien entendu, une taxinomie des habitats n'est pas
chose nouvelle et l'enorme developpement de la phyto­
geographie africaine depuis 50 ans a largement consiste,
precisement, en une definition toujours plus attentive
et plus poussee des unites de rangs divers identifiables
dans la couverture vegetate.
Mais avec la necessite non plus seulement de decrire
mais de conserver, avec la definition d'habitats-types
destines a devenir des temoins specifiques durables et,
on l'espere, permanents, des aspects un peu differents du
probleme se degagent, impliquant, tres legitirnement a
mon avis, la mise en chantier d'une taxinomie des habi­
tats et partant, ineluctablement, !'adoption d'une termi­
nologie adequate.
LE STATUT G ENE RAL DU « BIOTYPE »
Nous aborderons plus loin la question des criteres a
adopter dans le choix du biotype mais un certain nombre
de questions doivent se voir maintenant evoquees.
a) Scientifiquement, !'adoption d'un « biotype », c'est­
a-dire son inscription a un fichier central et sur une liste
publiee periodiquement mise a jour, devrait relever d'un
organisme international qualifie : on n'en voit evidem­
ment pas de mieux place que 1' Union Internationale pour
la Conservation de la Nature et de ses Ressources qui, a
cote de sa Commission du Service de Sauvegarde (Sur­
vival Service Commission), etc., pourrait tres bien
avoir une Commission des biotypes mondiaux (World
Acta Phytogeogr Suec 54
34
Th. Monod
Biotypes Commission) chargee de l'examen des propo­
sitions, soumises ensuite a !'approbation du Conseil de
l'Union; bien entendu, la oil une autorite scientifique
reconnue existe a !'echelon national (Nature Conservan­
cy, Musee National, Academie des Sciences, Service de
Protection de la Nature, etc.), c'est a celle-ci que revien­
drait, en principe, !'initiative.
b) Administrativement, c'est la responsabilite de l'Etat
interesse qui se verrait engagee, par le truchement d'un
de ses Services techniques competents ; les obligations
legales du pays auraient ete statutairement definies par
une convention internationale.
c) 11 serait essentiel en effet qu'au niveau le plus eleve
de l'activite internationale, les « biotypes » proposes et
retenus jouissent d'une reconnaissance officielle, qui
obligerait a les tenir pour des eh�ments permanents et
intangibles du patrimoine commun de l'humanite.
DEFINITION ET CHOIX DU « BIOTYPE »
S'il est aise d'edifier en imagination les constructions les
plus hardies, !'execution du plan reve ne tardera pas,
lui, a rencontrer les difficultes les plus serieuses.
C'est que, en face du choix a operer d'un element du
couvert vegetal a proteger, bien des problemes, imme­
diatement, se poseront et auxquels il faudra d'ailleurs
nous resigner a ne pouvoir apporter de reponse dogma­
tique, precise et simple.
Quelle unite naturelle, quelle parcelle de la biosphere
voulons-nous, sous le terme de « biotype », definir et
proteger?
11 doit etre d'abord bien entendu que nous raisonne­
rons en naturalistes plus qu'en botanistes et que notre
objectif est d'atteindre une realite synthetique dans la
designation de laquelle ne figureront, en prefixe, n i
phyto-, ni zoo-, mais peut-etre bio- ou eco-, o u , en suf­
fixe : -coenose.
11 est evident qu'il ne faudra choisir le « biotype » ni
trop generalise, ce qui lui oterait toute valeur specifique,
ni trop etroitement limite, car reduit au rang de biotope
(stricto sensu), de facies ou de station, il devra se voir
multiplie dans de telles proportions que le projet en de­
viendrait ipso facto totalement utopique.
11 faudra done maintenir la notion de « biotype » a un
niveau moyen, dont !'appreciation relevera toujours sans
doute du « flair » ou du « coup d'reil » du naturaliste
plus que de !'application d'une formule mathematique.
Plus de detail pourra apparaitre desirable mais c'est,
au moins dans une premiere approche du probleme, du
possible et non du souhaitable qu'il s'agit, en adoptant
des categories assez larges, quitte a en envisager ulte­
rieurement une eventuelle subdivision.
Ecologiquement parlant, le biotype se situera naturel­
lement au dessous du biome ( ou biocycle) et du bioActa Phytogeogr Suec 54
chore : on serait peut-etre aprioritente de situer le niveau
du biotype entre la « formation » purement physiono­
mique et les termes « alliance », « association » de la
nomenclature sociologique, c'est-a-dire en somme a peu
pres au moment oil apparait dans la hierarchie descrip­
tive un nom d'espece ou au moins de genre. 11 serait
absurde de vouloir preciser, mais la ou « foret tropicale
ombrophile planitiaire » me semble trop large et « une »
sous-ass. pterocarpetosum polyanthi » trop restreintet,
une « steppe desertique a Acacia (flava) - Panicum (tur­
gidum) » me semblerait pouvoir constituer un biotype.
Le « biotype » viendrait done s'identifier, dans la no­
menclature de Dansereau ( 1 95 1 , p. 1 90- 1 9 1 ) entre le
« biochore » (climat) et 1' « association » (microclimat),
avec 1' « habitat » (topographie).
Naturellement, les surfaces en cause n'entrent pas en
ligne de compte : la steppe a Aristida pungens dans un
peuplement monospecifique de laquelle j'ai pu parcourir
en ligne droite huit etapes (plus de 200 km) aura la
meme « valeur », ici, qu'une minuscule mare saharienne
ou sahelienne perenne a Characees, Potamots, Poissons,
Batraciens, voire Crocodiles, representant d'ailleurs un
biotype d'un interet tout a fait exceptionnel du fait des
segregations biogeographiques et genetiques qu'elle im­
plique pour nombre d'especes reliques.
Si le niveau ecologique ou se situera le « biotype » est,
au moins en gros, determine, il serait absolument vain,
par contre, de vouloir a priori lui assigner des dimen­
sions, meme theoriquement optimales : une « guelta »
saharienne de quelques centaines de metres carres, avec
sa faune relicte, pourra constituer un « biotype » tout
aussi valablement qu'un millier d'hectares de steppes
arbustives a Euphorbia balsamifera et Commiphora afri­
cana.
En fait, d'ailleurs, le choix d'un territoire a eriger au
rang de « biotype » officiel et permanent relevera dans
une large mesure de considerations pratiques et, en par­
ticulier, du degre de protection effective dont pourra
beneficier le « biotype », aux divers « niveaux » a envisa­
ger (cloture, gardiennage permanent, surveillance epi­
sodique, et, dans certains cas tres limites, protection
« spontanee »).
DIAGNOSES ET FORMULES
Si, comme on doit l'esperer, il est un jour ouvert une
liste officielle des biotypes africains « conservanda », il
sera indispensable que soit adopte un type commun de
diagnose, fournissant tous les elements d'identifications
desirables (site, coordonnees geographiques, limites, al­
titude, climat, description botanique et zoologique som1 Pas en theorie, bien sur, mais en fonction des possibilites
pratiques de protection d'un nombre, helas, limite de biotypes
africains.
Les pares nationaux comme archives de recherches
_
maire) : ces renseignements pourraient par exemple
tenir sur une fiche 2 1 x 27 cm, toutes les donnees com­
plementaires, historiques, bibliographiques, etc., fai­
sant l'objet d'annexes. On pourra egalement etre tente
de recourir, pour faciliter les comparaisons, a des for­
mules ou a des schemas graphiques. Des essais de ce genre
ont d'ailleurs deja ete effectues soit pour resumer les
conditions du milieu (p. ex. Monod, 1 9 5 1 pour le Sahara
occidental) ou !'aspect de la ·vegetation : rappelons par
exemple, entre d'autres, un systeme generalise, celui de
Dansereau ( 1 95 1 , etc.) [ 1 . « Life-form » - 2. taille
(stratification) - 3. «function» (periodicite) -4. feuille :
forme et taille - 5. feuille : texture - 6. recouvre­
ment] et deux systemes africains, ceux de Troupin ( 1 960;
1 966, pp. 1 10-1 1 8) [ 1 . stratification - 2. degre de recou­
vrement - 3. criteres floristiques - 4. groupes ecolo­
giques : heliophile a sciaphile], et de Roberty (1 964) [1 .
« series )) de vegetation - 2. physionomie (strates : 1 0
categories fondamentales) - 3 . « paysages » (forma­
tions)]. Ces trois exemples aboutissent a des notations­
formules; les deux premiers, de plus, a une schematisa­
tion graphique.
Serait-il possible d'integrer dans un seul procede de
schematisation !'ensemble des caracteres d'un habitat,
c'est-a-dire, avec la vegetation, les traits saillants du
milieu et de la faune? Je n'en suis pas certain, car si les
caracteres qui dependent du milieu sont susceptibles
d'une expression numerique, on ne voit vraiment pas,
pour une faune qui s'etend du Protozoaire au Mammi­
fere, sous quelle forme sa composition locale pourrait se
voir ramenee au niveau d'une courte formule : le monde
animal refusant de se laisser resumer, il sera vain sans
doute de vouloir l'y contraindre et plus sage de prevoir
pour lui, a cote des schemas « milieu » et « vegetation »
une courte enumeration descriptive.
CONCLUSIONS
Ces rapides et sommaires remarques n'avaient d'autre
objet que d'attirer !'attention des botanistes sur la neces­
site d'envisager leurs problemes de conservation a une
35
echelle suffisante pour que, transcendant l e niveau
« vegetation », la notion d'habitat - et un j our pro­
chain, on l'espere, la mise en route d'une collection de­
finitive de « biotypes » - sache intt�grer a la fois, avec
les caracteres majeurs de la vegetation, les conditions
locales du milieu et, non moins essentielle, la composi­
tion de la faune, de fa�on a parvenir a sauver non pas des
lambeaux du monde vivant artificiellement isoles, mais
des unites viables et fonctionnelles, c'est-a-dire des eco­
systemes (biocenoses + climat + substrat).
BIBLIOGRAPHIE
A.E.T. F. A.T., 1 965. [Nomenclature des types de vegetation].
Roneo, 4 p .
Dansereau, P . , 1 9 5 1 . Description a n d recording o f vegetation
upon a structural basis. - Ecology, 32, 2, pp. 1 72-229.
- 1 9 57. Biogeography. An ecological perspective. New-York.
- 1 9 5 8 . A universal system for recording vegetation. - Contrib. Inst. Bot. Univ. Montreal, 72, pp. 1-58.
- 1 96 1 . Essai de representation cartographique des elements
structuraux de la vegetation, pp. 2 33-255 in : Methodes de la
cartographie de l a vegetation, Colloque C.N. R.S., XCVII,
Toulouse 1 960. Paris.
Ellenberg, H., D. Poore and J. Schmithausen, 1 966. Tentative
Framework for a Classification of Plant Formation. Roneo,
PBI, Paris, March 1 966, 9 pp.
Monod, Th., 1 95 1 . Biotopes ouest-sahariens. - Bull. I nst. Fouad
I du Desert, I, N° 2, juillet 1 95 1 , pp. 9 5- 1 02.
- 1 964. The strict natural reserve and its role. - First
World Conference on National Parks, Seattle 1 962, pp. 2 58267. Washington, D.C.
Roberty, G . , 1 956. Expression chiffree de la physionomie de l a
vegetation. - Rapport . . . Reunion . . . Phytogeographie,
Yargambi 1 956, Conseil Scientifique pour l'Afrique au Sud
d u Sahara, Afrique (56), 2 1 4, pp. 320-32 1 . Roneo.
- 1 964. Carte de la vegetation de 1'Afrique tropicale occidentale
a l'echelle de 1 / 1 000 000. - I. Introduction et glossaires.
Paris, ORSTO M.
Streel, M., 1 963 . La vegetation tropophylle des plaines alluviales
de la Lufira moyenne (Katanga meridional). Liege.
Troupin, G., 1 960. L'application des formules dans le but de
caracteriser les formations vegetates. - Note preliminaire. ­
Fol. Scient. Afr. Centr., 6, 2-4, pp. 22-23.
- 1 966. Etude phytocenologique du Pare National de 1' Akagera
et du Rwanda Oriental. Recherche d'une methode d'analyse
appropriee a la vegetation d' Afrique intertropicale, these
d'agregation, Liege, 293 p . , 28 fig.
L E S P A R C S NATI ONAUX C O M M E ARCH IVES D E RECH E RC H E S
E T D O C U M E N T A T I O N D E L' E V O L U T I O N D E S E S P E C E S
K. Curry-Lindahl
I1 est evident que la recherche scientifique a besoin des
reserves integrales representant des habitats, des bio­
communautes et des biocoenoses qui sont dans un etat
nature!, c'est-a-dire ou l'homme n'influence pas la
nature, pour pouvoir les comparer avec des terrains qui
ne sont plus vierges. L'evolution des biotopes et des
Acta Phytogeogr Suec 54
36
K. Curry-Lindahl
especes dans l'un ou l'autre milieu peut nous indiquer
des faits importants, qui nous permettent de comprendre
de queUe fa9on il faut eviter de faire des erreurs, qui
peuvent etre fatales pour l'homme lui-meme.
Les pares nationaux sont done aussi important comme
sujets d'etudes pour la recherche scientifique pure que
pour la science appliquee.
Lorsqu'on parle du concept d'un pare national ou
d'une reserve integrale on exclut generalement l'homme.
On peut discuter s'il est biologiquement correct d'ecarter
l'homme d'une biocoenose natureUe.
L'homme est lui-meme un animal, une creature bio­
logique dont !'action doit done etre consideree comme
une phase naturelle, une eruption du dynamisme d'une
espece. Cela est vrai, mais il faut souligner que l'homme,
par ses dons inteUectuels et ses capacites techniques s'est
partiellement eleve au-dessus des lois de la nature.
La dynamique naturelle d'une biocommunaute mon­
tre combien il est important que la science ait des moyens
d'etudier des milieux naturels oil l'homme n'inter­
vient pas. La raison essentieUe de cette necessite est
bien simple : le climax naturel des differents habitats ne
se developpe presque jamais Ut oil l'homme industriel
fait part du biotope. 11 y a des exceptions, notamment
dans les regions tropicales. Au Congo les pygmees de
la foret d'Ituri en donnent un exemple. 11s existent dans
la foret tropicale depuis de tres longues periodes et
peut-etre representent-ils meme la population humaine
la plus ancienne. lis n'ont guere influence leur milieu
nature!, qui retient son climax. L'activite des pygmees
n'a jusqu'aujourd'hui, joue aucun role negatif dans
l'equilibre millenaire qui s'etait etabli entre les popula­
tions d'hommes, d'animaux et de plantes. Cette situa­
tion est sans doute expliquee par le fait que le pygmee
recolte et chasse mais ne cultive pas. 11 i ntervient dans
le milieu naturel exactement comme n'importe queUe
autre espece.
La situation est completement differente la oil
l'homme, directement ou indirectement, par example
par son betail, change le milieu naturel. Et c'est ce qu'il
fait presque partout en utilisant maintes methodes
differentes. La diversite des procedes d'exploitation
utilises par l'homme, la diversite des milieux naturels et
des regions biogeographiques impliquent des problemes
tres complexes. Ce seront des questions d'overgrazing,
de feux courants, de pejoration des sols, qui retiendront
!'attention dans les regions semi-arides et les savanes
seches; des questions de deboisement, de modifications
climatiques, et aussi d'erosion, le role important de la
foret, la recherche d'un equilibre necessaire entre patu­
rages, cultures et vie sauvage la oil s'affrontent la vie
pastorale et la vie agraire.
On s'aper9oit aujourd'hui, comme l'a fait remarquer
Dekeyser (1 963), qu'en fait la conservation et l'utilisaActa Phytogeogr Suec 54
t ion des ressources naturelles s'integrent dans le cadre
de l'ecologie humaine, distincte de l'ecologie animale,
en ce sens qu'avec les interactions d'ordre biologique
interferent des facteurs psychologiques et culturels.
Dans l'Afrique tropicale d'aujourd'hui, qui, dans pres­
que tous les milieux naturels, est menacee par l'homme
exploiteur, les pares nationaux et les reserves inte­
grales representent des ilots d'extreme importance, non
seulement pour !'evolution et la selection naturelle
comme sujets d'etudes pour la science, mais aussi comme
instruments, comme immenses laboratoires, qui nous
donnent des renseignements sur la nature, qui nous
aident a comprendre ce qui se passe autour de nous­
memes. Cela n'a pas seulement un interet scientifique;
il y a egalement des aspects et meme des implications
economiques et sociales.
Ce sont done les pare nationaux d' Afrique tropicale qui,
durant les dix dernieres annees, nous ont fait comprendre
!'immense productivite biologique des reserves integra­
les, oil ne vivent que des animaux sauvages. Si on com­
pare ces reserves avec des regions voisines qui sont
paturees par le betail, la difference est souvent enorme.
Bien qu'un pare national heberge en general une faune
de grands ongules bien superieure en individus et en bio­
masse aux troupeaux de betail qui paturent dans les
savanes voisines, originalement homologues, la fertilite
du sol du premier ne change pas, tandis que la vegeta­
tion disparait souvent et le sol est completement erode
Ut oil le betail influence le milieu.
Ceci n'est pas une theorie. Des denombrements effec­
tues au Pare National Albert au Congo ont montre que
la biomasse - c'est-a-dire le chiffre obtenu en multi­
pliant le nombre d'individus de chaque espece par le
poids moyen des adultes - s'y eleve a 24 406 kg de
viande par km2 (Bourliere et Verschuren 1 960, Bour­
liere 1 96 1 ). La biomasse est done ce que les agriculteurs
appelleraient le « poids vif » pour 1 00 hectares.
C'est done la situation dans un pare national qui,
depuis plus de trente ans, est une reserve integrale, qui
nous a ouvert les yeux devant le phenomene de la pro­
ductivite continuelle, on peut meme dire d'un symbiose,
entre la vegetation et la faune des ongules sauvages du
milieu tropical en Afrique (Curry-Lindahl 1 96 1 ) .
Comme l ' a souligne F. Bourliere (196 1 ), l a cause es­
sentielle des valeurs elevees des biomasses au km2 reside
dans la variete de la faune des ongules cohabitant dans
les differentes regions « ouvertes » de 1' Afrique tropi­
cale, ce qui est egalement !'opinion de Lebrun ( 1 947)
et Darling ( 1 960 a, 1 960 b). I1 n'est pas rare de rencont­
rer 10 a 20 especes vivant ensemble. Or, chacun de ces
animaux exploite, en quelque sorte, une categorie dif­
ferente des aliments vegetaux produits par le milieu. Les
pousses tendres sont broutees par les petites antilopes,
les buissons epineux sont manges par les rhinoceros noirs,
Les pGres nationaux comme archives de recherche
le feuillage des acacias de taille moyenne est consomme
par les girafes, et les elephants sont capables d'absorber
a peu pn!s n'importe quoi - petites branches, feuilles ,
fruits et herbes diverses, y compris certaines dont ne
veulent pas les autre3 especes. Ainsi la « charge » to­
tale des herbivores est-elle repartie sur la totalite de la
biomasse vegetale et non concentree sur un seul de ses
constituants (le tapis gramineen), comme dans le cas du
betail domestique. L'uti lisation des aliments vegetaux
par les ongules sauvages des savanes africaines est d'ail­
l eurs si parfaite qu'il constituent l'element « consom­
mateur » dominant de cette biocoenose et ne laissent
place qu'a peu de competiteurs herbivores, parmi les
vertebres du moins. C'est ainsi que dans les savanes
basses de la plaine des Rwindi-Rutshuru-Ishasha au
Pare National Albert le biomasse des rongeurs et lago­
morphes ne depasse pas 1 37 k gfkm2 (contre 20.485 kgj
kmz pour les ongules vivant au meme endroit) , alors
que dans les steppes argileuses d'Outre-Volga, il peut
avoir 32. 500 sousliks ( Citellus suslicus) et campagnols
(Microtus) par km2 contre 0,4 antilope saiga (Saiga ta­
tarica) seulement.
Tout ceci jette aussi une lumiere sur I' evolution non
seulement des especes mais aussi des milieux. Il n'est
guere possible de faire des etudes de la meme exactitude
en dehors des pares nationaux et des reserves integrates.
Leurs archives nous fournissent des informations pn!­
cieuses et importantes non seulement de l'ecologie des
biocommunautes naturelles mais aussi pour la mise en
valeur des ressources naturelles de 1' Afrique.
Le role des pares nationaux n'est cependant pas seule­
ment celui d'un laboratoire nature! et d'un domaine de
recherche; ils servent aussi commefoyers derepeuplement
vegetal et anim:il pour les regions avoisinantes. L'ex­
ploitation de la vegetation et de la faune peut etre etablie
autour des pares nationaux, qui payent leurs dividendes
en plusieurs fa�ons.
Les relations ecologiques dans un milieu sont tres
compliquees. C'est seulement par des recherches detail­
lees, entre autre taxonomiques, qu'elles peuvent etre
comprises. Il est egalement necessaire, pour les recher­
ches biologiques de fond, qu'il y ait a leur disposition
des milieux naturels vierges ou primitifs, en ce sens qu'ils
ressemblent a leur etat d'origine. Mais aussi les milieux et
les biocommunautes changees par l'homme sont d'un
grand interet et doivent etre analysees et comparee avec
la situation dans les pares nationaux.
L'homme, en tant que facteur ecologique, peut done
etre etudie dans le developpement d'une nature dont les
profonds transformations amenees par son intervention
dans le monde animal et vegetal peuvent etre enregistrees.
Pour le moment, une grande partie du monde scienti­
fique est en train d'organiser le Programme Biologique
International.
37
L'etude essentielle de ce programme est la bioproduc­
tivite des differents habitats. Dans ce programme am­
bitieux, les pares nationaux et reserves integrales du
monde entier vont jouer un role extremement important
comme bases de ces etudes simultanees. Un tres grand
nombre de chercheurs seront mobilises pour ces investi­
gations et envoyes partout ou il y a moyen de faire des
recherches fructueuses de ce genre. Il est certain que les
pares nationaux d'Afrique vont etre utililise dans ce
projet, car ils representent des biotopes tres importants
dans le programme d'etude.
Il devrait etre evident qu'il faut sauvegarder ce qui
est necessaire au developpement de la science. Mais ici
les disciplines biologiques sont entrees en conflit avec
une serie d'interets d'exploitation. En general, on n'a
pas voulu comprendre qu'a priori l'avenir depend du
materiel accessible aux recherches pures. On a tres sou­
vent inutilement devaste le milieu nature! et bouleverse
et extermine le monde animal et vegetal qui ne pourra
jamais etre retabli tel qu'il etait. Si les besoins de la
recherche empechaient le developpement economique
de la communaute humaine on pourrait croire qu'il
y ait conflit entre leurs interets respectifs. Mais tel n'est
pas du tout le cas. Cette necessite n'est qu'une tres petite
partie de !'ensemble des ressources terrestres et aqua­
tiques. Il est parfaitement possible d'accepter les exi­
gences de la science et en meme temps de pourvoir aux
necessites du developpement economique.
Meme si les associations animates et vegetales dans
toute leur unite, c'est-a-dire constituant un milieu natu­
re! en equilibre normal, ont droit en premier lieu aux
recherches biologiques, il faut admettre que chacune des
parties de ces associations doit etre consideree comme
indispensable. Une fraction ne peut disparaitre sans que
se produise un bouleversement ou un changement dans
l'unite et chaque espece a son role a jouer dans le deve­
loppement progressif des biocommunautes.
En considerant les pares nationaux comme archives
de recherches et de documentations de !'evolution des
milieux des especes, on peut consacrer une pensee a
l'avenir et a !'evolution biologique de l'homme, dont
les lois nous controlent. Nous vivons actuellement dans
un monde domine par les decouvertes nucleaires et
moleculaires. L'existence de l'homme sur cette plam!te
depend de la fa�on dont nous comprenons le fonctionne­
ment des forces de I'evolution et son influence sur nous.
Les recherches dans le domaine biologique et genetique
de !'evolution devraient, pour le bien de l'homme, dis­
poser des memes ressources que les recherches atomi­
ques. Sans cela nous ne pourrions peut-etre jamais
cueillir les fruits de ces dernieres.
Je suppose que nous sommes tous d'accord pour esti­
mer qu'une nature vierge ou, au moin, bien proteg��.
est une m!cessite pour les recherches dans plusieurs
Acta Phytogeogr Suec 54
38
M. Steentoft
domaines. Ce fait nous amene a la conclusion que les
recherches a longue echeance d'aspect biologique dans
un milieu nature! ne peuvent se faire ailleurs que dans
des pares nationaux et de grandes reserves. Les recher­
ches dans le domaine des sciences naturelles dans une
nature vierge peuvent nous dormer des n!sultats inatten­
dus, creer une voie a de nombreux facteurs et nous
mettre en garde a temps contre les malencontreuses
erreurs si souvent causees par l'homme. Des reserves
naturelles doivent done etre considerees comme indis­
pensables au bien de l'humanite.
BIBLIOGRAPHIE
Bourliere, F. 1 96 1 . « La grande faune africaine est-elle con­
damnee a disparaitre »? - Science et Nature. 43 , 2-10.
Bourliere, F. et Verschuren, J. 1 960. Introduction a l'ecologie
des ongules du Pare National Albert. Exploration du Pare
National Albert. Mission F. Bourliere et J. Verschuren, 1 ,
1-1 58.
Curry-Lindahl, K. 1 96 1 . Contribution a l'etude des vertebn!s
terrestres en Afrique tropicale. - Exploration du Pare National
Albert et du Pare National de la Kagera. Mission K. Curry­
Lindahl ( 1 95 1 - 1 952, 1 958-1 959), 1, 1 -33 1 .
Darling, F . F . 1 960 a. « An Ecological Reconnaissance o f the
Mara Plains in Kenya Colony ». - Wild Life Mono­
graphs, V, 1 -3 1 .
- 1 960 b . Wild Life i n a n African Territory, 1 60 pp. ­
London.
De Keyser, P. L. 1 963 . The physical and human environment
in West Africa in Conservation of Nature and Natural Re­
sources in modern African States. - I.U.C.N. Publ., new
series, 1 : 1 4 1 .
Lebrun, J. 1 947. L a vegetation d e la plaine alluviale au sud d u
lac Edouard. 1-11. - Exploration d u Pare National Albert.
Mission J. Lebrun ( 1 937-1 938), I, 1-800.
E D U CATI O N T O WA R D S T H E C O N S E RVAT I O N O F
N A T U R E I N T R O P I C A L A F R I CA
M. Steentoft
The problem of conservation education in tropical
Africa has been attracting attention for almost twenty
years now ( 1 ), and I have considered it relevant to
begin by trying to find out how much, and what
kind of, conservation is actually being taught in the
course of formal education, below university level.
By examining such syllabuses (2) and recom­
mended or widely sold textbooks (3) as I could ob­
tain, it has become apparent that only soil conser­
vation, expressed as "prevention of erosion" or
"maintainance of fertility", is anything like gene­
rally taught, at both primary and secondary levels.
I regret to say that I have been able to find out
very little about syllabuses and textbooks in French­
speaking countries. I have however seen IFAN's
"La Protection de la Nature" (4) together with
some articles, specimen lessons and so on, and it
seems to me that where conservation is taught, it is
interpreted more widely than in English-speaking
countries.
In looking through the English language material;
I have noticed that ecology is still the poor rela­
tion in most matriculation type syllabuses and text­
books are also weak in this respect, though whether
the textbooks are weak because the syllabus is vague,
or vice versa, is difficult to determine. A vague syl­
labus places too much responsibility on the teacher,
Acta Phytogeogr Suec 54
and this, coupled with a poor teaching toll, such as
a weak textbook, means that the teacher will avoid
the topic if possible. The ecological approach will
never be promoted while this situation exists. If syl­
labuses specified the principles of ecology, to be
studied in connection with one or two habitats, in
the same detail as for plant and animal physiology
for example, some progress might be possible.
But progress in either ecology or conservation
teaching will only become probable when the teacher
can be better informed. At the moment, the informa­
tion lies in learned journals and conference proceed­
ings. While a graduate teacher has had the oppor­
tunity to collect information as a student, he is cut
off from these sources once he moves away from
the Universi�y library. His counterparts in Teacher
training colleges and in Primary schools most likely
have only matriculation type texts available to them,
and we have already seen that these are often in­
adequate. The reprinting of Webb and Hill's Eco­
l ogy of Lagos Lagoon (5) by Ibadan University Press,
with advertising and distribution arranged by an edu­
cational publisher, is the first attempt I have come
across to get to the root of the information problem
for the teacher.
I think it is still true to say that a book published
by an ordinary educational publisher backed by ex-
Education towards the conservation of nature in Tropical Africa
perience in documentation and distribution is far
more likely to come into the hands of the teacher
or student, than either a local publication or a perio­
dical. If, for example, "La protection de la Nature",
were to be published in English-speaking countries,
where it would be most useful in Teacher training
colleges, then a specially created distribution agency
would be required. For governments and official
bodies to publish is not enough-there must be an
information service and distribution, and it is appar­
ent that only educational publishers can do this job
at the moment.
There are now numerous articles in learned jour­
nals on African ecology, and numerous government
publications, but I have been able to trace only 7
titles (6) published by ordinary educational publish­
ers, and I think this has a direct relationship with
the low state of ecology teaching. I hope there are
large numbers of texts undiscovered by me, lurking
in the bibliographical jungle, but I fear not.
To turn to conservation, if a teacher should wish
to introduce this subject, can he obtain informa­
tion and class material. On the whole and with
some exceptions, I should say no. There is IUCN's
"Our Mother Nature", of limited applicability and
with a bibliography almost entirely in French (7).
There is a handful of pamphlets, films and film­
strips of varying degrees of availability (8) . There is
"La Protection de la Nature" and after this the
large handbooks on the principles of conservation,
illustrated by American examples as a rule, and avail­
able only in University Libraries.
The graduate teacher, whether or not he has
studied conservation formally, is in a position to
find out, if he has the time and has access to a
University Library. For the rest of the teaching pro­
fession, conservation is not in a teachable condition.
At the moment I am bound to say that I do not
think the lack of conservation education is partic­
ularly serious. Conceptions of conservation have
been too narrow; too few children have been at
school to create the necessary weight of informed
opinion; those who have completed more than two
years of schooling have not returned to rural oc­
cupations to practise the new soil conservation they
have heard of, and in any case they cannot influence
their families. At least one is forced to this con­
clusion, for although soil conservation has been
widely taught for many years, new methods are not
practised except on demonstration farms.
It seems to me that conservation is now in the
state in which conservationists have recognised the
problems, including some of the human ones, and
have convinced each other of the need for conserva-
39
tion, but have not yet communicated effectively with
very many other people on the subject.
Conservationists must in fact communicate at
three distinct levels:
with governments, where policies are constructed
and laws and consequent educational directives are
given.
with educationalists, who translate educational di­
rectives into curricula and syllabi and ensure their
effective working, and
with teachers.
Where a Conservation Service exists, direct mass
communication can be attempted, and this is a fourth
level, but this kind of communication does not exist
effectively in tropical Africa, and it must probably
await development by African born and bred psy­
chologists, or if you like, advertising experts, before
programs can be expected.
Communication with governments is at present be­
ing taken care of by IUCN's African Special Project,
and it is to be hoped that all governments will in
due course adopt positive conservation policies. But
in passing I should like to say that I do not think
that we, as an association, need draw back from
proposals entailing considerable legislation. I have
come to the conclusion that the law, and especially
the litigation to which it can give rise, performs
a useful function in African society in a way not
familiar in other parts of the world. To give cause
to litigation is not entirely a bad thing.
Communication with educationalists and teachers
depends on demonstrating to them that conserva­
tion makes good teaching material, that is, material
through which the child can develop his apititudes
and abilities for himself, under the guidance of a
teacher. This is unfortunately not the object of edu­
cation as regarded by most African parents and stu­
dents, but I do not think we should subscribe to
any other philosophy because we should be insincere
if we did so.
Whether the child will have, or can develop, the
necessary attitude which will allow him to accept,
and later impel him to act on, the information con­
tained in his lessons, is a separate problem to which
I shall return in a moment.
I have come to the conclusion that there are three
glaring deficiencies in conservation education in tro­
pical Africa, which can be solved by more or less
ad hoc remedies involving co-operation between con­
servationists and other specialists.
Firstly, it is essential that conservation informa­
tion (and for that matter ecological information also)
be removed from the learned journal and the volume
Acta Phytogeogr Suec 54
40
M. Steentoft
of conference proceedings. A handbook, setting forth
the principles and practice of conservation in Africa
is required. It can be a large volume, many con­
tributors will be required, and wide distribution must
be ensured. In such a volume the particular interests
of this association will assume their rightful place.
For we must remember that conservation of the
habitat for scientific purposes is, of all aspects of
conservation, the most difficult to explain to the lay­
men. The ordinary man seldom comes to appreciate
this form of conservation, he merely accepts it on
trust as a "good thing". Labels are easily attached,
less easily detached, and it would be unfortunate if
our interest in one aspect of conservation came to
stand in such isolation and prominence that our label
read "cranks".
Secondly, we can attempt to capture the interest
of those most important people, the teachers of
teachers, that is, the lecturers in teacher training
colleges, where students are trained for primary
school teaching. The lecturers are by no means al­
ways graduates, but they are nevertheless key people.
Educationalists listen to them, teachers bow to them.
Not only do they train future teachers, but they are
consulted upon, and construct syllabi, write text­
books, read for and advise publishers. They seem
to have fingers in every educational pie. Few ad­
vanced teacher training colleges exist at the moment,
but their lecturers are just as important, though per­
haps initially better informed. Of these, only the
Kenya Science Teachers College seems to work to
an ecologically orientated syllabus with an adequate
conservation section, and this I suspect is largely
brought about by Dr. Hedberg, who headed the com­
mittee which wrote this syllabus.
While it might be possible to get syllabuses altered
in this direction, I think a better result might be
achieved by the regionally organised field course,
which can provide both new information and a new
point of view. The lecturers themselves can find out
how to reorientate the training they offer, how to
influence syllabi, textbook production and so on. But
it goes without saying that a handbook of conserva­
tion will still be one of their best teaching tools.
Thirdly, we can attempt to improve another teach­
ing tool, that really hardly exists-the picture dic­
tionary, that is, the small handbook of coloured il­
lustrations and brief notes. I have calculated that
to have reference works for the more common spe­
cies of plants and animals not merely flowering
plants and vertebrates, would involve me in the pur­
chase of something like 60 titles from an incredible
range of publishers, plus numerous government pub­
lications, if I am able to find out that they exist of
Acta Phytogeogr Suec 54
·
course. I may purchase, because I cannot see that
any education authority can provide every secondary
school and teacher training college with a biology
library of these dimensions, and in any case only
a proportion of each work is useful. The rest may
deal with other regions, or uncommon .species.
The regional, preferably ecologically arranged,
handbook can be compiled in several ways, for use
at several levels, but it will always be expensive in
terms of specialist services. I do not think educa­
tional publishers have the kind of contacts which
would allow them to undertake this sort of project
independently. After all, many publishers will happily
put out a biology book on Africa with the word
"tropical" in the title, when it is abundantly clear
from the text that the author had not only Africa,
but a particular region of Africa, in mind.
Both Swedish and Danish series of such hand­
books exist (9), which shows what can be produced
for a small population (41 I 2 million in the case of
Denmark).
Adams (1 0) has detailed a depressing list of defi­
ciencies in biology teaching in general, and there
is an immense amount of room for cooperation be­
tween specialists if the teachers' more unwieldy bur­
dens are to be removed.
Finally I wish to suggest three rather more fun­
damental educational remedies, one directly apropos
conservation, the others more general in character.
If you ask an African man or woman why he or
she wants children, what kind of person the child
should most rather grow up into; if you examine
the methods of child training ; if you examine the
societies in which the children must take their place,
the answers form a picture naturally somewhat dif­
ferent from the one obtained in any other continent.
In Africa the child assumes his place as a . con­
tributor to the family's economy almost as soon as
he comes down from his mother's back. A son is
important for example, because he will bring wives
to help with the work, and will take care of his
parents in their old age. If only one or two children
can be sent to school, those most likely to succeed
in holding a well paid steady job after their educa­
tion is completed, will be chosen. They then con­
tribute cash instead of labour to the family's eco­
nomy.
It is not surprising therefore, that both parents
and children commonly regard education as voca­
tional training. African teachers are well aware of
this and I suspect that many of them are in a con­
siderable state of conflict about what they are really
supposed to be trying to do. No selfrespecting
teacher, on the English or French model, that is,
Education towards the conservation of nature in Tropical Africa
cares t o admit that h e i s merely producing units for
the labour market.
It will take a generation or more to resolve this
p:-oblem one way or the other. In the meantime,
a career in conservation, with well marked educa­
tional steps of approach, is just as likely to be ac­
ceptable to the average father thinking of educa­
tion for a son, as agriculture and forestry have been
in the past. The important thing is that the career
should be recognisable, patently able to fulfill the
economic desires of its entrants.
African educationalists are not likely to approve
of this idea; they already complain that governments,
wi th their demands for paper qualifications, are too
often the employers, so that education is dominated
by the examination and the certificate. But in under­
capitalised countries governments are bound to be
the main employers and educationalists might rather
turn necessity into advantage by re-thinking the
forms of examination and certificate for example.
The second and more fundamental change in Af­
rican education which I would like to see, concerns
attitudes. So very many of the changes needed to
conserve the life and labour, mental and physical,
of the ordinary African, are unacceptable to him.
He opposes, whether positively or passively, changes
affecting his daily life, his management of his land,
his management of his family. Adams ( 1 0) has set
forth very vividly the reasons why advice on con­
servation itself is so often rejected by the average
man, and there is no doubt that the crux of the
problem, in Africa as elsewhere, is one of attitude.
In Africa there is an information problem. There
is scarcely any means of showing the average man
that other ways of management exist. But I am con­
vinced that to send the child to school is not to
educate the parent. Information available in this way
is unacceptable, probably because it lacks the re­
enforcements of a small scale practical demonstra­
tion under local conditions.
Here again, educationalists might make a contri­
bution. Just because the school has a particular use
in the community in Britain or France, or in America
for that matter, there is no reason why it should
follow the same pattern in Africa. The school re­
presents valuable resources in buildings and equip­
ment which should be put to use outside school
hours, and, where the school is already, or can be­
come to be, favourably regarded by the community
it serves, it is admirably suited for just that pur­
pose, the small scale demonstration under local con­
ditions, not simply of conservation, but of many
other things as well. But such schemes must be small
and simple, or they become unacceptable, and there
41
must, at least initially, be a local tradition for com­
munal activity which cuts across family and clan
alliances. It isn't only in the big cities of Europe
and America that the Smiths don't speak to the
Browns.
I am not, however, advocating removal of resist­
ance to innovation, for innovation can be iil-con­
sidered, and resistance to it gives times for discovery
of its unsuitability. But I would like to see the self­
limiting deterministic attitude replaced by a self-ex­
panding activistic a.ftitude.
Briefly, the deterministic attitude is characterised
by a belief that the environment, in the widest sense,
controls the individual. Almost all African societies
in tropical Africa hold this view to a greater or lesser
degree and its origin is perfectly understandable.
Most tribes are age-and-lineage hierarchies which
have shown themselves admirably adapted to sur­
vival through repeated natural catastrophes and wars.
Each individual is brought up to an assured and
valued place in this society, which can be visualised
as a strong and cohesive, but concave, age-pyramid.
Strength and cohesion are assured by training in
respect for elders and obedience to tribal custom.
These virtues are greatly desired in children, so
much so that if only one child can be sent to school,
the most obedient may well be chosen. At the same
time the importance of the family, in the sense of
the individual mother-and-child unit, is played down.
The society is thus the important unit, the indi­
vidual tends to be of secondary importance, and he
grows up in this belief, which results in his being
at least somewhat cramped in his abilities to think
and act independently especially if doing so involves
treading outside tradition. For to do so will mean
jeopardising his position in society, the thing that
gives most value to his existence.
The activistic attitude, characterised by a belief
that the individual controls his environment, is com­
mon in all the older democracies. Obedience for its
own sake has no value in these societies, indeed it
could be positively dangerous; instead the rational
and independent personality is cultivated, the em­
phasis is on the individual, his place in society is
more fluid, less important. But the individual really
believes he has a chance of improving his lot, even
of influencing the people around him.
At least for the time being, there are certain ad­
vantages to be gained from the activistic attitude,
which should make controlled innovation in tropical
Africa more acceptable.
What can we expect from education if the attempt
is made to promote the activistic attit�de?
Firstly, formal education seldom changes attitudes.
Acta Phytogeogr Suec 54
42
M. Steentoft
It can give information, develop aptitudes and abili�
ties, but ability to change attitude is usually con­
sidered to be possessed by only a highly rational,
independent-minded minority, who would in any case
examine each situation for themselves and come to
their own conclusions. I think only universal educa­
tion will bring these highly rational children into
the schoois of Mrica. Such children are seldom noted
for their obedience and there must be many who
are a sore trial to their parents and quite unsuited,
by parental standards, to education. But we cannot
expect that such children will necessarily become
primary producers, in direct contact with the natural
resources of their country. They are more likely to
add to the informed section of public opinion.
Secondly Mrican teachers and educationalists, in­
deed Mrican society as a whole is in a period of
confusion. Education is still largely alien in method
and intention, at cross purposes with itself and so­
ciety. But in just these circumstances the activistic
attitude could be the stabilising factor-willingness
to attempt control of the environment, whether phys­
ical, social or psychological, would be a tremendous
aid to progress, if only the initial ineffectiveness of
education can be overcome.
The deterministic attitude first takes hold of the
child when he is put down from his mother's back
and kept out of her bed, and unless the psycho­
logy of the Mrican is very different from that of
the peoples of other continents, that attitude is prob­
ably crystallised for good by the age of seven.
To tackle the problem at its root therefore entails
not only courage and resources but impertinence. It
means that, as soon as possible after the child comes
down from his mother's back he must be systematic­
ally helped to explore the world through his senses,
so that his experience of it is enriched, and then
he must be helped to control that environment, its
situations and events, through play or whatever else
can be devised. The school curriculum must reori­
entate towards two objectives-efficient use of the
basic techniques of communication in words and
numbers, and efficient exploration and control of
environment.
I do not expect that such a reorientation would
be popular nor would conservationists necessarily be
enthusiastic about the result, for the best one can
hope for is the passive acquiescence of the stable
democracy, and that sounds extremely negative, but
provided it is based on trust between laymen and
specialist, and at least a proportion of the laymen
conceive it their duty to be able and willing to ask
awkward questions from time to time, it is sufficient.
In order to avoid ending on a slight note of gloom,
Acta Phytogeogr Suec 54
I have left till last one more proposal, less revolu­
tionary, but potentially useful, and also of interest
to conservationists.
This is the idea of the adult college, on the plan
of the Danish "Folkeh�jskole"; if the curriculum
consisted of an examination of the country's internal
problems, history, economics, politics and sociology,
then its problems in relation to its neighbours, and
lastly the problems of Africa as a whole, then con­
servation would assume its natural place, if I may
so express it, an inconspicuously conspicuous one.
The problems of organisation of such colleges are
the familiar ones of manpower and money, the solu­
tions of these problems are equally familiar and not
necessarily more difficult than usual. Whether Afri­
cans want, and would value, such education requires
investigation: whether it would do enough good in
the time available is anybody's guess; but I feel rea­
sonably sure that it would only do good.
REFERENCES
(1) Conservation education in tropical Africa (in chronolo­
gical order):
UNESCO (First) International technical conference on
the protection of nature, Lake Success, 1 949. Sec­
tion I, Education, report pp. 26-63, papers pp. 192295.
IUCNNR Seventh technical meeting, Athens, 1958.
Theme 11. Education and Conservation, pp. 1 1 5-227.
- Seventh general assembly, Warsaw, 1 9 60. Report
of permanent commission on conservation educa­
tion 195 8-60, pp. 1 35-6. Report of education com­
mittee, pp. 1 3 7-8.
- Conservation of nature and natural resources in
modern African states, Arusha, 1961. IUCN publ.
no. 1. Discussions, section E. Local human atti­
tudes and international interest, pp. 52-9 and asso­
ciated papers.
- Workshop of conservation education, Nairobi, 1963.
IUCN publ. n.s. suppl. pa. no. 7, pp. ii + 75.
UNESCOjECA Outline of a plan for scientific re­
search and training in Africa. Education systems
and science training (recommendations), pp. 1 5-6
(International conference o n the organisation of re­
search and training in Africa in relations to the
study, conservation and utilisation of natural re­
sources, Lagos, 1 964).
ICSU Report of working group F, ed. J. G. Baer, of
Congress o n Science teaching and economic growth,
Dakar, 1965. Nature and Resources 1 (4), 9-14
(1 965).
(2) Syllabus:
Primary School:
Uganda: Ministry of Education. Approved syllabus for
Primary Schools, 1 965.
Zambia: Ministry of African Education. Approved syl­
labus for Primary Schools, und'ated (1963).
Education towards the conservation of nature in Tropical Africa
Secondary (Grammar) School:
Ordinary ("0") Level: University of Cambridge 1 966
(Oversea Centres). University of London, June 1967
and January 1 968 (Oversea). Sudan Examinations
Council, March 1 962 and 1963. West African Exa­
minations Council 1 967.
Advanced ("A") Level: University of Cambridge 1 967
(Oversea Centres). University of London June 1 967
and January 1 968 (Overseas).
Post "0" Level teacher training (teachers for secondary
schools):
Kenya: Kenya Science Teachers College. Proposed syl­
labus for Biology 1 966.
(3) Textbooks (pr�scribed or widely used):
Primary School:
('� = Teachers use only in Uganda)
Agiobu-Kemmer, R. S. G. Primary Science Course, bks.
1-6. Nelson, 1966 (in contin.)
*Chaplin, B. H. G. Life and Living, bks. 1-5. Long­
mans, 1 959-64. A Zambia edition of bk. 4 exists.
Cross, G. Tropical Library (22 titles in 3 series). Longmans.
Deakin, L. A. First Tropical Nature Study. Longmans.
Field, A. S. Nature Talks. Longmans, 1 948.
Nielsen, M. S. Biology and hygiene for tropical schools.
Evans 1958.
Onyekwere, A. 0. and Creaser, H. Beginning Science
in Eastern Nigeria, 2 bks, Longmans.
*Shanks, I. P. Simple science and nature study.
O.U.P. 1 963.
Shanks, I. P. School gardening and agriculture.
O.U.P. 1 964.
Secondary School ("0" Level):
Alien, L. R. Investigations in biology for tropical
schools. O.U.P. 1 965.
Elgood, J. H. Certificate biology for tropical schools.
Heinemann, 1 964.
English, L. R. Botanical notes and drawings for West
Africa. O.U.P. 1 964.
Hadman, R. Biology for East Africa, bks. 1-4. O.L.P.
1 967.
Holmes, E. J. and Gibbs, R. D. A Modern Biology.
C.U.P. 1953 (tropical ed.).
Ogunlade, R. A. A Biology Course for African Schools,
Bks. 1-2. University of London Press, 1 963 and
1 966.
Savory, H. J. Science for tropical Secondary Schools:
Junior Biology bks. 1-2, Senior Biology. Nelson,
1962, 1963, 1 966. An East African edition of Ju­
nior Biology 2 is in preparation, to be published
1967.
Stone, R. S. and Cozens, A. B . Biology for tropical
schools. Longmans, 1958.
Secondary School ("A" Level):
No text exists for these syllabi. Partial coverage is
given by a combination of several titles.
Teacher training and (primary school) teachers reference:
Atkinson, A. Teaching nature study. Longmans, 1 960.
Clarke, J. D. and Herington, G. N. Rural science for
secondary schools. Longmans, 1960.
43
CUP/NBS Science and the farmer. 1962.
Green, T. L. The teaching of biology in tropical sec­
ondary schools. OUP /UNESCO 1 965.
Greensill, T. N. Rural science for tropical schools,
4 (?) bks. Evans.
Haw, R. C. The conservation of natural resources. Faber
and Faber, 1959. (Out of print, soil conservation
only).
Irvine, F. R. West African Botany. OUP 1 952.
Joseph, E. D. The teaching of biology in tropical prim­
ary schools. OUP /UNESCO 1953.
Nairobi Science Teaching Centre. A scheme of work
. . . 4 year "0" level Biology course.
Saunders, H. N. Beginning science: a year's course for
tropical schools. Nelson, 1956.
Stone, R. H. A tropical nature study. CUP 1964 (can
also be used intitially in secondary schools).
Thistleton, G. F. Nature study for Mrican schools,
4 (5) bks. (Birds, mammals, insects, reptiles
(plants). Evans 1958. (Also issued as "Nature study
for East Africa".)
Uguru, 0. 0. A guide to practical rural science. Mac­
millan, 1 966.
UNESCO Source book for science teachers.
(4) IFAN, Dakar. La Protection de la Nature.
(5) Webb, J. E. and Hill, M. B. Ecology of Lagos Lagoon.
Reprinted by permission of the Royal Society Lon­
don, by Ibadan University Press and distributed by
Nelson. 1959.
(6) Other ecology texts.
Chapman, J. D. and White, F. The evergreen forests of
Malawi (in press).
Coe, M. J. The ecology of the alpine zone of Mount
Kenya. Junk, 1966.
Hopkins, B. Forest and Savanna. Heinemann, 1 965.
Lawson, G . W. Plant life in West Africa. OUP, 1 966.
Olaniyan, C. I. 0. Outlines of animal ecology. Heinemann, 1 966.
Owen. Animal ecology in tropical Africa. Oliver and
Boyd, 1 966.
Richards, P. W. The tropical rain forest. CUP. 1952.
Schnell, R. La foret dense. Lechevalier, Paris, 1 950.
Sillans, R. Les savanes de l'Mrique centrale. Lechevalier, Paris, 1958.
(7) Villiers, A. Our Mother Nature (with black-and-white
film strip) IUCN, 1 963.
(8) Miscellaneous conservation references.
Books
Collins, M. 0., ed. Rhodesia, its natural resources and
economic development. Salisbury, 1 965.
Huxley, J. The conservation of wild life and natural
habitats in Central and East Africa. UNESCO, Paris,
1961.
Huxley, J. et al. The conservation of nature and natural
resources in Ethiopia. UNESCO, Paris, 1963.
Russel, E. W., ed. The natural resources of East M­
rica. D. A. Hawkins Ltd., Nairobi. 1962.
Simon, N. Between the sunlight and the thunder. Col­
lins, 1 962.
Trustees of the National Parks of Kenya. Wild life
resources and the national parks. 1955.
Acta Phytogeogr Suec 54
44
G. F. Peterken
mals, fish, insects, larger fungi, birds, trees and
bushes of woods and hedgerows.
Ecological series: Mandahl-Barth, Hvad finder jeg
pa stranden (shore).
In the same series: Lakes and streams, woods.
Uganda National Parks Handbook.
UNESCO A review of the natural resources of the
African continent, Paris, 1 963.
Williams, J. G. National Parks of East Mrica. Collins
Field Guides, 1 967.
Periodicals or occasional pamphlets
East African Wildlife Society. East African W:Idlife
Journal (annually).
Institut fran�aise d'Mrique noire (now Institut fonda­
mental . . .)
Notes africaines 9 1 -2 (double issue "La nature
et sa conservation").
Notes africaines 99 "Principes et historique de l a
conservation d e l a nature".
IUCNNR Bulletin (quarterly, gratis to members, 3. p.a.)
Includes very occasionally literature reviews.
- Checklists of conservation organisation and infor­
mation (numbered as supplements to Bulletin) Ke­
nya, n9. 7 and Uganda no. 8.
- Review of world literature on conservation educa­
tion (first series) 1 963 (one number only).
Natural Resources Boards-occasional production of
pamphlets, filmstrips, etc.
Films and filmstrips
I . U.C.N. is reputed to have three strips, in addition to
that made to accompany "Our Mother Nature",
and a further colour film prepared with UNESCO
aid.
See also Natural Resources Boards above.
(9) Bolin, L. and Post, L. A. 0. Floran i Fiirg. Danish
edition: Hvass, H. ed. Flora i farver. Politikens
Forlag, Copenhagen, 1 95 6. In the same series: Ani-
( 1 0) Adams, C. D. Education and the conservation of tro­
pical vegetation. 1 Oth Int. Bot. Congr. Edinburgh.
1 964.
Science textbooks in French (list supplied by the International
Bureau of education, Geneva; books not seen)
Beart, Ch. & Jolly, R. Les Le�ons de choses et les
sciences appliquees. Fernand Nathan, Paris.
Emith, 0. J'observe les (plantes) (animaux) de mon
pays, 2 bks. Longmans, London.
Ernoult, J. Reg·arde et comprends. Editions de L'E<:ole,
Paris.
Godier, A. et al. Animaux et plantes des pays tropicaux.
Fernand Nathan, Paris.
Jeannin et al. Les sciences. Editions Prismes, Paris.
Institut Pedagogique Africain et Malagache. Sciences.
d'observation, cours elementaire. I.P.A.M., Paris.
A lso Cours myoen.
Marche-Marchad, J. Le monde vegetale en afrique in­
tertropicale. Editions de L'iEcole, 1 965.
Plummer, G. & White, D. J'observe et je cherche. Long­
mans 1 955. (Manual de Maitre seen.)
Salandre, H. & Cheyssac, R. Le�ons de chases tropi­
cales. Fernand Nathan, Paris.
Terrible, M. & Winkoun Hien, D. Vertebres et plantes
a fleurs de l'Ouest Africain; Invertebres et plants
sans fleurs d'Afrique; 2 bks. Editions de L'Ecole,
Par:s.
T H E I B P / CT S U RV E Y O F A RE A S O F S I G N I F I C A N C E
TO C O N S E RVATI O N
G . F. Peterken
Purpose of !BP I CT
"The establishment of the necessary scientific basis
for a comprehensive world programme of preserva­
tion and safe-guarding of areas of biological or phys­
iographical importance for future scientists." IBP I CT
is therefore not concerned with action, which is more
properly the responsibility of I.U.C.N. and National
bodies, except in so far as it will provide the informa­
tion on which action will be based.
The Survey
One of the major projects of IBP I CT is to collect
information about "IBP Areas" (defined below)
throughout the world by means of a Check Sheet.
The in-coming data will be stored on computer tape
Acta Phytogeogr Suec 54
and processed as required. When the survey is com­
plete, IBP I CT will possess a large quantity of infor­
mation about reserved areas and other areas of high
biological interest, which will be used:
1 . To prepare statements of the extent, nature and
contents of reserved areas as they are required for
any region-a single country, a continent, a biogeo­
graphical zone or the whole world.
2. To recommend areas not already reserved to
be considered for a programme of conservation ; of
these there will be two types:
(a) Areas forming adequate samples of the entire
range of ecological formations or ecosystems of
which a complete basic series should be safe-guarded
in the interests of science. An inventory of plant
Discussion
formations has been made for comparison with the
inventory of plant formations already adequately
safe-guarded.
(b) Supplementary areas, additional to the basic
representative samples of each ecological type, which
require to be safe-guarded on account of some ex­
ceptional interest, such as outstanding faunal and
floral features, or scientifically significant human im­
pact or use, including established use for scientific
research.
3. To act as the basis of an information service
to biologists and conservationists.
Numerous other applications may be envisaged.
To complete (2) above, IBP I CT requires a list of
areas already adequately safeguarded. This already
exists as the Liste des Nations Unies des Pares Na­
tionaux et Reserves Analogues (I.U.C.N., 1 967). This
List contains information from 1 3 6 countries and
lists 1 205 National Parks.
45
Timetable
The first Check Sheet was devised in 1 964 and
tested on a restricted scale. Subsequently, in 1 965,
the Mark Ill Check Sheet was tested in Antarctica,
Jordan, Malaya, Peru, Poland, U.K. and U.S.A.
With the experience of this trial before them, dele­
gates at the IBP I CT Technical Meeting on Require­
ments and Methods in Ecological Survey, held at
Monks Wood Experimental Station, England, in
March 1 9 66, considered and revised the Check
Sheet and fixed its general scope. The Mark VII
version has now undergone revision in detail and
was completed in May 1 967.
A G uide to the Check Sheet has been produced as
a small book and issued to all field surveyors. It is
designed to facilitate the work of field surveyors
and will incorporate information which will enable,
say, botanists to complete those sections outside their
subject, e.g. freshwater, fauna! features. It was
published in December 1 967 as IBP Handbook No. 4 .
!BP A reas
Organisation
One Check Sheet will be completed for each IBP
Area: an IBP Area is an area of significance from
the standpoint of biological research and conserva­
tion. In practice there will be four types of IBP
Area, namely
The Nature Conservancy's Biological Records Centre,
Monks Wood Experimental Station, England, will
organise the collection of information and undertake
the processing of data in colla!boration with the Smith­
sonian Institution, Washington. In each country it
will be necessary to have a national organiser who
will ensure that all suitable areas are surveyed and
that there is no duplication of effort. In those coun­
tries which possess a National Committee for the
IBP, this committee will act as national organiser, but
in other countries it will be necessary to find a
scientist prepared to act in this capacity. In Africa,
Ghana, Nigeria, Rhodesia and South Africa have
established National Committees and a number of
other countries have IBP correspondents. Generally,
it is expected that field surveyors · will normally be
scientists already familiar with the IBP Area they
survey.
1. Those included in the U.N. World List.
2. Those considered for inclusion in the U.N.
World List, but rejected. (These are listed separately
in the published List.)
3. Areas of some official conservation significance,
but not in (1) or (2) above.
4. Areas of biological interest, but of no official
conservation significance whatsoever.
Many National Parks will be too large and vari­
able to be covered by one Check Sheet. These will
be divided into two or more IBP Areas at the con­
venience of the field surveyor.
D I S C U S S IO N
Keay welcomed the choice of conservation of vegetation as
the topic for the A.E.T.F.A.T. symposium, particularly be­
cause so much of the activity for conservation in Africa is
by those whose main interest is the larger mammals. He
referred to the degradation of vegetation caused by animals
in African national parks and game reserves. He advised that
A.E.T.F.A.T. should exercise its special competence to say
which areas should be conserved because of their vegetation
and the plants species they contained. He proposed handing
to Dr. Peterken (LB . P.) a set of the papers on conservation of
vegetation in each country which had been prepared for the
meeting. Dr. Peterken would then get in touch with each
author and invite him/her to complete LB.P. Check Sheets
for each area considered worthy of inclusion in the list of
sites being prepared by I.B.P.
Morton: The main problem as I see it is not deciding on
areas which should be conserved, nor even of getting the
necessary legislation passed in the various countries-but
rather of enforcing it. Countries like Sierra Leone just have
Acta Phytogeogr Suec 54
46
Discussion
not the economic resources to staff and maintain these con­
served areas. Unless financial and technical help is forthcom­
ing from outside our efforts will be in vain and amount to
little more than pious hope.
Aymonin: Depuis que l'U. I.C.N. a entrepris son action inter­
should pass such a resolution about the need for the con­
servation of vegetation, but he did not think a resolution
would accomplish anything. It would be much more useful
for A.E.T.F.A.T. to give specific botanical advice about the
areas in need of conservation. He recognised that action­
legal and protective-to conserve vegetation was a matter for
each country to do for itself, and that international action
by A.E.T.F.A.T. would be most effective if channelled
through I.B.P. and I.U.C.N.
nationale, et aussi depuis la publication de 1' Atlas des Re­
serves ( « Derniers Refuges », 1956), is semble qu'apparaisse
une evolution nette dans !'esprit des promoteurs de la Pro­
tection de la Nature. Le programme actuel vise a organiser
la « Conservation de::- ressources naturelles » .
S i l'on a chercbe au debut a assurer l a survie d'une espece
(il s'est agit surtout des animaux qui ont souffert d'extermi­
nations impitoyables au cours des deux derniers siecles et
encore de nos jours), on a pris neanmoins conscience au­
jourd'hui que les mesures de protection trap exclusives pou­
vaient conduire a des resultats catastrophiques.
11 parait done tres souhaitable que !'action de l'A.E.T.F.
A.T. puisse se faire dans cet esprit nouveau mis en relief par
le Prof. Dorst ( « Avant que Nature meure » ), esprit qui
preside a certains des travaux du cadre du P.B .I.; it faut
prendre en consideration d'une maniere tres stricte les no­
tions de biocoenoses et d'ecosystemes pour mettre en oeuvre
des mesures de protection qui puissent veritablement respecter
les lois des " equilibres naturels )) sans !'existence desquels
tout essai de conservation des communautes biologiques ter­
restres risque d'etre voue a l'echec.
L'action de l'A.E.T.F.A.T. peut done, comme le souligne
M. le Prof. Monad, s'averer tres utile pour orienter les
autorites competentes, ceci en tenant compte a la fois des
problemes lies a l'endemisme vegetal et de !'existence des
ilots phytogeographiques remarquables. Les propositions a
faire doivent se referer evidemment au cadre de protection
existant, au mains theoriquement, actuellement, doivent etre
etayees par des faits presentes dans un ordre d'urgence ou
d'importance, et ne pas etre trap ambitieuses pour qu'elles
soient prises en consideration par des organismes supra­
n ationaux.
Osmaston: A clear distinction must be made between the
Keay: In order to assist in obtaining funds for conservation
Keay replied that he believed international funds (I.U.C.N.)
to be available for those areas which are immediately
threatened. He advised that priorities should be determined
and asked if A.E.T.F.A.T. could say which were the areas of
vegetation most in need of conservation on account of their
plant life. He recognized that in each country botanists
would wish to conserve an example of each vegetation type,
but that some of these sites would-on a pan-African view­
be more important than others.
Jaeger: Il parait indispensable, dans l'etat actuel des condi­
tions administratives et financieres, de confier la protection
du massif des Monts Loma a un organisme international, la
Sierra Leone ne pouvant a elle seule faire face aux neces­
sites du maintien d'un grand pare naturel.
Curry-Lindahl suggested that a resolution should be passed
to the African governments.
Keay would not oppose the suggestion that A.E.T.F.A.T.
basic importance of a particular site or vegetation type, and
its current priority as determined by the dangers to which it
is at present exposed. As one of those who expects to have
to complete some check sheets for hitherto unprotected I.B.P.
areas, I feel that the Association in whose name the recom­
mendations will be made, should provide some guidance as
to what are reasonable sizes and numbers to recommend so
as to secure uniformity of treatment, to avoid wasting our
time, and to avoid excessive lists being submitted, which
might prejudice the cause of conservation.
Goodier: I think it is important to recognize the stages that
must necessarily be passed through before the aims of con­
servation can be achieved.
In the first place there is the stage of the definition of
areas worthy of conservation. This is the stage that the
organisation (A.E.T.F.A.T.) can profitably consider at this
meeting, as it will lie within the sphere within which it is
competent.
The second stage is the choice of areas to be conserved­
here practical and sociological considerations are just as
important as the biological so that this stage must deserve a
wider consideration than can be achieved at the meeting.
The third stage is of course the management of such areas
so that the aims of conservation are attained.
in the various countries of Africa it will be necessary to
recognize priorities. Each country's contributor has listed the
sites in his country which require conservation and A.E.T.F.
A.T. should generally endorse these lists. However, the pres­
ent meeting, which comprises a widely representative and
highly expert group of botanists should try to prepare a quite
short list of sites of great botanical importance on a pan­
African level which are in very urgent need of conservation.
Wild: The request for one priority for each country in the
hope of getting outside assistance, financial and otherwise, is
still too wide to produce the best effect. Some countries are
well advanced in conservation, e.g. S. Africa and Rhodesia,
and outside financial support is neither necessary nor likely
to be given. The governments of these countries can and
probably will accept our recommendations when it is known
what they are. In other countries such as Bechuanaland and
the Sudan, etc., the need is desperate and our strongest
recommendation for outside assistance should be confined to
these.
Monod: Le moment serait d'autant mieux choisi pour une
Osmaston: I agree with this. For example in Uganda exam­
ples of most of the important types of vegetation are already
protected, some well, others moderately or temporarily, so
that the cases of highest current priority are mostly of less
fundamental importance but in serious danger of destruction.
intervention de l'A.E.T.F.A.T. aupres des Etats africains que
la Convention de Londres de 1933 sur la protection de la
faune et de la flare est actuellement en cours de refonte com­
plete, et que la nouvelle redaction doit faire leur place
legitime aux donnees ecologiques.
Goodier: I should like to add my support to Dr. Keay's
proposal. It is essential that proposals for conservation are
based on the existing knowledge of areas that merit conserva­
tion. There may of course be other areas of comparable
Acta Phytogeogr Suec 54
Discussion
importance that are as yet little known but these of necessity
must be given lower priority until a survey of their potential
can allow a definite proposal to be made.
Milne-Redhead: I should like to support Dr. Keay's sugges­
tion that for each territory this meeting should submit one
case of wider than national merit for conservation.
Trochain: 11 faut rappeler la technique suivie en Republique
Centrafricaine. Les Reserves naturelles integrates sont incluses
dans des Pares nationaux qui les entourent et les protegent.
Ces Pares eux-memes sont au sein de vastes Reserves de
chasse. Ainsi, des ceintures de territoires ou la protection
est de plus en plus stricte se succedent concentriquement.
De plus, et tout au mains du temps de la presence fran<;:aise,
des gardes assermentes assuraient le respect des reglements
edictes.
On doit emettre le vceu que ces diverses mesures conserva­
toires soient maintenues avant que soient delimites de nou­
veaux perimetres a proteger.
Cusset: La protection de la nature ne peut etre efficace
qu'a condition qu'elle soit pleinement appuyee par les Gou­
vernements des pays eux-memes. Je pense devoir signaler
qu' actuellement le Ministre de !'Education Nationale de la
Republique du Congo, Monsieur L. Makany et le Ministre
des Finances du Cameroun, Monsieur Vroumsia Tchinaye,
sont Docteurs en Botanique tropicale et qu'ils seraient pro­
bablement disposes a soutenir les vceux que pourrait emettre
l'A.E.T.F.A.T. 11 serait, sans doute, bon que ces vceux soient
adresses a ces hautes personnalites.
Kerfoot: Despite the suggested attention to priorities in
African territories, I would strongly urge that acquisition of
representative specimens from areas most nearly threatened
now, be undertaken by all field workers in the territories
concerned. The direction of botanists, ecologists, etc., should
be focused on these areas and herbaria should act accord­
ingly. University expeditions should also be guided along
these lines, and instead of re-collecting in comparatively well­
known habitats, or habitats more widely distributed in Africa,
break new and in some cases unique botanical ground which
may be, and often is, highly vulnerable to pressures of
domestic stocks, population increase, etc. This is particularly
true of riverine and montane (drier) habitats in East and
South Central Mrica.
Agnew: I would put forward a plea for more research on
plant population dynamics. Until we have such information
we cannot competently advise upon necessary areas or popu­
lations which are required for conservation of any given spe­
cies, especially in low density populations such as tropical
low altitude forest and in the families Orchidaceae and
Asclepiadaceae.
41
Leonard: Je profite de !'expose de Mr. Curry-Lindahl pour
attirer, une nouvelle fois, !'attention sur un grave danger qui
menace l a vegetation, la ou precisement on la croyait pro­
tegee.
11 a ete constate, dans certains Pares Nationaux, qu'apres
quelques dizaines d'annees de protection integrate, l'enorme
multiplication de certains animaux (buffles, hippopotames,
elephants, etc.) avait entraine une catastrophique degrada­
tion de la vegetation. L'ouvrage du Comte Claude Cornet
d'Elzius1 est edifiant a ce propos et montre que la creation du
Pare National Albert au Congo a entraine la degradation o u
meme l a quasi-disparition de l a vegetation s u r d e larges
etendues. 11 semble done indique que, profitant de cette
reunion consacree a la protecion de l a vegetation, les bota­
nistes soulignent le danger occasionne a la vegetation par des
rnises en reserve trap integrates de la Nature. 11 ne faut pas
favoriser la faune au detriment de la flare!
Ce ne sont pas les quelques personnes qui cueillent des
fleurs qu'il faut arreter, mais certains animaux trap nombreux
qu'il faut avoir le courage de supprimer!
Aymonin: 11 faut souligner que le fait qu'en certains terri­
toires equatoriaux ne semblent pas --; justifier apparemment
des mesures de protection, n'elimine en rien la necessite de
prendre conscience (meme pour des zones non menacees)
des problemes qui doivent ou devront necessairement etre
pris en consideration pour etablir un cadre de Reserves
Naturelles biologiques independemment des Reserves orien­
tees (Pares Naturels, reserves de chasse, etc.). 11 semble
qu'il etait du role d'une reunion de botanistes africanistes de
dire, apres avoir pris connaissance de !'ensemble des rap­
ports regionaux, quels sont les points essentiels qui doivent
etre retenus en vue d'une action vers la Protection des sites
botaniques et des ressources vegetales, et quels sont, eventuel­
lement, les ordres de priorite, a l'echelle africaine, c'est-a­
dire quels sont, en Mrique, a Madagascar et dans les groupes
d'tles peripberiques, les dix ou vingt sites botaniques les plus
remarquables, les groupes de vegetaux meritant le plus une
protection absolue dans le contexte mondial. Les points de
comparaison ne manquent entre les problemes poses aux bo­
tanistes par Aldabra et Socotra et ceux poses aux zoologistes
par les Galapagos; a l'echelle de toute l'Afrique, et du monde
entier, l'extraordinaire originalite des formations vegetates a
Welwitschia, de celles a Sene<;:ons geants, de celles a
Euphorbes candelabres, de celles a Did'iereacees n'echappe a
personne,
de
meme
qu'apparait
parallelement
tout
l'interet biologique que peut presenter une foret dense
intacte telle celle d'u Gabon. De tels points sembleraient
devoir etre des guides pour effectuer un choix.
1
Comte Claude Cornet d'Elzius: Evolution de la vegeta­
tion dans la plaine au sud du Lac Edouard, Institut des
Pares Nationaux du Congo et du Rwanda, 23 p., 4 pi ., 1
carte, Bruxelles, decembre 1 964.
Acta Phytogeogr Suec 54
Zone Sahelienne
LA M AU R I T A N I E
J. G. Adam
G EOGRAPHIE
Situee a l'Ouest de l'Afrique tropicale, la Mauritanie est
limitee au Nord par le Rio de Oro, le Maroc et l'Algerie,
a l'Est par le Mali, au Sud par le Senegal et a l'Ouest par
l'Ocean Atlantique.
D'une superficie de 1 086 000 km2 elle n'a qu'une po­
pulation de 1 000 000 d'habitants, ce qui fait une densite
moyenne de 1 habitant au km2•
Bile a 1 500 km du Nord au Sud et 1 200 km de l'Est
a l'Ouest dans ses plus grandes dimensions.
C'est un pays plat avec quelques regions accidentees
aux montagnes denudees peu elevees dont aucune n'at­
teint 1 000 m. Le point culminant de la Kedia d'Ijdil qui
est aussi celui de la Mauritanie est a 9 1 5 m, celui de
1' Adrar est a 830 . m et les cretes greseuses du Sud de
Tidjikja n'ont que 500 m.
Aucune riviere permanente n'existe, seul le Fleuve
Senegal qui lui sert de frontiere au Sud a de l'eau toute
l'annee. Quelques sources existent au pied des ravins en
montagne, mais elles sont tres rares.
Des depressions salees tres etendues voisinent le litto­
ral ou sont situees a l'interieur. Ce sont les Sebkras.
Les Regs, etendues caillouteuses ou gravillonneuses
et les ergs et autres dunes vives se partagent !'ensemble
du pays avec de grandes regions ou les sables sont plus
ou moins fixes.
La population est pour les 3/4 Maure (d'origine Ber­
bere et Arabe) et pour 1/4 de diverses ethnies (Peulh,
Soninke (Sarakole), Toucouleur, Bambara, Wolof).
LE CLIMAT
Le climat est sec et brfilant de Mars a Juillet, plus ou
moins humide et chaud de Juillet a Novembre, frais de
Decembre a Fevrier.
Il tombe chaque annee environ 300 a 400 m/m de
pluies de mousson d' Aout a Septembre vers le Sud. Ces
pluies diminuent s'espacent et meme ne sont plus regu­
lieres chaque annee vers le N ord oil elles disparaissent
presque completement. Les moyennes peuvent etre in­
ferieures a 1 0 m/m et elle ne tombent pas tous les ans.
4 - 6 8 1 557 Hedberg
Au Nord ces pluies de la mousson d'ete du Sud-Ouest
sont remplacees par les pluies d'hiver mediterraneennes,
mais elles sont peu abondantes et irregulieres chaque
annee.
Les temperatures sont extremes jusqu'a 50° en Mai
pour tomber a 3 ou 4 degres en Janvier-Fevrier.
TYPES DE VEGETATION
Cet immense territoire est principalement constitue de :
Steppes sahariennes depuis le Nord jusqu'aux envi­
rons de l'isoyete 1 50 (ligne reliant Nouakchott a Tid­
j ikja).
Prairies estivales ephemeres saheliennes de l'isohyete
1 50 jusqu'au Sud.
Prairies ephemeres (sahariennes Rbia ou Acheb) en
toutes saisons.
Steppes suffrutescentes a Chenopodiacees dans les de­
pressions salees.
Steppes sahariennes, elles sont herbeuses ou arbustives.
Aristida pungens occupe les dunes vives formees de sab­
les grossiers, il est souvent accompagne par Cyperus
conglomeratus, Moltkia ciliata, Indigofera semitrijuga.
Le Panicum turgidum prefere les sables fins fixes; de
nombreux genres l'accompagnent : Aristida, Farsetia,
Linaria, Aerva, Fagonia, Pergularia dont aucun n'est
exclusif de cette formation.
Les arbustes et petits arbres sont principalement
Acacia ehrenbergiana, Zizyphus nummularia, Boscia sene­
galiensis, Maerua crassifolia.
Les prairies estivales sont constituees par des plantes
annuelles, principalement des graminees dont les plus
banales sont Schoenefeldia gracilis, Aristida funiculata,
Aristida mutabilis, Aristida adscensionis, Latipes senega­
lensis, Cenchrus bifiorus, Tragus racemosus. D'autres
familles sont presentes avec les genres suivants : Alysi­
carpus, Borreria, Cassia, Chrozophora, Cleome, Crota­
laria, Cucumis, Euphorbia, Gisekia, etc.
En general ces prairies sont arbustives ou arborees
avec Acacia raddiana, A cacia senega/, Combretum acu­
leatum, Balanites aegyptiaca, Zizyphus mauritiana.
Les prairies ephemeres sahariennes sont egalement
Acta Phytogeogr Suec 54
50
J. G. Adam
RIO DEL ORO
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S E N E G A L
constituees principalement de plantes annuelles. Les
plus courantes sont : Anastatica hierochuntica, Aristida
meccana, Morettia canescens, Zygophyllum simplex,
Linaria monodiana, Fagonia jo/yi, Centaurea pungens,
Seetzenia africana, Andrachne te/ephioi'des, etc.
Les Steppes suffrutescentes a Chenopodiacees. Elles
sont constituees de plantes vivaces buissonnantes sou­
vent charnues : Arthrochnemum glaucum, Salso/afoetida,
Sa/sola vermicu/ata, Nucularia perrini, Zygophyllum
fontanaisii (Zygophyllacee).
D'autres types de vegetation existent qui sont moins
etendus.
Par exemple les cuvettes marecageuses avec de l'eau
presque en permanence avec Typha australis, les rebords
rocheux des plateaux a Achyroc/ine glumacea, Gail/onia
reboudiana, He/iotropium rarifolium, les sols inondes de
la vallee du Senegal avec ses fon�ts d'Acacia nilotica et
ses prairies aquatiques d' Oryza barthii, les ravins ro­
cheux a vegetation temporaire qui n'apparait qu'apres
plusieurs pluies avec Senecio flavus, les plateaux rocheux
a Aristida foexiana, les argiles salees a Sporobo/us
tourneuxii etc.
Nous ne parlerons pas de l'Assaba et de l'Affole,
deux massifs montagneux situes au Sud Est de la Mauri­
tanie qui n'ont pas encore fait l'objet d'etudes bota­
niques detaillees mais d'ou des specimens interessants
pour ce pays ont ete rapportes : Khaya senegalensis,
Gyrocarpus americanus etc.
PLANTES DEJA PROTEGEES DANS
LE TERRITOIRE
Deux services administratifs se sont interesses a la
protection de la flore et a son evolution progressive en
Acta Phytogeogr Suec 54
i
a r / � n n � .s
/
i
Fig.
Ma uritanie.
emplacements des perimetres
ayant ete l'objet de textes de protec­
tions adm inistratives.
J.
=
1.
Mauritanie. Ce sont le service des Eaux et Fon�ts et
l'Institut Franyais d'Afrique Noire.
Le Service des Eaux ei Forets a surtout eu en vue de
fixer des dunes vives qui menayaient certains Centres
Administratifs ; c'est ainsi que depuis 1 952, 54 ha ont
ete clotures et proteges autour de Mederdra, et depuis
1 957, 42 ha a Moudjeria, 23 ha a Tamchakett, 1 3 ha a
Boutilimit.
Des resultats spectaculaires ont ete obtenus, les
arbres et arbustes sahaliens (Acacia, Balanites, Euphor­
bia) auparavant coupes et broutes ont repousse, les
gramines et plantes vivaces se sont developpees (Ari­
stida, Pergu/aria, Andropogon) mais depuis 1 963 aucune
subvention n'ayant ete donnee au territoire, les clotures
ne sont plus entretenues, les terrains sont revendiques
par les riverains et une experience de pres de 14 ans est
vouee a l'echec.
L'Institut Fran�ais d'Afrique Noire (I.F.A.N.) en
1 95 5 avec l'aide de l' UNESCO et du Bureau des sols
de 1' Afrique Occidentale Franyaise a cloture aux en­
virons d'Atar, 44 ha en 7 parcelles representant les 7
principaux Biotopes de l'Adrar. Le but de cette ex­
perience etait de suivre !'evolution de la Vegetation
lorsque celle-ci est a l'abri des depredations humaines
et des animaux domestiques. Des comptages ont ete
effectues des la protection et des observations de detail
se font irregulierement.
Les 7 principaux Biotopes et les plantes qui les
caracterisent sont les suivants :
Sables sur ca/caires a Jatropha cheva/ieri et Schouwia
purpurea
Reg ensab/e a Zizyphus nummu/aria et Maerua crassi­
folia
Grara limoneuse a herbes annuelles (Aristida meccana ,
Mali
Cenchrus bzflorus, Euphorbia calyptrata, Schoenefeldia
gracilis.
Rochers calcaires a Aristida hirtigluma, Aristida
papposa, Elionurus royleanus, Eremopogon foveolatus,
Helianthemum lippii.
Grara limoneuse (Biotope voisin du N° 3) a Aristida
funiculata, Aristida meccana, Cassia italica, Chloris
lamproparia, Convolvulus fatmensis, Launea glomerata,
Matthiola maroccana . . .
Dunes fixees a Panicum turgidum, Chrozophora
brocchiana, Euphorbia scordifolia, Monsonia nivea,
Polygala obtusata, Morettia canescens.
Dunes vives a Aristida pungens, Cyperus conglomeratus
Moltkia ciliata, Indigofera semitrijuga, Asthenantherum
forskalei.
Malheureusement pour les parcelles de l'I.F.A.N.
aucune subvention pour l'entretien des cl6tures n'ayant
ete accordee depuis plusieurs annees, celles-ci sont en
mauvais etat, le gardiennage laisse a desirer, les chevres
vont pacager dans les enclos et aucun resultat vraiment
precis ne peut etre enregistre maintenant.
En plus de ces essais de protection integrale de la
vegetation qui disparaissent par manque d'entretien et
de surveillance, le service forestier a reserve de nom­
breuses superficies qui sont en principe soustraites a
certains usages degradant la Vegetation : cultures, feux,
mais la aussi la surveillance est pratiquement inexistante.
Quelques pare-feux sont desherbes lorsque !'incinera­
tion est deja faite et il n'y a pratiquement aucun resultat.
51
COMMUNAUTE S ET ESPE CES
DE PLANTES A PROTEGER
Nous pensons qu'il est inutile actuellement de proposer
de nouveaux perimetres de protection de la flore s'il
n'est pas possible d'assurer la protection des essais
precedents. Les immensites desertiques loin des agglo­
merations n' ont rien a craindre des mefaits des hommes
et des animaux domestiques et sont naturellement
protegees.
Par contre nous pensons que le maintien des 5 groupes
de parcelles serait utile. La remise en etat des cl6tures
etait estimee par le Chef du Service des Eaux et Forets,
au l er Janvier 1 966, a environ 35 420 dollars pour les
22 500 m de cl6tures pour les dunes a fixer a Mederdra,
Moudjeria, Tamchakett, et Boutilimit.
Les 7 parcelles I .F.A.N. d'Atar ont au total un
perimetre de 5750 m. En se basant sur Je meme prix que
celui propose pour la remise en etat des parcelles des
Eaux et Forets, le montant serait de 9050 dollars.
La remise en etat reviendrait done a : 44 470 dollars.
Si un organisme scientifique international etait
pressenti pour subventionner la remise en etat des
cl6tures il exigerait vraisemblablement de la part du
territoire interesse un minimum d'effort au moins dans
]a surveillance effective des parcelles et le sanctionne­
ment des delits par les riverains.
Mais c'est la !'aspect materiel de la protection que
nous ne faisons qu'aborder ici.
MALI
P. Jaeger
De toutes les anciennes possessions fran<;aises d'Afrique
Occidentale, la Republique du Mali est celle qui occupe
la superficie la plus vaste. Cet Etat s'etend sur pres de
quinze degres de latitude depuis le parallele de l'Eglab en
plein Sahara jusqu'a proximite de celui de Conakry en
Guinee; et dans le sens de la longitude on le suit depuis
le meridien de Kayes sur le Senegal jusqu'aux regions
desertiques qui s'etalent entre l'Adrar des Iforas et
l'Air, soit du 1 2° Long. W au 4° Long. E. Le Mali
couvre en effet I 500 000 km2 ; seul le Niger avec ses
1 247 000 km2 peut entrer en competition avec lui.
LE CLIMAT
En raison de son etendue dans le sens de · la latitude le
Mali jouit de toute une gamme de climats qui, comme
les paysages vegetaux, se succedent regulierement du
Nord au Sud : climats saharien, sahelien et soudanais.
Ce dernier qui seul nous interesse ici, est caracterise par
deux saisons alternativement seche et humide.
La saison seche qui, suivant la latitude, dure de 4 a 7
mois, se subdivise en une periode fraiche, agreable et en
une periode chaude, penible.
La periode fraiche correspond aux mois de decembre­
janvier; a ce moment la courbe thermique accuse le
minimum le plus bas de l'annee : + 1 1 o4 a Bamako, + 3 °
a Nioro (janvier).
La periode chaude correspond aux mois de mars­
avril-mai et les rigueurs de cette saison (40°-45°) sont
dues en grande partie a l'Harmattan, vent continental,
sec et chaud, qui toute l'annee durant souffle en direc­
tion Est-Ouest, a cette difference pres qu'en saison
Acta Phvtogeogr Suec 54
52
P. Jaeger
pluvieuse il circule en altitude cedant sa place a la
Mousson.
L'Harmattan est un des ·elements les plus typiques du
climat soudanien, et selon Richard Molard on com­
prendrait difficilement la repartition des croutes
ferrugineuses, la distribution des paysages vegetaux et,
partant, la plupart des faits humains et meme econo­
miques sans faire appel a l'Harmattan.
La saison pluvieuse est une saison fraiche et agreable ;
aout est le mois le plus arrose (387 a 400 mm a Kita),
mais aussi le moins chaud, le minimum estival etant
cependant moins accuse que celui de decembre-janvier.
LES ZONES DE VEGETATION
Aux zones climatiques correspondent les zones de vege­
tation, elles aussi disposees regulierement dans le sens
de la latitude. Du nord au sud on distingue : les do­
maines Saharien, Sahelien et Soudanien; ce dernier est
susceptible d'etre subdivise en secteurs :
secteur Soudano-sahelien (500 a 700 mm de pluie)
secteur Soudanien proprement dit (700 a 1 000 mm)
secteur Soudano-guineen (1 000 a 1 500 mm)
Dans le secteur Soudano-guineen, le plus arrose, le
tapis vegetal est constitue par une savane arboree a
strate gramineenne fermee qui, periodiquement, livre
passage aux feux de brousse. Les arbres eparpilles dans
la nappe herbacee, sont a feuilles caduques, leurs troncs
sont rarement droits, mais le plus souvent tortueux ou
rabougris et toujours marques par le feu.
Au Karite (Butyrospermum parkii) arbre caracteris­
tique du Soudan, s'associent des essences comme :
Terminalia macroptera, Pterocarpus erinaceus, Cordyla
africana, Parkia biglobosa, Daniellia oliveri, Khaya
senegalensis, etc., particulierement dignes d'interet sont
les especes gregaires comme Isoberlinia doka, Monotes
Kerstingii ou celles a affinites guineennes comme :
Lophira lanceolata, Erythrophleum guineense, Antiaris
africana, Carapa procera, Trema guineensis, etc. Les
cours d'eau sont jalonnes de galeries forestieres, le plus
souvent abimees; elles prolongent celles beaucoup plus
riches et plus importantes qui sillonnent les savanes
guineennes : Mitragyna inermis, Dialium guineense,
Pandanus candelabrum, Diospyros mespiliformis, Ptero­
carpus santalinoides, etc.
SITES, GROUPEMENTS ET ESPECES
A PROTE GER
Dans la region soudanienne du Mali les mouvements de
relief sont peu importants. Le voyageur est frappe par
des paysages d'une grande monotonie, « d'une grande
horizontalite d'ensemble ». Attirons cependant l'attenActa Phytogeogr Suec 54
tion sur le Plateau Soudanien. Par son extremite sud­
ouest il s'articule au Fouta-Djallon; vers le nord-est,
dans la boucle du Niger, il se termine par les pitons de
Hombori. Les sommets plats, proteges par une epaisse
cuira,sse ferrugineuse, n'atteignent que 600 a 620 m dans
la region de Kita, les pitons de Hombori, par contre,
depassent 1 000 m.
Ce plateau a soubassement greseux d'age cambro­
ordovicien, a ete fracture par des mouvements de fond,
disseque par !'erosion fluviale et ainsi se sont constitues
ces collines et buttes-temoins a silhouette etrange que
l'on aper9oit de la voie ferree entre Kayes et Bafoulabe.
Ces bastions rocheux, partiellement ou entierement
debarrasses de leur couverture ferrugineuse, haches de
diaclases, sculptes et burines par !'erosion, condition­
nent une diversite considerable de !'habitat, une serie
variee de microclimats et, partant, une gamme de
groupements vegetaux aux exigences ecologiques les
plus varies. De plus, ces massifs, abrites au moins
partiellement des feux, grace a de nombreux seuils
rocheux, ont donne asile a tout un cortege d'especes
relictuelles . Ainsi, ces rochers, comparables a de veri­
tables musees ou archives, recelent une documentation
du plus haut interet, susceptible de nous renseigner sur
l'histoire de la flore et par la sur les oscillations clima­
tiques de ces regions de 1' Afrique Occidentale.
Les forets relictuelles a Kololo
Le Gilletiodendron glandulosum (Port.) J. Leonard ou
Kololo est une Cesalpiniacee endemique du Mali. Son
aire de repartition s'inscrit a l'interieur d'un vaste
triangle dont les sommets sont marques par les lo­
calites de Kita-Bafoulabe-Kenieba. La region de
Kita-Toukoto en raison de l'abondance des peuple­
ments fait figure de centre de gravite. L'arbre ne se
rencontre que dans des milieux nettement definis par
leur topographic; ce sont des bosquets, des lambeaux,
des ilots forestiers blottis au fond des ravins, dans des
cirques rocheux, en contre-bas des corniches greseuses,
etc.
Cette essence surprend par son etonnante fertilite.
Loin d'etre atteint d'une mysterieuse senescence, elle
fleurit abondamment en juillet et ses gousses glandulo­
pustuleuses, uniseminees, arrivent a rnaturite en janvier­
fevrier. Le pouvoir germinatif des graines est pratique­
ment de 100 % et les plantules font preuve d'une
extraordinaire vitalite.
En depit de ces nombreux avantages l'arbre s'avere
incapable de conquerir de nouveaux espaces ; il est
litteralement prisonnier de son biotope rocheux. Des
1939 A. Aubreville a signale !'extreme sensibilite au feu
de cette Cesalpiniacee et c'est la raison pour laquelle
elle n'a pu se conserver qu'a l'abri des seuils rocheux
qui lui assurent une protection efficace. Ainsi se sont
Mali
constitues et maintenus jusqu'a nos jours ces Hots­
refuge de Kita, de Toukoto, de Kenieba, oil nous
contemplons les derniers survivants de cette paleoende­
mique qui, jadis a du constituer des peuplements bien
plus etendus.
L'Administration fran<;aise, soucieuse de transmettre
a la posterite cette Cesalpiniacee unique au monde, a
deja, en son temps, mis sous protection les peuplements
de Kololo ; et cette decision, fort heureusement, fut
maintenue par le gouvernement malien. Peuplant des
espaces impropres a toute culture, la conservation des
bosquets de Kololo ne saurait freiner en rien l'activite
du paysan malinke, bien au contraire, la presence sur
son territoire d'une espece relictuelle, de restes d'an­
ciennes forets qui n'existent nulle part ailleurs au monde,
ne peut que rehausser le prestige et meme l'interet
touristique qui s'attache a ce coin de la terre d' Afrique.
En meme temps que le Kololo d'autres especes in­
feodees a ces collines, meritent d'etre prises en con­
sideration en raison de leur valeur documentaire; ce
sont des endemiques, des vicariantes, des especes
attardees au-dela des limites actuelles de leur aire, des
saxicoles imprimant a ces rochers leur physionomie
particuliere soit tout un cortege de plantes susceptibles
de marquer ces « stations-types » que sont les bastions
greseux soudanais. Citons des endemiques comme
1'Elatine fauquei, herbe aquatique decouverte par Th.
Monod dans les rochers humides du vallon de Balasokho
pres de Bamako, 1' Otomeria tenuis (Batopedina tenuis)
des corniches greseuses de Banfora-Sindou (Haute
Volta), le Tee/ea sudanica ( Vepris heterophylla) signale
jadis par A. Chevalier et puis par Duong Hu Thoi dans
les escarpements du plateau mandigue et dont l'ende­
micite a la suite des recentes decouvertes de R. Letouzey
et de J. Raynal, doit etre etendue au Cameroun.
Non moins interessant est le cas de l'Acridocarpus
monodi, espece vicariante nouvellement decrite qui, dans
les ravins de Douentza (Kikara) colonise les memes bio­
topes rocheux, quoique plus arides, que l'Acridocarpus
chevalieri dans les crevasses et couloirs rocheux de la
colline de Kita, ou celui du Senecio cliffordianus, espece
d'Abyssinie qui, dans la boucle du Niger (region de
Douentza-Hombori) atteint sa station la plus avancee
vers I' ouest.
Notre attention est aussi retenue par de nombreuses
especes a affinites meridionales qui, dans les collines du
Soudan occidental occupent des stations situees bien
au-dela des limites septentrionales de leur aire de repar­
tition. C'est le cas du Streptocarpus nobilis, Gesnereacee,
53
abondamment representee dans les bosquets de Kololo
pres de Oualia au NW de Kita; i1 en est de meme d'un
peuplement dense· d'Erythrophleum guineense accroche
aux parois greseuses de l'ergot rocheux de Ouoro-Kou­
rou proche de la colline de Kita; ou du Calyptrochilum
christyanum, Orchidee dont nous ne connaissons qu'une
seule station limitee a une gorge du massif de Kita oil
elle vit en epiphyte dans la couronne d'un Cola cordifolia;
no us la suivons depuis 1 943 . Le Carapa procera est d'une
grande rarete dans le massif de Kita oil il se refugie dans
les ravins (Boudofo) . . .
Enumerons aussi quelques saxicoles infeodees aux
dalles et aux falaises et qui impriment a ces biotopes un
cachet particulier : Euphorbia sudanica, Steganotaenia
araliacea, Gyrocarpus americanus, Croton zambesicus,
Ficus lecardii, F. kerstingii, Tephrosia mossiensis, Com­
bretum nioroensis, Sarcostemma viminale, Adenium obe­
sum, Monechma ndel/ense, Hibiscus longisepalus, etc.
Particulierement attrayantes sont les mares temporai­
res sur gres que 1' on remarque dans des depressions ou
cuvettes du substrat rocheux : sur la dalle aride et nue,
elles apparaissent comme autant d'enclaves, souvent
minuscules, mais richement :fleuris en saison pluvieuse;
c'est la que le Dopatrium senegalense avec ses :fleurs pour­
pres, joue la note dominante; de ce meme groupement
hygrophile font partie des especes comme : Eichhornia
natans, Nymphoides indica, Marsilea sp., Isoetes me/ana­
theca, Aeschynomene sp., Hygrophila senegalensis, Mono­
choria vagina/is, Cyperus podocarpus, Eleocharis fistulosa,
Lipocarpha triceps, Pycreus capillifolius, Oryza brachyan­
tha, Parahyparrhenia jaegeriana, Echinochloa colona,
etc. En saison seche par contre, ces vasques fieuries ne
sont plus que des taches de sable marques par des debris
herbaces desseches dont l'aridite ne le cede en rien a celle
de la dalle qui les enserre.
Au meme titre que la foret relictuelle a Kololo toutes
ces especes, et le milieu qu'elles habitent, reclament notre
sollicitude. Mais s'il parait relativement aise d'obtenir
des gouvernements, toujours comprehensifs, des decrets
assurant la protection de sites naturels et, par voie de
consequence, celle des especes qui y vivent, une telle
decision, si heureuse soit-elle, risque fort de rester lettre
morte si I' on neglige de convaincre !'indigene de l'utilite
et de l'urgence d'une telle mesure. lnfiniment mieux
qu'un texte de loi vaut la protection assuree par !'indi­
gene lui-meme, soit par un homme conscient des riches­
ses naturelles de son pays, conscient aussi de l'interet
qu'il y a a conserver aux generations a venir ce patri­
moine d'un prix inestimable. Mais c'est la affaire d'edu­
cation.
Acta Phytogeogr Suec 54
TCHAD E T SAH EL TCHAD I EN
H. Gillet
GEOGRAPHIE
Le Tchad est un immense territoire, l'un des moins
peuple d'Afrique : 1 284 000 km2 pour 2 700 000 habi­
tants, inega1ement repartis. Sa grandeur est a l'echelle
du continent africain, il couvre 20 degres de latitude
(du 8e au 24e) et 10 degres de longitude (du 1 4e au 24e).
A vol d'oiseau 800 km separent Fort-Lamy d'Adre,
suivant le principal axe Ouest-Est, mais 1 760 km se­
parent !'extreme Nord de !'extreme Sud.
Dans sa plus grande partie, le Tchad apparait comme
une vaste cuvette plate d'une altitude moyenne de 4 a
500 metres s'inclinant dans !'ensemble insensiblement
vers le Lac Tchad. Les reliefs sont localises vers le Nord :
Tibesti (341 5 m) et vers l'Est : Ennedi ( 13 00 m) prolonge
vers le Sud par les Monts du Ouaddai. D'importants
pointements granitiques parsement la region du Guera
(Abou Tolfan, Guera 1 800 m).
Seul le Sud connait des rivieres permanentes, toutes
drainees par le Chari et son affluent le Logo ne. Les oua­
dis du Centre et du Nord ne coulent que pendant la sai­
son des pluies. L'un des plus important est le Batha qui
alimente le lac Fitri.
Dans un pays aussi etendu en latitude, le climat pre­
sente de gran de variations du Sud au Nor d. Au Sud, le
climat est typiquement soudanais, caracterise par une
saison des pluies de 7 mois (debut avril a fin octobre) et
une saison seche de 5 mois. Dans la partie moyenne, le
climat est sahelien avec une saison des pluies qui dure
au plus 4 mois et une saison seche qui s'etend sur plus
de 8 mois. Au N ord du 1 8e parallele la saison seche
est pratiquement continue, interrompue seulement en
aout par quelques averses orageuses dont le nombre et
!'importance sont variables avec les annees.
La population vit de l'elevage du chameau dans la
zone Nord (Toubous), de l'elevage des bovins et des
ovins dans la zone sahelienne (Arabes), de !'agriculture
(coton, roil, arachide) dans la zone soudanaise (Saras).
TYPES DE VEG ETATION
Les facteurs climatiques commandent la repartition de
la vegetation dont !'aspect, la composition, la densite
dependent essentiellement de la quantite d'eau re9ue.
Les grandes zones climatiques et les. territoires phyto­
geographiques se superposent. Comme les isohyetes augActa Phytogeogr Suec 54
mentent regulierement du Nord vers le Sud, les change­
ments de flore sont progressifs et l'on passe insensible­
ment d'un secteur au suivant. Cependant en certaines
zones les isohyetes sont plus rapprochees et l'observateur
qui se deplace suivant un meridien constate alors des
modifications floristiques assez brutales. Ces bandes de
territoire correspondent a des frontieres climatiques et
il semble rationnel de les choisir comme bande fronta­
liere pour definir les principaux secteurs de vegetation.
L'apparition par exemple des champs de roil a chandelle
cultives a grande echelle entraine un changement pro­
fond du paysage et du genre de vie des habitants; i l
definit assez bien a notre sens l a separation entre l a zone
sahelienne et la zone soudanaise.
Le Sahara tropical
Sahara tropical. Au Nord du 1 8e parallele, les pluies
sont rares et insuffisantes pour entretenir une vegeta­
tion permanente. Elles se produisent en general en
aout mais des crachins et des pluies fines liees a des de­
pressions soudano-sahariennes peuvent intervenir pen­
dant la periode hivernale.
Les froids hivernaux favorisent la reprise de la vegeta­
tion et en particulier celle du « had » Monacantha tria­
cantha Del.
La vegetation est concentree surtout sur les dunes oil
dominent des peuplements a Aristida pungens L., tandis
que dans les creux de rares Indigofera semitrijuga Forssk.
et Aerva javanica (Burro. f.) Juss. ex Schult. se trouvent
a l'etat dissemine.
Sahara meridional. Entre le Sahara tropical et le Nord
Sahel s'intercale une zone oil les pluies sont faibles (30 a
1 00 mm) mais reviennent a peu pres chaque annee. Elles
sont apportees par !'extreme avancee du front intertropi­
cal. 11 n'en faut pas davantage poU:r qu'une florule com­
posee presque exclusivement de therophytes de petite
taille Ieve avec les precipitations sous forme d'un tapis
aere de petites plantes eparses. Le genre Tribulus a diffe­
rencie deux especes endemiques au Sahara meridional :
T. longipetalus Viv. et T. ochroleucus Maire.
La flore est une flore Nord sahelienne appauvrie dont
les principaux representants sont des ecotypes capables
en une duree tres limitee de fleurir et fructifier. L'appa­
reil vegetatif est reduit au strict minimum. Une telle
vegetation se developpe dans les sables du Mourdi. En
voici deux releves realises dans les conditions suivantes :
Tchad et Sahel tchadien
Localite : Mourdi entre 0. Matar et 0. Michero. Date : 9
septembre 1 964. Surface : 1 m2• Pente nulle. % de recouvrement
d u sol par la vegetation : 3 a 5 % .
Nombre Hauteur en cm
Especes
II
Requienia obcordata 2 8
Indigo/era sessili23
flora
Gisekia pharna10
cioides
5
Crotalaria thebaica
6
Aristida acutiflora
Danthonia Forsskaa!ii 2
Indigo/era semitrijuga 1
Tribulus terrestris
16
16
II
Phenologie
4 a. 5
5
boutons ftoraux
5
1,5
boutons ftoraux
8 2,5
3 3,5
8 11
9
1
fructifie
2
plantule
3
1 3 a 1 4 debut ftoraison
ftoraison
plantule
2
ftoraison
Dans une region ou il ne pleut pas forcement tous les
ans une flore composee de plantes annuelles a croissance
rapide semble plus apte a tirer parti d'une ondee qu'une
ftore perenne. C'est sans doute la raison pour laquelle
certaines especes ont differencie des ecotypes annuels :
Requienia obcordata (Lam.) DC., Aristida acutiflora Trin.
et Rupr.
Zone sahelienne
Le Sahel correspond a une region climatique bien definie
par l'alternance d'une tres longue saison seche (8 a 1 0
mois) e t d'une courte saison des pluies (2 a 4 mois). Les
pluies reviennent chaque annee pendant l'ete (juillet a
septembre). Chaleur et humidite sont deux facteurs
favorisant le demarrage subit de la vegetation. Le Sahel
prend alors un aspect verdoyant qui contraste singuliere­
ment avec !'aspect aride de la saison seche. La saison des
pluies est trop courte pour assurer le plein developpe­
ment de plantes cultivees, mais elle permet la levee de
paturages annuels tres apprecies du betail. Le Sahel est
la grande zone d'elevage du Tchad : chameaux et chevres
dans la partie Nord, bovins et moutons dans la partie Sud.
L'eau est le facteur limitant de la presence de l'homme
et du betail. En saison des pluies pasteurs et animaux
domestiques se dispersent, s'abreuvent aux mares; en
saison seche ils se concentrent autour de quelques rares
puits. De vastes etendues de paturages pailleux sont alors
inexploitees, faute d'eau, mais des Herbivores sauvages
qui possedent la precieuse faculte de pouvoir se dispenser
de boire peuvent y vivre et s'y refugier. Ce sont l'Oryx,
1' Addax, la Gazelle Dama et la Gazelle Dorcas.
Entre le Nord et le Sud les differences tant climatiques
que biologiques sont suffisamment marquees pour dis­
tinguer une zone Nord sahelienne ou Nord Sahel et une
zone Sud sahelienne ou Sud Sahel.
Nord sahelienne. Sur le plan climatique, il est relative­
ment facile de fixer au moins theoriquement les limites
de la zone Nord sahelienne par les isohyetes l OO mm au
55
Nord et 250 mm au Sud. Dans ce secteur il pleut chaque
annee suffisamment pour assurer le developpement de
therophytes specialises mais pas assez pour faire croitre
des phanerophytes, tout du moins en plaine. Le paysage
Nord sahelien est inarbore. Les arbres sont uniquement
concentres le long des voies d'ecoulement des eaux ou
dans les zones d'epandage.
La limite Nord du Sahel est assez bien marquee par
celle des peuplements importants de Cenchrus biflorus
Roxb., Graminee qui exige plusieurs ondees totalisant
au moins 1 00 mm pour parvenir a complete ftoraison en
epis bien degages. La limite Sud est ftoue. Au Sud le
Nord Sahel passe insensiblement au Sud Sahel. Les
changements les plus manifestes sont caracterises par
!'apparition d'abord sporadique puis generalisee des
arbres (Acacia raddiana Savi et Balanites aegyptia Del.).
Le Nord Sahel est le domaine du Panicum turgidum
Forssk. dont les touffes, separees les unes des autres
par un intervalle de plusieurs metres, se succedent d'Est
en Ouest sur des centaines de kilometres. Des que les
pluies depassent 300 mm le Panicum turgidum regresse.
Le Nord Sahel presente au Tchad deux types princip­
aux de -paysage : le reg pierreux et la steppe a Panicum
turgidum Forssk.
Regs pierreux : sans vegetation pendant la saison
seche, ils se couvrent les pluies venues d'un tapis herbace
ras (hauteur 1 1 a 1 5 cm) a base d'Aristidafuniculata Trin.
& Rupr.
Considere a la bonne epoque (debut septembre) et
observe de loin, le reg pierreux ressemble a une fine
prairie rase, mais vue de pres, celle-ci se resout en pieds
isoles d'Aristida chacun largement separe de ses voisins,
le recouvrement apparent de la vegetation etant de 7 a 9
%. L'Aristida est presque pur et intervient en nombre
d'individus pour plus de 90 %. Les autres especes sont
au second plan. De ci, de la on trouve Aristida mutabilis
Trin. et Rupr., Aristida papposa Trin. et Rupr. (sous une
forme annuelle), Mollugo cerviana (L.) Seringe , Era­
grostis tremula Hochst. ex Steud., Anticharis linearis
(Benth.) Hochst.
Steppe a Panicum turgidum Forssk. : les peuplements
de Panicum turgidum Forssk. installes sur les dunes du
Nord Sahel sont veritablement steppiques. Chaque
touffe de Panicum est nettement isolee, la densite de la
Graminee etant de l' ordre de 2 touffes pour 10 m 2 (2000
pieds/ha), l'intervalle entre les touffes est vide en saison
seche mais occupe en saison des pluies par des therophy­
tes lachement dissemines. Parmi les plus frequents
citons : Aristida mutabilis Trin. et Rupr., Tephrosia pur­
purea (L.) Pers. , Eragrostis tremula Hochst. ex Steud.,
Farsetia ramossisima Hochst. , Polycarpaea corymbosa
Lam. Indigo/era sessiliflora DC.
Reseau hydrographique : dans les regions subdeser­
tiques les eaux de pluie ne sont pas retenues par la vegeActa Phytogeogr Suec 54
56
H. Gil/et
,,
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1
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..... .....
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.....
..... .....
..... .....
..... .....
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)
20° 1-------i---=---------"'-;;;:----i 20°
. �
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S A H A R A
).
, ..._ _ } S U O S O U OA N I E N
10° 1---'-::------------,'---------i 10°
o FA
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Fig.
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Tchad. Secteurs phytogeographiques.
tation; le ruissellement est important. Les eaux se cana­
lisent dans les ouadis dont les crues sont souvent spec­
taculaires. Au Nord Tchad ils suivent la ligne generale
de la pente de la cuvette et sont orientes de l'Est vers
l'Ouest s'etirant ainsi souvent sur plusieurs centaines de
kilometres (0. Chili, 0. Saala, 0. Hawach, 0. Mafaze,
etc.). Par leurs affluents ils recuperent les eaux qui tom­
bent sur de vastes bassins versants et leurs rives restent
longtemps mouillees apres chaque crue. Ces conditions
sont favorables a !'installation d'une vegetation arboree
dense qui ne trouve son plein epanouissement qu'en
zone Sud sahelienne.
Les principales essences sont : Grewia tenax (Forssk.)
Fiori, Acacia Raddiana Savi, Acacia mellifera (Vahl)
Benth. , Balanites aegyptiaca (L.) Del. , Combretum acu­
leatum Vent. Meme la vegetation basse montre la meme
influence et les especes suivantes sont frequentes le long
de 1'0. Hawach : Bidens pilosa L. , Ipomoea kentrocarpa
Hochst. ex A. Rich . , Merremiapentaphyl/a Hallier, toutes
tres communes dans les cuvettes limono-argileuses du
Sud Sahel.
Vers le Sud, le Nord Sahel devient progressivement
Sud Sahel. Les arbres quittent le bord des oueds et se
repandent d'une maniere diffuse a travers la plaine. Le
changement de paysage s'opere de maniere insensible.
Les Acacia s'ecartent d'abord quelque peu des rives des
ouadis, puis apparaissent groupes a quelques-uns dans
les depressions, puis enfin appartiennent definitivement
au paysage.
Sud sahl?lienne. La zone Sud sahelienne se distingue de
Acta Phytogeogr Suec 54
la zone Nord sahelienne par sa couverture arboree. Les
arbres font partie integrante du paysage. Il y en a un
certain nombre sur chaque hectare de terrain. Les pluies
comprises approximativement entre 250 et 500 mm sont
suffisantes pour entretenir une vegetation ligneuse en
general sempervirente et une vegetation herbacee dense
pendant la saison des pluies, mais insuffisantes pour
assurer la fructification complete de plantes cultivees
telles que le Mil Penicillaire, le Sorgho ou 1'Arachide.
Elle correspond a un resserrement des isohyetes; en effet,
les pluies reviennent chaque annee avec une certaine re­
gularite et les variations interannuelles n'atteignent pas
!'amplitude enregistree en zone Nord sahelienne. C'est
une bande assez etroite dont la limite Sud est franche­
ment marquee par les champs de Mil et dont la limite
Nord se fond insensiblement dans la bande Nord sahe­
lienne. Sa largeur est au Tchad de l'ordre de 1 30 kilo­
metres.
La zone Sud sahelienne est le domaine de predilection
de l'elevage des Bovides qui, lorsqu'ils disposent d'une
alimentation hydrique assuree par des puits, peuvent
exploiter des paturages secs pailleux pendant toute la
saison seche. L'abondance et la richesse des herbes qui
levent avec les pluies attirent alors de nombreux trou­
peaux qui viennent en transhumance. Pendant la saison
des pluies elle est largement parcourue par les eleveurs
qui se deplacent de paturage en paturage. Les hommes
habitent dans des cases demontables qu'ils transportent
avec eux. Pendant la saison seche pasteurs et betail se
regroupent autour des points d'eau permanents et de
larges etendues de la zone sont momentanement delais­
sees.
La vegetation herbacee, au moment de sa plenitude
en aout-septembre, couvre largement le sol, qui n'appa­
rait pas visible, tout du moins en vision oblique. Vers
le Sud elle est organisee en plusieurs strates : une strate
basse plaquee sur le sol, une strate moyenne et une strate
de hautes Graminees annuelles ou perennes depassant
le metre de hauteur. La richesse aerale est nettement
plus importante que dans le Nord Sahel.
Au Tchad le Sud Sahel revet essentiellement l'aspect
d'une plaine sablonneuse. Le tapis vegetal herbace aug­
mente en densite du Nord vers le Sud. Le nombre des
especes a l'unite de surface augmente egalement.
Examinons la composition floristique de deux plaines
sablonneuses situees, l'une dans la partie Nord, l'autre
dans la partie Sud de cette bande Sud Sahelienne.
Plaine sablonneuse sur le parallele 1 5°40' : les Gra­
minees annuelles sont dominantes. La hauteur de la
couverture vegetale est de l'ordre de 30 cm, la strate
elevee manque. La vegetation annuelle est dense (sou­
vent plus de 400 pieds au m2) mais le recouvrement est
faible en raison de la tenuite de chaque individu dont le
poids est de l'ordre de 0,5 g en moyenne.
Tchad et Sahel tchadien
Voici un releve d'un tel tapis realise dans les conditions
suivantes :1
Lieu : a 1 00 metres du lit de 1'0. Kharma. Date : 26 aout
1 963. Surface : 1 m2 • % de recouvrement du sol par la vegeta­
tion : 1 0 % .
Especes
Nombre
Phenologie
Aristida mutabilis
Eragrostis tremula
Cyamopsis senegalensis
Indigo/era Hochstetteri
Indigo/era viscosa
94
1 65
68
13
40
Dacty/octenium aegyptium
Zornia diphylla
Fimbristylis exilis
Schoenefeldia gracilis
Cleome viscosa
Trianthema sp.
24
2
nombreux
2
1
1
fleuri
fleuri
fructifie
fructifie
fleuri et
fructifie
fructifie
fructifie
fructifie
plantule
plantule
plantule
Plaine sablonneuse sur le parallele 1 3° 54' (et 1 8°43'
de longitude) : Le tapis herbace annuel est plus fourni.
Le nombre d'individus plante recense sur un m2 est
moins eleve que dans l'exemple precedent, mais chaque
pied est plus vigoureux emettant a sa base plusieurs
tiges.
Le releve suivant illustre ce cas. 11 a ete realise dans
les conditions suivantes :
Lieu : Ranch de l'Ouadi Rime a 3 km de la bordure Nord .
Date : 5 septembre 1 9 6 1 surface : 1 m2 % de recouvrement du
sol par la vegetation : 20 % .
Especes
Nombre
Brachiaria dejlexa
Eragrostis tremula
Aristida mutabilis
Brachiaria distichophylla
0/denlandia senegalensis
Fimbristylis exilis
Phyllanthus pentandrus
Borreria radiata
Aristida stipoides
Monsonia senegalensis
Crotalaria microcarpa
Polycarpaea corymbosa
Euphorbia convolvuloides
Blepharis linariae/olia
22
66
9
10
9
1 74
6
5
4
4
4
2
1
1
Le poids de matiere vegetate est 295 g (2,950 T /ha) dont 90
g pour Eragrostis tremula, 55 g pour Brachiaria deflexa, 40 g
pour Crotalaria microcarpa et 1 1 0 g pour le reste.
La difference de poids pour l 'individu plante est tres accen­
tuee. lci, un pied d'Eragrostis tremula pese trois fo is plus lourd
que dans 1' exemple precedent ( 1 , 3 g contre 0,3 g) et un pied de
Legumineuse vingt cinq fois plus ( 1 0 g contre 0,4 g) .
La richesse areale est plus grande : 1 0 m2 ici contiennent 24
especes differentes contre 1 4.
1 Il est bien entendu que cet exemple et le suivant soot donnes
pour fixer Ies idees et qu'ils ne peuvent etre consideres d'une
maniere absolue pour caracteriser une vegetation dont la compo­
sition et le developpement varient beaucoup avec les stations et
les annees.
57
Ainsi done lorsqu'on se deplace du Nord vers le Sud
tout en restant dans la bande Sud sahelienne la vegeta­
tion change d'aspect. Le tapis vegetal se diversifie par
l'adjonction de nouvelles especes; en meme temps chaque
individu plante s'etoffe, et le poids de matiere vegetale a
l'unite de surface augmente. Plus que les facteurs speci­
fiques, les facteurs phenotypiques interviennent.
Bords des ouadis : les ouadis en raison de l'abon­
dance des pluies coulent d'une maniere continue pendant
le mois d'aout. Aussi la strate arboree n'est plus allongee
lineairement comme c'est le cas en zone Nord sahelienne
mais prend de !'extension de part et d'autre du cours; par
place d'epais fourres prennent de !'extension. Les prin­
cipales especes sont : A cacia Raddiana Savi, Acacia flava
(Forssk.) Schw., Balanites aegyptiaca (L.) Del., Ziziphus
mauritiana Lam., Grewia tenax (Forssk.) Fiori, Cordia
Rothii Roem. & Schult. , Bauhinia rufescens Lam., Bo­
scia senegalensis (Pers.) Lam. ex Poiret (0. Kharma).
Plus au Sud Tamarindus indica L . , Piliostigma reticula­
turn DC, A cacia ataxacantha DC. se melent aux especes
precedentes.
Dans l'eau Ipomoea aquatica L. est envahissant.
PROTECTION DE LA FLORE
La zone sahelienne s'etend au Tchad sur de tres vastes
surfaces, extremement peu peuplee en dehors de la sai­
son des pluies. En dehors de la vallee du Bahr el Gazal
de Moussoro a Koro Toro et des petits centres d'Oum
Chalouba et de Fada il n'existe pas de postes habites per­
manents et la plus grande partie du Sahel tchadien est
vide d'habitants. Aussi la protection de la flore se pose
avec moins d'acuite qu'ailleurs, tout du moins pour
l'instant. Mais a l'echelon local des destructions souvent
irreversibles sont deja a deplorer par deboisement et
surpa.turage.
Deboisement
Autour des centres le bois est activement recherche
comme bois de cuisine ou comme materiau de construc­
tion. La charge d'ane se vend 1 00 francs CFA a Fada et les
habitants doivent maintenant aller jusqu'a 1'0. N'Dou
25 kilometres) pour se ravitailler en bois de feu. Les
stipes de palmier et notamment d' Hyphaene thebaica
Mart. ont disparu du pourtour de l'Ennedi, partout oil
ils sont accessibles. Ils ont ete completement elimines du
Ranch de l'Ouadi Rime alors qu'il en existait deux petits
boqueteaux avant son implantation. Les gros arbres en
zone Sud sahelienne sont serieusement malmenes, les
Stereospermum Kunthianum Cham. sont mutiles. Les
Acacia (Raddiana, nilotica) sont elagues sans menage­
ment en vue de l'etablissement de haies de protection
(zeriba) pour le betail. Toutes ces deteriorations con­
duisent a un deboisement lent et progressif autour des
lieux habites.
·
Acta Phytogeogr Suec 54
58
H. Gillet
Surpaturage
Le surpaturage fait sentir ses effets partout oil un exces
de betail stagne sur une aire trop limitee. C'est ce qui
arrive fatalement autour des points d'eau pendant la
longue saison seche.
Le sol tasse en permanence par les sabots des herbivo­
res et recevant des dejections d'une maniere continue se
modifie dans sa structure et sa composition. La flore se
banalise. Quelques especes de peu d'interet adaptee a ce
milieu se multiplient : Gynandropsis gynandra (L.) Briq.,
Amaranthus graecizans L., Tribulus terrestris L., Trian­
thema pentandra L .
Disparition d 'especes
En zone Nord sahelienne toute l'economie du pays,
basee sur l'elevage nomade, est fonction de la quantite
de pluie tombee pendant la saison. Or celle-ci est variable
d'une annee sur l'autre. 11 y a les bonnes annees, celles
oil il pleut beaucoup en aout, celles oil les paturages
seront fournis et les reserves d'eau suffisantes, et les mau­
vaises annees, celles oil le paturage est rare et maigre et
les puits et les puisards rapidement epuises. Alors les
troupeaux se concentrent autour des rares points d'eau
permanents, qui rec;oivent des densites excessives d'ani­
maux. Ce phenomene a tendance a prendre de l'ampleur
avec la creation de nouveaux puits en ciment dans des
regions oil il n'en existait pas, et a la suite d'une serie
d'annees de bonne pluviosite pendant lesquelles le betail
se multiplie.
Que survienne une mauvaise annee les animaux
affames et en surcharge auront une action tres agres­
sive sur la vegetation C'est ainsi qu'a la suite des pluies
deficitaires de 1 963 la guelta d'Archei dans l'Ennedi a
ete completement saccagee par un surcroit de betail qui
n'avait jamais ete enregistre dans la region. Les mareca­
ges d' Archei ont ete pietines et surpietines et quelques
especes abondantes avant cette date semblent a voir dis­
parues a titre definitif comme : Glossostigma diandra
(L.) 0. Kuntze, Conyza aegyptiaca (L). Aiton; d'autre
part, Cissampelos pareira L. signale de cette localite par
Murat ( 1 937)1 n'a pas ete revu.
Les memes causes ont produit les memes effets a Kor­
di Gale sur le versant Nord de l'Ennedi et les Sesbania
punctata DC. et Cissampelos Pareira L. observes en
Acta Phytogeogr Suec 54
abondance en 1 962 n'ont ete revus qu'a l'etat de quel­
ques specimens en 1 964. Partout dans cette localite la
vegetation portait les marques de la dent du betail,
les Phragmites eux-memes etaient reduits a l'etat de
moignons et de larges tonsures vides apparaissaient sur
le sol entierement recouvert d'herbe auparavant.
Communautes et especes de plantes a proteger
Au Nord Tchad le probleme de la protection de la flore
est etroitement lie a celui de la faune. 11 n'est pas possible
d'envisager localement des restrictions de circulation
des animaux ou d'exploitation des paturages aux abords
des puits. L'eau est vitale pour les hommes et les ani­
maux. L'elevage est la seule ressource des habitants de
ces regions. Leur niveau de vie est l'un des plus bas du
monde. Apporter des genes dans leur mode de vie, qui
est traditionnel depuis des siecles, reviendrait a accroitre
leur misere.
Les especes vegetales interessantes comme les relictes
remarquables de certaines gorges et certains sites de
l'Ennedi2 se trouvent presque toujours au voisinage de
source. Deux cas sont a envisager : ou bien la localite
est inaccessible aux animaux et la plante est protegee
d'elle-meme, ou bien elle sert d'abreuvoir au betail et
dans ce cas la il est bien difficile d'agir efficacement.
Au Nord Tchad la Nature est pour !'instant moins
gravement menacee qu'ailleurs. Les espaces libres sont
trop vastes, la population est trop diluee.
Mais une grave lacune demeure, il n'existe aucun
perimetre de protection. Partout les chasseurs autorises
peuvent se livrer a la destruction de la faune. La creation
d'une reserve de faune qui serait ipso facto une reserve
de paturage s'impose. Elle aurait sa place en zone Nord
sahelienne au Nord de 1'0. Kharma dans une region peu
parcourue par les nomades, zone d'election de ces Anti­
lopes merveilleusement bien adaptees a la vie desertique
puisqu'elles peuvent rester tres longtemps sans boire,
l'Oryx et l'Addax. Un projet a deja ete depose. Tout
doit etre entrepris pour que de telles mesures soient
menees activement. Demain il sera definitivement trop
tar d.
1 Murat, 1 937. Bull. Soc. H ist. Nat. Afr. Nord, XXVIII, p . 3 1 .
2 Adina microcephala (Del.) Hiern, Syzygium guineense DC.,
Rauwolfia cajfra Sond.
S U DAN
E. A . Bari
INTRODUCTION
In the Sudan people are not "conservation con­
scious" mainly due to ignorance of the vegetation,
vegetation exploitation being not great and the great
need of the natives for the land either for grazing,
cultivation or for wood consumption. The idea of
conservation first started in 1 9 3 7-39 when people
started to feel the need of leaving some areas en­
closed because of the great damage done by goats
and human interference. With the War all progress
stopped, but later talk started again which led to the
formation of the Soil Conservation Board on 1 3- 1 21 942 with the idea of soil erosion. prevention and
availability of rural water supplies. There are few
areas in the Sudan that are enclosed and a short ac­
count of each is given later in the text.
GEOGRAPHY
The Sudan, an area of approximately one million
square miles, lies wholly within the tropics between
latitudes 22 ° and 3 ° N. It is a country of one vast
plain broken only by the Marra range in Darfur,
N uba Mts. in south Kordofan, Red Sea Hills in the
east and the Immatong Mts. at the Sudan-Uganda
border. It's almost entirely landlocked and except
for the "sudd" region, there are no large lakes or
inland water surfaces to affect the climate.
CLIMATE
The climate is typically tropical continental. The
Red Sea introduces certain maritime characteristics
confined to the narrow coastal plain and the eastern
slopes of the Red Sea Hills. The climate may be
divided into three types (Ireland 1 948).
1. North of about latitude 19 ° N lies a desert re­
gion where the dry northerlies prevail and rain is in­
frequent; diurnal and annual variations in tempera­
ture, characteristic of desert climate, exist.
2. South of about latitude 1 9 ° N is a tropical con­
tinental type dominated by annual movement of the
boundary between the "dry" northerlies and
"moist" southerlies, the latter associated with rain.
Therefore, a short rainy season is experienced in
the north which increases as we go southwards. The
dry season is rather stable in winter and immense
dust storms are experienced in summer.
3. The Red Sea coast and eastern slopes of the
Red Sea Hills: Here the northerlies prevail through­
out the year and the climate is modified by the
influence of the Red Sea. Rain is possible at all
times but falls mostly in winter. On Tokar area,
local topography influences the weather and at the
Baraka gap severe dust storms are experienced.
In Fig. 1 diagrammatic representation is given ac­
cording to Gaussen and Bagnouls 1 95 2 of the mean
monthly maximum temperature in °C and the total
monthly rainfall in mm in 1 6 stations for the years
1 9 3 1-1 960.
VEGETATION
The vegetation of the Sudan has been described by
Andrews (1948), Jackson (1953-54), Harrison and
Jackson (1958) and Lebon ( 1 9 65). A short account
of the main vegetation zones is given below:
Desert Zone (located north of 1 7 ° N and ex­
cluding the Red Sea Hills) : Annual rainfall less than
2 inches (50 mm). No vegetation except for what
could be found in Bayuda and Atbai deserts. A few
ephemeral herbs and grasses grow after the scanty
rain and form the "gizzu".
Semi Desert Zone (located between 1 4 ° - 1 7 ° north,
including the Red Sea Hills): The vegetation is made
up mainly of annual or perennial grasses and herbs
with or without woody vegetation. According to soil
types and amount of rain this zone is subdivided
into 5 subzones named according to · the dominant
species in the area or the type of soil.
1. A cacia tortilis-Maerua crassifolia Desert
Scrub, found mainly in the east, forms about 7 8,000
sq.m. of the total area.
2. A cacia mellijera-Commiphora Desert Scrub,
found mainly in the west.
3. Semi Desert Grassland on Sand (in the west),
a vegetation of mixed grasses and herbs alternating
with A cacia-Commiphora desert scrub plus a few
trees along "khor" beds and drainage lines.
4. Semi Desert Grassland on Clay (in the east),
a vegetation of mixed grasses and herbs with trees
along water courses. The Butana, which lies between
the Blue Nile and Atbara, is a typical area (1 6,000
sq.m.).
5 . Acacia glaucophylla-Acacia etbaica Desert
Scrub, found in the Red Sea Hills (8000 sq.m.).
Woodland Savanna Zone (monsoon rainfall rang­
. ing between 300- 1 500 mm) : Here, because of the
Acta Phytogeogr Suec 54
60
E. A. Bari
presence of tall grass, fires play an important role
in determining the climax vegetation. Most plants are
fire resistant and the vegetation is of · mixed grass
and bushes with or without trees. According to the
amount of rain we get Low Rainfall and High Rain­
fall Savanna types.
(a) Low Rainfall Woodland Savanna has a vege­
tation of thorny low stature trees (acacias), thickets
of A cacia mellifera, few broad-leaved deciduous
trees, few herbs, few perennials and some annuals.
This type of vegetation is found mainly in Central
Sudan. In East Central Sudan, where we get dark
cracking clays, we either get A cacia mellifera thorn­
land associated with Commiphora africana ( 102,000
sq.m.), Boscia senegalensis on hill sides, or A cacia
m.ellifera-Commiphera desert scrub. On dry areas
Acacia mellifera could be found as pure stands. On
wetter areas A . seyal-Balanites savanna (1 05,000
sq.m.) alternating with grass areas occur and A. seyal
is dominant throughout. On more wet areas A . sene­
ga/ is dominant (48 ,000 sq. m.). On lowlands A . cam­
pylacantha is common while on areas liable to flood­
ing A . fistula and A . drepanolobium are widespread.
In West Central Sudan, where we get sand mainly,
the following savanna �ypes occur: A. senega/; Com­
bretum cordofanum-Dalbergia-Albizzia serico­
cephala (30,000 sq.m.); and Terminalia-Sclero­
carya-Anogeissus schimperi mixed deciduous wood­
land ( 1 9 ,000 sq.m.).
(b) High Rainfall Woodland Savanna is a vege­
tation of mixed deciduous woodland of A nogeissus­
Khaya senegalensis and Isoberlinia (1 06,000 sq.m.).
Flood Zone: According to the amount of water,
we have three types of vegetation with a total area
of 1 1 6,000 sq.m.
(a) Highland (rarely flooded). On sandy soils the
vegetations is mainly palm type. Hyphaene thebaica
is generally dominant, Borassus aethiopum locally
dominant, few acacias with A . sieberiana most com­
mon. On clay soils A . seyal-Balanites savanna type
occurs.
(b) Intermediate (flooded during the rainy season).
The vegetation is mostly grassland with Hyparrhenia
rufa and Setaria incrassata as dominant with few
areas of A . seyal-Balanites savanna.
(c) Swamps, either permanent ( 1 3,500 sq.m.) in
areas flooded by rain, rivers and inland "khors"
where the most dominant species is Cyperus papyrus,
or seasonal with Echinochloa stagnina, E. pyramida­
lis usually dominant. Other common swamp species
are: Phragmites communis, Hyparrhenia rufa, Veti­
veria nigritana, Pistia stratiotes, Ipomoea aquatica
and recently Eichhornia crassipes which is very wide­
spread.
Acta Phytogeogr Suec 54
Montane Zone: Areas with high altitudes where
the vegetation changes with height.
Immatong Mts. and Dongotona Mts. : Podocarpus
milanjianus (50 sq.m.) is dominant. At 5500-7000
ft. Olea hochstetteri, 0. welwitschii and Syzygium­
aff. S. gerrardii, which forms pure stands, are domi­
nant. Other common species are Protea gaguedi, Ha­
genia abyssinica, A cacia xiphocarpa, A lbizia gummi­
fera and Maesa lanceolata.
Didinga Mts: Podocarpus, Juniperus procera and
Olea chrysophylla are dominant.
Red Sea Hills: Juniperus procera, confined to Ko­
rora Hills and Olea chrysophylla on Jebel Elba.
Jebel Marra: Open grassland with areas dominated
by Olea laperrini and A cacia albida.
One should mention, besides the main zones, the
Gallery forests ( 1 50 sq.m .) which are a type of rain
forests with Khaya grandifolia, Cola cordifolia,
Erythrophleum guineense. Mitragyna stipulosa and
Syzygium guineense as common species. Also, rain­
forests (20 sq.m.) with Celtis zenkeri, Chrysophyllum
albidum, Mildbraediodendron excelsum and Entand­
rophragma angolense. Lastly, Acacia nilotica and A .
arabica found as pure forests in areas, N . of Lat. 1 0 ° ,
flooded annually by the Nile.
ENCLOSED AREAS
As previously mentioned, there are few areas en­
closed in the Sudan as nature reserves or enclosures.
Most of these belong to the Forestry Department.
A general outline of the history of the area and the
vegetation associations of each of these is given plus
any other information available.
Erkawit: K. Cooke in 1 9 3 9 , governor of Kassala
Province at that time, suggested to replace goats by
sheep because of the great damage the goats caused
to the vegetation but Armstrong decided that control
measures should be taken rather than extermination.
Thus Erkowit (a summer resort) was declared as an
enclosed area and goats were kept away. The vege­
tation of the area has been described by a number
of authors. M. Kassas ( 1 954) divided the vegetation
of the area into five zones.
Zone 1 . Pure stands of Maytenus senegalensis.
Zone 2. A community of Maytenus-Euphorbia
abyssinica.
Zone 3. Pure stands of Euphorbia abyssinica. On
Jebel Auliai Dracena ombet is common and in
"khor" beds A cacia raddiana occurs.
Zone 4. An association of Dracena ombet and
Euphorbia abyssinica with A cacia etbaica and A .
tortilis found as common shrubs.
Sudan
--
·····
·
Rainfclll in m m .
(figs. to th� ri gh t )
1,(j 2
· · · · · · · ·
· ·Ttmpqrature i n ° C
(figs. to t� left)
4r:f
..
40
5
4
·
.
160
61
6
40
ll:f
3
· · · . . . . .· · ·.
11
�
7
8
20
120
10
9
20
40
'If
12
40
40
16
200
200
13
15
160
160
120
120
4d'
4(f
�
40
Fig. I. Diagramatic representation of the mean monthly maximum temperature and the total monthly rainfall in 16 stations. The
figures in brackets represent the period (in years) over which the means for temperature (T) and rainfall (R) are plotted.
Stations:
1.
2.
3.
4.
Karthoum (T, R 30).
Wadi Halfa (T 30, R 24).
Abu Hamad (T 18, R 3 0) .
El Gedaref (T, R 21).
5.
6.
7.
8.
Kassala (T, R 30).
Port Sudan (T, R 30).
Atbara (T, R 30).
Wad Medani (T, R 30).
Zone 5. An area, just outside Erkowit, dominated
by Euphorbia thi.
For a long time Erkowit was well kept. Recently,
no control seems to be applied and thus the vegeta­
tion has changed tremendously. Dracena ombet has
completely disappeared and on a visit to the area in
1 9 6 1 only dead Dracena trees were found. Recent
reports tell of more deterioration of the vegetation.
Umbedda: An area of 77. 8 acres north west of
Omdurman on the west of the Nile, was declared
as an enclosure in 1 947 when the old part (20. 8
acres) was fenced. In 1 9 55, the new part (57.0 acres)
9.
10.
11.
12.
Kosti (T 23, R 28) .
El Obeid (T, R 30).
El Fashir (T, R 30).
El Geneina (T 24, R 30).
13.
14.
1 5.
1 6.
Kadugli
Juba (T,
Malakal
Wau (T
(T 23, R 30).
R 3 0).
(T, R 30).
29, R 30).
was fenced. The area, as described by Halwagy
(1 9 62), is flat with very localized gentle undulations; ·
soil mainly sand and gravel with sand predominating.
The vegetation is of mixed annual and perennial
grasses. A ristida species and Panicum turgidum are
dominant and lndigofera spinosa, A cacia tortilis, A .
nubica and Capparis decidua are common i n the
area.
Mesquite: An area, south of Khartoum, planted
by the Forestry with Prosopis chilensis (mesquite) for
dust and soil stabilization. This is now abandoned
and clearing started in March 1 966.
Acta Phytogeogr Suec 54
62
E. A. Bari
=
Wadi Seidna: An area of 2 1 43 feddans (1 feddan
L 3 8 acres), north west of Khartoum, was declared
as an enclosure on 1 5-7- 1 94 1 . The most common
species in the area beside annual and perennial
grasses, which are dry most of the year, are Boscia
senegalensis, A cacia ehrenbergiana, A . tortilis and
Maerua crassijolia.
Two areas that are not enclosures but kept as
such are the two game reserves Dinder (in the east)
and Nimoli (in the south). Animal protection means
partial protection for the vegetation. The Dinder re­
serve was visited in 1 9 6 3 and the vegetation was
found in a good state. Fires are not permitted and
felling is controlled. The vegetation is mainly of for­
est trees with A cacia sieberiana (most common), A .
seyal, Terminalia sp. and Combretum hartmanni­
anum widespread. Unfortunately no information
about Nimoli is at hand.
It should be mentioned that besides the fact that
the Mesquite Enclosure being abandoned, Umbedda
Enclosure is not well controlled and any informa­
tion, nowadays, is unreliable. Erkowit's vegetation
has changed due to extensive grazing, and talk has
been going on between the Forestry and the villagers
who want to convert the Wadi Seidna Enclosure
into cultivation land but the Forestry is doing its
best to keep the enclosure. The Forestry is quite
active and since 1 9 3 2 they got 2,574,494 feddans
as forest reserves (0. 5 % of the total Sudan area) and
7 3 7 , 5 1 2 feddans under reserve. Afforestation is go­
ing at a rate of 1 3,000 acres / ann.
SUGGESTED AREAS FOR FUTURE
. ENCLOSURES
Seeing how much damage is done due to negligence,
strict measures should be taken in future if we wish
to have "nature reserves" in the full meaning of
the word. Some areas should be enclosed immediately
and others should first be surveyed. All the enclo­
sures should best be left under the Forestry, Ministry
of Agriculture. A report of all vegetation changes
in these enclosures due to fires, animal and human
control plus all other vital information, such as the
different species association, should be published an­
nualy. A list of the areas that should be enclosed
and general information about these areas is given
below:
1 . Didinga Mts. In Mt. Lotuke Juniperus procera,
once forming a Juniperus belt associated with Podo­
carpus milanjianus, was found as relicts (Jackson
1 95 1 ). The only living Juniperus trees are found
along banks and on rocks. Immense fires in the
area before cultivation destroyed all Jun lperus trees
Acta Phytogeogr Suec 54
which are now unable to regenerate. Podoca·rpus re­
sists fire more than Juniperus because of its moist
nature. All area above 3 500 ft. should be protected
and all Juniperus trees in the Sudan should be pro­
tected because of the tendency of this species to dis­
appear from the Sudan.
2. lmmatong Mts. Podocarpus milanjianus faces
another danger since it provides good roofing poles.
Up to 1 940, felling was to such an extent that in
1 95 6 (Jackson 1 95 6) 3-4 km out of Gilo all middle
aged Podocarpus were completely absent. The Im­
matong Mts. should first be surveyed and its vege­
tation should be well studied so that the best suitable
sites for reserving are fenced, specially those areas
dominated by Podocarpus.
3. Jebel Marra. This area suffers from fires since
fires are necessary in order to clear the 4-5 ft tall
grass. The area has a rich fern flora. Bracken (Pte­
ridum aquilinum) is a common feature while A cti­
nopteris sp. is found in rock crevasses (Macleay
1 95 3). Since ferns are not common in the Sudan
flora and the Jebel is also dominated by Olea sp. ,
i t i s advisable t o declare the Jebel and the crater a s a
nature reserve.
4. Mt. Rajaf (near Juba) should also be protected
being a locality for Pallaea longipilosa (Macleay
1 9 5 3).
5 . Boma Plateau (on the borders of Ethiopia). An
area of volcanic loam with good crumb structure and
free drainage according to Willimott 1 95 7 . It is lo­
cated within 5 ° 5 0'-6 ° 25' N Lat. and 3 4 °20'-3 5 ° 00'
East Long. The Plateau dominates the whole area,
3 5 5 0 ft above sea level, with an annual rainfall of
1 3 00 mm and a dry season of three months. The
area is not densely populated and no shifting culti­
vation is experienced. The vegetation is of grass
woodland of the lulunut tree (Butyrospermum parkii,
var. niloticum) dominant in the area mixed with
Combretum species. Few acacias with A cacia dre­
panolobium as a common feature and Balanites
aegyptiaca that stretches for 1 I 2 a mile.
6. Nuba Mts. These are the most important catch­
ment area east of the Nile, but the runoff is being
increased by annual fires and agriculture without
terracing. Most of the tall grasses such as Hyparrhe­
nia rufa have been burnt . On a visit to the area in
M ay 1 964, pure stands of Boswellia papyri/era with
their stems smoked were a common feature on the
road to Rashad. This species faces another danger
since its wood makes good matches. The Nuba Mts.
carry a rich flora of plants not common elsewhere
in Sudan. Combretum sp., Terminalia sp., Acacia
sp. , Erythrina abyssinica, Gardinia sp., A brus pre­
catorius and a number of other tree species found
·
around Rashad are common in the area. On Jebel
Nuba few ferns and A loe sp. were found. The idea
of fencing the Nuba Mts., which started in 1 94 1 ,
should b e put into practise immediately.
7. Jebel El Merkheiat. In the north a few jebels
should be kept because of their distinct vegetation
e.g. Merkheiat Jebels. In Kassala province, in the
east, a few jebels were recommended a long time
ago to be fenced. All of these should be fenced and
the areas kept under control.
8. Red Sea Coast. Part of the Red Sea coastal
vegetation should be enclosed so as to keep some of
the typical plants in the area protected. The
coastal vegetation was described by Kassas ( 1 957).
The best site is an area near Swakin where the follow­
ing species are common: A vicennia' marina, Arthroc­
nemum glaucum, Suaeda fruticosa and S. monoica.
9. "Sudd Region". Part of the "sudd" should
be preserved so as to keep some of the swamp vege­
tation since clearing of water plants, especially Eich­
hornia crassipes, could mean the death of most of the
swamp plants in the near future. Some of the com­
mon swamp plants known are : Cyperus papyrus
(always dominant), V ossia cuspidata, Phragmites
communis, Typha australis, Pistia stratiotes, Ipo­
moea aquatica, Cissus ibuensis, Vigna nilotica, Echi­
nochloa stagnina and E. pyramidalis.
-
My thanks are due to Professor M. Kassas, Head, Botany
Dept., University of Khartoum, for his generous advice;
Discussion
63
Mr. Ali Mousa, A. C. Forestry, Min. of Agriculture, for
providing vital information; staff of the Meteorological Of­
fice, Khartoum; and Mr. M. Dawoud for typing my manu­
script.
REFERENCES
Andrews, F. W. 1 948: The Vegetation of the Sudan. - Agri­
culture in the Sudan.
Gaussen, H. & Bagnouls, F., 1952. L'indice xerothermique.
- Bull. Ass. Geogr. franc. (Paris), J anv.-fevr. p. 222223.
Halwagy, R., 1962. The Incidence of the Biotic Factor in
Northern Sudan. - Oikos 13 ( 1 ).
Harrison, M. N. & Jackson, J. K., 1958. Ecological Classi­
fication of the Vegetation of the Sudan. - Forests Bull.
No . 2 (New Series), Min. of Agriculture, Sudan.
Ireland, A. W., 1 948. The Climate of the Sudan. - Agri­
culture in the Sudan, pp. 62-83.
Jackson, J. K., 1 95 1 . Mount Lotuke, Didinga Hills. - Me­
moirs of Forestry Division, No. 3, Min. of Agric., Sudan.
1 953-1 954. Report for the Period July 1953 to June
1954, Forest Dept. Sudan.
1956. Vegetation of the Immatong Mts., Sudan. - J.
Ecol. 44, 341-3 74.
Kassas, M., 1 954. The Mist Oasis of Erkowit, Sudan. - J.
Ecol. 44, 1 80-194.
- 1 957. On the Ecology of the Red Sea Coastal Land. ·
J. Ecol. 45, 1 8 7-203.
Lebon, J. H. G. 1 965. Land Use in Sudan. - The World
Land Use Survey, Monograph No. 4.
Macleay, K. N. G., 1 953. The Ferns & Fern Allies of the
Sudan. - Sudan Notes & Records Vol. 34, Part 2.
Willimott, S. G., 1 957. Soils & Vegetation of the Boma
Plateau and Eastern District Equ. - Sudan Notes and
Records Vol. 38.
DI SC U S S I O N
Wickens: It is a pity that Miss Eklas Bari was unable to
attend and present her paper. I feel that she h as been rather
optimistic in her recommendations regarding the possibilities
of plant conservation in the Sudan.
It is a country without the benefit of a government
botanist or ecologist assigned to a study of the country's
flora. The Forest Department's interest in plant protection is
receiving insufficient co-operation. The southern part of the
Sudan is still largely unknown botanically. It is also in the
throes of a civil war during the course of which many areas
of botanical interest have been deliberately destroyed. It is
therefore impracticable to consider any recommendation for
conserving vegetation in the southern Sudan until more
peaceful conditions prevail.
The Red Sea Hill region has deteriorated' rapidly within
recent years, beyond hope of salvation. The proposed increase
in irrigable lands in the Nile valley and the reduction in the
traditional dry-season grazing areas of the nomadic tribes
will tend to aggravate the problem east of the Nile. Jebel
Marra is definitely worthy of consideration. It is perhaps a
surprise to many here that Miss Eklas Bari should consider
bracken (Pteridium aquilinum) as a species worthy of protec­
tion but ferns generally are rather uncommon in the Sudan,
especially in the northern half.
Here a correction must be made to Miss Eklas Bari's
paper. Acacia albida and Olea lapp errini are thinly scattered
on Jebel Marra, not dominant, although the latter does occur
in a very few sites as an open "savanna woodland". Jebel
Marra is of immense interest to the phytogeographers. It
marks the eastern extent of many West African species, it
has close affinities with the Saharan mountains and is the
sole station outside Ethiopia for several eastern species, etc.
F.A.O. is at present investigating agricultural development
possibilities in the area and I shall shortly be making my
recommendation to the Proj ect Manager there regarding plant
conservation.
The Nuba Mountains have been mentioned as worthy of
protection. I agree but it is a heavily populated area and a
fencing scheme is impracticable. I would suggest that the
sparsely populated northern outlier, Jebel Ed Dair would be
more suitable. It contains many unusual species including the
sole station, as yet, in the Sudan for Croton zambesiacus.
Acta Phytogeogr Suec 54
64
Discussion
Vegetation patterns of the Somaliland type are unusual in
the Sudan. A unique Terminalia b rownii pattern occurs near
En Nahud. This is at present in danger of destruction due to
overgrazing. Run-off now is such that the trees are dying
of drought. Protection by excluding livestock is recommended.
Near Bara there is an interesting area of unstable dunes, the
Kheiran. The presence of species such as Andropogon gaya­
nus in 250 mm rainfall is surprising. The communities should
be protected from excessive cultivation and overgrazing.
In conclusion I would like to stress the international im­
portance of the flora of Jebel Marra and recommend that
immediate priority should be given by the Sudan Government
to ensure its protection.
Monod: La protection du Djebel Aouenat presente des pro­
blemes assez particuliers : d'une part, la vegetation ne
semble pas s'y trouver particulierement menacee (absence de
population permanente, absence d'eau sur les sommets),
d'autre part le massif se trouve cloisonne par des frontieres
internationales et appartient de la sorte a trois pays (Libye,
Sudan, Egypte). Ceci rend douteux la possibilite d'obtenir
une protection etendue a I'ensemble du massif (ce qui par
ailleurs serait, en pratique, difficilement realisable).
Acta Phytogeogr Suec 54
Milne-Redhead: Whilst I would strongly support action to
conserve Jebel Marra, I feel that strong support should also
be given to any attempt to save the Imatong Mountains.
In my opinion the Imatong Mountains are a most important
area phytogeographically and I find it hard to believe that
all the vegetation in the Sudan side has been destroyed. I
would like this meeting to pass a resolution stressing the
importance of conserving as much as possible of the upland
rainforest and upland grassland of these mountains.
Boughey: The Sudan is the most varied country in Africa,
ranging from desert in the North to gallery forest in the
South, with the largest papyrus swamp in the world. One
would perhaps like to conserve the whole of this but as this
is obviously impossible, at least some 30 or 40 different
reserves would seem to be required. However, it is quite
unrealistic to expect people who are fighting for their lives
to take any notice of a resolution from this or any other
body asking them to respect the preservation of any partic­
ular vegetation type.
West Tropical Africa
S E N E GAL
J. G . Adam
G EOGRAPHIE
Le Senegal est situe a l'Ouest de 1' Afrique tropicale. 11
est compris entre les paralleles 1 6° 41 au Nord et 1 2° 1 8
au Sud et les meridiens 1 1 o 22 Ouest a l'Est et 1 7° 32
Ouest a l'Ouest.
Il a environ 200 000 km2 ce qui represente la 1 50e
partie de 1' Afrique. Sa population est de 2 300 000 habi­
tants, soit une densite moyenne de 1 1 ,2 ha, au km2•
11 a 440 km du Nord au Sud et 560 km de l' Est a
l'Ouest. 11 est limite par l'Ocean Atlantique a l'Ouest,
le fleuve Senegal au Nord qui le separe de la Mauritanie,
la Faleme et une ligne conventionnelle a l' Est qui le
separent du Mali et par des limites artificielles au Sud
qui le separent des Guinees Francophone et Portugaise.
C'est un pays plat dont le point culminant est situe a !'ex­
treme Sud-Est, pres de la Frontiere de la Guinee Franco­
phone, aux premiers reliefs du Fouta Djallon a 400 m
d'altitude. Une profonde enclave etrangere, la Gambie
separe le Nord du Sud (Casamance).
Le Climat est tropical avec une saison seche de 7 a 1 0
mois e t des pluies d e 1 700 m m a 300 m m suivant que 1 'on
se trouve au Sud ou du Nord du pays ; ce sont des pluies
d'ete de la mousson du Sud-Ouest. En hiver et au prin­
temps l'Harmattan vent chaud et sec qui souffle de l'Est
repousse la mousson. Sur la cote, entre St-Louis et
Dakar les Alizes canariens du Nord soufflent de Novem­
bre a Mai et temperent le littoral.
Les sols sont sablonneux sur le 1 /3 Ouest du Senegal
et sont favorables aux Arachides. Ils sont ferrugineux
sur les 2/3 Est et forment des carapaces etendues dans
la partie la plus orientale.
La population est composee de plusieurs ethnies dont
les principales sont : les Wolofs (a l'Ouest) les Peulh
repartis dans tout le pays, les Toucouleurs dans la Vallee
du Fleuve, les Sereres au Sud de Dakar, les Diolas en
Casamance, les Sarakoles, Bambaras, etc.
TYPES DE V EG ETATION
La grande difference entre le climat sahelien du N ord
avec 300 mm de pluies en 2 mois et le climat guineen du
5 - 6 8 1 557 Hedberg
Sud avec 1 700 mm en 7 mois fait que les formations sont
tres variees. Elles suivent fidelement !'influence de l'eau
et on les classe en trois grandes divisions comme le
climat. Ce sont :
La Region Sahelienne
Cette region est nette jusqu'a 700 mm de pluies; elle est
formee d'immenses prairies tropicales ephemeres esti­
vales (ou plus simplement de prairies estivales) souvent
parsemees d'arbustes et d'arbres isoles ou en bouquet,
parfois les peuplements arbores sont assez serres pour
cacher !'horizon. C'est la region des Aristida mutabilis,
Aristida stipoides, Aristida longiflora, Aristida funiculata,
Cenchrus biflorus, Schoenefeldia gracilis. Les Arbres
dominants sont Acacia raddiana, Acacia senega!, Acacia
seyal, Balanites aegyptiacea, Bauhinia rufescens, Commi­
phora africana. Trois principaux secteurs sont a sepa­
rer :
La valtee inondable du Senegal avec des peuplements
purs d' Acacia nilotica ssp. nilotica formant de veri tables
.
forets separees par des steppes egalement inondables de
Vetiveria nigritana.
Le delta du Senegal avec des argiles salees portant des
steppes suffrutescentes plus ou moins halophiles a
Arthrocnemum glaucum et Sa/sola foetida.
Le nord Ferlo avec des Fourres de Pterocarpus lucens
accompagnes de Loudetia togoensis dans les clairieres
sur les sols ferrugineux.
La Region Soudanienne
Cette region est comprise approximativement entre les
Isohyetes 700 et 1 500 mm. Elle traverse le Senegal de
l'Ouest a l'Est. De nombreux secteurs phytogeographi­
ques existent mais dans !'ensemble elle est assez homo­
gene pour beaucoup d'especes. Tres modifiee par les
cultures a l'Ouest elle presente encore de tres belles
forets seches ·e t savanes boisees a l'Est et au Sud. Elle
sont surtout constituees par des Pterocarpus erinaceus,
Sterculia setigera, Bombax costatum, Anogeissus leiocar­
pus, Combretum glutinosum, Combretum nigricans, Com­
bretum micranthum, Combretum !ecardii, Combretum
mol/e. Le tapis herbace est a base d'Andropogonees
vivaces ou annuelles : Andropogon gayanus, Andropogon
Acta Phytogeogr Suec 54
66 J. G. Adam
tectorum, Andropogon pinguipes, Cymbopogon giganteus,
Hyparrhenia diplandra, Hyparrhenia amoena, etc. 11
atteint 3 a 4 m de hauteur et brille tous les ans. Le Bam­
bou ( Oxytenanthera abyssinica) est tres abondant par­
tout ou les cultures ne sont pas installees; mentionnons
egalement les prairies permanentes sur carapaces ferru­
gineuses avec Andropogon pseudapricus (non exclusif),
Danthoniopsis tuberculata (exclusif), Pobeguinea arrecta
(non exclusif).
La Region Guineenne
Cette region qui commence avec 1 500 mm de pluies est
situee au Sud-Ouest du Pays. Elle doit sa vegetation
ombrophile plus au sol humide en permanence a faible
profondeur du fait de son niveau peu eleve au dessus de
la mer qu'a l 'abondance des pluies qui ne sont reparties
que pendant 5 mois de l'annee. Les forets d'origine sont
un melange d'arbres a feuilles persistantes et a feuilles
caduques. La presence du Palmier a huile en abondance,
meme hors des depressions man!cageuses et l'absence
de feux dans les taillis qui se reconstituent apres les
defrichements sont les deux criteres choisis pour limiter
cette region.
Comme autres especes typiquement guineennes on
rencontre Parinari excelsa, Pentaclethra macrophylla,
Treculia africana, Mammea africana, Raphia gracilis
(marecages), Pycnanthus angolensis, Samanea dinklagei,
etc. Des graminees de Foret : Olyra latifolia, Strepto­
gyne gerontogaea, etc. Par contre Musanga cecropioides
ne vient pas jusqu'au Senegal.
Les forets sont constituees principalement par Deta­
rium senegalense, Erythrophleum guineense, Chlorophora
regia, Parinari excelsa, Copaifera leonensis, Afzelia afri­
cana, etc.
·
Formations dependant du sol
D'autres formations qui dependent plus de l'edaphisme
que du climat existent dans les trois grandes regions
phytogeographiques. Ce sont :
Les Mangroves qui occupent les estuaires, les sols
sales littoraux et les diverticules d'eau de mer qui pene­
trent profondement dans le territoire le long des cotes
tres basses. Elles ne different pas comme composition
des autres Mangroves Ouest-africaines. On y rencontre
les 3 Rhizop/wra, R. mangle, R. racemosa, R. harrissonii;
Avicennia africana, L aguncularia racemosa, Conocarpus
erectus. Elles sont plus etendues et vigoureuses au Su d
(Casamance) qu'au Nord (Embouchure du Senegal).
Les R6neraies (Borassus .flabellifer aethiopum). De
beaux peuplements existent sur le Fleuve Senegal (Da­
gana), au Nord de Thies (Pire goureye), dans le Sine
(N'Dangane), en Casamance maritime et le long des
Vallees des rivieres permanentes du Senegal oriental.
Les Bourgoutieres de la Vallee inondable du Senegal
qui sont des prairies flottantes de graminees dont la
Acta Phytogeogr Suec 54
principale est Echinochloa stagnina avec ses compagnes :
Oryza barthii, Paspalidium geminatum, Echinochloa
pyramidalis, Vossia cuspidata, Polygonum senegalense,
Diplachne fusca, etc.
Forets ripicoles. Elles sont peu etendues mais leur
habitat special et leur composition font qu'il est inte­
ressant de les mentionner. Elles subissent une submer­
sion complete pendant environ 1 mois de grandes crues
(jusqu'a 10 m d'eau en Septembre) et elles sont comple­
tement exondees pendant 9 a 1 0 mois. Elles sont princi­
palement constituees par Symmeria panicula, Hunteria
elliotii, Acacia nilotica nilotica, Cola laurifolia, Ficus
capraefolia, etc.
COM MUNAUTES ET PLANTES DEJ A.
PROTEGEES DANS LE TERRITOIRE
Il faut reconnaitre que presque rien n'a ete fait au Sene­
gal pour tenter de proteger des types de vegetation pour
un but scientifique. Si vers un but economique lointain,
le service des Eaux et Forets a protege de nombreuses
forets dans toutes les regions climatiques, les responsa­
bles de !'Administration les maintiennent avec difficulte
contre les reclamations justifiees seulement par l'interet
personnel et le profit immediat. Mentionnons cepen­
dant :
L'Ile des Madeleines, au large de Dakar; c'est un ilot
basaltique de 1 7 ha, battu par les vagues et par les vents.
Il est recouvert d'une steppe prairiale a Andropogon gay­
anus, Brachiaria distichophylla et Bothriochloa intermedia
qui n'existe pas ailleurs sur le continent en tant que
groupement vegetal. Quelques Baobabs difformes se
cachent dans un repli de falaise et leurs cimes depassent a
peine le plateau ventile. Un texte du 1 9 Janvier 1 949 pro­
tege sa Faune et sa Flore.
La reserve Botanique du Noflaye, de 1 6 ha, situee a
34 km au Nord-Est de Dakar a ete creee en 1 957. Cloturee
pendant de nombreuses annees, la surveillance mainte­
nant se relache et les droits de recolte du Vin de palme
qui avaient ete suspendus restent a nouveau a la libre
disposition des riverains.
Elle est constituee par les 2 principaux types de Vege­
tation de la presqu'ile du Cap Vert, qui sont :
La Niaye ou depression constamment humide a Elaeis
guineensis et Lonchocarpus sericeus.
La steppe prairiale estivale sahelienne a Aristida lon­
giflora et Cenchrus bi/lorus.
Le Pare National du Niokolo Koba, d'une superficie
de 250 000 ha est une reserve de Faune et de flore depuis
1 953.
Si la Faune est surveillee, car sa conservation sert
d'attrait aux touristes, la flore ne fait l'objet d'aucune
mesure particuliere pour sa protection. Les feux pre­
coces, moins nocifs que les feux tardifs sont mis chaque
Senegal
Mangn�v�s
-
67
�:;-""'
Prairies es tivales
e"'
.§
arbus tiVP..s ou arbories
�"' �
--- - ---... �- - - - <>t
\.�"
NOFLAVE
.._e�'\_
".i
Senegal. .A = Emplacements des
parcelles protegees; e = Sites a pro­
teger.
Fig . 1 .
annee par les agents de !'Administration et toute ou
presque toute la vegetation brfile. Le Pare est principale­
ment constitue par des Forets seches, des savanes boises,
arborees ou arbustives soudaniennes. Pterocarpus erina­
ceus, Bombax costatum, Erythrophleum africanum, Ster­
culia setigera et de nombreux Combretum sont les essen­
ces les plus communes. Andropogon pseudapricus, Andro­
pogon gayanus, Hyparrhenia divers forment la base du
tapis herbace.
De grandes carapaces lateritiques ont une flore speciale
qui se trouve a l'Ouest de sa repartition venant de la
Guinee. On y rencontre ainsi : Eragrostis pobeguini,
Adelostigma perrottetii, Andropogon felicis, Cyathula
pobeguini et de nombreuses especes de Lepidagathis.
Quoique la flore du Senegal soit pauvre et que les
especes endemiques y soient rares, peut-etre meme in­
existantes, il serait souhaitable que quelques formations
vegetales qui representent des types climatiques du pays
soient integralement soustraites a I' influence de l'Homme.
Contrairement a la Mauritanie qui est immense et tres
peu peuplee, le Senegal continue a se developper ra­
pidement, les defrichements de forets seches s'accen­
tuent et i1 est necessaire de conserver des temoins dans
les regions les plus menacees.
COMMUNAUTE S ET ESI>ECES DE
PLANTES A PROTEGER
En plus des trois zones deja enumerees il y aurait lieu de
proteger les suivantes :
Une foret d'Acacia nilotica de la Vallee du Fleuve.
(Foret de N'Dioum Walo) (Region sahelienne) (Podor).
Cette formation qui est speciale a la Vallee inondable
du Senegal est appelee a disparaitre par suite de l'ame­
nagement agricole et forestier du territoire. Elle se de­
veloppe sur de bons sols argileux favorables a la culture
du Sorgho et du Coton et la plupart d'entre elles ne sont
que de tres anciennes jacheres.
Ce groupement est homogene et il n'est pas necessaire
de proteger une grande superficie pour conserver un
temoin. 2 0 hectares de la foret citee semblent suffisants
pour englober des groupements voisins, mais differents :
Foret d'Acacia nilotica ssp. nilotica.
Steppe a Vetiveria nigritana.
Prairie aquatique a Bourgou (Echinochloa stagnina et
autres graminees flottantes):
Prairies estivales arbustives a Schoenefeldia gracilis
et Salvadora persica. (Sols rarement inondes appeles
« Fonde ») .
Sa superficie est de 950 ha. Elle est protegee depuis
1 939.
Un peuplement de gommiers (Acacia senega/) et sa
flore herbacee (Foret d'Amboura) (Region sahelienne)
(Podor).
Le Gommier (Acacia senega/) forme rarement des
peuplements etendus- et denses au - Senegal. Quelques
boisements clairs existent <;a et la et la dune fixee de la
reserve d'Amboura est un des beaux peuplements.
La protection integrale ne doit pas soulever de gran­
des difficultes, aucune culture ne s'y pratiquaiit ainsi
'
que dans les environs immediats et le betail ne recher­
chant pas particulierement ces lieux de pauvres patu..;
rages.
Les Gommiers y ont un rendement tres bas mais la
cueillette de la gomme pourrait etre toleree a cond ition
_
de ne pas mutiler les arbres.
_
Acta Phytogeogr_Suec 54
68
J. G. Adam
La reserve est une prairie estivale arbustive claire ou
les Acacia senega! et Acacia raddiana dominent avec
d'autres essences epineuses : Balanites aegyptiaca, Com­
bretum aculeatum, Capparis decidua, ou non epineuses :
Boscia senegalensis, Maerua crassifolia . . .
L e tapis herbace est a base d e Cenchrus biflorus, Aris­
tida stipoides, Aristida mutabilis, Latipes senegalensis et
nombreuses herbes annuelles.
La superficie totale de la reserve est de 1 200 ha. Elle
est protege depuis 1 937.
Une foret seche soudanienne (Essences variees) (Foret
de Patako Est) (Kaolack).
La Foret de Patako (Sine Saloum-Kaolack) est prin­
cipalement constituee par une Foret seche soudanienne
a essences tres variees : Prosopis africana, Afrormosia
laxiflora, Ostryoderris stuhlmannii, Daniellia oliveri, Par­
kia biglobosa et Combretum divers. Le tap is herbace est
a base de grandes Andropogonees. Bile est bordee au
Sud par une Mangrove a Rhizophora-A vicennia et des
p�uplements purs d' Acrostichum aureum. Les groupe­
ments des sols s:1lins sont bien representes. A !'oppose
se trouve une galerie d'eau douce avec des forets mare­
cageuses a Ficus congensis et des jungles a Typha austra­
lis.
Cette foret est un temoin partiellement climacique de
l'ancienne vegetation qui existait dans le Sud du Saloum
ou actuellement tous les sols sont occupes par la culture.
Elle est tres revendiquee par les cultivateurs, aussi pen­
sons-nous que sa mise en reserve integrale, si le Gouver­
nement du Senegal est d'accord permettrait de sauvegar­
der d'une maniere plus certaine ce temoin du passe. Elle
a une superficie de 1 250 ha. et est protegee depuis 1 933.
Une foret guineenne (Parinari excelsa, Guibourtia co­
pallifera, Mostuea hirsuta).
Foret de Diantem (ou d'Essikene) (Casamance) d'une
superficie de 95 ha. Elle est protegee depuis 1 938. Elle
est particulierement menacee, le Copalier etant tres re­
cherche pour la fabrication des manches d'outils et la
fabrication d'un charbon de bois de premiere qualite.
C'est le seul temoin qui existe au Senegal. En plus des
Copaliers, d'autres especes guineennes situees a la limite
occidentale de leur aire sont presentes : Ceistopholis pa­
tens, Macaranga heterophylla, Rinorea ilicifolia, Garcinia
polyantha, Piptadeniastrum africanum, Daniellia ogea,
Guibourtia leonensis, etc.
Une Niaye marecageuse. La « Niaye » de Sangalkam.
Les « Niayes » des environs de Dakar sont des depres­
sions remplies d'eau douce ou le Palmier a l'huile est
I' essence caracteristique. Les sols etant humides et humi­
feres elles sont toutes cultivees et les forets guineennes
qui existaient auparavant ne sont plus maintenant que
des souvenirs.
Acta Phytogeogr Suec 54
La Reserve Botanique de Nofl.aye dont nous avons
parle precedemment est une Niaye seche et pauvre. A
l'origine c'etait la Niaye de Sangalkam qui devait etre
protegee, mais pour des raison� de facilites administra­
tives c'est la Niaye de Noflaye qui a ete retenue.
I1 est utile de reprendre le projet de protection de la
Niaye de Sangalkam. Elle contient des groupements et
des especes vegetales qui ne se retrouvent pas avant la
Casamance maritime et leur protection integrate a proxi­
mite de Dakar est une necessite pour les etudiants de
l'Universite qui y yont frequemment en excursions Bio­
logiques. On y remarque par exemple : Lygodium scan­
dens, Psilotum triquetrum sur les Elaeis, Psychotria psy­
chotrioides, Cyrtosperma senegalensis en peuplement,
Annona glabra, Antidesma venosum, Xylopia aethiopica
etc. 1 5 ha suffiraient pour englober les principaux grou­
pements.
CONCLUSIONS
Pour la realisation de ces projets le Chef du service des
Eaux et Forets qu i represente le Gouvernement du Sene­
gal pense qu'il ne doit y avoir aucune difficulte majeure
a ce que tout ou partie de certaines reserves forestieres
soient transformees administrativement en reserves inte­
grates de flore par des textes nouveaux. Mais, comme
pour la Mauritanie ces textes seront sans effet, si les
parcelles ne sont pas effectivement cloturees et si leurs
clotures ne sont pas regulierement entretenues par la
suite. La seule reserve de Nofl.aye qui etait protegee, est
actuellement delaissee faute de credits d'entretien.
11 est a penser que les futures reserves auront le meme
sort si auparavant il n'a pas ete prevu un organisme ou
un service qui sera effectivement responsable de la sur­
veillance et de l'entretien et qui recevra de ce fait, les
credits necessaires.
Le Senegal est loin d'etre oppose a ce que des creations
d'utilite scientifique soient envisagees, mais il demande
l'aide materielle pour leur realisation. Nous pensons
qu'il est normal qu'un organisme international subven­
tionne la mise en place des clotures, leur entretien et
assure le salaire des gardiens.
En contrepartie, le Gouvernement devra s'engager a
fournir son appui moral et a sanctionner les delits qui
pourraient avoir lieu.
11 y aurait lieu de prevoir, pour le Senegal :
la refection des clotures de la reserve de Nofl.aye,
le cloturage de 20 ha a N'Dioum,
le cloturage de 20 ha a Amboura,
la solde de 4 gardiens
(un pour N'Dioum- Amboura)
(un pour Noflaye - Sangalkam- Madeleine)
(un pour Patako - Est)
(un pour Diantem).
Guinee
des credits d'entretien annuels pour clotures et gar­
diennage.
Si ce principe est admis, il sera facile de chiffrer les
depenses et d'en fournir le montant a l'organisme qui
prendrait en charge le financement.
Si aucune subvention exterieure ne peut-etre assuree,
il est certain que toutes les recommandations et textes
resteront lettres mortes.
69
11 n'appartient pas actuellemt!nt a notre association
de subventionner ces travaux n'ayant aucun credit ni
aucune structure reglementaire pour cela, mais elle peut
faire un appel aux grands organismes internationaux
qui, soit directement, soit par notre intermediaire et
sous notre controle, aideront a la realisation de ces pro­
tections.
GUI NE E
R. Schnell
GENERALITE S
Le territoire de la Republique de Guinee englobe une
tres grande diversite de territoires geobotaniques et de
formations vegetales. On peut y reconnaitre, de prime
abord, un certain nombre d'entites naturelles, nettement
differentes par leur climat, leurs paysages, et les modes
de vie humains :
la region cotiere, constituee par une plaine dominee
par les contreforts abrupts du rebord des plateaux gre­
seux; la pluviosite y est de l'ordre de 3000 mm par an, et
meme plus ; cette plaine, soumise a une saison seche
assez longue, est cependant, dans son ensemble, cou­
verte de savanes ; il s'y rencontre toutefois des reliques,
souvent alterees, des forets primitives; ces reliques sont
abondantes vers la frontiere de Sierra-Leone; il s'agit
la de forets riches en Parinari excelsa Sab . ; elles sont
peu stables, et les feux qui parcourent les savanes voi­
sines mordent sur leur lisiere et concourent a leur regres­
sion; il existe egalement des vestiges de foret dense haute
dans les vallees humides, notamment au pied du mont
Kakoulima et des plateaux greseux, - notamment au
pied du Benna; ils sont en voie de regression rapide sous
!'action du deboisement.
les plateaux greseux de la moyenne Guinee; il s'agit
essentiellement du Fouta-Djallon, et de son prolonge­
ment meridional, le Benna; d'une altitude qui varie de
1 000 a 1 500 m sur leur rebord septentrional, qui con­
stitue leur point culminant (region de Mali), ces plateaux,
grace a !'altitude, beneficient d'un climat plus humide;
la pluviosite y varie de 1 700 a 2000 mm environ, et les
brouillards sont frequents dans leurs parties les plus
elevees, notamment a Mali, pendant une partie de !'an­
nee; ces plateaux sont en grande partie couverts de
savanes guineennes banales, dans lesquelles se maintien­
nent frequemment quelques arbres forestiers : Parinari
excelsa et, aux altitudes moyennes, 'Erythrophleum gui-
neense G. Don; en diverses regions, subsistent des eten­
dues plus ou moins grandes de la foret primitive, carac­
terisee par la dominance de Parinari excelsa; ces reliques
forestieres sont en general plus ou moins alterees; parti­
culierement dans la region de Mali, les lisieres nettes de
ces reliques forestieres, et !'existence de groupements
vegetaux de transition (fourres avec arbres reliques)
attestent cette deforestation, en bien des endroits re­
cente.
les savanes de la haute Guinee, typiquement guineen­
nes (au sens de Chevalier, 1 933 et 1 938), mais passant
vers le Nord a un facies soudanien.
la chaine de Fon, dans la region de Beyla, qui, dans la
partie Sud de cette region de savanes, est en contact
avec les savanes guineennes; celles-ci atteignent ses
cretes et s'y individualisent par la presence d'especes
montagnardes ou submontagnardes (Protea angolensis
Welw. , Eupatorium africanum Oliv. et Hiern, Eulophia
propinqua Hutch. , etc.).
la regionforestiere, qui prolonge celle de Cote d'Ivoire;
elle comporte essentiellement des forets denses cadu­
cifoliees, a Triplochiton scleroxylon K. Sebum. , Termi­
nalia, Chrysophyllum perpu/chrum Mildbr., etc. ; ces
forets sont souvent degradees, et meme remplacees par
des groupements secondaires plus ou moins bas ; au­
dela de la lisiere Nord, ces forets irradient dans les
savanes du District preforestier des ilots forestiers re­
liques;
/es massifs montagneux du Domaine forestier : massif
du Ziama ( 1 300-1400 m environ), presque entierement
boise, et chaine du Nimba (culminant a 1 752 m), qui est
le massif le plus eleve de la Guinee, et se prolonge en
Liberia.
Sur le plan phytogeographique, la Republique de
Guinee se trouve, pour sa plus grande part, situee dans
le Domaine des savanes guineennes ; le passage au DoActa Phytogeogr Suec 54
70 R. Schnell
maine soudanien se ferait, suivant les auteurs, soit a
!'extreme Nord de la Guinee, soit dans la region de
Kankan, - ou Butyrospermum parkii apparait deja a
.
une centaine de kilometres au Sud de cette ville. Enfin
la axti� meridionale de la haute Guinee appartient au
domaine de. la foret dense.
�
INTE RET BOTANIQUE DE LA GUINEE ET
PROTECTION DE LA VEG ETATION ET
DE LA FLORE
La diversite de ses milieux naturels, malgre !'altitude
reduite de ses massifs montagneux, donne a la Guinee
un interet botanique particulier.
La chaine du Nimba, qui avait ete erigee, des 1 944,
en une reserve naturelle integrale, d'une superficie de
1 7 1 30 hectares\ - s'etendant sur le territoire de la
Guinee et sur la portion ivoirienne (plus reduite) de la
chaine, - offre a la fois de nombreux groupements
planitiaires et des groupements submontagnards ren­
fermant un certain nombre d'orophytes. La foret des
basses pentes est, dans I' ensemble, une foret dense semi­
decidue, souvent degradee, a Triplochiton scleroxylon
et Chrysophyllum perpulchrum; dans les vallees humides
de la portion occidentale de la chaine, on trouve une
foret ombrophile a Tarrietia uti/is Sprague et Mapania
div. sp. , - moins riche toutefois que ses homologues
de la basse Cote d'Ivoire, qui ont une plus large exten­
sion geographique. Au-dessus de 900-1 000 metres, la
foret, qui se localise surtout dans les ravins, mais atteint
les cretes SW, est caracterisee par la dominance de Pari­
nari excelsa; elle se rattache ainsi au type forestier sub­
montagnard caracteristique · des sommets de la Guinee
et de la Cote d'Ivoire, dont le Fouta-Djallon offre une
variante moins hygrophile; dans les hauts de ravins, on
note l'abondance de Syzygium staudtii (Engl.) Mildbr. ;
il y existe de beaux peuplements de Cyathea manniana
Hook . ; sur des sols minces vivent des forets basses a
Eugenia leonensis; sur des substrats rocailleux, la vege­
tation ligneuse basse renferme notamment Maesa lan­
ceolata Forsk. La savane submontagnarde, qui couvre
la quasi-totalite des cretes dans la portion guineenne de
la chaine, se caracterise par !'existence, sur un fonds
gramineen banal, d'un certain nombre d'especes mon­
tagnardes ou submontagnardes : Acidanthera aequinoc­
tialis Baker, Gladiolus unguiculatus Baker, Eupatorium
africanum Oliv. et Hiern, Disa subaequalis Summ., Pro­
tea angolensis Welw., etc. ; sur les escarpements rocheux
vivent Osbeckia porteresi Jacques-Felix, Blaeria mannii
(Engl.) Engl. ; l'origine de cette formation herbacee a
1 U n texte recent mention ne une superficie de 1 3 000 ha. Ce
chiffre parait correspondre a la seule partie guineenne de l a
reserve.
Acta Phytogeogr Suec 54
ete controversee; si !'existence d'orophytes plaide pour
son anciennete, les formations secondaires developpees
sur les lisieres indiquent un recul de la foret a Parinari
sous l'action des feux, qui ont parcouru chaque annee
Ies cretes avant la mise en reserve de la chaine; sans
doute les feux sont-ils responsables de son extension, a
partir de clairieres edaphiques, qui avaient constitue le
refuge des orophytes.
Le massif du Ziama presente l'interet de renfermer,
dans les forets basses de ses cretes, sur la lisiere des
clairieres naturelles, la seule station connue en Guinee
d' Olea hochstetteri Bak., espece qui se retrouve sur quel­
ques sommets de Sierra-Leone et de Cote d'Ivoire, et en
diverses regions montagneuses d' Afrique. Sur les dalles
rocheuses non boisees, on note des peuplements d' Aci­
danthera aequinoctialis.
Le massif de Fon, si sa fl.ore parait, dans l'etat actuel
des faits connus, moins riche en especes interessantes, a
du moins l'interet de presenter des vestiges de forets
su bmontagnardes a Parinari, surtout sur son versant
accidental expose aux vents humides et en contact avec
les forets denses de la region de Macenta; dans ses
regions basses, les vallees renferment d'importants res­
tes de forets denses. Enfin, dans les regions moyennes
de la chaine, les savanes, guineennes par !'ensemble de
leur fiore, presentent d'importants peuplements de Pro­
tea angolensis.
Sur les plateaux greseux du Fouta-Djallon, les reliques
forestieres qui subsistent sont des temoins des forets
primitives a Parinari excelsa,
moins hygrophiles que
celles des massifs meridionaux, et de composition diffe­
rente. Les escarpements rocheux des sommets, parti­
culierement dans la region septentrionale, plus elevee,
presentent un certain nombre d'especes interessantes :
Steganotaenia araliacea Hochst., Pycnocycla ledermannii
Wolff, Pimpinella praeventa Norm., Dicoma sessi!iflora
Harv., Echinops longifolius A.Rich., Aloe barteri Baker,
etc.
En moyenne Guinee, pres de Kindia, le mont Gangan,
boise a son sommet, se trouve en region de savanes; il
possede a sa base des escarpements greseux, avec des ma­
recages de rochers a Utricularia subulata L . , Burmannia
bicolor Mart., Cyanotis, Scleria, Xyris, Eriocaulon,
Mesanthemum auratum Lee., etc. , et sur certaines
dalles rocheuses, Microdracoides squamosus Hua. C'est
sur certaines de ces falaises que se trouve la seule station
connue de !'unique Bromeliacee africaine, Pitcairnia
feliciana (A. Chev.) Harms et Mildbr. Enfin, au pied de
la montagne, sur des dalles greseuses horizontales, vit
une tres belle Euphorbe cactiforme en candelabre.
Il importe enfin de souligner l'interet des reliques de
foret dense qui subsistent dans le domaine des savanes
guineennes, au voisinage du domaine forestier. C'est le
cas des ilots de foret de la region de Kissidougou (Dis-
Guinee
71
Fig. 1 . Monts Nimba. Vue de la partie N.E. de l a chaine, montrant la foret des basses pentes e t les reliques de foret d'altitude a
Parinari exce/sa dans les ravins.
trict preforestier), qui presentent un type extreme de
fon�t semi-caducifolie, a Khaya grandifoliola C. DC. et
Afzelia africana Sm. 11 est a souhaiter que ces vestiges
de ce groupement forestier particulier, temoins vrai­
semblable d'une ancienne extension de la foret, soient
preserves. 11 en est de meme pour les vestiges forestiers
de la plaine cotiere, au voisinage de la frontiere de
Sierra-Leone.
CONCLUSIONS
Sites et groupements vegetaux
La Republique de Guinee presente un certain nombre
de sites et de groupements dont la conservation presente
un interet scientifique indiscutable :
Chaine des monts Nimba : cette chaine, erigee en re­
serve naturelle integrale, il y a plus de vingt ans, sous
l'egide scientifique du Museum National d'Histoire
Naturelle et de l'IFAN, presente un interet scientifique
majeur, tant par ses groupements que par sa flore; il est
a souhaiter que cette reserve continue a etre l'objet d'une
attention particuliere, et que lui soient epargnes les ris­
ques que pourrait entrainer la recente mise en exploita-
tion d'une partie de la chaine dans sa portion liberienne.
11 est a souligner que, dans cette partie liberienne, mal­
gre cette mise en exploitation (camps miniers, pistes
carrossables, etc.), un interet est manifeste pour la re­
serve et la preservation de sa vegetation; des missions
scientifiques y sont organisees. En ce qui concerne la
partie guineenne des Monts Nimba, une station scienti­
fique existe au pied de l'extremite orientale de la chaine;
cette Station Scientifique Nationale des Monts Nimba
est geree par l'Institut National de Recherches et de
Documentation de Guinee (I.N.R.D.G.), qui a la direc­
tion scientifique de la reserve, et dont il faut louer l'in­
teret manifeste pour sa conservation.
Fouta-Djallon : la protection d'un certain nombre de
reliques forestieres, precedemment deja realisee dans
certains cas au titre de reserves forestieres, apparait de­
sirable; ces reliques forestieres devront etre choisies de
fa90n a donner un echantillonnage des divers groupe­
ments caracteristiques ; notamment les restes de foret
du Mont Loura (pres de Mali, sur le rebord septentrio­
·nal du plateau, a 1 500 m) meriteraient d'etre proteges ;
plus au Sud, dans la region de Dalaba, ou des reserves
forestieres avaient deja ete instaurees, les mesures de
Acta Phytogeogr Suec 54
72
J. K. Morton
protection pourraient s'integrer dans le plan general
d'amenagement de la region. Par ailleurs, la protection
des sommets rocheux non boises de la region de Mali
(mont Loura, mont Lanza), interessants par leur flore,
permettrait de conserver un bel ensemble de groupe­
ments vegetaux et d'especes; la protection de ces som­
mets rocheux ne peut d'ailleurs leser en rien les interets
agricoles de la region. La creation d'une vaste reserve
au mont Loura pourrait sauvegarder a la fois les vestiges
forestiers et la vegetation non forestiere, rupicole en par­
ticulier.
Mont Gangan, pres de Kindia : protection de ses escar­
pements inferieurs.
Massif du Ziama : protection des regions superieures,
au moins dans une partie du massif; cette protection
engloberait les forets montagnardes, parmi lesquelles les
forets basses a Olea hochstetteri, et un certain nombre
de clairieres edaphiques.
Chaine de Fon : la protection pourrait porter sur les
regions superieures, au Sud du col de Kanikoke.
Ilots forestiers du District pniforestier : il serait sou�
haitable de proteger au moins l'un des ilots de foret de
la region de Kissidougou.
Ilots forestiers reliques de la plaine cotiere : un ou
plusieurs bosquets reliques a Parinari excelsa de la re­
gion de Benty.
Especes vegetales meritant une protection particuliere
Nous ne mentionnerons ici que les especes qui, par leur
rarete et leur vulnerabilite, peuvent risquer de disparai­
tre; elles meritent, de ce fait, une protection particuliere :
Blaeria mannii1 et Osbeckia porteresi sur les cretes du
Nimba;
Pitcairnia feliciana et Euphorbia sp. sur les contreforts
inferieurs du Gangan;
Microdracoides squamosus sur les dalles greseuses des
plateaux du Benna et de la base du Gangan;
Olea hochstetteri sur les cretes du Ziama.
1 Il est a souligner que cette bruyere n'a ete rencontree qu'a
l'etat de tres rares individus isoles, en trois ou quatre endroits
de la chaine.
SI ERRA LEON E
J. K. Morton
INTRODUCTION
Sierra Leone lies on the bulge of Africa some go north of
the equator. In topography it consists, for the most part,
of low�lying land near the coast, rising gradually as one
moves inland to the much dissected edge of the main
African plateau with an elevation of some 2000 ft (c.
600 m). Rising out of this lower-lying land are several
important, and in places spectacular hill and mountain
masses. Highest of these are the Tingi Hills and Loma
Mountains of the interior whose main peaks of Sankan­
birewa and Bintumane exceed 6000 ft (c. 2000 m). The
only elevated land on the coast is found on the Freetown
Peninsula where hills rise steeply out of the beautiful
coastline to a height of 3000 ft (c. 1 000 m). Rivers dis­
sect the country, for the most part flowing from north�
east to south-west. Their lower reaches flow through
extensive areas of fresh water and mangrove swamps,
some of which are now being cleared for the cultivation
of rice. Geologically the bulk of the interior of the coun­
try consists of granites and gneisses. On the plains to­
wards the coast there is a belt of crystalline schists which
give way to extensive tertiary to recent deposits of sands,
Acta Phytogeogr Suec 54
grits, clays and gravels. The hills of the Freetown Penin­
sula consist of a complex of igneus rocks. Lateritic soils
cover much of the centre of the country with extensive
areas of sandy soils in the savannas of the north-east.
Over much of the central, northern and western parts
of the country the soils have been impoverished, often
as a result of cultivation and burning.
Sierra Leone's climate is perhaps best typified by its
extremes. Day temperatures range from about 1 00°F.
(38°C) during the dry season to about 70°F. (2 1 °C)
during the rains, with night-time minima reaching the
lower forties in the north and east during the dry season .
Rainfall ranges from about 240 in. (61 0 cm) p.a. on the
hills of the Freetown Peninsula through about 1 00 in.
(254 cm) on the plains, down to about 70 in. ( I 78 cm)
in parts of the savanna of the north. The distribution of
this rain is very uneven with prolonged dry seasons of
from 2 to 6 months and an intense wet season during
which soil leaching and erosion commonly occur.
Though humidity is high for much of the year, the hot
dry harmattan winds from the Sahara affect much of
the country for at least part of the dry season.
Sierra Leone
VEGETATION AND CONSERVATION
Most of Sierra Leone lies within the natural limits of the
tropical rain forest. Only in the interior of the country
in the north and east is natural Guinea savanna to be
found. However the vegetation pattern in Sierra Leone
is probably the most complex of any country in West
Africa. This complexity arises from the interaction of a
variety of factors, principal amongst which are topo­
graphy, soil and climate together with the devastating
influence of man in recent centuries. In few countries
of West Africa are the effects of man on the vegetation
more apparent. Little remains of the mature forest which
once covered much of the country. In its place are exten­
sive areas under shifting cultivation, where crops rotate
with a period of regeneration of farm bush. Within this
area increasingly large expanses of uncultivable land
occur on degraded soils. Some of these soils are impov­
erished through natural causes but most are the result
of unwise farming practices-practices which are un­
fortunately still prevalent. These degraded areas include
innumerable laterite pans where leaching has produced
a hard subterranean iron pan from which the surface
soil has been eroded. These areas are frequently more
or less inundated during the rains but extremely dry for
the rest of the year. They are covered with a short grass­
land and the older ones harbour a rich ephemeral and
geophytic flora. There are large areas in which the iron
pan has not been exposed by erosion and where drainage
is adequate. Many of these are covered by Lophira wood­
land in which stunted trees of Lophira lanceolata pre­
dominate to the virtual exclusion of other woody species.
In addition many of the valleys and other low-lying areas,
particularly where the soil is of sand or silt, have been or
are being cultivated for rice. During their fallow periods
these areas are occupied by grassland. Regeneration of
woody vegetation is prevented by the degradation of the
soil combined with the annual fires which sweep these
areas.
Several areas of mature forest remain in Sierra Leone,
particularly on the hills of the Freetown Peninsula,
around Kambui in the S.E. portion of the country, at
the foot of the Loma Mountains and in the extensive
Gola forest adjoining the Liberian frontier. A number of
forest reserves have been created for protection of the
soil and vegetation and for timber production. They
occupy about 4.25 % of the country but about half of
this area is intended for exploitation rather than conser­
vation. It is important that representative areas be con­
served both for future study and to provide a pool of
genic material of the more important timber species,
many of which are near the limits of their range in Sierra
Leone.
Montane and submontane associations of plants
73
occur in the Loma Mountains and Tingi Hills and many
important discoveries have been made there in the last
few years. The main plateaux of these two massifs are
at an altitude of some 4000 ft ( 1 200 m) and are occupied
by submontane grassland with a rich and interesting
herbaceous flora. Gallery forest ascends the water cour­
ses and contains many noteworthy submontane species.
The main peaks rise steeply as a series of spectacular
granite inselbergs, whilst that of Bintumane is unique
in its dolerite cap. These mountains have a remarkable
montane herbaceous flora showing affinities with neigh­
bouring peaks in the Fouta Djalon and the Nimbas, and
with mountains further afield in the Cameroons and
eastern Africa. In addition there is an important endemic
element which serves to emphasize the unique nature
of these plant communities. Severe fires sweep the
mountains each year, started in some cases by lightning
but more frequently by hunters who are fast destroying
the once rich mammalian fauna. These fires, though
they play an important part in maintaining the natural
montane grassland communities, are now of such sever­
ity and frequence that they are degrading the soil, des­
troying the gallery forest and pushing back the forest on
the slopes, which until recently has provided a barrier
between the lowland and montane savannas. This bar­
rier is rapidly diminishing and has been breached in
several places with the danger of an invasion of lowland
species. Early action to control these fires is essential if
irreparable damage is not to be done to these two very
beautiful and scientifically unique areas. Though both
areas have been designated forest reserves and efforts
are in progress to make the Lomas into a game reserve,
no effective protection is being afforded to either the
vegetation or animal life. With the resources available
in Sierra Leone it is unlikely that such protection will be
forthcoming in the foreseeable future without assistance
from outside.
Two other upland areas warrant mention because of
their interesting floras. The first are the forested hills of
the Freetown Peninsula. Much of this area has been pre­
served from damage as a forest reserve since 1 9 1 2 and
it is to be hoped that this wise policy will be continued,
for these forests are of an unusual type, being dominated
in their mid and lower areas by the two trees Daniellia
thurifera and Parinari excelsa. Higher up, where frequent
cloud maintains humidity during the severe dry season
this forest gives way to a submontane forest, whilst on
the peaks outcrops of sloping rock have interesting plant
communities with a few important submontane relics
,
such as Acidanthera aequinoctialis.
The second area, and an area of note for its spectacu­
lar scenery and rich flora, is the Gbengbe Hills lying to
the north of Makeni. These consist of a series of remark­
able granite inselbergs together with extensive rocky
Acta Phytogeogr Suec 54
74 A. G. Voorhoeve
plateaux. Though the altitude does not exceed 3000 ft
( 1 000 m) and the plant communities are not strictly sub­
montane, the assemblage of rare and interesting species
found in these specialized habitats is remarkable. Note­
worthy species include the peculiar sedge Microdracoi­
des squamosus which covers large areas of the exposed
gently sloping rock. There is probably no immediate
danger to these communities for the land is of no value
for agriculture or forestry. However, it is desirable that
the clear streams which rise on the plateaux should have
the vegetation around their headwaters protected to
maintain their flow through out the year. Consideration
might also be given to preserving these hills because of
their scenic as well as scientific interest.
Mangrove swamps occupy much of the coastline of
Sierra Leone, penetrating inland up the main tidal rivers.
In places extensive areas of mature mangrove occur with
trees reaching a considerable height. Interesting herba­
ceous communities occur in the swamps behind the man­
grove where rice is extensively cultivated. It is desirable
that representative areas of this mature mangrove forest
be preserved, for with the rapid extension of rice culti­
vation they are increasingly vulnerable. Suitable areas
occur along the Ribbi River where the forest reaches a
height of 80 ft and more.
Strand vegetation occupies limited areas of the coast
on the Freetown Peninsula and extensive areas on Sher­
bro Island and the adjoining mainland where there is a
vast system of old dunes, with thicket and forest on the
dunes and herbaceous vegetation in the slacks. The
coastal grassland is of an unusual type, being dominated
by the annual grass Anadelphia afzeliana with scattered
trees of Parinari macrophylla. The slacks have a rich
ephemeral and geophytic flora. Representative areas of
these peculiar habitats should be preserved. In the south
of the country, behind the coast, are extensive areas of
freshwater swamp with Vossia meadows along the water
courses and swamp forest behind. This is the home of
the endemic climbing shrub Habropetalum dawei.
Though the plant abounds in restricted areas its habitat
on the firmer ground at the edge of the swamps and
watercourses is inevitably vulnerable as building and
development in this part of Sierra Leone progress. Hence
it is of considerable importance that an area be set aside
for the preservation of this unique plant which has
attracted so much interest in botanical circles in recent
years.
As previously noted natural savanna woodland only
occurs in the north of the country. Much of it is being,
or has been, brought into cultivation and cattle are
grazed over extensive areas. A large area to the east of
Fintonia has recently been designated as a game reserve
and with suitable management this could .provide a re­
servoir of natural savanna vegetation. The savanna
woodlands around Falaba are particularly fine and rich
in their species composition. During the past twelve
months many new records to Sierra Leone of savanna
species (several of them, such as Vernonia poskeana,
being rarely encountered elsewhere in West Africa) have
-been made in this area and there is no doubt that much
remains to be discovered. In view of the rapid develop­
ment of agriculture in the savanna it is desirable that a
representative area be conserved.
From this brief account it will be seen that only limited
progress has yet been made in Sierra Leone towards
conserving the vegetation and flora. The country is par­
ticularly rich in its variety of vegetation types and in
interesting species, but extensive forestry and agricultu­
ral activities during the past few centuries have led to
the destruction of large areas of natural vegetation and
the impoverishment of soil over considerable parts of
the country. The need for effective measures to conserve
representative areas of the natural vegetation and to
protect individual species is indeed urgent if much is not
to be forever lost. It is suggested that the Sierra Leone
Government should be asked to set up a committee of
interested persons from government and university de­
partments to advise it on the most suitable course of
action. This might be achieved by reviving the Com­
mittee for the Preservation of the Fauna and Flora of
Sierra Leone set up some years ago, under the chair­
manship of the Permanent Secretary to the Minister of
Agriculture and Natural Resources.
LI B ERIA
A . G. Voorhoeve
GEOGRAPHY
Liberia is situated between 7° 30' West and 1 1 o 30'
West, and 4° 8' North and 8° 30' North. The total area
Acta Phytogeogr Suec
54
is about 1 1 1 ,500 km2• The coastline has a length of c.
560 km, and is orientated NW-SE. In northeastern di­
rection the country is not more than 270 km deep. A
Liberia
75
low coastal belt, 80-1 30 km wide, changes fairly abrupt­
ly into a dissected table-land, with nearly all rivers
flowing in SW direction. Only in the Nimba area and
the Wologisi area there occur mountains up to c. 1 350 m
high.
CLIMATE
The climate of Liberia is typically a monsoon climate.
Rains fall from April to November, with a more or less
distinct short dry season in July. Owing to the direction
of the coast, being perpendicular to the SW monsoon,
rainfall is high in the coastal area, up to 4500 mm annu­
ally, decreasing to c. 2000-1 800 mm in the interior. A
severe dry season with more than a month without rain .
is rare.
VEGETATION
The vegetation of Liberia is essentially a tropical moist
evergreen forest, towards the interior changing into a
more deciduous type of forest but never becoming the
true semi deciduous forest as dominant in Ivory Coast
except locally near the northern boundaries. The ever­
green forest is characterized by single dominant Legu­
minosae, whereas the drier forest types have a less Legu­
minous character. .
Secondary forests in all stages, and lands actually
used for agriculture form c. 2/3 of the total area. Along
the coast a man-made savanna occurs in a belt of c. 1 5
km wide. Locally mangrove forests are found in estua­
ries. In the north the country is locally invaded by the
Guinean savannas. In the mountainous areas in the
north tropical montane evergreen forest is found.
An area of about 1 600 000 ha is included in "Natio­
nal Forests". These, however, are not National Parks
which are not to be touched, but are forest reserves put
aside to be utilized under controlled management plans.
A true national park was planned in the Mount W utivi
area in the northwest of the country, but boundaries
are not yet surveyed. No specific species are protected.
As far as known at present there is no long-term plan­
ning for the conservation of Nature. A land-classifica­
tion, determining lands suitable for agriculture, forestry
and other needs is non-existent but badly needed. In
view, however, of the unique features of the Liberian
evergreen forests in West-Africa (excessive single-domi­
nance of a number of Caesalpiniaceae, endemism of some
species), it would be worth-while to recommend on
short term the formation of a few National Parks in
which these features are conserved. It is therefore recom­
mended that :
A coastal savanna-mangrove forest swamp area should
be set aside, including the estuary of a river. Size
at least 1 0 000 ha anywhere along the coast where both
Fig. 1. Mount Nimba, Liberia. The beginning of the ravine,
1 2 50 m.s.m.
c.
vegetation types are found, and where such a reserve
could be installed without interfering with the inter­
ests of the local population.
An evergreen forest area should be reserved in the
western part of the country, notably including single
dominant forests of such species as Cynometra leonensis
Hutch. & Dalz., Tetraberlinia tubmaniana J. Leonard,
and possibly Parinari excelsa Sabine. At least 20 000 ha,
possibly in the more rugged lands of the Vai National
Forest, else in the present Gola National Forest.
An evergreen forest area should be reserved in the
eastern part of the country, notably including single
dominant forests of the species Gilbertiodendron preussii
(Harms) J. Leonard, Monopetalanthus compactus Hutch.
& Dalz., Loesenera kalantha Harms, and Cynometra
ananta Hutch. & Dalz. At least 40 000 ha, possibly in the
present Sapo National Forest or the Krahn-Bassa Natio­
nal Forest. Also important as a wildlife reserve : hippo­
nana.
The whole of the Gio National Forest should be de­
clared to be a National Park. This national forest inclu­
des both moist evergreen and semi deciduous vegetation
elements, respectively on the western and eastern slopes
of a steep ridge in the centre of the forest. Also important
as a wildlife reserve: bush-elephants.
Acta Phytogeogr Suec 54
76
E. Adjanohoun, L. Ake Assi et J. L. Guillaumet
As large a part of the Nimba area as possible, outside
the mining concession of Lamco, but including the whole
East and West Nimba National Forests, should be pro­
tected (vide also the recommendations of Mr. J. G.
Adam, formerly at the I.F.A.N. of Dakar).
The Mount Wutivi National Park should be surveyed,
and protected from further burning.
This list is far from complete; detailed knowledge of
the vegetation is not yet available. Vegetation maps do
not exist. But implementation of these recommendations
could be the beginning of the protection of Nature in
Liberia. Reservation and maintenance of such National
Parks would be the task of the Bureau of Forest and
Wildlife Conservation. However, staff shortage, lack of
training, and perhaps above all lack of tradition make
the implementation of conservation of Nature in Li­
beria difficult.
LA C O T E D' IV O I R E
E. Adjanohoun, L . Ake Assi et J. L . Guillaumet
APER<;U GEOGRAPHIQUE
Bordee au Sud par !'Ocean Atlantique, sa seule frontiere
naturelle, la Cote d'lvoire etend ses 322 000 km2 entre
le Liberia et la Guinee a l'Ouest, le Mali et la Haute­
Volta au Nord, le Ghana a l'Est. Elle appartient essen­
tiellement au socle precambien de l'Afrique occidentale,
largement cristallin dans la partie septentrionale et le
Sud-Ouest, schisteux au Sud-Est avec cependant une
bande de sables argileux tertiaires le long de la Cote.
Pays de plaines bosselees et de plateaux interrompus
par des buttes solitaires ou groupees, couvertes de cuiras­
ses ferrugineuses ou seulement domes de roches nues, la
Cote d'lvoire presente cependant deux paysages origi­
naux. Au Nord-Ouest, l'extremite orientale de la dorsale
guineenne donne lieu a une suite de massifs montagneux
dont les principaux sommets depassent 1 000 m (Mont
Momy, 1 1 80 m; Mont Tonkoui, 1 1 89 m; massif des
Dans, 1 240 m; Mont Dou, 1 340 m; Mont Nimba, 1 752
m, aux confins de la Guinee, du Liberia et de la Cote
d'lvoire); a !'oppose, le long du golfe de Guinee, le has­
sin sedimentaire a donne naissance a une serie de la­
gunes. Le reseau hydrographique, important, comprend
quatre grands fieuves, aux vallees larges et profondes;
d'Ouest en Est, leur cours s'accroit en longueur : Caval­
ly, Sassandra, Bandama, Comoe.
APER<;U CLIMATOLOGIQUE
Entre 4° 20' et 1 0 ° 50' de latitude Nord, la Cote d'lvoire
presente tous les intermediaires entre climat equatorial
et climat tropical. Les deux secteurs Sud-Est et Sud­
Ouest, axes l'un sur le Cap des Trois-Pointes, l'autre sur
celui des Palmes, avec leur pluviosite elevee et bien re­
partie, jouissent d'un climat equatorial typique. Ailleurs,
du Sud au Nord, la secheresse apparait et s'accentue de
Acta Phytogeogr Suec 54
plus en plus. Elle se fait d'abord sentir par deux fois au
cours de l'annee, longuement pendant l'hiver boreal,
brievement pendant l'ete (climat tropical humide ou
guineen). Au dela du 8e parallele, la petite saison seche
disparait, mais la grande s'allonge et s'aggrave; on a
affaire au climat tropical subhumide ou subsoudanien
de transition devenant tropical semi-aride ou soudanien
dans les regions limitrophes de la Haute-Volta. Enfin
au dessus de 1 000 m, le climat du massif des Dans doit
etre distingue en subequatorial montagnard, caracterise
par des moyennes thermiques peu elevees et une forte
humidite permanente.
APER<;U G ENERAL DE LA VEG ETATION
Forets denses humides, forets claires et savanes se par­
tagent I'ensemble du territoire de la Cote d'Ivoire. Apres
le rideau de vegetation littorale, localement interrompu
par des savanes humides d'un type tres special (savanes
cotieres), commence le domaine des forets denses hu­
mides. Au Nord des lagunes, ces forets sont parsemees de
quelques savanes, differentes des precedentes (savanes
prelagunaires) et en relation avec celles du Nord .. Les
forc�ts sempervirentes occupent la bande meridionale du
pays et remontent a l'Est au dela du 6e parallele et a
l'Ouest, au niveau du 8e parallele. Remarquablement
homogenes dans leur ensemble, elles s'appauvrissent sur
les sols depourvus de reserve en eau, issus des sables
tertiaires, pour, au contraire, atteindre leur plus grande
luxuriance et diversite fioristique sur les roches schisteu­
ses riches en materiel fin susceptible de retenir une grande
quantite d'eau. Ce sont les forets a Legumineuses (Au­
breville 1 957). Plus au Nord, les forets denses humides
semi-decidues dominees par les Malvales et Ulmacees
(Aubreville 1 957) se differencient en plusieurs types qui
restent a preciser. Leur limite septentrionale des sine un
La Cote d'Ivoir.e
large V (cf. Mangenot 1 955). Au dessus de 1 000 metres,
dans le massif des Dans, apparait une foret dense humide
de montagne riche en especes specilisees.
Signalons dans ce vaste domaine forestier les forma­
tions d'un type particulier comme la mangrove a Rhizo­
phora racemosa liee aux lagunes cotieres, les forets ma­
recageuses et la vegetation herbeuse de certains domes
rocheux.
Sous la poussee actuelle de la mise en valeur de la
Cote d'Ivoire, cette vegetation forestiere tend a se diver­
s ifier en de multiples stades de degradation mal connus
dans leur detail et dont l'un des termes est le groupement
a Pennisetum purpureum.
Entre la lisiere septentrionale de la foret et jusque
vers le ge parallele, se situent les savanes guineennes ou
preforestieres, mosaique de bosquets, forets-galeries et
etendues herbeuses parsemees d'arbres et de Roniers.
Sans brUl is, elles evoluent en forets denses de type semi­
decidu (Adjanohoun 1 964).
Des forets claires et des savanes subsoudanaises et
soudanaises se partagent le reste du pays. Les forets
claires sont plus particulierement intactes dans les peri­
metres proteges par le Service des Eaux et Forets (n!ser­
ves de Bouna, forets classees) ou dans les endroits diffi­
ciles d'acces (domes et chaos rocheux). Parmi les especes
ligneuses qui les caracterisent, citons Isoberlinia doka,
Uapaca togoensis, Monotes kerstingii, Anogeissus leio­
carpus. Sont associees aux forets claires, des savanes
arborees ou arbustives tres inegalement reparties. Exi­
stent egalement des savanes strictement herbeuses, mais
ces dernieres sont edaphiques et localisees su-r -les cuiras­
ses lateritiques ou bowals, les inselbergs, certains sols
hydromorphes et les basses plaines alluviales des grands
fleuves, inondables en periode de crue.
APER<;U DES ASSOCIATIONS ET DES ESPECES
D EJA PROTEG EES (cf. Fig. 1 )
La majorite des associations vegetales reconnues en
Cote d'Ivoire se trouvent dans les reserves integrales,
pares nationaux, reserves botaniques, forets · classees,
relevant du Service des Eaux et Forets et y beneficient,
avec les especes qui les composent, d'une protection
plus ou moins definitive.
Reserves integrates
Monts Nimba (depuis 1 944) : Situee autour du point
culminant de l'Afrique occidentale (Mont Richard-Mo­
lard, 1 752 m), elle se partage entre la Guinee (9500 ha)
et la Cote d'Ivoire (5000 ha). Le versant ivoirien, oriente
au Sud-Est est couvert de foret dense humide semi­
decidue a Malvales et Ulmacees (Aubreville 1 957), rem­
placee au dessus de 1 000 m par une foret montagnarde
a Parinari excelsa dominant, riche en epiphytes varies :
77
Fig. 1. Cote d'Ivoire.
Orchidees, Moracees, Melastomatacees, Pteridophytes,
localisee dans les ravins. Les croupes sont occupees par
des savanes et prairies altimontanes. 11 existe en outre
des ravins rocheux humides et des eboulis recelant une
flore speciale. Les Monts Nimba ont plusieurs ende­
miques montagnardes (cf. Schne11 1 952).
Lamto-Pakobo (en voie de realisation) : 2600 ha dans
la sous-prefecture de Tiassale, sous climax de forets
denses humides semi-decidues, elle englobera la foret
riveraine du Bandama et les savanes a Loudetia simplex,
parsemees d'arbres et de Roniers et parcourues par de
nombreuses galeries forestieres (cf. Roland et Heydacker
1 963; Adjanohoun 1 964). Un laboratoire d'Ecologie
Tropicale y est implante depuis 1 96 1 .
Pares nationaux
Il n'en existe qu'un seul actuellement (foret du Banco),
deux reserves de faune et flore vont acquerir ce statut
(la Comoe et Tai), deux autres sont en elaboration
(Marahoue et Mont Peko ).
Banco : Cree en 1 924 par le Service des Eaux et Forets,
il recouvre, aux portes d' Abidjan, 3000 ha de foret dense
humide sempervirente sur sables tertiaires, traverses par
un ravin etroit et encaisse. Lieu de promenade pour les
Abidjanais, il est lie a l'Ecole Forestiere (arboretum,
plantations experimentales, pisciculture). C'est aussi,
par sa proximite, un excellent terrain d'enseignement
(Faculte des Sciences) et de recherches (Office de la
Recherche Scientifique et Technique Outre-Mer). L'as­
sociation vegetale de la foret psammohygrophile du
Banco est le Turraeantho-Heisterietum (Mangenot 1 9.S 5).
Acta Phytogeogr Suec 54
78
Ji. Adjanohoun, L. Ake Assi et J. L. Guillaumet
La Comoe : Prevue depuis 1 926, l'actuelle « Reserve
de Bouna » est inscrite dans l'annexe de la Convention
de Londres ( 1 933) sous le nom de « Reserve in the
North ». Elle fut en 1 953 decretee « Reserve totale de
faune et foret classee ». Le futur Pare national de la
Comoe s'etendra sur 1 000 000 ha (Reserve de Bouna
et foret classee de Kong). Ainsi defini il recouvrira une
vaste peneplaine percee de quelques petits massifs orien­
tes N.NE-S.SO et traversee dans sa partie occidentale
par le cours de la Comoe.
C'est le domaine des forets claires et des savanes sub­
soudanaises et soudanaises. Les forets claires sont carac­
terisees par Isoberlinia doka, Uapaca togoensis, Monotes
kerstingii, Anogeissus leiocarpus, Burkea africana, Khaya
senegalensis, Afzelia africana, etc. pour la strate ligneuse
contigue et Kaempferia aethiopica, Fadogia agrestis,
Andropogon tectorum, Aframomum latifolium, Amorpho­
phallus spp., etc. pour la strate herbacee.
Les savanes arborees et arbustives sont plus riches en
especes gramineennes et comportent une strate ligneuse
plus ou moins discontinue. Le groupement dominant,
sur les sols draines, est !'association a Panicum phrag­
mitoides avec de nombreux facies (cf. Adjanohoun 1 964).
Les savanes herbeuses, pour la plupart des groupements
edaphiques se repartissent comme suit : !'association a
Loudetia phragmitoides sur les sols hydromorphes; I' as­
sociation a Vetiveria nigritana dans les basses plaines
alluviales avec parfois des individus disperses de Mitra­
gyna inermis; !'association a Sporobolus pectinellus et
Cyanotis rubescens sur les bowals; !'association a Erio­
spora pilosa sur les inselbergs.
Les mares a Thalia welwitschii liees aux groupements
paludicoles et les « marules » des bowals a Dopatrium
senegalense et Marsilea polycarpa, ou des inselbergs a
Isoetes nigritiana et Ophioglossum gomezianum, sont
relativement dispersees.
Les forets-galeries sont pauvres en especes de foret
dense semi-decidue, mais possedent certaines especes
exclusives comme Garcinia ovalifolia et Crateva religiosa.
Quelques rares ilots de foret dense seche d'un type par­
ticulier s'individualisent sur certains plateaux.
Tai' : Foret classee, « reserve of Sassandra » de la Con­
vention de Londres, elle sera erigee en pare national de
425 000 ha.
Situe entre les fieuves Sassandra et Cavally dans une
region totalement inhabitee depuis tres longtemps, ce
Pare est recouvert de foret dense humide sempervirente,
climacique dans son ensemble. La fiore y est riche en
especes speciales a l'extremite occidentale du massif fo­
restier africain, endemiques ou que l' on retrouve dans le
massif equatorial. Quelques groupements vegetaux don­
nent une physionomie speciale : foret marecageuse a
Gilbertiodendron splendidum, foret ripicole a Plagiosiphon
emarginatus et Neosloetiopsis kamerunensis. Au SudActa Phytogeogr Suec 54
Quest, sur la rive gauche d'un affluent du Cavally, se
dresse un tres beau dome granitique, le Nienokoue, tota­
lement isole en fon�t.
La Marahoue : Reunissant en totalite ou en partie les
forets actuellement classees, reserves de faune et bota­
nique de Zuenoula, Seninlego et Bouafie, plus quelques
terres environnantes, ce Pare national de la Marahoue
s'etendra sur 1 25 000 ha. Situe a la limite entre foret et
savanes, il represente une mosaique d'ilots de foret dense
semi-decidue et de savanes guineennes. (Pour plus de
details sur les differents groupements vegetaux, voir
Adjanohoun 1 964).
Le Mont Peko : Dans la region de Bangolo-Duekoue,
ce pare de 35 000 ha englobera les Monts Peko et Kaoue.
Le premier recouvert seulement de foret basse seche ru­
picole, hebergeant quelques especes des forets claires et
savanes septentrionales ; il est egalement caracterise par
!'association a Eriospora pilosa; le second est entiere­
ment boise d'une foret dense humide semi-decidue.
Reserves botaniques
Differents arretes ont mis en reserves botaniques 1 5
forets classees : 2 en regions de savane, 1 3 dans le do­
maine des forets denses humides, dont 9 pour les forets
semi-decidues, 3 pour les forets sempervirentes et 1 en
foret sublittorale humide.
Forets classees
Actuellement, si nous tenons compte de celles qui sont
destinees a devenir des pares nationaux et des reserves.
botaniques, les forets classees comme telles par le Service
des Eaux et Forets sont au nombre de 246, recouvrant
5 253 700 ha. Les 3/5 sont en region de savane. A ceci
vient s'ajouter 7 746 300 ha de forets protegees.
Theoriquement, ce domaine de l'Etat est defendu con- ·
tre les defrichements culturaux, les droits d'usages y
sont reglementes, des permis d'exploitation y sont accor-·
des temporairement; trop souvent, cependant, leur sta­
tut n'est pas respecte, et depuis quelques annees le declas-­
sement se fait de plus en plus actif pour permettre l'im-·
plantation de cultures industrielles (plus de 400 000 ha
de forets classees sont maintenant passes a }'agriculture).
En savane, elles sont un peu mieux protegees, puisque:
ne possedant pas d'essences commerciales.
Les especes protegees
Un decret recent (3 1 mars 1 966) du President de la Re-·
publique et Ministre de !'Agriculture, interdit « la des-·
truction des fruits et semences, l'arrachage, la mutilation
et l'endommagement » sans autorisation de 26 essences­
commercialisees qui sont une des sources primordiales:
de revenus pour la Cote d'Ivoire (20 % du montant des.
exportations).
La Cote d'Ivoire
79
2. Cote d'lvoire. Aspect de la vegetation du complexe « Mont Tonkoui » a Man . Les rochers nus portent des taches
d'Eriospora pi!osa (Cyperaceae). Photo : E. Adjanohoun .
Fig.
ENUMERATION DES ASSOCIATIONS ET DES
ESPECES QU'IL FAUDRA
ENCORE PROTEGER
Le Gouvernement a toujours eu, on le voit, un souci
constant de proteger la nature centre des destructions
intempestives des superficies mises en defens, les projets
de Pares nationaux et de Reserves integrales font de ce
pays un des premiers de 1' Afrique occidentale dans ce
domaine. En outre, nous savons qu'actuellement des
etudes, demandees par le Gouvernement ivoirien, sont
en cours pour definir un programme destine a asseoir
une politique forestiere et de conservation des sols. Nous
ne pouvons que nous rejouir des realisations effectives
ou projetees et feliciter la Cote d'Ivoire de I' action entre­
prise pour assurer son avenir.
Il nous faut cependant faire quelques remarques et
emettre quelques vreux. Il existe maintes especes inte­
ressantes en Cote d'Ivoire, soit par leur rarete, soit par
leur endemisme; mais plutot que de demander leur pro­
tection, pratiquement impossible a assurer pour une
plante sans interet economique, il est plus souhaitable
d'obtenir la mise en reserve des quelques regions oil elles
sont presentes. C'est dans ce sens que nous ferons des
propositions. En second point, nous insisterons sur le
fait que le statut des reserves botaniques est mal connu
et demanderons son exacte application.
Reserves proposees (cf. Fig. 1 )
Guides dans notre choix par des motifs d'ordre bota­
nique, nous n'oublions pas que le monde vegetal et le
monde animal ferment un tout. Les regions que nous
proposons presentent toutes un interet pour le zoolo­
giste, quelque soit sa specialite.
Region d'Abidjan : Il serait souhaitable dans un but
d'enseignement de conserver quelques reliques de la
vegetation cotiere naturelle : mangrove d'Azuretti et
savane marecageuse de Moossou pres de Grand-Bassam,
fourre littoral a l'Ouest du canal de Vridi. Ces reserves
pourraient n'etre que de quelques hectares, la derniere
serait prise sur la foret classee de Vridi. Plusieurs especes
n'existent que la, dans les e_I!-Vir<?):;tS d'Abidjan.
Nord du canal d'Asagni : Reserve a but cynegetique,
ce sont 30 000 ha de savanes marecageuses entrecoupees
de savanes a Roniers, ilots de Pandanus et Raphia, bos­
quets de foret dense humide sempervirente. Inhabitee,
cette region ne semble pas propice a la culture. Elle est
un temoin des savanes du bas-pays. La flore est riche en
Acta Phytogeogr Suec 54
80 E. Adjanohoun, L. Ake Assi et J. L. Guillaum�t
Fig. 3. Cote d ' Ivoire. Com­
plexe « Mont Tonkoui >> a
M an : savane sommitale a
Eriospora pilosa avec rocher
decouvert macule de Lichen.
Photo : E . Adj anohou n .
Cyperacees, elle recele le Sphagnum albicans, extr�me­
ment rare en Afrique Occidentale.
Foret apres Ayame : Represente un Diospyro-mapa­
nietum- d'un type particulier avec des especes sassan­
driennes.
Mont Kope a Grabo : Cette region, la plus pluvieuse
du pays, est riche en endemisques du bas-Cavally, dont
certaines comptent parmi les plus grands arbres de Cote
d'lvoire, et possede la majorite des especes propres a
l'extremite du massif accidental africain. Tres accidente,
ce petit massif inhabite est entrecoupe de ravins humides
et rocheux hebergeant une fiore tre3 speciale. Le relief
exclut toute possibilite d'exploitation forestiere ou mise
en culture rationnelle.
Mont Tonkoui : Cette foret classee meriterait sans
aucun doute d'etre mise en reserve. De peu d'etendue,
autour d'un jardin d'essai et d'anciennes plantations de
Quinquina, la foret du Mont Tonkoui est digne d'interet
a plus d'un titre : bel example de fon�t montagnarde
facilement accessible, avec plusieurs especes ligneuses
speciales, presence de plusieurs rochers nus a Eriospora
pilosa et nombreuses petites herbacees speciales, peuple­
ment de la fougere arborescente Cyathea manniana,
nombreux epiphytes appartenant a des familles variees
(Orchidees, Aracees, Begoniacees, Moracees, Melasto­
matacees, Pteridophytes), abondance de fougeres et d'Or­
chidees terrestres, sans compter les innombrables mous­
ses, hepatiques et lichens prosperant a merveille dans ce
climat toujours humide.
Monts du Toura : Au Nord de Man comportant une
savane guineenne d'un type particulier.
Acta Phytogeogr Suec 54
Region d ! MankonJ : Aux sites de Kouroukouroung-:1
ou h foret claire, intacte dans le3 chaos granitiques, se
trouve en contact avec la foret dense.
Les domes rocheux couverts de foret claire, avec
d:ms les suintements et les replats des especes typiques.
Region d' Odienne : La pluviosite tres forte ( 1 600 mm)
favorise !'installation d'une vegetation luxuriante, des
plus interessantes et encore mal connue.
Les domes granitiques autour de Seguelo, avec une
fiore particuliere qui rappelle celle du Fouta Djalon.
Foret classee de Dienguele, etendue vers l'Ouest.
Une longue zone a l'Ouest de Tienko comportant des
groupem�nts de bowal, de domes rocheux et de basse
plaine alluviale.
Region de Tingrela : Au Nord de Boundiali, devant
permettre I' etude de la vegetation soudanaise qui entame
peu la Cote d'Ivoire septentrionale.
Reserves botaniques (cf. Fig. 1 )
Certaines des actuelles reserves botaniques sont traitees
en tant que telles, mais d'autres ne sont pas mieux pro­
tegees que le reste du domaine forestier national. Nous
voudrions obtenir une juste application des textes, en
particulier, interdiction des exploitations forestieres et
des defrichements culturaux. Etant donne la superficie
minime des forets considerees, ces interdictions ne peu­
vent nuire au developpement economique de la Cote
d 'Ivoire, mais tout au contraire favoriser des etudes
scientifiques indispensables pour son avenir.
Ghana
BIBLIOGRAPHIE
Adjanohoun, E., 1 964 : Vegetation des savanes et des rochers
decouverts en Cote d'Ivoire Centrale. - Memoire n° 7 ,
O.R.S.T.O. M . , Paris, 1 78 p p .
- 1 965 : Comparaison entre l e s savanes cotieres de Cote d'lvoire
e t du Dahomey. - Ann . Se. Univ. Abidjan, n° 1, pp. 4 1 -5 8 .
A k e Assi, L., 1 963 : Contribution a l'etude floristique de la Cote
d'lvoire et des territoires limitrophes. 1 - Dicotyledones,
2 - Monocotyledones. - Enc. Bioi., LXI, Lechevallier,
Paris, VII + 3 2 1 pp.
Aubreville, A., 1 957-1 958 : A la recherche de la foret en Cote
d'Ivoire. - Bois et for. trop . , n° 56, pp. 1 7-3 2 ; n° 58, pp.
1 2-28.
Guillaumet, J. L., 1 966 : Recherches sur la vegetation et la flore
81
de l a region d u Bas Cavally (Cote d 'Ivoire). - These Fac.
Se. Univ. Paris.
_
Mangenot, G., 1 95 5 : Etude sur les forets des plaines et des
plateaux de la Cote d'lvoire. - Etudes eburneennes, IFAN,
4, pp. 4-56.
Miege, J., 1 95 5 : Les savanes et les forets claires de Cote d'Ivoire.
- Etudes eburneennes, I FAN, 4, pp. 62-8 1 .
Roland, J . Cl. et Heydacker, F., 1 963 : Aspect de l a vegetation
dans la savane de LAMTO (Cote d 'lvoire). - Rev. Gen .
Bot. t. 70, pp. 605-620.
Schnell, R . , 1 952 : Contribution a une etude phytosociologique
et phytogeographique de 1'Afrique occidentale; les groupe­
ments et les unites geobotaniques de la region guineenne. M em. I nst. Fr. Afrique Noire, n° I 8, pp. 45-234.
G H AN A
G . W. Lawson
GEOGRAPHY
Ghana, occupying an area of 9 1 ,843 sqare miles, lies
north of the equator and wholly within the tropics form­
ing a roughly rectangular block about 250 miles from
east to west and 400 miles from north to south. The
terrain is mostly flat or gently undulating especially to­
wards the north though upland areas never reaching
more than 1 000 metres do occur especially in the forest
area, some of the most notable being the Akwapim ridge
limiting the northern extension of the coastal Accra
plains, the Voltaian or Mpraeso escarpment running
roughly along the line from Koforidua to Mampong
and bounded to the north by the Afram river, and the
hills of the Volta region of the south east. Some upland
areas do occur outside the forest a prominent example
being the Gambaga scarp in the extreme north east. A
new feature of importance is the partly formed Volta
Lake at present occupying about one third of the final
size of 3275 sqare miles it will be a year or two from now.
CLIMATE
The heaviest (over 80 in. p.a.) and best distributed rain­
fall occurs in the extreme south west though two rainy
seasons giving an average annual rainfall curve with
double maxima take place over a wide area of southern
Ghana. The south-eastern part of the country however,
though having this two-peak type of rainfall, is excep­
tional in having a very low (c. 30 in.) total annual rainfall.
Towards the north only one rainy season is experienced
and hence there is a very long intense dry season with
low humidity in the intervening period.
6 - 6 8 1 557 Hedberg
From an ecological point of view average temperature
figures tend to be very misleading. Published figures for
the Accra plains for example give the greatest mean
.
monthly maximum temperature as 32.0°C (March) and
the lowest mean monthly maximum temperature as
2 1 .3°C (August)-a range of 1 0.7°C. But the tempera­
ture at 1 0 cm above soil level in grassland was found to
vary from 24.5°C at 4.0 a.m. to 39 .0°C at 1 .0 p.m. during
a 24 hour series of observations in March 1 966. Thus
the range of temperature met with in this 24 hour period
was 1 4.5°C, considerably greater than the mean range
for the whole year. Incidentally in the thicket a few
yards away the range was only 8. 5°C (25.0°C-33.5°C).
VEGETATION
With the exception of a relatively narrow band of strand
and mangrove vegetation along the coast the vegetation
of Ghana can be broadly divided into two categories
-forest and savanna.
The forest lies in the south west within the two-peak
rainfall area and occupies rather less than one third of
the country. Moist Evergreen forest growing on an oxy­
sol type of soil occupies only a relatively small area in
the extreme south west. The area occupied by evergreen
forest is however even less than that usually shown on
the published maps since near the coast edaphic condi­
tions often prevent the occurrence of forest. However
the small savanna patches that occur on poor podsolised
sandy soils subject to marked seasonal fluctuations of
the water table are of considerable botanical interest.
The remainder of the forest is moist semi-deciduous
forest and here ochrosol conditions prevail. The latter
Acta Phytogeogr Suec 54
82
G. W. Lawson
3'
2'
o·
E:ZJ Strand
-
and Mangrov�
- Proposed Forest Reserve
Reserved Forest
Fig. 1. Ghana.
may be divided up into a number of subzones on a
floristic basis as was done by Taylor (1 952). He recog­
nised a narrow transition zone lying adjacent to the ever­
green forest and characterised by a mixture of species
belonging to evergreen and semi-deciduous forest. The
main bulk of the forest falls into his Celtis-Triplochiton
association and includes the most fertile agricultural
land. Another relatively narrow zone of forest however
separates it from the savanna. This is a relatively dry
type of forest classified as the Antiaris-Chlorophora
association.
As well as fringing forest, patches of forest are found
in the savanna north of the forest zone and undoubtedly
some of the savanna of this region can be regarded as
being "derived" from forest. It should be noted that
an attempt to classify Ghana's forests was also made
by Mooney (see Ahn 1 961). The main difference from
Taylor's classification is that the semi-deciduous forest
area is divided into wet and dry facies on the basis of
distribution maps of many important tree species.
Acta Phytogeogr Suec 54
The savannas are conveniently divided into northern
and southern types. The latter, occupying the low rain­
fall coastal plains forms a relatively narrow strip along
the coast south of the forest beginning at Takoradi and
widening as it stretches east towards the Togo border.
Parts of the western end of this strip are occupied by
more or less continuous thicket but this becomes much
broken up towards the east giving a type of tree savanna
where only isolated clumps of thicket and trees surround­
ed by grass occur. Were it not for the fire factor most
of this area would probably be a dry forest and there
are in fact occasional patches of "relict" forest. Though
it is true that there is a strong admixture of typical
savanna woodland (Guinea) species especially in the
eastern part, the Accra plains has a climate and vegeta­
tion unique in West Africa. At present there are large
almost uninhabited areas but irrigation and large-scale
farming may, in the near future, alter its character.
The northern savanna woodland stretches from north
of the forest to the border with Upper Volta and occu­
pies by far the greatest area of Ghana. It is sometimes
divided into a relatively moist southern half and a relati­
vely dry northern section though it would be difficult to
draw a clear line separating the two. Large tracts of the
southern section are almost uninhabited but the popula­
tion increases rapidly as one proceeds north and the
land becomes much more exploited agriculturally.
Farmed parkland . (Sudan type) is met with in Ghana
only in the north-eastern tip of the country around the
Bawku area.
The upland areas of Ghana such as the Togo plateau
may be said to have a distinctive vegetation and many
individual examples of mountain plants are found.
These upland areas are usually covered by a drier type
of forest or savanna though some summits are covered
by short grass only.
CONSERVATION OF VEGETATION
Conservation in Ghana is the responsibility of the
Ministry of Forestry and the fact that a separate Minis­
try is considered necessary is an indication of the impor­
tance that is attached to this work. Formerly the Forest­
ry division looked after both forest reserves and game
reserves but more recently a new division has been
created to take care of the latter. One cannot help but
be impressed by the considerable areas covered by the
forest reserves which number 266. The figures are
given in Table 1 .
Unfortunately from the point of view of the nature
conservationist the picture is not quite so rosy. Though
the Forestry division in theory has jurisdiction over the
whole of the forest (and the Savanna as well) for practi­
cal reasons little control is exercised over the forest out-
Ghana
Table 1 . Forest reserves of Ghana
Total area
(sq. miles)
Production Protection Percentage
reserves
reserves
of total
(sq. miles) (sq. miles) area reserved
3 3 ,7 3 2
Forest
Savanna 5 8,368
4,364
1 99
1 ,4 4 1
2,3 8 5
1 7. 2
4.4
92, 1 00
4,563
3 , 8 26
9. 1
Total
side of the reserves and the forest reserves themselves
are certainly not true nature reserves. From the foresters
point of view conservation is achieved when the amount
of timber extracted does not exceed the amount of new
growth necessary for its replacement and improvement
over a period of time. This means that explo�tation is
continuously going on but under controlled conditions.
Most of the production reserves are let out as. conces­
sions to the two hundred or so timber firms which oper­
ate in Ghana but each tree that is felled has previously
been individually mapped and sanctioned by the Forest­
ry department.
Since from about 1 70 common species of trees only
17 are commercially valuable and of these only 7 or 8
form the bulk, the removal of mature trees does not
disturb the forest to the extent that is sometimes believed
to be the case. The system at present employed is a poly­
cyclic one with a cut every 20-25 years (though in some
cases as little as 10 years) combined with improvement
thinning and stock mapping. A monocyclic system with
a much heavier cut and a longer regeneration period of
45-60 years has been recently suggested however and is
under consideration.
As a general rule farming is forbidden in reserved
areas. There are also protected timber lands outside the
reserves where farming, which as practised under the
traditional system of shifting cultivation involves de­
struction and burning of most of the natural vegetation,
is prohibited until after the timber has been extracted.
As manpower for control is limited ho�ever there is
much abuse of this rule in such areas by the farmers.
Even in the reserves themselves farming is sometimes
carried out with the approval of the Forestry division
according to the Taungya system in areas of poor forest
lying adjacent to villages where there is shortage of farm­
ing land. In this system the farmer is allowed to clear
and then the area planted up with such quick-growing
species as Terminalia ivorensis, Cedrela mexicana or Tri­
plochiton scleroxylon. The farmer then grows his crops
in the space between the young trees. As the trees grow
up he moves on to another site and repeats the process.
The protection Reserves quoted in Table I are usually
areas of forest on hills or ground otherwise difficult for
exploitation. Up to the present time they have been corn-
83
pletely preserved but as extraction methods improve and
if demand for timber increases it is anticipated that more
of these areas will pass into production.
It should be noted that several new forest reserves
have been proposed especially in the moist evergreen
forest of the south west. Many years may elapse however
before such areas are finally taken over by the Forestry
division since the legal and other matters to be settled
are tedious and complicated. On the other hand three
forest reserves in the Afram area, the Pawnpawu, Dedeso
and Mankrong reserves are being largely drowned by
the rising floods of the Volta Lake. All three of these
reserves were marginal from the point of view of timber
extraction.
The Forestry division is to be commended in taking
steps to protect certain areas which are of botanic rather
than commercial value, a notable example being the
Pusupusu ravine in the proposed Atewa Range Forest
Reserve,. one of the few places in Ghana where tree
ferns ( Cyathea spp.) and other rare ferns, mosses and
liverworts are found. Similarly certain sacredfetishgroves
such as the one belonging to the people of Akokoasi
in the Nsuensa Bediake Forest Reserve are to be entirely
free from interference apart from ritual acts which do
not disturb the vegetation. Such areas are always very
small however and do not usually exceed 1 /4-1 /2 of a
square mile.
To summarise the position as far as the forests are con­
cerned it may be said that their destruction outside the
reserves has been proceeding at an accelerating rate over
the past few years mainly for the establishment of cocoa
or other farms. Many areas which were heavily forested
about fifteen years ago when I first went to Ghana are
now opened up and farmed and have completely changed
in character. Within the reserves conservation is prac­
tised alongside exploitation. Unfortunately no sizeable
area of anything like virgin forest is entirely protect­
ed from interference. Ahn (1 959) has pointed out that
the destruction of forest has been much less rapid on
the poorer leached soils of south western Ghana than
elsewhere.
To turn to the Savannas it will have been noted from
the table given earlier in this article that large areas of
these are also reserved. Some of these areas are more or
less natural and others are planted up for poles or light
timber. Occasionally Teak is planted. In these reserves
an effort is made to foster early burning which is much
less destructive to the trees than the much fiercer burn­
ing that takes place late in the dry season (see Ramsay
and Rose Innes 1 963).
In addition to the forest. reserves a number of game
reserves have been set aside in Ghana during the past
few years as explained above. The most important of
these is the Mole game reserve in savanna woodland
Acta Phytogeogr Suec 54
84
G. W. Lawson
Fig. 2. Fresh-water lake-Avu Lagoon in the Volta Estuary with floating islands of sudd. Trees and shrubs: Aeschynomene ela­
phroxylon, Ficus congensis, Alchornea cordifolia (all floating). Grasses and herbs: Leersia hexandra, Eulophia longifolia, Cyclo­
sorus striatus (all floating). Photo: J. Jenik. February 1 966 (peak of the dry season) .
near Damongo supervised by a Ghanaian Mr. E. 0. A.
Asibey who has proposed its extension to cover a very
large area. He is well aware of the problems associated
with conservation and extremely keen to get new reserves
started and into operation. Another very large game
reserve has been proposed for the northern part of the
Afram plains. This is the Sene-Obosum Rivers Game
Reserve and will lie adjacent to the Kujani bush Forest
Reserve. A small supervised game reserve is situated in
the Shai Hills on the Accra plains. But many of the game
reserves in the forest exist more or less only on paper
without adequate supervision and control. Although
these game reserves are primarily concerned with pre­
serving animals of course they will also incidentally pre­
serve the vegetation in providing a natural environment
for the game. It must not be imagined however that such
reserves are entirely free from human interference of
various kinds. For example in the Mole game reserve,
though hunting is forbidden, periodic burning of the
vegetation is allowed and encouraged as it serves to
Acta Phytogeogr Suec 54
improve the quality of the grass. It should be noted that
most of these game reserves are in the savanna areas
where conservation of vegetation is not such a pressing
necessity as in forest.
It must also be pointed out that certain small areas in
the savanna region outside the reserves are of particular
botanic interest. These are usually areas where unusual
edaphic factors operate such as in swampy areas and
bowals. This applies also to the coastal savanna, for
example some of the lagoon� in the lower Volta area
such as the Avu lagoon have a surrounding swampy
vegetation of considerable interest. Such areas might be
endangered by plans to extend rice cultivation.
Thomas ( 1 962) has pointed out that much of the sa­
vanna in Ghana is marginal or submarginal with respect
to growing crops. Furthermore since many of the in­
digenous ungulates are better adapted to exploiting the
plant environment for food than cattle he suggests that
large areas should be set aside for wildlife management.
This proposal has not been acted on but if it were then
Ghana
85
Ankasa Forest Reserve,
south western Ghana.
Interior of well preserved rain
forest. Trees : Dialium aubre­
Fig. 3.
villei, Tarrietia uti/is, Cynome­
tra ananta, Drypetis aylmeri.
Shrubs: Rinorea oblongifo!ia,
etc. Photo : J. Jenik. January
1 967 (dry season) . .
arge areas of savanna would be preserved in a little
disturbed condition.
Another important proposal recently came from the
Zoology Department of the University of Ghana which
put forward a scheme for a large nature reserve in the
moist evergreen forest of the south west (Cole 1 964). It
was suggested that an area of about 36 sqare miles of as
near as possible virgin forest within one of the forest
reserves preferably the Ankasa reserve should be desig­
nated as a nature reserve. This area should remain com­
pletely untouched except for scientific research. The
forestry division is very sympathetic to this proposal
but points out that there are formidable difficulties since
nearly all of the land has been let out as timber conces­
sions and to revoke these would be a complicated proce­
dure probably involving payment of compensation if
the concessionees could not be induced to give up their
concessions voluntarily.
PROTECTION OF INDIVIDUAL SPECIES
Nothing has been said up till now about teh protection
of individual species and indeed none are protected in
Ghana. One tree, however, Chlorophora exelsa is not
allowed to be exported. The reasons for this are probab­
ly partly economic and partly historical. This does not
prevent its exploitation in Ghana where it is used a
great deal in building. Proposals have also been made to
restrict the export of certain plants believed to contain
chemical substances of value.
Under present conditions the only species that could
be protected are those that are locally abundant in cer­
tain areas-for example the tree ferns already mentioned.
Another example might be West Africa's only in­
digenous cycad Encephalartos barteri. This plant occurs
in abundance on high ground west of the Volta gorge.
Formerly this area was rather inaccessible and little fre­
quented but with the formation of the Volta Lake new
roads have been driven through it and at least one re­
settlement township-New Ajena has been built there.
Consequently there has been a great deal of clearing of
the vegetation for building and farming. Luckily Ence­
phalartos grows well on rocky ground and this fact may
save it from the farmers' hoe and cutlass.
PROPOSALS
From the preceeding discussion the following proposals
for conservation of vegetation in Ghana are put for­
ward:
1. Top priority should be given to conserving good
examples of moist evergreen forest and moist semi­
deciduous forest as nature reserves.
For the former it is suggested that at least 36 square miles of
nature reserve within the western part of the Ankasa forest re­
serve or the eastern part of the Draw forest reserve should be
designated.
For the l a tter, a nature reserve of similar size in a suitable
part of the moist semi-deciduous forest should be set aside. For
the practical reason that forest Game reserves will not be ex-
Acta Phytogeogr Suec 54
86
E. Adjanohoun
ploited for timber one of the following Game reserves might be
most suitable: Aboma Reserve, Onuem Bepo Reserve, Bom­
foum Reserve.
2. The following protection reserves should be declared nature reserves :
ACKNOWLEDGEMENTS
I thank Mr. John Fran�ois for valuable assistance in the prepa­
ration of this paper. I am also grateful to Dr. Jan Jenik, Mr.
Peter Ahn, M r. John Hall and Dr. John Morton for making
helpful suggestions.
The Banda Hills Watershed Forest Reserve.
The Gambaga Scarp Forest Reserve (East).
The Togo plateau Forest Reserve.
REFERENCES
3 . A number of areas outside the forest reserves which
are of considerable botanic interest but which are per­
haps not in such immediate danger should also be set
aside as nature reserves. The following localities are
suggested:
(a) An area of the dry fiat land on the Accra plains between
Dawa and Sege. (N. B . : this is in addition to the Shai Hills which
are already designated as a Game reserve.)
(b) An area of savanna with abundant Encephalartos barteri
in the neighbourhood of New Ajena.
(c) Lake Amonsuri together with an area of nearby swamp
forest and edaphic grassland.
(d) The marshy savanna near Sampa.
(e) Some of the bowals between Berekum and Sampa.
(f) The Avu lagoon and its surrounding swamps.
(g) Grass meadows on top of the Nkawkaw Scarp in the
Kwahu-Tafo and Pepiase area.
(h) Talbotiellia gentii forest at Akosombo.
Ahn, P., 1 959. The principal areas of remaining original forest
in western Ghana, and their potential value for agricultural
purposes. - J. West Afr. Sci. Ass. 5 (2), pp. 9 1 -1 00.
- 1 96 1 . Soil-vegetation relationsh ips in the western forest areas
of Ghana. - Tropical Soi l s and Vegetation. Proc. Abidjan
Symp. UNESCO 1 96 1 , pp. 75-84.
Cole, L. R., 1 964. Proposal for the reservation of a substantial
area of undisturbed closed forest in Ghana and the creation
of a field station for biological research a nd teaching (pri­
vately circulated), pp. 1 - 1 0.
Ramsay, J. M. and Rose Innes, R., 1 963. Some observations on
the effects of fire on the Guinea savanna vegetation of
Northern Ghana over a period of eleven years. - African
Soils 8 ( I ) , pp. 4 1 -8 5 .
Taylor, C. J., 1 952. The Vegetation Zones o f t h e G o l d Coast. ­
Gov't. Printer, Accra, pp. 1-12.
Thomas, J. n., 1 962. Observations on the conservation of wild
life in Ghanaian savanna. - Ghana J. Sci. 2 (2), pp. 1 59-1 75.
LE D A H O M E Y
E. Adjanohoun
APER<;U GEOGRAPHIQUE
Le Dahomey, d'une superficie de 1 1 2 600 km2, repre­
sente un long couloir perpendiculaire au littoral dans la
partie du Golfe de Guinee denommee Golfe du Benin.
Il est limite a l'Ouest par le To go et la Haute-Volta, au
Nord par le Niger et a l'Est par le Nigeria. 11 a environ
1 20 km de cote entre les meridiens 1 o et 4o Est. Son plus
grand axe mesurant pres de 700 km est compris entre le
6e et le 1 2e paralleles Nord. De forme rectangulaire, du
ge parallele au littoral, il s'elargit progressivement jus­
qu'a atteindre 300 km entre le ge et le 1 1 e paralleles et
se retrecit de nouveau vers la frontiere Nord, sur le
fleuve Niger.
Au point de vue relief, le Dahomey est un pays peu
accidente. Il comporte deux zones elevees dont I'altitude
varie de 400 m a 650 m. La premiere correspond au
massif de l'Atacora oriente N.N.E-S.S.O qui se pro­
longe au Togo ou il atteint plus de 1 000 m. La seconde
chevauche sensiblement le 1 oe parallele et correspond a
la ligne de partage des eaux des bassins du Niger et de
Acta Phytogeogr Suec 54
l'Oueme. De part et d'autre du toe parallele, la pene­
plaine granito-gneissique s'incline en pente douce vers
le Niger au Nord et l'Atlantique au Sud. Elle est inter­
rompue localement par des inselbergs et des batholithes
granitiques ou migmatiques, des chainons de gneiss dans
les regions de Save, Dassa-Zoume, Savalou, Djougou,
Parakou. Des buttes temoins cuirassees sont de plus en
plus nombreuses a mesure que l'on se rapproche du
Niger.
A I'extreme Sud, precedant le cordon littoral, se trou­
vent des basses plaines facilement inondables par les
fleuves, des lacs et des lagunes aux rives marecageuses.
Le reseau hydrographique du Dahomey est important.
De nombreux cours d'eau dont l'Oueme (450 km), pren­
nent leur source dans l'Atacora (cf. Fig. 1).
APER<;U CLIMATOLOGIQUE (cf. Fig. I )
O n peut distinguer, a u Dahomey, trois grandes zones
climatiques :
Le Dahomey
87
La zone littorale et sublittorale : Elle depasse legere­
ment le 7e parallele Nord (Abomey) et est soumise a un
climat tropical humide ou guineen (type cotier daho­
meyen) caracterise par l'alternance de deux saisons de
pluie et de deux saisons seches d'inegale dun!e. Les
courbes pluviometriques accusent un premier maximum
en juin et le second en octobre. La petite saison seche
qui s'intercale entre les deux excede rarement deux mois
(juillet-aout). La grande saison seche couvre les mois de
decembre a fevrier. La pluviosite annuelle augmente le
long de la cote d'Ouest en Est (900 mm a la frontiere
togolaise et 1 450 mm a la frontiere nigerienne).
L'hygrometrie est toujours elevee. La moyenne men­
suelle des minima journaliers de l'humidite relative est
toujours superieure a 60 % a Cotonou, a 40 % a Bohicon;
la moyenne des maxima etant toujours comprise entre
90 et 1 00 %.
La zone de transition : Comprise entre les 7e et 9e
paralleles Nord, elle est soumise a un climat tropical
subhumide (subsoudanien de transition). L'influence du
climat soudanien, de plus en plus marquee vers le Nord,
se traduit par une accentuation de la pluviosite moyenne
annuelle, un rapprochement des deux maxima pluvio­
metriques et correlativement la disparition progressive
du minimum intermediaire, dont la valeur, toujours
elevee ne permet plus comme dans le Sud, !'installation
d'une veritable saison seche. La pluviosite annuelle
oscille entre 1 000 et 1 200 mm. Elle est plus elevee a
l'Ouest qu'a l'Est.
Les maxima et minima de l'humidite relative sont
respectivement superieurs a 80 % et compris entre 30 et
0
(.!)
70 % .
0
.....
La zone Nord : Le climat est tropical semi-aride (sou­
danien) devenant sahelo-soudanien a l'extreme Nord.
�1 n'y a plus que deux saisons : une saison seche de
novembre a mars et une saison des pluies dont le maxi­
mum est en aout ou en septembre. La pluviosite est plus
forte dans les secteurs topographiquement plus hauts
(sud du massif de l'Atacora) avec 1300 mm a Natitingou
et decroit jusqu'au Niger (avec 900 mm a Malanville).
L'harmattan, vent chaud et sec du NE est responsable
de la baisse brutale de l'humidite relative en novembre.
Les minima sont inferieurs a 30 % pendant 4 a 6 mois;
les maxima sont compris entre 45 et 75 %.
• • • ••
___
••
�
APER<;U G ENERAL SUR LA VEG ETATION
Bile est fortement degradee par l'homme, surtout dans
le bas-Dahomey oil la densite de population est elevee
et au voisinage des principaux axes de communication.
Malgre cela, on arrive facilement a etablir une certaine
succession des differentes formations vegetates qui se
Fig.
1.
L imite for�ts denses et s a vanr:s ,quin eenn�s
Forets
clair e s
et
L imite des secteur-s
savanes subsoudanais es
subsoudanien
Regions m ontagneuses,
et soudanien
400 a 600 m.
Res er ves in tegrates propose�s
Carte du Dahomey avec des isohyetes annuelles
subdivisent en trois groupes : les formations littorales
au Sud des lagunes, le domaine des forets denses hu­
mides qui s'etend jusqu'au se parallele et couvre la zone
sublittorale et la partie meridionale de la zone de tranActa Phytogeogr Suec 54
88
E. Adjanohoun
sition precedemment definie, le domaine des forets
claires et des savanes ·subsoudanaises et soudanaises
qui caracterisent la zone Nord.
Les formations littorales
On observe par endroits, de la cote vers l'interieur, les
restes discontinus, plus ou moins degrades suivants :
Fourre littoraP a Diospyros tricolor et Chrysobalanus
orbicularis continuant la bande etroite des herbes psam­
mophiles stoloniferes les plus resistantes a l'embrun.
Savanes c6tieres ou littorales (cf. Adjanohoun 1 965).
Elements de mangrove a Rhizophora racemosa et
A vicennia africana.
Forets marecageuses a Symphoniaglobulifera avec Ra­
phia gigantea, Ficus congensis et Anthocleista vogelii.
Marais ou prairie fiottante a Paspalum vagina/is, Cype­
rus articulatus, Cyperus papyrus, Phragmites vulgaris et
Echinochloa pyramidalis.
Le domaine des forets denses humides
Le type de forc�t qui caracterise cette vaste region est la
foret dense humide semi-decidue a Celtis (Mangenot
1 955) ou a Malvales et Ulmacees (Aubreville 1 957).
Cette foret est detruite un peu partout et n'existe que sous
la forme de reliques. Ces dernieres sont so it des forets sa­
crees (regions de Porto-Novo, Ouidah, Allada, Abomey,
etc.), soit des ilots proteges dans certaines stations de
recherches agronomiques (I.R.H.O.-Pobe et Niaouli),
soit des taches dans les regions rocheuses, difficilement
accessibles (Savalou, Dassa-Zoume, Save). Quelques
especes de grandes dimensions, caracteristiques de ces
forets, sont parfois individuellement protegees dans les
villages; ce sont Cola cordifolia, Ceiba pentandra, Tri­
plochiton scleroxylon et plus particulierement Chlorophora
excelsa.
Partout ailleurs, la foret est remplacee par des pal­
meraies a Elaeis guineensis, frequemment associees a une
brousse forestiere et aussi par des savanes guineennes
(cf. Adjanohoun 1 964). Nous sommes dans la zone des
mosaiques foret-savane.
Les savanes sont de plusieurs types :
Les savanes arborees a Daniellia oliveri et a Parkia
biglobosa qui sont particulierement developpees dans la
partie septentrionale de notre domaine.
Les savanes arbustives ou arborees a Lophira lanceolata
et Borassus aethiopum dans la partie meridionale, carac­
teristiques des cordons anciens de l'Ouest. Elles sont
egalement parsemees de bosquets riches en Elaeis gui­
neensis. Dans les secteurs les -plus secs domine parfois
Adansonia digitata.
Les savanes marecageuses avec Mitragyna inermis,
caracterisent les basses plaines alluviales longuement
Acta Phytogeogr Suec 54
inondees en periode de crue. Ces dernieres comportent
egalement des bouquets de Phoenix reclinata.
Quelques forets ripicoles sont particulierement deve­
loppees. Certaines, installees sur des sols hydromorphes
ou dans les zones alluviales accusent une abondance
remarquable de Dialium guineense.
Dans toute cette region, en bordure de route ou dans
les endroits frais, se rencontrent des bandes ou des
taches de Pennisetum purpureum ou Panicum maximum.
Le domaine des forets claires et des savanes subsoudanaises et soudanaises (cf. Fig. 1 )
S a limite meridionale se trouve entre Savalou e t Save,
au niveau du 8e parallele. Dans ce domaine, les forets
claires sont intactes et des plus belles sur certaines col­
lines, dans les chaos rocheux impropres a la culture ou
dans les perimetres partiellement proteges par le Service
des Eaux et Forets (forets classees), sous une pluviosite
annuelle oscillant entre 1 200 mm et 1 350 mm. Ce s'ont
des forets claires a Isoberlinia doka, Uapaca togoensis,
Monotes kerstingii etc.
Dans la region de Djougou et Bassila, existent quel­
ques rares ilots forestiers de plateau de type foret dense
semi-decidue tres pauvre. lis possedent d'evidentes affi­
nites fioristiques avec certaines galeries forestieres qui
pourraient etre a leur origine.
Plus au Nord, dans les regions de pluviosite moindre
( 1 200 mm a 900 mm) les forets claires devenant de plus
en plus ouvertes sont caracterisees par certaines especes
ligneuses deja citees, mais de petites dimensions aux­
quelles s'ajoutent des epineux (Strychnos spp., Acacia
spp., Faidherbia albida, etc.) et aussi Hyphaene thebaica.
De belles r6neraies (Borassus aethiopum) sont localisees
sur les alluvions du fieuve Niger a !'extreme Nord.
Les savanes arborees ou arbustives derivees des forets
claires sont les plus variees. Les savanes herbeuses sont
edaphiques et se trouvent sur les cuirasses lateritiques
ou bowals, les inselbergs, dans les basses plaines allu­
viales des rivieres ou sur certains sols hydromorphes.
LES ASSOCIATIONS ET LES ESPECES
DEJA PROTEGEES
11
n'y a pas de reserve botanique integrale proprement
dite au Dahomey, mais de nombreux groupements vege­
taux beneficient d'une protection relative, parfois defi­
nitive. Ce sont ceux des pares nationaux et des forets
classees, relevant du Service des Eaux et Forets, ainsi
1 Cette formation est detruite presque partout, remplacee par
les plantations de Cocotiers (Cocos nucifera) et de filao ( Casuarina
equisetifolia) ou d' Anacardium occidentale.
Le Dahomey
89
et celui de la boucle de la Pendjari au Nord-Ouest. Ces
derniers peuvent etre consideres comme des reserves
botaniques integrales puisque la protection de la faune
implique celle des groupements vegetaux dont elle de­
pend. Les forets classees sont relativement importantes
dans ce domaine. Les principaux groupements individua­
lises dans les perimetres provisoirement proteges sont :
les forets claires avec une strate ligneuse caracterisee par
Isoberlinia doka, Uapaca togoensis, Monotes kerstingii,
Anogeissus leiocarpus, Burkea africana, Khaya senegalen­
sis, Afzelia africana, Butyrospermum parkii, Securidaca
longepedunculata, Diospyros mespiliformis, Cassia sie­
beriana, Pterocarpus erinaceus, Terminalia spp., Gardenia
spp . , Strychnos spp . , Bombax costatum, Daniellia oliveri,
Vitex spp., etc. La strate herbacee comprend entre
autres : Kaempferia aethiopica, Fadogia agrestis, Afra­
momum latifolium, Andropogon tectorum et de nombreu­
ses autres Andropogonees, Cissus spp., Amorphophallus
2. Dahomey : Region de Savalou a pn!s de 200 km de la
cote atlantique. Savane arboree a Encephalartos barteri (Cyca­
daceae). Photo : E. Adjanohoun.
Fig.
que certains ilots forestiers sacres ou proteges dans les
stations agronomiques.
Concernant les forets classees, celles des formations
littorales et du domaine des forets denses humides ne
representent pas strictement le climax; elles sont pour
la plupart replantees en essences introduites telles que
Gmelina arborea, Cassia siamea, Tectona grandis, etc.
Quant aux ilots forestiers, ceux de l'I.R.H.O.-Pobe, de
Niaouli et d' Attogon sont typiques et representent une
foret dense humide semi-decidue a Malvales et Ulmacees
(Aubreville 1 957). Les releves indiquent une strate haute
a Triplochiton scleroxylon, Celtis zenkeri, Celtis mild­
braedi, Antiaris africana, etc., une strate moyenne a Tri­
chilia prieureana, Lecaniodiscus cupanioides, Malacantha
alnifolia, Dracaena spp., etc., une strate basse a Diospy­
ros monbuttensis, Mallotus oppositifolius, Teclea ver­
doorniana, etc., et de nombreuses lianes telles Motandra
guineensis, Baissea breviloba, Prevostea heudelotii, Cis­
sus petiolata, Dioscorea spp., etc.
Dans le domaine des forets claires et des savanes sub­
soudanaises et soudanaises existent deux pares natio­
naux, celui du W du Niger qui entame le Nord du pays
1 Pour plus de renseignements sur ces groupements, voir
Adjanohoun ( 1 964).
spp. et Legumineuses diverses.
Les savanes arborees et arbustives sont plus riches en
especes gramineennes. Sur les sols draines, le groupe­
ment le plus repandu est tres comparable a I'association
a Panicum phragmitoides deja decrite en Cote d'lvoire
(Adjanohoun 1 964).
Les savanes herbeuses, pour la plupart des groupements
edaphiques se repartissant comme suiF :
I' association a Loudetia phragmitoides, tres repandue,
constitue un groupement hydrophytique sur sols hy­
dromorphes et se rencontre dans les thalwegs ou au
bout des galeries forestieres et a leur flanc;
!'association a Vetiveria nigritana, constitue le prin­
cipal groupement des basses plaines alluviales des
grandes rivieres inondables en periode de crue;
I' association des mares a Thalia geniculata, en relation
avec les savanes marecageuses ou les basses plaines
alluviales;
!'association a Sporobulus pectinellus et Cyanotis ru­
bescens, caracterise les bowals et constitue une pe­
louse rase, les elements arbustifs etant tres spora­
diques;
!'association a Eriospora pilosa, qui est le groupement
pionnier des domes rocheux denudes en partie de la
vegetation forestiere;
les associations de micro-marecages sur bowal a
Dopatrium senegalense et Marsilea polycarpa et sur
inselberg a Isoetes nigritiana et Ophioglossum gome­
zianum.
Pour ce qui concerne les especes protegees, il existe
une liste d'une cinquantaine d'especes « dites protegees »
par le Service des Eaux et Forets pour !'ensemble de
l'ex-A.O.F. La moitie environ de ces especes se trouve
au Dahomey, repartie entre les forets denses et les forets
claires.
Acta Phytogeogr Suec 54
90
E. Adjanohoun
Fig. 3. Encephalartos barteri
( Cycadaceae). Photo : E. Ad­
janohoun.
LES ASSOCIATIONS ET LES ESPECES QU'IL
FAUDRA ENCORE PROTEGER
Outre les pares nationaux de la boucle de la Pendjari
(275 000 ha) et du W du Niger (502 000 ha), nous pen­
sons qu'il faudrait obtenir des autorites locales la pro­
tection integrale de tout ou partie de certaines fon�ts
actuellement classees qui comportent les associations
vegetales les plus indicatrices, les ilots forestiers relevant
des stations de recherches, ainsi que les groupements
particuliers non encore sous reserve et menaces.
Domaine des forets denses
Les forets classees comportant des elements de foret
dense semi-decidue :
Agrimey (2800 ha) , en partie
Atcherigbe (3 1 50 ha), en totalite
Djigbe (4300 ha) , en partie
Ketou ( I I 000 ha), en partie
La Lama ( 1 6 250 ha), en partie
Sakete (60 ha) , en totalite.
Les forets classees comportant des elements de savanes guinecnnes :
Dan ( 1 237 ha), avec bowal a Sporobo!us et Cyanotis, en
totalite
Pahou-Ouidah (765 ha) : S3.Vanes a Lophira et Borassus, en
partie
Seme (1 290 ha) : savanes littorales, en partie.
Sites nouveaux, non classes,
a
proteger :
Groupe des rochers de Dassa-Zoume avec la foret a Hilde­
(environ 1 00 000 ha).
gardia barteri
Acta Phytogeogr Suec 54
I.R.H.O.-Pobe (foret dense semi-decidue), en totalite
Niaouli (foret dens� semi-decidue), en totalite
Foret m3.recageuse au Nord de Porto-Novo ( 1 000 ha)
Foret et prairies man!c3.geuses entre Seme et Porto-Novo
( 1 000 ha)
Form:1tions littorales avec elements de mangrove entre
Ouidah et Grand-Popo (5000 ha)
Prairie marecageuse du Lac Nokoue (5000 ha)
Foret riveraine a Dialium guineense et basse p laine associee ,
region d' Athieme ( 1 000 ha).
Domaine des forets claires
et des savanes associees
Principales forets claires
a
proteger integralement
L'Alibory superieur (256 000 ha) , en partie
Les 3 Rivieres (259 000 ha), en partie
Les Monts Koutfes ( 1 80 000 ha), en totalite
L'Oueme superieur ( 1 77 540 ha), en partie
Ouari-Maro ( 1 07 000 ha), en partie
Agoua (7 5 300 ha), en totalite
Goungoun (73 200 ha), en totalite
La Sota (53 000 ha), en totalite
Penessoulou (5470 ha), en totalite
Bassila (2500 ha), en totalite.
Sites nouveaux, non classes,
a
proteger
Atacora Sud (environ 50 000 ha)
Zone alluviale du Niger avec Borassus aethiopum ( 1 000 ha)
Rochers de Hedjinnamonnou au Sud-Ouest de Savalou
avec peuplement nature! d' Encephalartos barteri.
Ces reserves comprennent les differents facies de tous
les groupements vegetaux indiques ainsi que les especes
susceptibles d'etre protegees.
Nigeria
CONCLUSION
Le choix de ces differentes formations vegetates, classees
ou non, a proteger integralement, est guide par des sou­
ds d'ordre precis. Il devient urgent de proteger a !'eche­
lon national des elements de la nature contre les destruc­
tions de plus en plus intempestives entrainees par l'ac­
croissement de la population des hommes. Le probleme
de la conservation des ressources naturelles est un pro­
bleme d'actualite; aussi, pour exploiter au mieux ces
ressources, i l faut connaitre parfaitement les biocenoses.
L'etude botanique et ecologique du Dahomey est a ses
premiers pas et seules les reserves integrates judicieuse­
ment choisies pourraient permettre, dans un avenir que
nous souhaitons prochain, sa pleine realisation. Parmi
les sites proposes, certains, deja tres abimes pourraient
se reconstituer et nous eclairer sur la vegetation naturelle
si variee de ce pays. D'autres, situes a proximite des
centres universitaires devront constituer un materiel
d'enseignement precieux et aider a la formation des
jeunes ecologistes dahomeens appeles a resoudre les
differents problemes economiques.
91
Les reserves proposees representent moins de 15 %
de la superficie totale du Dahomey, la plupart se trou­
vant dans le Nord peu peuple. Elles ne sauraient done
aucunement entraver son developpement economique et
social.
BIBLIOGRAPHIE
Adjanohoun, E., 1 964 : Vegetation des savanes et des rochers
decouverts eri Cote d'lvoire Centrale. - Memoire n ° 7 O . R.S.T. O.M. , Paris, 1 7 8 pp.
- 1 965 : Comparaison entre les savanes cotieres de Cote d'lvoire
et du Dahomey. - Ann. Se. Unic. Abidjan, n ° 1 , pp. 4 1 -58.
Aubrevil!e, A., 1 957-1 958 : A la recherche de la foret en Cote
d'lvoire. - Bois et for. trop. , n° 56, pp. 1 7-32 ; n° 5 8 , p p .
1 2-2 8 .
Mangenot, G., 1 965 : Etude s u r les forets des plaines et des
plateaux de la Cote d'lvoire. - Etudes eburneennes, IFAN,
4, pp. 4-56.
Pliya, J. et Mondjannagni, A., 1 963 : Cartes Republique du
Dahomey au 1 /550 oooe. - Edition M.B. I . St Germain-en­
Laye (S. et 0), France.
A.E.T. F.A.T. (ed.) 1 9 5 9 : Carte de la vegetation de l'Afrique au
S ud du Tropique du Cancer. Londres.
N I G E RI A
J. R . Charter
GEOGRAPHY
Nigeria covers an area of 356,000 square miles, and
lies between 4 and 14 degrees north latitude and 2
and 1 5 degrees east longitude.
To the south a low-lying coastal belt of sandy
beach ridges, coastal creeks and lagoons up to 60
miles wide, flanks a 4000-square mile area of man­
grove and swamp comprising the Niger Delta.
Inland, the mainland rises steadily in the West to
some 2000 feet at a distance varying from 1 20 to
200 miles from the coast. North of the great rivers
of the Niger and Benue much of the country lies at
an altitude of 2000 feet, but in the west these areas
are separated by the Niger valley, and further east
the great Benue trough similarly marks the southern
limit of the high northern plains. Other areas below
1 000 feet are found in the Sokoto plains to the north­
west and in the Lake Chad basin to the north-east.
In the centre of the northern region lies the Jos
Plateau, rising abruptly from the high plains and
with an average level of some 4000 feet. Along the
eastern border of the northern region run the Came­
roon-Adamawa-Mandara mountains, attaining in Ni-
geria an average elevation of 3 000-5000 feet with a
southerly outlier reaching 6000 feet in Ogoja Prov­
ince in the Eastern Region.
To the south-east, west of the mountains and east
of the Niger, the land is generally lower than in the
other major regions. Summit heights rise to a maxi­
mum of 1700 feet west of the Enugu scarp, and
most of the Cross River Basin is of low altitude.
CLIMATE
The climate of Nigeria is of the monsoon type and
is regulated by seasonal movements of the Equatorial
Maritime and Tropical Continental air masses. The
former is characterised by moist south-westerly winds
from the Gulf of Guinea, the latter by hot and dry
north-easterly winds (the Harmattan) blowing across
the Sahara Desert. The Intertropical Front, the
boundary between these two air masses, moves north­
wards beyond the Nigerian Border at the height of
the wet season in July and August, and southwards,
sometimes even as far as the coast, in the middle of
the dry season in December and January.
Acta Phytogeogr Suec 54
92
J. R. Charter
The southernmost parts of the country, particu­
larly the south-east, are least affected by the dry and
rainless harmattan. This dry wind is increasingly
dominant as one moves northwards where the moo­
soon is of correspondingly shorter duration: annual
rainfall decreases markedly and the dry season be­
comes longer and more desiccating.
Mean annual rainfall is highest near the sea coast,
averaging 70 inches (1 750 mm) in the west, and 1 20
to 1 60 inches in the Niger Delta and in the south­
east, falling sharply to 1 5 to 25 inches (3 75 mm to
625 mm) on Nigeria's northern border. The rainfall
isohyets lie approximately east-west except in areas
of locally high rainfall south and west of the higher
ground of Jos Plateau and Cameroun mountain
massif.
VEGETATION
Three major plant formations may be recognized in
Nigeria-the swamp forests of the Niger Delta and
coastal belt, the lowland forest of the humid south,
and the savannas of the subhumid Middle Belt and
the drier North.
The swamp forest zone, about 1 0,000 square miles
in extent, comprises mangrove (dominated by the
Red Mangrove, Rhizophora racemosa) developed un­
der brackish water conditions in coastal creeks . and
the outer margin of the Delta, and freshwater swamp
forests mainly further inland. The latter, including
areas of periodic swamp forest in intimate mosaic,
accounts for over one half of the swamp area. A
floristically distinct type of fresh-water swamp forest
also , occurs in the mangrove belt on the sandy soils
of abandoned beach ridges. The mangrove is separa­
ted from the sea by a narrow zone of coastal forest
and halophilous strand vegetation.
Lowland forest occurs further inland as a con­
tinuous zone of variable width ranging from 50 miles
in the west to 1 5 0 miles in the east. This zone covers
an area of about 40,000 square miles, but not more
than 1 0 per cent of this has escaped farming in
recent times and no significant areas of high forest
now remain outside the forest reserves. Forests in
the wettest areas in the south and south-east, have
been referred to elsewhere in this report as evergreen,
and in the drier northern and western parts of the
zone as semideciduous.
North of the limits of continuous forest, savanna
derived from forest by farming and grass fires con­
stitutes an increasing proportion of the vegetation,
which rapidly changes in character from a "forest­
with-savanna" mosaic into one of "savanna-with­
forest". Forest becomes increasingly restricted to
hilly or ill-drained sites unsuitable for farming.
Acta Phytogeogr Suec 54
CONSERVAT10N
Introduction
Conservation of Nigerian vegetation in its widest
sense (i.e. the preservation and rational use of a
renewable natural resource) is achieved in the coun­
try's Forest Reserves and Game Reserves. Such areas
are not, in their entirety, dealt with in this report.
In the strict sence of the 1 93 3 London Convention
(Art. 2, Sect. 2), conservation in perpetuity of diverse
samples of Nigerian vegetation in their natural state
is confined to eleven areas, designated Strict Natural
Reserves, situated within Forest Reserves. These are
demarcated by cement pillars, and boundaries which
are annually cleared of woody growth to a width of
1 I 4-chain (5 m) in forest and 1 I 2-chain (1 0 m) in
savanna. Strict Natural Reserves are unfenced ;
boundary inspections are carried out at least an­
nually by both Federal and Regional Forest staff.
There are no resident guards.
The fir�t of these areas ("Inviolate Plots" Nos.
1 and 2, see J ones 1 948) was established by the then
unified Nigeria Forest Department in 1 946. Since
the inception of a Federal system of government in
1 954, Strict Natural Reserves have become the re­
sponsibility of the Federal Forest Research Depart­
ment, an anomalous situation since all Forest Re­
serves are administered by Regional Forest Depart­
ments on behalf of the Native Administrations. Strict
Natural Reserves have at present no legal status dis­
tinguishing them from the Forest Reserves in which
they are situated.
Vegetation Types at Present Preserved as Strict
Natural Reserves in Nigeria (1 965-66)
Nomenclature as AETFAT Vegetation Map of Africa Ed.
2, and interpreted according to A ubreville ( 1 958): Nomen­
clature of African Forest Formations. - Proc. 2nd Inter.
Afr. For. Conf. Pte. Noire.
I A.
TROPICAL FOREST
1 a. Moist Lowland Evergreen
Omo Forest Reserve (Strict Natural Reserve No. 1 ) :
Western Ijebu-Ode Province, 1 1 60 acres (460 hectares), mean
annual rainfall 80 in. (2030 mm), altitude 300 feet ( 1 00 m).
Usonigbe Forest Reserve (Strict Natural Reserve No. 3):
Central Benin Province, 1 60 acres (64 hectares), mean annual
rainfall 96 in. (2440 mm), altitude 350 feet (120 m).
Oban Forest Reserve (Strict Natural Reserve No. 4):
Northern Calabar Province, 1 60 acres (64 hectares), mean an­
nual rainfall 175 in. (4440 mm), altitude 1 600 feet (500 m).
Oban Group Forest Reserve (Strict Natural Reserve No.
12): Northern Calabar Province, 150 acres (60 hectares),
mean annual rainfall 1 10 in. (2800 mm), altitude 250 feet
(80 m).
Nigeria
1 a. Moist Lowland Semi-deciduous
Akure Forest Reserve (Strict Natural Reserve No. 2):
Central Ondo Province. Area 80 acres (32 ha), altitude 800
feet (250 m), mean annual rainfall 60 in. (1 500 mm).
1 d. Moist Permanent Swamp
Strict Natural Reserve Nos. 1 and 4 (see above) include
areas of permanent marsh: The large Shasha River flows
through Strict Natural Reserve No. 1 .
2 a . Dry Lowland Semi-deciduous
This type occurs as an outer zone on the margins of
fringing forest, see Section II A. 1 (Inland, digitate).
11 A.
TROPICAL FOREST-GRASSLAND MOSAIC
93
(Kagoro Hills or Jos Plateau escarpment as recommended
by C. C. F.).
1 b. Moist submontane
Northern Region: W. Mambila Plateau (occurrence not
known with certainty: may be in other parts of Adamawa
Province).
1 d. Moist Swamp permanently flooded
Western Region: S. Omo F. R., Ogun River F. R.; Middle
Western Region: Gilli-Gilli F. R., unreserved area of beach
ridge and coastal swamp forest in Delta Province; Eastern
Region: Stubbs Creek F. R., Uwet Odot F. R., Osomari
F. R., Anambra F. R. ; Northern Region: Ibayi-Ojoko or
Adoru F. Rs.
1 . Lowland Inland Digitate
Bonu Forest Reserve (Strict Natural Reserve No. 7): East­
ern Niger Province, 360 acres (144 ha), mean annual rainfall
54 in. ( 1 370 mm), altitude 1 800 feet (600 m) .
Ill A.
TROPICAL THICKET
An area of bamboo brake with Oxytenanthera abyssinica,
occurs in Strict Natural Reserve No. 6 (see Section IX).
IV.
Western Region: probably occurs on forest margins ad­
joining savanna in Forest-Grassland Mosaic (type II A 1 .) ;
Middle Western Region: Nil-but prob ably occurs locally on
forest margins adjoining savanna in Forest-Savanna Mosaic
(see Sect. II A 1 . ) ; Northern Region Included as transitional
type in Forest-Grassland Mosaic (Sect. II A 1 .).
Il A .
MANGROVE
Stubbs Creek Forest Reserve (Strict Natural Reserve No.
1 6) : Southern Calabar Province, 320 acres ( 1 30 ha), mean
annual rainfall 1 60 in. (4000 mm), altitude 0 feet (0 m).
V A.
2 a. Dry Lowland semi-deciduous
TROPICAL FOREST - GRASSLAND MOSAIC
1 . Lowland Inland Digitate (forest outliers)
Northern Region: Sanga River F. R., F. R. in Abuja area
as recommended by C. C. F., F. R. in Sha area on Plateau
escarpment as recommended by C. C. F.
TROPICAL WOODLANDS
Woodlands, as defined by Aubreville (19 58), e.g. of Ano­
geissus leiocarpus, and Terminalia glaucescens, Isoberlinia
doka or Uapaca somon, occur in the Strict Natural Reserves
Nos. 5, 6, and 8 included under Section IX and Strict Natural
Reserve No. 7 under Section II A.
IX A. TROPICAL GRASSLANDS
1 a. Lowland Savanna
AND WOODED GRASSLANDS
1. Lowland Inland Patchy (forest-savanna mosaic)
Western Region: Lanlate F. R., Okpara or Meko F. Rs.,
Upper Ogun o r Old Oyo F. R., F. R. W. Abeokuta Prov.
(see also Sect I A 1 a.), Ifon F. R. ; Middle Western Region:
F. R. Afemai Div., Usonigbe F. R. (Sobo Plains) ; Eastern
Region: Occurs in the East, but may not be reserved. C. C. F.
to 11).ake recommendations if suitable area available; Northern
Region: Acharane F. R., Ibayi-Ojoko or S. Adoru F. Rs.
Ribako Forest Reserve (Strict Natural Reserve No . 5):
Zaria Province, 420 acres ( 170 ha), mean annual rainfall 50
in. (1250 mm), altitude 1900 feet (630 m).
2. Montane (properly submontane in N. Nigeria)
Vegetation Types Proposed for Preservation in Strict
Natural Reserves in· Addition to those A lready Existing
(1966-69)
Ill A .
Note. The localities are grouped according to the former
Regions which were discontinued early in 1 966.
I A.
TROPICAL FOREST
1 a. Moist Lowland Evergreen
Western Region: S. Idanre F. R. ; Middle Western Region:
Sapoba or Obaretin or Ekenwan or Ologbo F. R., Okomu
F. R. ; Eastern Region: Ekinta River or S. E. Oban F. R.,
Afi River F. R., Okwangwo F. R., Boshi F. R.
1 a. Moist Lowland Semi-deciduous
Western Region: Ala or Owo or Akure-Ofosu F. Rs.,
Ifon F. R., Oluwa F. R. (hilly type), F. R. W. Abeokuta
Prov. (see also Sect. II A 1), Ogotun F. R., Osho F. R.;
Middle Western Region: Owam River or Ora-Ozolla F. R.,
S. Ehor or Ekiadolor F. R.,; Eastern Region: Ukpon River
F. R., Effium F. R. (80-160 acres); Northern Region: S.
Adoru F. R., Acharene F. R., Sanga River F. R., F. R.
Northern Region: Areas in Adamawa Prov. (Vogel Peak
and Mambila Plateau) as recommended by C. C. F.
TROPICAL THICKETS
Northern Region: Bamboo Oxytenanthera occurs in S.N.R.
No. 6 Naraguta F. R.
IV.
MANGROVE
Western Region: Ogun River F. R., Eba Island F. R.
(1 60-320 acres); Eastern Region: Area of Avicennia nitida
swamp forest in estuary of Qua Ibo River or Cross River.
V A.
TROPICAL WOODLANDS
Western Region: Probably occur in Grasslands a:n d
Wooded Grasslands Sect. IX; Northern Region: Included
under Grasslands and Wooded Grasslands in Sect. IX a.
IX.
GRASSLANDS AND WOODED GRASSLANDS
1 a. Tropical Lowland Savanna
Western Region: Ogbesse or Ise F. Rs., Okpara or Meko
F. Rs ., Upper Ogun or Old Oyo F. Rs.; Northern Region: No
specific proposals for savanna Strict Natural Reserves are
made. Instead it is recommended that at least one or two
Acta Phytogeogr Suec 54
94 L. A. Grandvaux Barbosa
Savanna Strict Natural Reserves should be located in each
Northern Province: a total of between 1 1 and 22.
B. with. G ramineae
1 b. Lowland Grass Steppe
Northern Region: One or more areas in N. E. Bornu as
recommended by C. C. F.
2. Montane (properly plateau or submontane in North)
Northern Region: Share, Saiya, Jarawa Hills (Jos) Tembis
Hill (Pankshin).
XI. (HERBACEOUS)
gion: Orle River F. R.; Eastern Region : Anambra F. R;
Northern Region: Suitable area on Lake Chad shore.
FRESH WATER SWAMP FORMATIONS
A. with Cyperaceae
Western Region: Ogun River F. R.; Middle Western Re-
Western Region: Ogun River F. R. ; middle Western Re­
gion: Orle River F. R.; Eastern Region: Anambra F. R. ;
Northern Region: Areas chosen under Lowland Savanna
(Sect IX A. 1 a) should include this fadama type.
XII.
HERBACEOUS HALOPHJLOUS FORMATIONS
a. Strand Vegetation
Western Region: Unreserved area of beach ridge and
coastal swamp forest in Ondo or Ijebu-Ode Provinces; Middle
Western Region: Unreserved area of beach ridge and coastal
swamp forest in Delta Province; Eastern Region: Stubbs
Creek F. R. (shore line).
L'ARCHIPEL DU CAP-VERT
L. A. Grandvaux Barbosa
G EOGRAPHIE
L'Archipel du Cap-Vert, situe en plein Ocean Atlantique
avec une surface totale de 4033 km2, comprend 10 iles
et 8 Hots. 11 se developpe entre les paralleles 1 7° 1 2'5 et
1 4°48' de lat. N, et les merid. 22°44' et 25°22' de long.
W. de Greenwich. Les altitudes, environ, du point cul­
minant des iles, sont : Pogo 2829 m, Santo Antao 1 979
m, Santiago 1 392 m, S. Nicolau 1 304 m, Brava 976 m,
S. Vicente 725 m, Maio 436 m, Sal 406 m, Santa Luzia
395 m, Boa Vista 387 m.
La population est d'environ 1 60 000 habitants, avec
plus de 1 1 6 000 melangee (metis).
L'Archipel se trouve un peu au N. de l'etendue maxi­
mum annuelle du front pluviogenique intertropical. La
pluie tombe de juillet a octobre, et elle se montre faible
et assez variable.
Plus les iles sont plates et pierreuses, plus elles sont
improductives. Aux periodes de grande secheresse la
campagne a une physionomie aride dans les parties
plates ou dressees au SSW. Les iles sont nees d'eruptions
volcaniques et constituees par des basaltes, des phono­
lites et des coulees de laves. Elles etaient inhabitees a
l'epoque de leur decouverte et ne temoignaient d'aucun
indice de presence humaine.
11 n'y avait pas de plantes comestibles ni aucun mam­
mifere terrestre lorsque les portugais commencerent a
s'y etablir.
En ce qui concerne les sols ils se situent dans le do­
maine de Pedocals, au caractere aride ou semi-aride, or­
dinairement alcalins.
Acta Phytogeogr Suec 54
La secheresse se manifeste comme l'aspect le plus
grave de la localisation geographique du Cap-Vert. Dans
la capitale, la ville de Praia, la temperature moyenne est
25° et la pluviosite moyenne annuelle est 2 1 3,3 mm
(juillet a oct. 1 82,9 mm et 30,4 mm le reste de l'annee.
VEGETATION
L'Archipel, quoique en plein Ocean Atlantique, est:
soumis a !'influence generale de la latitude, qui dans ces.
endroits imprime un climat aride ou semi-aride. La zone·
avec une latitude semblable dans le Continent Africain
correspond a une longue zone qui vient du Senegal jus­
qu'au Soudan et a la Somalie. Cette zone presente une,
vegetation de transition entre la savane (et steppes)
boisee ou herbeuse, types relativement secs non differen-·
cies, et la steppe boisee avec abondance d'Acacia et.
Commiphora1 ou steppe herbeuse.
L'aridite est due au voisinage des grandes regions.
desertiques qui separent la zone torride des zones tempe-·
rees dans notre planete. La vegetation depend d'une
fa�on generale du degre d'humidite qu'elle re�oit des
vents. Dans les conditions geographiques de l'Archipel
1
Au Cap-Vert, etant donne sa situation insulaire, on peut .
trouver en dehors des formations avec une tendance pour la
savane ou la steppe, d'autres formations plus humides. Presque
toutes sont soumises a une tres forte influence exercee par ·
l'homme, les animaux domestiques et les vents maritimes. On
n'y trouve pas de Commiphora et le seul Acacia qu'on peut
considerer spontane est 1'Acacia a/bida (Faidherbia a/bida) tres.
endommage.
L 'Archipel du Cap- Vert
le degre d'humidite d'une region de ces iles depend sur­
tout de !'exposition et de !'altitude.
La meilleure iac;on de comprendre rapidement les
ditferents types de vegetation consiste a baser }'observa­
tion de la vegetation, dans le graphique theorique de
la distribution d'humidite dans ces iles, qui resulte de la
localisation geographique de l'Archipel (voir A. J. da S.
Teixeira et L. A. Grandvaux Barbosa, Agricultura do
Arquipelago de Cabo Verde, in Mem. Junta Invest. do
Ultramar n° 2, Lisboa 1 958).
De ce travail on presente ici un graphique semblable,
avec des changements. En !'observant on peut constater
que les vents qui apportent l'humidite sont les vents
alizes de NNE qui soufflent regulierement et pendant
presque toute l'annee sur la mer. Ceux-ci, charges d'hu­
midite, frappent pendant une longue periode de l'annee
contre les iles, montent les versants NE, et subissent un
refroidissement qui provoque les petites condensations,
les brouillards et les condensations occultes dans les
regions exposees au NE, specialement entre 400 et 1 300
m d'altitude.
On doit aussi remarquer que ce vent persistant exerce
une action traumatique et dessechante en dehors des
regions plus favorables a la condensation. On peut
noter cette action dans toute la vegetation qui se trouve
dans les regions exposees, parce qu'elle prend les
aspects def9rmes par les vents.
Le cote SSW de ces iles est soumis a un regime de
pluies tout a fait different. Il est caracterise par des pluies
violentes, rares ou sporadiques qui peuvent survenir
dans une courte periode de l'annee. Ces precipitations
surviennent quand la mousson de 1 'Atlantique Sud,
chaude et humide, venant de W ou de SSW, arrive a
l'Archipel. Ce phenomene survient periodiquement. Ce
sont les souhaitees annees d'abondance de mais et d'hari­
cot et de denses paturages. Ce sont encore ces annees
qui correspondent a une diminution de la production
dans les regions plus humides, une fois que !'action de
la mousson s'oppose a celle des vents alizes.
Les basses altitudes de ces Hes sont toujours arides, et
plus elles sont basses, plus elles sont desertiques. Done,
les plus hautes (avec plusieurs etages de vegetation) et
les plus larges seront aussi les plus riches en especes.
Celles qui ont un plus large etage superieur au NNE en
relation avec la superficie totale, sont celles qui ont
moins d'oscillations dans la production vegetale. C'est
le cas de l'ile de Santiago qui a sa plus grande longueur
selon la direction ESE-WNW (voir graphique). Sa posi­
tion est done la plus favorable de toutes les iles.
Selon le graphique inclus on peut considerer 4 regions
principales et distinctes pour les iles de plus hautes
altitudes, moins pour les autres.
95
ALIZES
DU
�-- NNE
(persistonts)
Om
500m
J.ooom
1.500111
2-000m
�
p
�
s
()
POSinON DEFAYO�
EXAMPLE SANTO ANTAO
ET FOGO
:
J �
� a
CillJ l. PRAIRIE MONTAGNARDE SECHE, STEPPE ET CULnJRES.
S2.HUMIOE OU SUB-HUMIDE, CULTURES TROPICALES.
mn�.SAvANe sus-AR1oe: ARBOReE,cuLruRes oe MAis Er HARicoT.
04.STE.PPE HERBEUSE� ARI DE , PATURAGES.
Fig. I. Schema theorique approximatif des zones phyto-ecologi­
ques du Cap-Vert.
1. Prairie montagnarde seche, steppe et culture
Dans les plateaux au-dessus de 1400-1 500 m d'altitude.
Dans ces aires on peut trouver les suivants sub-types
principaux :
Prairie montagnarde seche : Paturages des plateaux
superieurs en sols plus ou moins evolues. Abondance
de Labiatae : Lavandula dentata var. rendelliana, L. ro­
tundifolia, Micromeria forbesii, etc. ; parfois abondance
de Graminees t�lles que : Hyparrhenia hirta qu'on peut
trouver jusqu'a 2000 m d'altitude, Pennisetum polysta­
chyon, Melinis minutiflora, etc.
Steppe : Formation dependant surtout de )' eda­
phisme :
a. Falaises abruptes, lithosols, crevasses des rochers
tres battus par les vents. Les especes les plus communes
sont : Sonchus daltonii, Echium stenosiphon, E. vulcano­
rum (ile de Fogo) , Cytisus stenopetala, Matthiola cabo­
verdeana, Celsia insularis, Campylanthus salsoloides, Son­
chus daltonii, Lytanthus amygdalifolius, Melanoselinum,
etc.
b. Anciennes coulees de lave
: Euphorbia tukeyana,
Lytanthus amygdalifolius, Artemisia gorgonum, etc.
c. Zones de « lapilli pomitique » Helianthemum gor­
goneum (dominante), Eragrostis sp., et parfois Artemi­
sia gorgoneum, etc.
Acta Phytogeogr Suec 54
96 L. A. Grandvaux Barbosa
Cultures : Dans les hautes regions avec des sols conve­
nables, generalement en petites parcelles, abritees, avec
une humidite suffisante, on peut trouver les plantes cul­
tivees de la region mediterraneenne (beaucoup impor­
tees du Portugal) : Cydonia oblonga, Ceratonia siliqua,
Punica granatum, Ficus carica, Rosmarinus officinalis.
Plus rarement on peut trouver : Prunus persica, Malus
sylvestris, Eriobotrya japonica, etc. Ici on cultive la
pomme de terre (Solanum tuberosum) pour propagation.
Dans les hautes altitudes relativement seches, on cultive
tres souvent Ricinus communis (specialement a Fogo).
Envahisseurs des cultures d' altitude : Centaurea meli­
tensis, Trifolium spp., A venafatua, Silene gallica, Papaver
rhoeas, Plantago psyllium, Rumex spp., Ruta chalepensis,
Hordeum vulgare, etc.
2. Vegetation humide ou sub-humide, cultures tropicales
Dans les versants exposees aux vents alizes de NNE
d'altitudes moyennes (voir tableau). Ces versants sont
favorises par -les pluies plus frequentes et plus regulieres,
une plus grande nebulosite, des condensations et un plus
grand nombre d'irrigations. Le sol est construit dans les
versants avec des terrasses. Ce sont les zones vertes des
iles.
Vegetation des zonesplus humides : Entre 400 et 1 000 m
d'altitude, dans iles les plus humides, on cultive meme
dans les terrains sans arrosement la canne a sucre, le
bananier, le cafeier (arabica), etc. Done, toute la vege­
tation primitive a ete detruite pour etre remplacee par
les cultures. Les associations naturelles ont disparu, on
pourra seulement nommer les envahisseurs des jacheres,
avec abondance de Compositae comme : Tagetes patula,
Bidens pilosa, Acanthospermum hispidum, Ageratum co­
nyzoides, Artemisia gorgoneum, Erigeron, Nidorella,
etc. Et encore Brassica nigra. Pres des ruisseaux : Pteris
longifolia, Dryopteris parasitica, Equisetum ramosissi­
mum, Samolus valerandi, Sesbania, etc. Des Gramineae
comme : Agrostis semiverticillata, A . stolonifera, Melinis
minutiflora, Oplismenus, Paspalum, Rhynchelytrum,
etc. Dernierement on a aussi trouve Elvira biflora.
Cultures tropicales : Apres les cultures deja mentio­
nees, les plus importantes etant : la canne a sucre, le
bananier, le cafeier, il y a encore la patate, le tabac,
l'igname, · le « Cajanus », quelque plantes potageres et
fruitieres tropicales comme : Carica papaya, Mangifera
indica, Psidium guajava, Cicca disticha, etc.
Vegetation des regions declives au NNE. - Elles
peuvent etre couvertes par des fourres epais de Lantana
camara. Dans les escarpes abrupts est installe Furcraea
foetida. Quelquefois, tres rarement, un exemplaire de
Dracaena draco. Descendant les grandes altitudes par les
ravins jusqu'a des endroits tres bas, on trouve Hyparr­
henia hirta, qui a done un role assez important pour la
fixation des versants.
Acta Phytogeogr Suec 54
3. Savane sub-aride plus ou moins arboree et cultures de
mai's et haricot
Aire de transition entre les types de vegetation 2 et 4.
Savane a Hyparrhenia hirta ou Heteropogon contortus
avec Acacia (Faidherbia) albida. - Ces sa vanes sont pres­
que toutes remplacees par des cultures de ma'is et haricot.
Elles sont des jacheres anciennes generalement servant
de paturages. Dans cette zone et meme dans les regions
littorales, plus arides, on peut trouver Ziziphus mauri­
tiana, certainement introduit a cause de ses fruits co­
mestibles et aussi pour sa resistance a la secheresse. Nous
citerons les plantes suivantes introduites dans les patu­
rages : Desmanthus virgatus, Desmodium tortuosum,
Crotalaria retusa, Sorghum spp., Panicum maximum,
Rhynchelytrum repens.
Culture de mats et haricot
: Ce sont les principales
cultures alimentaires du Capverdien. Les especes tres
cultivees sont : Lab/ab niger, Vigna unguiculata, Phaseo­
lus lunatus et P. vulgaris. Cajanus cajan est cultive dans
la zone plus humide. En parcelles tres restreintes, Mucu­
na (Stizolobium) et Canavalia.
4. Steppe herbeuse aride, piiturage
Formations desertiques ou sub-desertiques des basses
altitudes tournees vers le SSW. Paturages arides avec
un grande nombre de chevres.
Ces paturages peuvent etre de types varies comme :
a) Paturages a Aristida adscencionis, A. cardosoi, ou
A . funiculata, parfois avec Schmidtia, etc.
b) Paturages a Elyonurus royleanus tres arides.
c) Paturages sans dominantes definies, avec : Aerva
persica, Boerhavia verticillata, B. repens, Cleome arabica,
Lotus glinoides, L. spp., Corchorus spp. (beaucoup de
Sterculiaceae, Malvaceae, etc.).
d) Paturages desertiques avec Sclerocephalus arabi­
cus, Zygophyllum simplex, etc.
Les principaux arbustes de ces paturages sont : Acacia
farnesiana, A. nilotica, Gossypium hirsutum var. puncta­
turn, Jatropha curcas (largement cultive), J. gossypiifolia,
Nicotiana glauca, Parkinsonia aculeata, etc.
Formations speciales avec forte influence
edaphique
Rupicoles : Sur affleurements de roches, coulees de lave,
etc. (toutes iles). Plus de cinquante especes de Lichens.
Halophytes (Sales arides) : Steppes suffrutescentes a
Chenopodiacees dans les depressions salees. (Maio et Sal
specialement).
Psammophytes desertiques (Dunes vives) : Desert pur
avec Sporobolus spicatus
L'Archipel du Cap- Vert
97
On a deja mentionne les altitudes des dix iles, ce qui bleme general de la regeneration de la vegetation qui in­
no us amene a deviner quels sont les types de vegeta­ teresse ici.
L'alimentation traditionelle de mais et d'haricot exige
tion possibles pour chacune. On peut conclure logique­
ment que les iles les plus arides sont : Santa Luzia, Sal, une grande depense de bois, ainsi que !'exploitation de
la chaux.
Boa Vista et Maio.
Centre tous ces facteurs ont deja lutte les « Servi9os
Comme I' erosion est tres active, « extraordinaire », les
altitudes baissent constamment et les iles ont une ten­ Agricolas, Florestais e Pecmirios » et quelques brigades
dance a devenir plates; c'est pourquoi la desertification speciales.
Dans l'ile de Santiago on a deja etabli les plantations
sera progressive et lente.
Dans les regions correspondant aux types de vegeta­ et pepinieres suivantes :
tion de 1 a 3 existent aussi de grandes aires caracterisees
a) Curralinho (377 ha) - Plantations dans la regions haute
par une grande aridite due a la nature des sols tels que : d'Eucalyptus botryoides, E. rostrata, Khaya senegalensis, Acacia
sols squelettiques et « lagedos », cendres volcaniques et melanoxylon, Cupressus lusitanica, C. sempervirens, etc.
b) Pico Ant6nia (795 ha) - Comme la precedente, dans l a
coulees de lave avec des rochers.
region d'altitude, fraiche, relativement humide et venteuse, on
Les regions ou la vegetation se developpe en condi­ y trouve les memes especes.
tions plus favorables (2 et 3) sont intensivement et com­
c) Malagueta - Elle se situe dans la deuxieme elevation plus
pletement utilisees dans les cultures les plus rentables. importante de l'ile, dans une region venteuse, aussi avec des
Dans les grandes surfaces incultivees (4), la flore, resultats tres semblables et les memes especes plus abondam­
ment cultivees. On y trouve encore Trichilia emetica, Casuarina
soumise a de si rigoureux facteurs limitants, est haute­ sp., etc. et dans un ravin Cinnamomum zeylanicum, Jaca�anda
ment specialisee en presentant un nombre d'especes tres mimosifolia et Coffea arabica, tous cultives.
reduit, souvent avec des varietes endemiques.
d) S. Jorge - Dans une vallee abritee tournee vers le NNE,
Le cafeier, la canne a sucre, et la patate sont cultives elle a u n interessant arboretum avec Eucalyptus citriodora, E.
j usqu'aux limites des possibilites de la terre, et surtout des botryoides, E. rostrata, Terminalia catappa, Cassia siamea, De­
lonix regia, etc.
disponibilites hydriques. C'est le cas aussi du mais et du
e) Trindade - Petit bois avec Albizia lebbeck, Terminalia
!'haricot (3). Les paturages ont toujours trop de betail catappa, Adansonia digitata, etc. Vallee de l a zone basse pres
et sont tres degrades (4). 11 n'y a pratiquement pas de de la ville de Praia.
f) Tapada da Praia - Plantation de Parkinsonia et Acacia
reliques d'ancienne vegetation dans les bonnes regions
uilotica dans la ville de Praia.
de 1'Archipel. Les destructions dues a !'utilisation meti­
culeuse de toutes les plantes profitables pendant les
Dans l'ile de Fogo :
famines periodiques de l'homme et de la chevre, ont du
g) Monte Velha - Plantations au-dessus de 1 050 m d'altitude,
amener a une selection negative des paturages. La pre­ avec Eucalyptus, specialement ceux deja cites. Il y a encore
dominance des herbes ameres, agressives ou toxiques est Ceratonia siliqua, Acacia dealbata, Grevillea robusta, etc.
notable.
Dans l'ile de Santo Antao :
Si l'on considere que la vegetation a ete introduite
h) Chii de Mesa - Plantations d' Eucalyptus des especes
apres les grandes eruptions et ayant en consideration referees et encore E. globulus, E. saligna.
l'isolement geographique, on s'aper9oit comme il est diffi­
Dans cette ile se trouvent encore trois pepinieres qui
cile d'interpreter la signification ecologique de ce qui
fournissent
des plantes : Pero Dias, Passagem (a Ribeira
reste de la vegetation non cultivee. Comme I' agriculture
do
Paul)
et
Cha de Arroz (a Ribeira da Torre). Dans
est faite sans artifices de la technique et !'irrigation se
cette
pepiniere-ci
on a vu Cupressus lusitanica se pro­
reduit a des aires restreintes - etant donne l'insuffisance
pager
par
bouture.
des filets d'eau et la grande permeabilite des sols - il
11 n'y a pas de pares ni de reserves naturelles dans
serait done de toute necessite de profiter de la vegetation
1 'Archipel.
cultivee pour l'etablissement des unites phyto-ecologiques
Plantes a proteger
de l'Archipel. Dans ce cas les regions de differentes cul­
tures ont une signification ecologique tres appropriee.
11 faudrait done prendre les mesures suivantes :
1) Reserver dans toutes les iles une petite parcelle
pour !'observation de la regeneration naturelle pour
LA PROTECTION
chacune des zones considerees (dans le tableau ci -dessus)
Plantes deja protegees dans le territoire
et qui existent sur chacune des iles.
Toutes les iles sont soumises a !'influence de l'homme
2) Augmenter la vigilance pour proteger les especes
et des chevres, et on peut considerer cet Archipel comme suivantes : Dracaena draco, Sideroxylon marmulana,
ayant une vegetation assez detruite, etant donne l'ari­ Echium spp., Launea spinosa (de Boa Vista), Tamarix
dite et la grande densite de population pourJ les gallica, Gossypium capitis-viridis, Cytisus stenopetala,
ressources agricoles existantes tres limitees. C'est le pro- Papaver gorgoneum (endemique).
7 - 6 8 1 557 Hedberg
Acta Phytogeogr Suec 54
R E G I O NA L S YN T H E S I S
F. N.
Hepper
Any consideration of the vegetation in West Africa exceptional locality may provide a focal point of
must take into account the condition of the vegeta­ scientific interest, and we tend to pin-point such
tion at the . present time rather than what it was or places as potential nature reserves or at least as
might be. A glance at a map of Africa showing its places that must be safeguarded. While in no way
vegetation will present the illusion, for instance, of despising this view to which I shall return later, we
a great deal of rain forest in the West. In fact, as I must not be diverted by these tasty morsels and
need hardly say, the whole of the forest zone has thereby neglect the bread and butter, as it were. In
been greatly altered by human interference, and even other words the ordinary, typical vegetation which
may at present be abundant in some areas, must be
if rain forest is present its floral composition may be
markedly different from its virgin state. This is not subject to the closest scrutiny in order to ensure that
some portions are maintained in a natural state.
to say that there are no places in which one can find
Otherwise
we may find that in the future we have
more or less original ground cover, but it is essential
retained
the
exceptional and lost what was thought
to have up-to-date information for any particular
to
be
unexceptional.
I can illustrate this by stating
area.
the
well
known
fact
that
the top of many mountains
Zoological conservation has pioneered the field,
have
acted
as
magnets
to
botanists and explorers and
leaving botanical conservation as the poor relation,
the flora and vegetation have been thoroughly inves­
but if this Conference can instil a sense of urgency
into those with responsibility for the plants and veg­ tigated, while the much more accessible vegetation
on the lower slopes has been totally neglected. Again,
etation of their countries, and then provide them
with scientific information, something will be many parts of Africa carry large areas of more or
achieved. While there is still some natural vegetation less uniform vegetation which at present may not
left we must work to see that as much as possible . seem very attractive, yet unless something very posi­
is maintained for educational, scientific and cultural tive is done to see that its natural condition is main­
reasons as well as for human well-being. Time is tained we may find that before long it has changed
short; new techniques are being invented whereby the irreparably. The cause of the change may at first be
natural environment is being rapidly changed and the unspectacular and not give ground for concern: such
subtle changes are difficult to recognize and to
demand for land is increasing as the human popula­
counter
before it is too late. It would be a shame as
tion rises. There is no need to reiterate here the
well
as
unscientific
to lose something through default
arguments in favour of conserving the natural vege­
when
a
little
thought
and action could have fore­
tation and its constituent species.
stalled the disaster. True, a convincing case for the
I shall try to answer the three questions: what
requires to be conserved in West Africa, what has preservation of an ordinary piece of vegetation may
been achieved and what should be done now? The be more difficult to formulate than for a spectacular
or particularly interesting locality, but we are con­
reason for this paper is, as I see it, to take a broad
view of the problems involved from a scientific point cerned here with the scientific aspects and not with
of view. Although my own field work in West Africa the ways and means, however important these may
be from a practical point of view, of achieving our
has not been as extensive as other contributors I have
acquired a deep concern for the conservation of the objectives.
plant-life during the fourteen years I have been ac­
A reas of National Importance
tively engaged on the Flora.
WHAT REQUIRES TO BE CONSERVED
IN WEST AFRICA?
There is no doubt that natural vegetation is in danger
of being modified by various degrees down to its
total elimination and its replacement by cultivation,
degraded vegetation or even by desert in drier areas.
From our point of view a mountain top or some
Acta Phytogeogr Suec 54
The contributors to the various papers have drawn
attention to the needs as they see them within each
country and it is not necessary to repeat them here.
What is of national importance may or may not be
internationally so and the areas proposed for con­
servation should be regarded in the national context
rather than judged by international standards.
Almost every country possesses several different
vegetation zones and in West Africa where the zones
Regional synthesis
often pass at right angles to the political frontiers
there are usually marked contrasts in the vegetation
from one part of the country to another. It is im­
portant, therefore, that every country should con­
serve a representation of each vegetation zone and the
communities and habitats should be safeguarded in
as great a diversity as possible. This can only be
achieved by those concerned having an intimate
knowledge of the country and what it contains and
by systematically selecting sites for conservation in
the various zones.
A word should be included here about the methods
being adopted by the Conservation section of the
International Biological Programme. It is gratifying
to note that, if regional committees are functioning
properly, an enormous volume of information will
be provided on areas of biological interest. This in­
formation will be used, among other things, to re­
commend for conservation "areas forming adequate
samples of the entire range of ecological formations
or ecosystems of which a complete basic series
should be safe-guarded in the interests of science".
In this way there will be an integration of effort on
the conservation of the African flora.
A reas of International Importance
Certain sites support vegetation that is so outstanding
that it may be regarded as being internationally im­
portant and I have selected from the reports those
areas that I think come into this category.
The sahel zone is dealt with in another paper but
not all of Senegal falls into this zone. Perhaps the
G uibourtia copallifera forest at Diantem is the most
important vegetation type in Senegal and it is feared
that the forests are in danger from exploitation.
Another type which might fall into the international
category is that found in the "niayes" near Dakar.
These local swamps do not support any rare species
but they are refuges for the common oil palm and
other forest species at the extremity of their distribu­
tion.
In G uinea the most important areas are undoubt­
edly the mountains of Nimba and certain parts of the
Fouta Djalon massif. Here are to be found montane
-or perhaps strictly sub-montane-communities with
an interesting pattern of forest and savanna.
Much work has been carried out on the Nimba re­
gion and it is now well documented, with research
still continuing. Besides the mountains themselves
there are areas between the coast and the western
side of the Fouta Djalon which are reported to sup­
port dense savanna woodland that is now rarely
found in West Africa due to human influence. This
may therefore merit international status, not least
99
because of its chimpanzee population, but already it
is subject to increasing pressure and only relics are
being left.
The mountains in Guinea already referred to ex­
tend into Sierra Leone as the Loma Mountains and
Tingi Hills. There is no doubt about the internation­
al importance of these mountains (Bintumane Peak
in the Lomas at 2000 m. is the highest to the west of
the Cameroons) with their zoological as well as bo­
tanical interest which is well borne out by a recent
paper by Jaeger, Lamotte and Roy who pleaded for
the protection of the area. Elsewhere in Sierra Leone
the Freetown Hills represent an important forest
area, while the Gola Forest spreads across the fron­
tier and links up with the very important Liberian
rain forest. Only in recent years has the uniqueness
of this Liberian forest become apparent. It is not
matched anywhere else in tropical Africa by its
single dominants of several Caesalpiniaceous genera.
The interesting discontinuities also apparent in the
genera and species occurring in this forest block and
that from Nigeria south-eastwards are still not fully
documented. The mangrove and adjacent savanna
in certain Liberian estuaries are probably not to be
found elsewhere in tropical Africa, certainly not with
the same species.
The small portions of the Nimba Mountains oc­
curring within the borders of Liberia and Ivory Coast
are continuations of the main part in Guinea to
which reference has already been made. Ivory Coast
supports a continuation of the eastern forest block
which differs in its structure and composition from
that found in Liberia. It again changes in Ghana
where the forest rather abruptly terminates. Here the
Ankasa Forest Reserve is of paramount importance
and its status should be raised to that of a Strict
Reserve. Clearly, then, representative examples of the
moist evergreen forest need to be carefully chosen
and preserved since they can assume immense inter­
national significance.
The coastal savanna of the Accra Plains contains
unusual thicket clumps and urgent steps should be
taken to preserve this interesting feature. The
savanna of the hinterland is rather uniform from
West to East although of course within the savann:a,
zones can be distinguished when moving in a north­
erly direction. West African savanna is not as rich in
species as that occurring in many other parts of
Africa, but the ecology is no less interesting and ef­
forts must be made for large representative portions
to be conserved. It is difficult to say which areas
would merit the designation of international impor­
tance. Certainly an area containing the West African
cycad Encephalartos barteri should be conserved in
Acta Phytogeogr Suec 54
100
F. N. Hepper
Ghana, Dahomey and Northern Nigeria and, as the
plant usually occurs in rocky places which have been
little disturbed by man, many other interesting spe­
cies would be safe-guarded at the same time. The
riverine forest extending far into the savanna is suf­
fering severe destruction in many places and the
more interesting representatives should be selected
for conservation as soon as possible.
on such a high mountain (for West Africa) situated
just north of the equator makes it an area of great
importance from the botanical point of view.
A re any Rare Species in Danger of Extinction?
The title of this symposium covers not only the
vegetation but the individual species. Rare species or
those with a limited distribution have particular value
and interest from many points of view and their
In Nigeria the coastal mangrove swamps reach
their finest development in Western Africa and it is conservation is important. It is not sufficient to main­
important that the interesting area at Stubbs Creek tain the last remnants in a botanical garden! The po­
Forest Reserve, Calabar, be maintained as a strict pulation must be maintained in its natural environ­
reserve. Other strict reserves should also be desig­ ment which means that the habitat needs to be con­
nated to include the freshwater swamps and high served in such a way that the whole ecosystem is
swamp forest. The rain forests of Nigeria are again self-perpetuating. Size is often the determining factor
here '(Hepper, 1 968). The presence of a rare species
different from those mentioned to the west, and
within Nigeria there are marked differences in the whether as a discontinuity or more especially an en­
composition of the forest of Western and Eastern demic will help to indicate the importance of an area
Nigeria. In the east the rain forest at Oban is remark­ of natural vegetation. Where, we may ask, are the
able for its diversity of species and high rate of endemics to be found? Are they trees, shrubs or
endemism which will be referred to again below. herbs and in which zones do they grow?
Similar floristically rich high-forest is to be found in
For West Africa an analysis of the revised edition
West Cameroun in the Southern Bakundu Forest of the Flora of West Tropical Africa is most instruc­
Reserve near Kumba, but again with its own compo­ tive. Taking the 5200 species of Dicotyledons re­
corded there it is possible to sift out those known
sition.
The extensive savanna of Northern Nigeria has from a single locality and represented by only one or
a few specimens, amounting to 55 0 species or about
been mentioned above and within it there are several
1 0 % of all the Dicotyledons. True, this raises awk­
notable areas. In particular the Jos Plateau may be
noted for its upland savanna vegetation which is now ward taxonomic questions about the authors' concept
sadly depleted. In the extreme east Vogel Peak and of a species, and how well that part of West Africa
Mambila Plateau carry a similar highland flora en­ is known from a botanical point of view. Anticipat­
riched by the proximity of the Cameroun highlands ing such criticisms and taking into account later ad­
ditions to our knowledge regarding specific delimita­
to the south, but its wild life (plant and animal) is
rapidly disappearing although it is still one of the tions and distributions, I am convinced that there are
richest natural regions of West Africa. Obudu Pla­ still many good species that really do occupy very
teau in Eastern Nigeria and the Bamenda District of small areas. Besides these, there are many less local­
ised endemics whose existence may also be in jeop­
West Cameroun carry a highland flora similar to that
ardy. The results of my analysis can be broken
of eastern Africa. Montane forest still exists in places
down into various categories as shown in Table I.
and having such a limited possible distribution in
West Africa it is vital that as much as possible is
From Table I we can deduce that the woody
conserved. Some of the montane forest is already in endemics out-number the herbs by more than two to
forest reserves but the forestry policy is replacing one (3 80 : 1 59) and that endemics in lowland forest
native with exotic species for the sake of their timber.
are 4 1 j 2 times more frequent than in l owland sa­
This will mean that although a forest will continue vanna {3 2 1 : 68) which accentuates the importance
in the same position it will bear little resemblance of maintaining reserves of natural forest. On the
to the original montane forest in either its structure other hand there are more endemics in the montane
or composition. Cameroon Mountain, like the Clar­
(or upland) savanna than in the montane forest (76 :
ence Peak in Fernando Po, is of volcanic origin. The 5 1 respectively) as shown by Table 11. These totals
lava flows from the periodically active volcano on will help to give a picture of the relative requirements
Cameroon Mt. obliterate some of the vegetation for effective conservation of the rarest species in
from time to time but constitute an interesting virgin West Africa. A similar analysis could be prepared for
medium for re-colonisation from the summit at . any region of the World, but its compilation is fre­
1 3,370 ft. (4070 m.) sometimes even down to sea­ quently likely to be hampered by lack of a complete
level. The diversity of habitats and altitudinal zones regional flora and / or inadequate botanical exploraActa Phytogeogr Suec 54
Regional synthesis
Table 1 . Rare endemic species in West Africa, each re­
corded by one or a few specimens from one small area.
Analysis according to habit.
According to Flora of West Tropical Africa (Vols. 1 and 2 ,
1 954-63) t h e total number of species o f Dicotyledons is approx.
5200
No. of
species
(totals)
Tree
Shrub
(incl. large
shrub and
undershrub)
Liana
Herb
Perennial
Annual
Climber
Epiphyte
% of entire
W. African
Dicotyledons
98
1 .9
236
4.3
46
0.9
1 09
17
24
9
2.1
0.4
0. 5
0.2
}
%
Woody
7. 1
Herbaceous
3.2
1 59
Habit unknown
Total number of
rare endemic species
13
0.3
0. 3
552
1 0.6
Table 2. Rare endemic species in West Africa, each re­
corded by one or a few specimens from one small area.
Analysis according to vegetation zone
No. of
species
Forest
Lowland (incl.
"Forest")
Coastal
Montane
303
18
51
% of entire
W. African
Dico­
tyledons
5.6
0.4
1 .0
372
Savanna
Lowland (incl.
"Savanna")
68
Montane (incl.
"Upland")
76
7.0
1.3
1.5
1 44
Coastal (not forest)
Total
%
10
526
2.8
0.2
0.2
10
Plus others whose habitat is unknown.
tion, in which case one would tend to b e recording
the species occurring in certain monographed fami­
lies or even the locations of collecting expeditions
rather than true concentrations of species.
1 01
By plotting the localities of the West African en­
demics on a map it is possible to recognize that the
distribution is uneven and that certain places have
high concentrations of endemic species that is more
than coincidental. For instance there is a high concentration in the forests of Oban in south-eastern
Nigeria and carefully chosen strict reserves in that
area would secure a large number of them. In ad­
dition to the actual endemics near Oban there are
many other species with limited distribution in that
part of Africa which would also be included in the
reserves. The ecological structure and physiognomy
of the Oban rain forests are also of great interest.
As for the isolated endemic species, there is clearly
little that can be done about them and it seems that
the first requirement is accurate information on their
taxonomic status and their distribution. Many
sources can yield information which could be syste­
matised according to status and the species given
priority in the following way:
1 . Families with one or a few species,
2. Genera with one or few species and those
species with a very restricted distribution, and
3. Species subdivided into the following categories:
(a) Those species known to be in particular dan­
ger and for which immediate action needs to
be taken to ensure their preservation,
(b) Rare endemics known from 1 or 2 places
about which there may or may not be full
information,
(c) Species whose distribution for some reason is
known to have been greatly reduced to such
an extent that it may now be in danger of
extinction,
(d) Species of special interest and of local distribu­
tion, e.g. from morphological or phytogeneti­
cal considerations ; as the wild ancestor of a
cultivated plant, etc.,
(e) Species occurring as outliers or relics.
Many plants will fall into two or more categories
and the one with greatest priority should be accorded
to them. For instance in West Africa Medusandra
richardsiana is a rare endemic and falls into category
3 b, and as it is also the only species in its genus in
a small family it would also be recorded in categories
2 and !-thereby achieving almost maximum status.
As further information is gained about each species
it may be found necessary to change its category up
or down.
Blaeria mannii in Nimba Mountains would be acActa Phytogeogr Suec 54
1 02
F. N. Hepper
corded 3 a status for it is in danger of extinction.
Pitcairnia feliciana in Guinea and the only representa­
tive of Bromeliaceae in Africa, is a rare species,
although as it is not known to be actually in danger
it would be placed in 3 b.
In Nigeria and other West African countries many
species are legally protected, but this has little signif­
icance from the conservation point of view since
most of the species are timber or fruit trees which
may be felled by licence. The legal protection of
botanically interesting species is for the most part
quite impracticable, except for certain distinctive
plants like cycads.
WHAT HAS BEEN ACHIEVED SO FAR?
The wild fauna of West Africa cannot compete with
the spectacular herds that have made East Africa
famous. Even so a number of large game reserves
have been established in most of West Africa for the
preservation of animals with varying degrees of
success� Little consideration has been given, how­
ever, tQ the botanical aspects of these reserves and
the plants appear to be incidental as food and shelter
for the animals. There is scope for the integration
of the two aspects as Petrides ( 1 965) has done to a
certain extent in his Nigerian report, and especially
for co-ordinated management plans, which are, how­
ever, outside the terms of reference of this paper.
Suffice it to say that warning should be taken from
certain East African national parks where the ani­
mals have destroyed the vegetation before manage­
ment plans were prepared, or at least effectively op­
erated. From the botanical point of view the smaller
nature reserves, forest reserves and relict areas of
natural vegetation are more important than the large
game reserves.
In Senegal the Niokolo Koba national park has
dry savanna woodland. There is a small botanical
reserve containing a "niaye" at Noflaye, which is
unfortunately neglected due to lack of funds, and the
Ile des Madeleines near Dakar where the windswept
flora is protected. Guinea has a fine reserve on Mt.
Nimba in the south of the country which includes
the montane grassland and upland gallery forest.
Further reserves are urgently required in other parts
of the country.
In Sierra Leone the forest reserves are for the
exploitation of timber rather than for the conserva­
tion of plants. In such cases the structure and com­
position of the forests is likely to change markedly
according to forestry practice and there is no guar­
antee of the continuity of the vegetation in its present
state. The interesting forest on the Freetown HiHs
Acta Phytogeogr Suec 54
owes its continued existence to the fact that it was
designated as a reserve for reasons of water conserva­
tion but owing to population pressure more intensive
cutting has recently been allowed. Even the large
highland mass of the Loma Mts., which has been
designated as a national park, is subject to extensive
and frequent burning with the ensuing degradation of
the vegetation and loss of animal life.
The Liberian National Forests, like forest reserves
elsewhere in West Africa, are for the sake of their
timber. Some strict reserves are urgently required to
protect the interesting leguminous forests. A true
national park in the Mount Wutivi area was planned
but as far as is known the boundaries have not yet
been surveyed. A small part of the Nimba Mts. oc­
curring in Liberia has been put aside as a nature
reserve and recently investigations have been under­
taken there. Its close proximity to the iron ore mines,
while providing facilities for the scientists engaged
on the work, means that the reserve is increasingly
vulnerable to the activities of people attracted to the
area by the mining operations. Nevertheless, one is
grateful to LAMCO for making the concession avail­
able and for providing funds for its maintenance and
it is hoped that strict control of the reserve will be
possible.
On the southern side of Nimba the strict reserve
is continued from Guinea into the Ivory Coast and
the three portions of the reserve amount to a consid­
erable area ( 1 7, 1 30 ha. plus the Liberian portion).
Elsewhere in Ivory Coast there appears to have been
an enlightened policy concerning conservation for
many years. The result has been the creation of two
large national parks (in the forest and savanna zones
respectively) as well as several small ones. There are
also 28 botanical reserves scattered over the country
but clearly they cannot account for every type of
vegetation and there is urgent need for the realiza­
tion of the newly proposed reserves.
Large areas of Ghana are declared forest reserves
which has helped to check the widespread destruc­
tion of the natural vegetation for agricultural pur­
poses that is taking place outside them, but no "vir­
gin forest is entirely protected from interference".
This applies to the forest and savanna zones alike
although parts of the savanna are probably compara­
tively safer than the forest and several large game
reserves help to ensure refuge for savanna species.
The afforested Protection Reserves are so designated
for reason of water and soil conservation rather than
for their own intrinsic value, yet there is at least
one small area, the Pusupusu ravine, safeguarded for
its botanical value. No other true reserves are in
existence in Ghana.
Regional synthesis
There are no strict botanical reserves in Dahomey
but as in the case of other countries mentioned the
vegetation is afforded an element of protection for
similar reasons. Two national parks in the north of
the country are game reserves and some forest re­
serves are to be found in the south. Elsewhere the
vegetation is considerably degraded and immediate
protection of certain areas is necessary.
The vast country of Nigeria has eleven Strict
Natural Reserves situated within forest reserves re­
presenting a number of different vegetation types.
They are small in area, 320-640 acres ( 1 3 0-259
ha.), but they are valuable as they have been selected
primarily for their botanical interest. Unfortunately
close control is not possible for all of them and
absolute protection cannot be guaranteed.. The
numerous forest reserves themselves are subject to
exploitation and commercial plantings and for our
purposes have varied merit. The large Yankari Game
Reserve in Northern Nigeria includes Isoberlinia
Sudan savanna woodland and some Guinea savanna
and is a useful area for the conservation of these
types of vegetation.
A concluding remark should be added to this sec­
tion on achievements about the value of legislation
governing certain human practices. I think it is true
to say that enforcement of such legislation in any
country can have a marked effect upon the vegeta­
tion in general over a wide area. For instance the
legal control of savanna burning during the dry
season by restricting it to a certain time of year is
beneficial to the vegetation and wild life. Legislation
must clearly be adapted to local conditions and based
on scientific knowledge. Unwritten local "legisla­
tion" has been a powerful force in retaining many
an African sacred grove from destruction and al­
though these are unfortunately small areas they often
act as valuable reservoirs and as an indicator of the
former vegetation.
WHAT SHOULD BE DONE NOW?
It is abundantly clear from the papers prepared for
this Conference that very little has been done speci­
fically for the conservation of the natural vegetation
and its constituent species in West Africa. Such as
has been achieved is almost incidental to other pur­
poses and not for its own sake. Thus we have large
areas kept as game reserves where the plants may
enjoy a great deal of protection, or they may be eaten
out of existence by the protected animals thereby
destroying their own habitat. Again we find forest
reserves with rich natural vegetation that may be
safe until it is cut out in a day for the sake of the
timber or planted with exotic species that will one
1 03
day shade the nursing native plants out of existence.
Other places may be kept for the sake of the soil or
for the water resources and requirements may change
from time to time so jeopardizing the ground cover.
No longer is it possible to rely on chance that the
many plant associations will survive. What is ur­
gently needed in West Africa, as in other parts, is for
a concerted effort in each country to assess the
resources of natural vegetation and to set about sys­
tematically ensuring their safety in the best possible
way. It will be necessary to tackle the problem at
every level to ensure that the full scientific and cul­
tural merit of the vegetation of each country is con­
served. Thus the vegetation zones, types and associa­
tions need to be critically considered, even to hab­
itats and the conservation of species. There seems to
be no doubt that the speedy declaration of Strict
Natural Reserves (Reserves naturelles integrates)
with legal backing to ensure their continuance for all
time is essential for the conservation of natural vege­
tation in Africa. Petrides (1965) has suggested three
types of national areas for Nigeria which are equally
applicable to other West African countries and I feel
it is useful to repeat here his comments since they
deal with plants as well as animals. (The terminology
may need to be modified.)
" 1 . National Parks. Areas of natural landscape
and scenery in each major vegetative zone, which
contain the vegetation and animal life native to that
zone, and which are legally dedicated to the preserva­
tion of nature and wilderness for public enjoyment,
education and inspiration.
2. Modified National Parks. Tracts similar to
the basic park type, but located in rain forests or in
other vegetation of high commercial value, and cen­
tred on one or more strict natural reserves containing
samples of mature vegetation. These reserves, which
form the nuclei of the parks, should be enlarged to
a minimum of about 4 square miles (c. 1 000 ha)
each. Then, if it is essential to do so, other forest
lands in the national park could be lumbered under
a system of long-cutting rotation, resulting in the
maintenance of a relatively old-age forest commu­
nity. This would easily permit of a further enlarge­
ment of the undisturbed nucleus, if the needs for
natural area protection increased.
3. National Monuments (or Natural A reas).
Smaller tracts which would provide for the preserva­
tion of plant and animal species and communities
peculiar to limited areas outside the major national
parks. "
CONCLUSION
It is very important that those in positions of author­
ity take action at once in certain eleventh hour cases
Acta Phytogeogr Suec 54
1 04 Discussion
and that they are sympathetic at the highest level to
matters concerning biological conservation as a
whole. They must be convinced that these are not
only academic details but are of vital agricultural and
economic importance for the welfare of their coun­
tries. Although the matter is so urgent that the top
people must be convinced, the whole policy needs to
be backed up by long-term public education at all
levels and by concentrating on those in colleges and
universities who are likely to be in positions of re­
sponsibility. One way of achieving these aims has
been suggested in the paper on Sierra Leone
(Morton) and by Petrides ( 1 9 65) for Nigeria. In ef­
fect they suggest that a committee of keen conserva­
tion-minded persons from the national government,
local government and higher educational institutions
be set up in each country to advise and act. The
mere establishment of such a body will not ensure
conservation of anything unless it is active and is
given powers to be effective. Ways and means must
be found to supply the necessary finance to carry
through its proposals.
REFERENCES
Hepper, F. N., 1 968. The Conservation of rare and vanish­
ing species of Plants. - The Red Book. London (ed. by
J. Fisher).
Jaeger, P., Lamotte, M., and Roy, R., 1966. Les richesses
floristique et faunistiques des Monts Loma (Sierra Leone):
urgence de leur protection integrate. - Bull. !FAN Ser.
A, 28: 1 149- 1 1 90.
Petrides, G. A., 1 965. Advisory report on Wildlife and Na­
tional Parks in Nigeria, 1 962. - American Committee for
International Wild Life Protection, Special Publication
No. 8 .
D I S CU S S I O N
Hepper: On reading the various reports prepared for this
conference it has been very evident to me that there is a
variation in interpretation of the definition of terms such as
Forest Reserve, Strict Natural Reserve, etc. Not only is this
true between countries in English speaking Africa but their
French equivalents are often obscure. I should like to prop­
ose that A.E.T.F.A.T. prepares a series of definitions with
their French and Portuguese equivalents. Perhaps this idea
should be referred to I.U.C.N.
D. Gledhill: I agree with Mr. Hepper that a standardized
terminology for conserved areas would be useful. It appears
that the ex-French and ex-British West African territories
differ widely both in the facility with which areas have been
and can still be conserved and in the effectiveness of such
conservation.
Monad signale qu'en ce qui concerne la nomenclature des
divers types de territoires proteges (Pares Nationaux, etc.), il
faut evidemment se reporter aux definitions de la Convention
de Londres de 1 9 3 3 et a la Liste O.N.U. des « Pares Na­
tionaux et Reserves equivalentes » preparee par l'U.I.C.N.
systematique, qu'anatomique, morphologique et biologique.
Dans son rapport sur le Nimba, il met surtout !'accent sur
ce qu'il est possible (et urgent) de proteger, et non sur
tout ce qu'il serait souhaitable de mettre en reserve.
des Abbayes: M. Ake Assi a incidemment signale, dans son
rapport sur la Cote d'Ivoire, l'interet que presentait le
Rocher d'Issia, qui maintenant est exploite en carriere. Mais
des biotopes equivalents existent dans les savannes de la
region de Seguela, ce sont les bombements granitiques appeles
Boka. Le sommet est occupe par des bosquets et, sur les
pentes, se trouvent des rigoles ou l'eau ruisselle lentement et
temporairement au moment des pluies. Dans ces rigoles existe
une association de Lichens subhydrophiles a Heppia qui
meriterait d'etre protegee. A la base de ces Boka, Ia ou
aboutissent les rigoles, la terre graveleuse humifere porte
une association a plusieurs especes du genre Ophioglossum
et Isoetes de grand interet. Ne serait-il pas possible de
mettre en Reserve, afin qu'ils ne soient pas exploites en car­
rieres, 1 ou 2 de ces Boka? Je songe particulierement a
celui se trouvant a environ 13 km a 1'E de Segwfla et au
Rocher de Mankono qui abrite, en plus, Euphorbia unispina.
des Abbayes: I1 n'a pas ete question dans le rapport sur la
Guinee par M. Schnell des chutes et cascades qui sont des
biotopes riches en Podostemonacees. Les Grandes Chutes, au
N. de Conakry, ont deja ete transformees en barrage pour la
production de l'electricite. Cette transformation a probable­
ment detruit, en plus des Podostemonacees, une population
de l'interessante espece Microdracoides squamosus. Il ap­
parait comme important de preserver certaines chutes de
l'amenagement industriel. Les chutes du Kinkon, pres de
Ditinn, au Fouta-Djalon, seraient dans ce cas. J'y ai en effet
recolte 5 especes de Podostemonacees dont 2 nouvelles,
decrites par Mr. Taylor.
Ake Assi: Toutes les mesures ont ete prises pour que toutes
les associations vegetates interessantes detruites soient rempla­
cees par d'autres associations analogues dans d'autres regions,
notamment dans les reserves que nous proposons dans notre
rapport.
Cusset: M. Schnell s'interesse lui-meme tout particuliere­
ment a !'etude des Podostemonacees, tant au point de vue
D. Gledhill: In the ex-British territories, and especially in
Acta Phytogeogr Suec 54
Adjanohoun: Pour appuyer !'intervention de M. Ake Assi et
apaiser les inquietudes de M. des Abbayes, je tiens a souligner
que nous avons retrouve depuis, les memes associations ve­
getates dans d'autres regions que Seguela et dans nos proposi­
tions de sites d'interet botanique a proteger nous avons tenu
compte de la conservation de ces groupements speciaux.
Sierra Leone, Forest Reserves and protected forests and ex-
Discussion
port restrictions on certain animal species suggest a certain
conservation awareness. In Sierra Leone, neither of these
steps is very meaningful, however; all forests (with one pos­
sible exception) are ultimately destined to provide timber and
hunting of all animals is the accepted perquisite of the tribes
and societies.
It is doubtful if most of the areas which we have proposed
for proper conservation are in any immediate risk of destruc­
tion (e.g. the laterite pans, mangrove swamps, Bamban Hills)
but the two mountain areas require urgent and complete
protection.
To my personal knowledge, hunting activities on the Zingi
mountains, since 1 960, have almost completely destroyed the
populations of larger game animals. As burning is employed
as a concomitant of the hunting of such game, it is hardly
surprising that large areas heavily wooded in 1 960, have been
completely denuded. It may be possible to convince the Sierra
Leone Government that these mountains will only provide the
tourist attraction, which it is hoping to make of them, if and
when it takes the necessary action to stop all exploitation in
them.
Milne-Redhead: With regard to conservation areas in Ghana
I would like to see some part of the Accra Plains included.
So far as I know this area of coastal thicket and derived
savanna is unique in Africa and is therefore of pan-African
importance phyto-geographically. The thicket, when allowed
to develop, is rich in local species and the characteristic
clumps, dominated by Elaeophorbia drupifera in the grazed
derived savanna is in my opinion well worth preserving,
whilst being very vulnerable to destruction through develop­
ment, overgrazing, planting for firewood or irrigation. I
would add that the Accra Plains have considerable historic
interest as being one of the areas where Thonning made h is
famous collections.
105
Lawson: I wish to support what Mr. Milne-Redhead and Dr.
Keay have said about the Accra Plains. Though they cover
a very large area and are not in immediate danger there are
nevertheless increasing herds of cattle on them and in addi­
tion there are several schemes afoot to irrigate large parts
of the eastern end of the plains. Since the Shai Hills to the
east of Accra are already reserved it would perhaps be best
to nominate an area of the denser thicket to the west of
Accra for conservation which is in any case over a very
different type of soil.
The Shai Hills are designated as a game reserve with a
single game warden stationed nearby. Formerly Game Re­
serves were under the Forestry Division but now a new Game
Division is, I understand, responsible.
Keay pointed out that Mr. Charter's paper on Nigeria as
circulated was very brief; if Nigeria had been presented as
fully as some other countries the paper would have been very
much longer. The Forestry Departments have recognized the
value of setting aside Strict Natural Reserves as examples of
the different vegetation zones; much has been done but the
Departments might be helped by encouragement from A.E.T.
F.A.T. On the pan-African scale, perhaps, the Strict Natural
Reserves in the lowland forest of the Oban region are the
most important.
He also asked if anything was being done to conserve the
interesting lowland forest of Southern Bakundu where B renan
and Richards worked in 1 948 and where Brenan discovered
Medusandra. Keay had seen the area in 1 95 1 , and again in
1 96 1 when the forest destruction by farming, cocoa planting
and timber exploitation was very noticeable. He also drew
the attention of the French botanists to the proposals for
Strict Natural Reserves in West Cameroun which had been
made by British forestry departments before the political
reunion of Cameroun.
Keay supported Mr. Milne-Redhead on the importance, on a
pan-African scale, of conserving some area of thicket on the
Accra Plains, possibly in the western part. The need for con­
servation was underlined by the fact that none of these areas
had even the protection of being in a forest reserve.
Monod demande si, aux Iles du cap Vert, la vegetation som­
mitale du volcan du Fogo d'une part, la Sapotacee endemique
Sideroxylon mirmulans d'autre part ne meritent pas une pro­
tection particuliere.
Acta Phytogeogr Suec 54
Central Africa
R E P U B LI Q U E C E NT RA F R I CA I N E
G. Guigonis
LE CADRE PHYSIQUE
Territoire vaguement trapezoidale compris entre les
latitudes 2° 16' et 1 1 °20' Nord et la longitude 14°20' et
27°45' Est, la Republique Centrafricaine apparait comme
une vaste peneplaine separant aux confins de la zone
equatoriale, les cuvettes Tchadiennes et Congolaise. Si
I' on ajoute qu'a l'Est sur 700 kms, la frontiere est tracee
sur la ligne de partage des eaux du Nil et qu'a l'Ouest
prennent naissance des cours d'eau tributaires du Golf
de Guinee et d'autres de la Benoue affluent du Niger,
l'on ne peut qu'etre convaincu de la propriete du terme
de Centrafrique.
La monotonie de cette peneplaine n'est coupee <;a et
la que par des Kaga, pointements eruptifs anciens,
vestiges de reliefs primaires desagreges et, a l'Est et a
l'Ouest, par deux massifs d'etendue et de relief medio­
cres, importants cependant par leur role hydrologique.
La peneplaine tombe brutalement au Nord sur les eten­
dues de la plaine Tchadienne. Au Sud elle se fractionne
en molles collines delimitant des vallees aux plaines allu­
viales reduites. Les rivieres ne s'en degagent que pour
confiuer avec l'Oubangui ou la Sangha qui menent leurs
eaux vers les platitudes de la cuvette Congolaise.
LE CLIMAT
Le climat est commande par deux zones de hautes pres­
sions l'une centree sur l'Atlantique dite de Sainte-Helene
et l'autre sur le desert Lybien. Le manque de fantaisie
du relief, l'echelonnement en latitude et la situation con­
tinentale conferent a ce climat de grandes lignes relative­
ment nettes.
L'extreme Sud de la Haute-Sangha est couvert par la
climat Guineen forestier dans sa nuance septentrionale.
11 lui succede un climat Guineen forestier Oubanguien
etroitement apparente, mais presentant en Decembre,
Janvier une petite saison seche. 11 se manifeste sur une
bande alignee suivant les latitudes, etroite et irreguliere
et n'interessant la Republique Centrafricaine qu'a
l'Ouest oil sa limite Nord passe a peu pres sur la ligne
Bangui-Berberati, et a l'Est dans la region de Bangassou­
Mobaye.
La quasi totalite restante du territoire sur plus de 5°
de latitude appartient au climat Soudano-Guineen, on
y distingue dans la partie Sud un sous-climat nettement
marque par une saison seche plus courte avec en contre­
partie 6 a 7 mois de pluie.
L'extreme Nord est le domaine du climat Sahalo-Sou­
danais.
Les climats cites se presentent avec les caracteristiques
generales qui leurs sont reconnues dans les manuels. 11
semble cependant qu'en Republique Centrafricaine la
saison seche manifeste quelques particularites ; si l'on
excepte le climat Sahalo-Soudanais, l'on n'enregistre, en
effet, pratiquement pas de mois sans pluie. La saison
seche des divers climats doit s'y definir par le nombre
de jour de pluie et la quantite d'eau constatee. L'on a
ainsi :
Climat Guineen forestier, pluviosite minimale pendant I a 2
mois.
Climat Guineen forestier Oubanguien, saison seche comportant
13 jours de pluie et 1 80 mm en 3 mois.
C/imat Soudano-Guineen Oubanguien, saison seche compor­
tant 1 3 jours de pluie et 1 50 mm en 4 mois.
Climat Soudano-Guineen, saison seche comportant 11 jours
de pluie et 1 40 mm e n 5 mois.
Climat Sahalo-Soudanais, saison seche comportant 4 jours de
pluie et 20 mm en 6 mois.
Si les grandes lignes du climat sont nettes, il n'en est
pas de meme des climats locaux car la Republique Centr­
africaine se trouve de par sa position, soumise a des
influences peripheriques puissantes : Golfe de Guinee,
cuvette Congolaise, zones desertiques au Nord et Nord­
Est; les regions du relief Est et Ouest agissent aussi. 11
est done difficile, I'indigence des releves meteorologiques
et la variabilite s'y ajoutant, de delimiter avec precision
les sous-climats de detail. Nous les passerons done.
LA VE GETATION
11 en est de la vegetation comme du climat, les grandes
!ignes sont evidentes mais l'on se trouve sur le terrain
en presence d'un veritable habit d'arlequin et l'on est
long a s'y reconnaitre.
La foret dense humide de basse altitude (type 7 de la
Acta Phytogeogr Suec 54
108
G. Guigonis
Carte de la vegetation en Afrique de l'AETFAT) s'etend
au Sud du pays ,
a l'Est dans la region de 1\1obaye-Bangassou oil tres
degradee par l'homme elle se presente sous la forme de
rares lambeaux tropophiles,
a l'Ouest dans les vallees de la Haute-Sangha et de la
Lobaye oil elle est encore tres puissante et tres belle
sous la forme ombrotropophile.
Ce n'est qu'au Sud de Bayanga, done sur une super­
ficie modeste en Republique Centrafricaine, qu'elle pre­
sente le facies equatorial a feuilles persistantes.
La mosa'ique forestiere (type 8) aureole la formation
precedente sur une profondeur variable difficile a deter­
miner puisqu'il y a etfrangement.
Bile cede la place aux savanes boisees (type 1 7) et aux
forets claires (type 1 6) dites indifferenciees, ces dernieres
. etant plus particulierement frequentes au Nord et a
I' Est.
Enfin dans le Nord au dela du Bahr-Oulou regne
la savane du type sec non differencie (type 20).
Dans le detail, l'on rencontre comme il a ete dit, une
infinie diversite. Aux conditions climatiques locales fort
variees se surimposent en effet, !'action de l'homme, les
conditions edaphiques souvent severes : (nappe, lateri­
sation, arenes greseuses, termitieres, etc. et les influen­
ces des flores fort individualisees voisines : nilotique,
tchadienne montagnarde camerounaise et forestiere de
la cuvette .
Les subdivisions phytogeographiques que les divers
auteurs n'ont pour !'instant fait qu'esquisser, sont done
nombreuses et compliquees. Nous adopterons comme
hypothese de travail celle qu'avance Sillans dans son
Etude des savanes oubanguiennes.
LA PROTECTION
La protection de la nature en Republique Centrafricaine
bien que demandant une attention soutenue, ne pose
pas, pour !'instant, de probleme vraiment insoluble
comme dans beaucoup d'autres pays africains. Diverses
raisons y concourent.
Il y a, en premier lieu, le tres faible taux d' occupation,
2 habitants par km2 environ. De plus, apres de com­
plexes itinerances qui ont aux siecles passes interesse
!'ensemble du pays, les populations se sont condensees
dans les regions les plus favorables, laissant d'immenses
interlands inhabites. Le tiers environ de la super.ficie
totale se trouve ainsi soustraite a !'action de l'homme.
(0,2 habitant par km2 sur 1 80 000 km2) or l'homme
est, chez nous, le facteur preponderant a courte echeance
d'evolution regressive de la vegetation.
Il y a aussi le prise de conscience des responsables du
Gouvernement qui ont ete favorables a une bonne ges­
tion et enfin !'importance economique que l'on reconActa Phytogeogr Suec 54
nait a la faune et la dependance admise de sa conserva­
tion avec celle de la flore qui ont aide a prendre des me­
sures adequates.
Le resultat global est qu'actuellement outre les super­
ficies qui sont hors d'atteinte du fait de leur position,
plus de 5,8 millions d'hectares sont soustraites aux de­
frichements par un texte reglementaire, so it 9 % environ
du pays, sur lesquels on compte :
1 50 000 ha de reserves integrales,
1 270 000 ha de pares nationaux,
390 000 ha de forets domaniales de protection,
630 000 ha de forets domaniales d'exploitation,
4 000 000 ha de reserves de chasses oil le defrichement est soit
interdit, soit cantonne sur de faibles etendues peripheriques.
Dans !'ensemble les interdictions sont respectees. La
veritable difficulte reside dans les moyens materiels limi­
tes que l'Etat peut consacrer a cet objectif particulier.
L'on est ainsi amene a grouper les zones d'action au
detriment quelques fois d'une repartition plus harmoni­
euse mais qui conduirait a la dispersion des efforts, ou a
negliger des stations isok�es de faible superficie.
APER<;U DES ASSOCIATIONS ET DES ESPECES
, PROTEGEES
Foret dense humide de basse altitude
I . District ombrophile de Bayanga-Sangha. I1 comporte :
des formations de terre ferme encore mal connues a Irvingia
excelsa, Manilkara mabokeensis, Entandrophragma, Pericopsis,
Sapotacees et Legumineuses,
des formations inondees ripicoles a Uapaca et ses satellites,
des formations de forc�t mouilleuse a Gilbertiodendron dewevrei
pur, sur de grandes superficies.
Ce district est mal connu mais va etre l'objet en 1 967
d'une prospection sondage sur les 300 000 ha de son
etendue. Cette prospection couvrira aussi 500 000 ha du
·district suivant :
II. District ombrotropophile. Il comporte : des for­
mations de transition entre le district I et Ill, c'est la
foret actuellement exploitee en partie ( 1 1 0 0 00 ha con­
cedees) et bien connue puisque pres d'un million d'ha
des districts II et Ill ont ete inventoriees exhaustivement
au taux de 1 % environ. A l'issue des prospections 1 967
!'ensemble de la foret dense humide sera done correcte­
ment connue.
Dans les deux districts precedents d'immenses super­
ficies ne sont parcourues que par les pygmees, elles sont
protegees en fait par leur inaccessibilite.
Ill. District tropophile. La foret s'y rencontre sous
forme :
de foret dense continue avec de peuplements d'ayous, limbo,
Entandrophragma (surtout cylindricum), Celtis divers, Combreto­
dendron, Staudtia, Eribroma, etc.
Republique <;entrafricaine
DIST R I C TS
� Riser�
1 09
int�gra/11
Fig. 1 . Carte de la Republique Centr­
africaine. Territoires geobotaniques
(d'apres Sillans).
de massifs isoles de meme composition entourees de savane
a especes d'apport recent Crossopteryx, Anona, Bauhinia, Lophira,
Vitex, etc.
sous forme de boqueteaux oil souvent ne subsistent que des
especes de formations secondaires.
C'est evidemment dans ce district que s'est fait sentir la
necessite de nombreux classements, ils ont ete effectues
aux endroits ou la pression demographique faisait cour­
rir un danger certain aux formations fermees.
Dans les trois districts precedents la gestion logique
devra, une fois les inventaires termines, conduire a un
amenagement sylvo-agricole qui definira les massifs a
conserver a l'etat boise pour !'exploitation ou pour toute
autre fin..
Mosai"que foret-savane
IV. District des savanes preforestieres :
il y predomine un facies de savanes arbustives claires du type
deja rencontre dans le district precedent et d'autres d'un type
plus evolue a Danielea, ou a Burkea, Lophira ou a Anogeissus et
A lbizia, etc.
ou y rencontre aussi :
de vastes etendues de savanes herbeuses (Alindao - Mobaye)
des galeries parfois larges et denses
et, rarement, des lambeaux de foret tropophile humide assez
vastes pour faire l'objet d'un classement (Pepelou)
V. District de la Kotto-M'Poko : il ne comporte
pratiquement que de savanes de type divers a lsoberlinia,
Monotes, a Legumineuses, a Legumineuses et Anogeissus, a Terrninalia et Combretum hypopilinum dans la
partie centrale, etc.
VI. District du M'Bomou : il comport des savanes
analogues a celles du district precedent mais aussi :
des forets seches denses a sous-bois tres serre, a Anogeissus
pur ou a Anogeissus, A lbizia (les 4), Khaya et Cola cordifo!ia.
des savanes arbustives derivees des formations precedentes.
Forets claires et savanes boisees et herbeuses
VII. District de Yade il : est premontagnard et carac­
terise par :
des savanes forestieres quelques fois tres denses a Burkea et
Lophira ou a Isoberlinia, Monotes, Uapaca ou a Legumineuses,
dans certaines stations le sous-bois est envahi par Dryopteris
athamantica,
des savanes reforestees en Pithecellobium eriorachis par le
paturage,
des beaux bois de ravin,
des lambeaux de foret dense semi-humides (?) dont la tres
curieuse foret de Donghe ou l'on trouve sur 1 500 ha environ des
formations a limba, Gambeya subnuda, Lovoa, Ayous, Celtis
africana, Anogeissus, Afzelia, Aubrevillea, le tout melange pied
a pied. Cette foret est fort entamee par la culture du cafe Nana,
'etage dominant y est cependant concerve comma couvert.
1
11 est a signaler que dans la region culminante du mas­
s i f, le tres beau mont Pana beneticie d'un interdit �t
presente les seules associations a Commiphora du pays.
VIII. District de l'Ouham, ou parmi des savanes arbo­
rees des types deja decrit et de forets seches a Anogeissus,
existent de nombreux collines gneissiques et lateritiques
au manteau herbace encore peu connu.
IX. District Central de la Ouaka-Gribingui et district
X prolongement oriental du precedent, ils comportent :
Acta Phytogeogr Suec 54
1 10
G. Guigonis
de grandes etendues de bambousaies prenant en echarpe Jes
deux districts,
des forets seches denses a Anogeissus
des savanes forestieres a lsoberlinia, Monotes, Uapaca avec en
sous-bois des Oxytenanthera et Encephalartos septentrionalis.
des savanes a Terminalia, Grewia, Combretum ou a Burkea ,
Prosopis, Detarium, Erythrophleum.
Dans ce district se situent la reserve integrale de la
Wasoko-Bolo, le Pare du Bamingui-Bangoran et les Re­
serves de Faune qui l'entourent :
XI. District du Chari-Logone, le facies foret claire dis­
parait dans ce district on y rencontre :
des savanes forestieres en Isoberlinia avec sous-bois a Oxy­
tenanthera,
des savanes arbustives claires a Terminalia, Grewia, Combretum
avec apparition d' Acacia stenocarpa, Ziziphus, etc.
des bush denses a Oxytenanthera,
quelques lambeaux de forets seches surpaturees par les
elephants,
des galeries parfois encore puissantes avec les derniers repre­
sentants des flores humides : Pycnanthus, Mitragyna stipulosa,
Cola cordifolia, Sterculia tragacantha.
XII. District du Haut-Aouk. On y note en avan<;ant
vers le Nord la rarefaction puis la disparition des forets
seches et des bambous, !'apparition d'especes exclusive­
ment soudanienne : Balanites, Capparidacees diverses,
Poupartia.
La vegetation s'y presente sous forme :
de savane pare a bouquets d'arbres de faible stature, en gene­
ral sur termitieres : . Terminalia, Tamarindus, Bauhinia, Combre­
tum, Kigelia. Ces savanes presentent parfois le facies leoparde,
des savanes herbeuses inondables avec bouquets de Mitragyna
inermis et Adina microcephala,
sur le relief a l'Est, des savanes arborees a lsoberlinia, Haplo­
coelum, Vangueria cf venosa, Boswel!ia, Ficus etc.
A cheval sur les deux districts precedents se trouvent :
le Pare Saint-Floris dans une plaine alluviale,
le Pare Andre Felix dans la region de basses montagnes de
la dorsale Tchad-Nil,
des Reserves de Chasses,
les deux Domaines concedes pour !'exploitation touristkc­
cynegetiques.
XIII. District de Birao, voisin du precedent; c'est une
ava:ricee de la plaine Tchadienne. Il comporte une vaste
etendue sabloneuse appelee « Goz » dans le pays
limitee au Nord et au Sud par de large vallees d'inonda­
tions.
La partie exondee supporte une steppe a epineux.
ASSOCIATIONS DONT LA PROTECTION
EST ENVISAGEE
Dans la secteur forestier et la mosai"que foret-savane,
pratiquement chacune des associations et leurs divers
Acta Phytogeogr Suec 54
composants beneficient d'une protection soit de fait soit
par classements. 11 est cependant envisage d'etendre
ceux-ci a l'avenir :
a d'importantes forets domaniales d'exploitations dans le
districts ombrophile I et 11,
a des reserves botaniques a but scientifiques et touristiques de
quelques centaines d'hectares faciles d'acces et decoupees dans
les forets classees existantes ou a creer dans les districts I,
11 et Ill. Des projets sont deja a !'etude ou en cours de realisa­
tion :
pres de la Maboke, annexe du Museum d'Histoire Naturelle
de Paris, sur 300 ha decoupees dans la foret ombro-tropoph ile
avec savane incluse,
a proximite de Bangui dans la foret tropophile concedes a la
F.A. O., pour son Centre Pilote 2 ou 3 placeaux de 1 00 ha,
dans la region de Berberati-Nola sur 300 ha, dans des peup­
lements ripicoles a Cyathea, seule fougere arborescente du pays.
Le district VI (et le X qui lui fait suite au Nord) feront
en 1 967/68 l'objet d'une etude zoo-botanique qui sera
effectuee par une mission Allemande, en vue de la crea­
tion d'un nouveau Domaine pour !'exploitation touris­
tico-cynegetique, une partie de ce Domaine beneficiera
d'une protection to�ale.
Dans le secteur des savanes, les classements ont portes
sur des forets denses seches, des savanes arborees et sur
une roneraie.
11 conviendrait de multiplier ces classements de pro­
tection mais ils ne sont efficaces qu'avec l'accord spon­
tane des populations, qui est rarement accorde; nous
l'avons obtenus dans certains cas par le biais des reserve
communales de chasses.
Deux ont ete crees a ce jour :
a Wakanga a l'Ouest de Berberati sur 1 4 000 ha
a Waka 11, au Nord d'Ippy sur 8000 ha, d'autres sont en
projet.
Par ailleurs des projets a !'etude ou en cours d'execu­
tion prevoient le classement de series touristiques et de
certaines stations contenant des associations typiques :
a Donghe a 30 km au Sud de Bouar dans la formation humide
deja signalee plus haut sur 1 000 ha environ,
a Baboua dans les savanes a couverture vivante a Dryopteris
anthamantica sur 50 ha,
dans les galeries du district XI, a facies humide, par placeaux
de 10 a 20 ha,
dans les Domaines touristiques deja concedes, sur des super­
ficies de plusieurs millieux d'hectares interessant des boisements
divers de belle venue.
A !'echelon especes, seules beneficient d'un regime de
protection celles classiquement retenues par les regle­
ments forestiers et 1'Encephalartos septentrionalis. Pour
aller plus avant il faudra attendre une plus complete
connaissance botanique du pays.
La Nature et avec elle les formations botaniques, les
associations et les especes constituantes beneficient deja
en Republique Centrafricaine d'une protection fort
Gabon
avancee. L'on s'est fort logiquement interesse au depart
a de vastes ensembles comportant des formations utili­
taires.
Au cours de la prochaine etape l'on se preoccupera
en plus, d'ensembles moins generaux d'interet scienti­
fique ou touristique qui pourront aller dans le detailjus­
qu'aux associations et aux especes. Les actions seront
111
menees au fur et a mesure que la connaissance plus ap­
profondie de la faune et de la flore en montrera la neces­
site et aussi, il faut bien le dire, en fonction des moyens
materiels qui seront impartis car comme partant ailleurs,
les mesures reglementaires qui demeurent purement
theoriques sont plus nefastes qu'utiles.
GABON
( Note preliminaire)
N. Ha/le et A . Le Thomas
GEOGRAPHIE
267 000 km2; 650 km W-E; 700 km N-S; equateur pres­
que median. - Frontieres : Guinee espagnole (Muni)
300 km; Cameroun 250 km; Congo Brazzaville 1 500 km.
- 750 km de rivages marins. - Fleuve Ogooue de 800
km ; la source est au Congo; affluents rive droite : Aban­
ga, Okano, Ivindo, Sebe; rive gauche; Ngounye, Ofooue,
Lolo; region des lacs vers le bas-Ogooue.-Riviere Noya
et estuaire du Muni, riviere Mondah et son estuaire,
riviere Como et l'estuaire (Gabon p.p.d.) drainent le
NW. - Au SW, les rivieres Rembos et les lagunes co­
tieres (Fernan-Vaz, Ngove, N dogo, Mbanio) . - Au Sud,
la Nyanga (400 km). - Les Monts-de-Cristal presentent
divers sommets de pres de 1000 m; le massif du Chaillu
de 300-900 m d'altitude, atteint 1 300-1 500 m au mont
Iboundji; au NE, des cretes ferrugineuses atteignant 1 000
m (Belinga, etc.) ; au NNW, grands domes granitiques ;
vers le S, les monts Tandous forment les chaines du
Mayombe gabonais.
CLIMATOLOGIE
Au NW, 3-4 m de pluie, saison seche reduite ou nulle
dans les Monts-de-Cristal. - 2-3 m avec une saison
seche marquee (juin-aofi.t) dans le bas Ogooue et l'Es­
tuaire. - 1 -2 m avec saison seche marquee dans le moyen­
Ogooue, le haut-Ogooue et la Ngounye. - Au S, 1 m
de pluie avec une saison seche atteignant 5 mois dans la
Nyanga. - Au N, Woleu-Ntem, et au NE, haut-Ivindo
et Djouah, 2 saisons seches dont une d'hiver (dec. a
fev.).
VEGETATION
Le pays appartient au Domaine chorologique camerou­
no-gabonais, sauf la region du S qui se rattache au Do-
maine peripherique meridional (affinites avec le Mayom­
be congolais et le NW de I'Angola). - La surface est
revetue a 8 5 % de foret dense humide sempervirente. Le
N et NE, depourvu d'Okoume, tendent vers le caractere
semi-decidu. - Mangrove, forets a Burseracees, a
Legumineuses, forets ripicoles periodiquement inondees
ou marecageuses, forets de montagne, sont les princi­
paux aspects de la vegetation forestiere. - Les savanes
(1 5 % de la superficie) se presentent en taches subco­
tieres, plaines et enclaves (region des cirques entre l'Es­
tuaire et le bas-Ogooue; savanes de Booue), vallees schi­
stocalcaires (Mayombe) et plateaux sablonneux (re­
gion de Franceville). Bas-Ogooue et region des lacs
avec des savanes marecageuses a Papyrus.
FLORE
Elle se presente pour le systematicien comme d'une
exceptionnelle richesse en especes. On peut l'evaluer
entre 8000 et 10 000 especes de Phanerogames et Pteri­
dophytes. La flore du Gabon est relativement peu me­
nacee de destructions anthropiques car la population
est de faible densite (2 habitants au km2) ; malgre I' in­
tense exploitation forestiere et les methodes d'agriculture
transhumante, le Gabon gardera encore longtemps et a
l'etat pratiquement intact, des aires oil la quasi-totalite
des especes endemiques pourra se maintenir. D'im­
menses etendues peu penetrables restent encore inex­
plorees et les endemiques sont bien loin de ne pouvoir
subsister que sur des ilots inaccessibles.
CONCLUSIONS
La flore du Gabon attend le recensement et I'etude piu­
tot que les mesures de preservation. Un choix anticipe
de reserves botaniques nous parait premature en l'etat
Acta Phytogeogr Suec 54
1 12
C. Farron
Tableau 1 . Comparaison entre les Flores du Gabon et du
Cameroun
Pteridophytes
Gabon
Nombre moyen de
recolteurs par
espece
Nombre moyen de
recoltes p ar espece
2,6
3,7
Tableau 2. Comparaison entre les Flores du Gabon et du
Cameroun
Pourcentage par classe d'especes :
Rutacees
Cameroun
4
6
Gabon
Nombre de Pteridophytes
recoltes
Camepar espece
Gabon roun
Cameroun
4,6
2, 3
5
Especes mal
connues
8,2
Pourcentage d e
n!coltes anterieures
a 1 940
58
48
94
32
Pourcentage de
recoltes posterieures a 1 940
42
52
6
68
Nombre total d e
recoltes
484
1 5 47
88
182
Nombre d'especes
1 30
255
17
22
actuel des reseaux routiers ou ferres d e c e pays. Un effort
accru de prospection botanique est a souhaiter dans les
Monts-de-Cristal, dans le massif du Chaillu et dans les
regions sublittorales a peu pres inconnues du SW. La
necessite de cet effort est rendu evidente par la carte
d'exploration floristique de 1' A.E.T.F.A.T.
Notes annexes sur !'exploration botanique
au Gabon
Les collaborateurs, encore peu nombreux, de la Flore du
Gabon publiee par le .laboratoire de Phanerogamie du Museum
Gabon Cameroun
29
51
13
27
29
35
4
18
6
31
35
29
41
7a 11
12 a 23
18
0
24
14
35
0
18
23
Plus d e 7
18
38
35
41
1 ou 2
Especes
moyennement 3 a
connues
Especes bien
connues
Rutacees
de Paris, sont tres loin d'etre approvisionnes en recoltes suffi­
santes alors que la richesse botanique, certainement sous-esti­
mee, a deja ete reconnue exceptionnelle par plusieurs mono­
graphes de families forestieres.
Quelques donnees statistiques, comparaisons entre les Flores
du Gabon et du Cameroun, sont presentees ci-dessus. Elles
mettent en evidence l'insuffisance des materiaux gabonais d'etude
et surtout la pauvrete en recoltes posterieures a 1 940. Les don­
nees de base sont tirees des Pteridophytes etudiees pour les deux
Flores par Mme Tardieu-Blot, et des Rutacees etudiees de meme
par M. R. Letouzey. Chaque auteur ayant fait simultanement
son etude pour les deux Flores, et tous les materiaux etudies
ayant ete cites pour chaque pays, les resultats sont significatifs.
Les Membres de l'A.E.T.F.A.T., comme nous le souhaitons,
pourraient-ils aider a accelerer la recherche et la prospection
botaniques au Gabon?
C O N G O - B R A Z Z AV I L L E
C. Farron
GEOGRAPHIE
Au point de vue geographique, le Congo-Brazzaville est
a cheval sur l'Equateur : possedant 225 km de cote a
l'Ocean atlantique, le Congo s'enfonce sur 1 200 km
sur la rive droite du Congo, puis de l'Oubangui, en fai­
sant un coude a la hauteur de Brazzaville, qui delimite
un Congo Sud-Occidental et un Nord-Congo.
Dans le Congo Sud-Occidental, pays au relief varie,
a saison seche de 4-5 mois, se concentre la plus grande
partie de la population (600 000 habitants). Le Nord­
Congo a un relief presque inexistant, un climat nettement
plus humide et une population plus clairsemee. (240 000
habitants.)
Acta Phytogeogr Suec 54
C'est un pays de basse altitude oil le point culminant
ne depasse guere 800 m.
11 presente une variation de climats qui est en relation
avec son etendue en latitude : du Nord au Sud on ren­
contre le sous-climat oubanguien (au N. du 3e parallele
N.) le sous-climat equatorial, decale vers le Nord, le sous­
climat lukenien, le sous-climat congolais-meridional et
le climat bas-congolais dans le Sud du pays.
TYPES DE VEGETATION
La vegetation la plus diversifiee au Congo-Brazzaville
est la foret. Elle recouvre toute la region Nord et austro-
1 13
Congo-Brazzaville
1"�---+----1---,--
I�
·
,10 0
13"
Fig
-----
1 . Republique du Congo (Brazzaville) : Emplacement des Regions
a
s�----"'
_ ..
,___>,oo m
17·--- -- ------w---_j5.
proteger integralement au point de vue botanique. 1 ,
Reserve forestiere d e la Tsiama. 2 , Foret galerie de l a Djoumouna. 3 , Forets a u bord d u Congo d e Mou tampa
4, Foret
de
Mandiele. 5, Foret du Petit Bangou. 6, Foret d u Grand Bangou.
8, Lambeau forestier pres de Boko-Songo.
9,
a
l a Foulakari.
7, Lambeau forestier entre Marche et Mindouli.
Foret primaire pres d'Aubeville. 10, Fourres littoraux
Cirque de Diosso. 1 2 , Foret littorale entre Djeno e t le Cabinda. 1 3 , Lambeaux forestiers pres
du lac
de
la Pointe-Indienne. 1 1 ,
Cayo. 1 4 , Forets galeries de
la Lefini. 15, Forets sur plateau entre Ngo et Nsa. 1 6, For�ts sur sable Bateke entre Gamboma et Abal a . 1 7, Region
de
Kaka­
moeka (Foret dense). 18, Region Ouest Sibiti-Komono (Foret dense).
8 - 6 8 1 557 Hedberg
Acta Phytogeogr Suec 54
1 14
C. Fctrron
occidentale du pays, et n'est vraiment absente nulle
part, ne ffit-ce que sous forme de reliques. Relevons tout
de suite que sauf dans le Mayombe facilement accessible,
elle est beaucoup moins connue que celle des pays voi­
sins.
On peut distinguer parmi les forc:!ts tropicales humides
de basse altitude :
Ce/les de terre ferme, qui sont soit sempervirentes so it
semi-decidues, et qui recouvrent tout le Nord-Ouest qui
fait la frontiere avec le Gabon et le Cameroun, ainsi que
le Sud-Ouest ou le Mayombe et le Chaillu sont comple­
tement boises.
Les forets inondees qui occupent une grande surface
(env. 4 millions d'ha) dans les rivieres a meandres du
Nord-Est, afftuents du Congo puis de l'Oubangui.
Relevons qu'il existe une foret claire curieuse, a un
etage de grands arbres dominant une strate basse, d'ori­
gine inexpliquee. L'action de l'homme est difficile a sou­
tenir, la region etant tres peu peuplee.
Enfin, de part et d'autre des cours d'eau sur les pentes
tres douces, on trouve des peuplements a peu pres purs
de Gilbertiodendron dewevrei.
Aux environs de Brazzaville existe sur le sable une
foret seche, semi-decidue, pas tres elevee, 1 0-1 5 m de
haut, a Hymenocardia ulmoi'des, Pentaclethera eetveldea­
na, Dracaena reflexa, etc . , et comprenant beaucoup de
lianes : Calycobolus, Landolphiees, Connaracees, Dicha­
petalacees, etc. D'apres Mildbraed ( 1 922)\ cette for­
mation serait sans equivalent en Afrique tropicale. Bile
abrite de nombreuses especes endemiques.
Les galeries forestieres sont souvent tres peu etendues,
celles des environs de Brazzaville sont d'une richesse
etonnante, et comprennent egalement de nombreuses
especes endemiques.
Relevons aussi l'interet des fourres littoraux des
environs de Pointe-Noire, a Fegimanra africana, nom­
breuses Meliacees, Colatiers, etc.
Les savanes arbustives (a Annona arenaria, Hymeno­
cardia, Brideliaferruginea) et les savanes nues recouvrent
au Congo-Brazzaville, une grande partie des surfaces
defrichees.
LA PROTECTION
Aucune espece n'est protegee expressement au Congo­
Brazzaville, sauf quelques grands arbres (Limba, Okou­
me) dont la coupe est reglementee. La loi forestiere com­
prend bien une reglementation des feux, des defriche­
ments et des exploitations forestieres, mais les infractions
sont nombreuses et le systeme des forets classees et pro­
tegees est trop soumis aux fluctuations de la politique
locale.
1 Mildbraed, J. 1 922. Wi ssenschaftliche Ergebnisse der Zwei­
ten Deutschen Zentral-Afrika-Expedition 1 9 1 0-1 9 1 1 .
Acta Phytogeogr Suec 54
· La veritable et totale protection de la foret n'est reelle
que par son eloignement des grands centres ou par sa
difficulte d'acces.
Il est navrant pour le botaniste systematicien de voir
les perimetres de forets denses et les lieux naturels riches
en especes endemiques disparaitre irremediablement
d'une annee a l'autre dans la region de Brazzaville, par­
ticulierement atteinte. En moins de deux ans nous avons
vu disparaitre une grande partie de la reserve de la Patte
d'Oie, le Ravin de la Glaciere, espace vert dans la ville
meme. Il ne reste, a la place de la reserve de la Corniche,
au bord du Congo, que quelques arbres et des planta­
tions de manioc.
ASSOCIATION DONT LA PROTECTION
EST ENVISAGEE
Nous proposons de mettre en reserve naturelle integrale
les perimetres suivants directement menaces par le de­
frichement total ou !'exploitation forestiere, et qui sont
menacees directement par leur grande fragilite.
Dans les environs de Brazzaville, il faudrait proteger
efficacement (voir carte annexee).
1 . La reserve forestiere de la Tsiama, type de la foret seche sur
sable.
2. L a foret galerie de l a Djoumouna, pres de Linzolo.
3. La foret du bord du Congo et des lies du Congo de Mou­
tampa aux chutes de la Foulakari.
4. La foret de Mandiele sur les plateaux Batekes, reste des
forets du couloir du Congo.
5. La foret du Petit Bangou, de type semi-caducifolie pres de
Mayama (presence du rare Paraphiadanthe j/agellifiora,
Flacourtiacees).
6. La foret du Grand Bangou, pres de Kindamba (riche en
especes endemiques, foret magnifique a biotopes tres varies,
qui a echappe j usqu'a present a !'exploitation forestiere).
Dans la valtee du Niari :
7. Lambeau forestier entre Marche et Mindouli, sur les som­
mets de colline dans la vallee du Niari .
8. Lambeau forestier pres de Boko-Songho, egalement sur les
collines.
9 . Lambeau forestier pres d'Aubeville, foret primaire.
Dans la region de Pointe-Noire :
1 0. Fourres littoraux pres de la Pointe-Indienne.
1 1 . Site du Cirque de Diosso.
1 2 . Foret littorale a Mani/kara et Fegimanra entre Djeno et l a
frontiere du Cabinda.
1 3 . Lambeaux forestiers au N . E . d u Lac Cayo, foret ayant subi
une exploitation forestiere.
Dans le Nord-Congo :
14. Les forets galeries de la Lefini, entre la route du Nord et le
Congo.
1 5. Les forets sur plateau entre Ngo et Nsa, sur l a route de
Djambala, forets tres fragiles.
1 6 . Les forets entre Gamboma et Abala, au Sud de Boundji,
forets sur sable Bateke.
Cameroun
Ces perimetres de faible ou moyenne surface devraient
etre constitues en reserves naturelles integrales, ou du
moins jouir d'une protection reelle contre les feux
et d'une interdiction d'exploitation forestiere, avec un
gardiennage efficace.
Dans un avenir plus lointain, avec un souci d'amena­
gement rationnel du pays, des regions plus etendues
1 15
devraient etre erigees en pares nationaux pour completer
ceux qui existent deja.
La region entre Kakamoeka et la frontiere du Gabon,
( 1 7) sur la rive droite du Kouilou, la region a l'Ouest de
Sibiti-Komono, ( 1 8) seraient particulierement inte­
ressantes a proteger, comme region de grande foret en­
core peu modifiee par l'homme.
CAfviEROUN
R. Letouzey
GEOGRAPHIE
La Republique federale du Cameroun s'etend sur
475 000 km2, entre les paralleles 1 °4 et 1 3°0 de latitude
Nord et les meridiens 8°3 et. 1 6° 1 de longitude Est. Qua­
tre bassins hydrographiques (atlantique, congolais, nige­
rien, tchadien) sont separes par des reliefs formant, d'une
part un large plateau meridional vers 600-900 m, d'autre
part le plateau central de 1' Adamaoua entre 900 et 1 500
m, enfin un axe montagneux important; cet axe s'allonge
depuis l'angle de la baie de Biafra jusqu'au lac Tchad,
avec le cone isole littoral du mont Cameroun (4070 m),
puis une succession de sommets atteignant entre 3000
et 1 500 m.
Le soubassement geologique est constitue essentielle­
ment par le vieux socle precambrien avec granites, mig­
matites et ectinites, surmonte �a et la de lambeaux pre­
cambriens plus recents, surtout schisteux ; le Cretace et
le Tertiaire sont representes par des terrains de faible
superficie au long du littoral atlantique et dans la va1lee
de la Benoue; des sediments quaternaires s'etendent lar­
gement au Sud du lac Tchad. De nombreuses intrusions
volcaniques parsement l'axe montagneux occidental,
ainsi que le centre du plateau de 1'Adamaoua.
Toute la moitie Sud du territoire est recouverte de
sols ferrallitiques, jaunes au voisinage de la zone litto­
rale, rouges partout ailleurs et de plus sou vent indures,
avec concretions et cuirasses ferrugineuses dans les zones
des savanes periforestieres et de l'Adamaoua. Au Nord
de cette region dominent des sols de type ferrugineux
tropical, alternant avec des lithosols, des sols jeunes sur
alluvions, des sols calcimorphes ou halomorphes ; des
sols hydromorphes se trouvent un peu partout, formant
un reseau de vallees a mailles serrees extremement im­
portant.
De par sa position geographique le Cameroun est sou­
mis au climat equatorial au Sud du parallele 5°30 et au
climat tropical au Nord. L'influence d'une pseudo-mous-
son s'exerce sur le fond septentrional de la baie de Biafra
et la presence de reliefs importants permet !'existence
de climats montagnards de type equatorial ou tropical.
Les temperatures moyennes annuelles oscillent entre
20° 1 (Dschang) et 28°5 (Maroua), avec des amplitudes
mensuelles allant de 1 °7 (Souanke) a 8°7 (Fort Lamy) ;
les minima et maxima absolus ne depassent pas 1 2°3
(Poli) et 4 1 o4 (Fort Lamy). La pluviometrie moyenne
annuelle se tient pour la plus grande part du territoire
entre 1 500 et 1 750 mm mais, au Sud-Ouest, atteint j us­
qu'a pres de 10 000 mm sur les basses pentes du mont
Cameroun, avec saison seche pratiquement inexistante ;
au Nord de l'Adamaoua, cette pluviometrie moyenne
s'abaisse a 635 mm pour Fort Lamy et la saison seche
dure ici 8 mois.
L'importance du facteur humain ne peut etre ignoree
car la population, malgre une repartition tres inegale,
represente en moyenne 9 . 7 habitants au km2• De Douala
a Nkongsamba se succedent des plantations agricoles
industrielles, le paysage vegetal des montagnes de l'Ouest
est entierement domestique, de Douala a Yaounde tra­
vaillent des exploitations forestieres, d'importantes sur­
faces de la foret meridionale centrale sont transformees
en cacaoyeres, les savanes du Cameroun central sont
parcourues par les feux annuels d'herbage, le plateau
de 1' Adamaoua est soumis a une intense vaine pature,
les plaines du N ord sont des champs de mil et des terres
de parcours de betail, les monts Mandara sont couverts
de terrasses de culture, etc. Seules la foret dense hu­
mide meridionale au Sud-Ouest et surtout au Sud-Est, les
vastes savanes arbustives desertes au pied de l'Ada­
maoua, enfin les savanes boisees au Nord de ce plateau,
echappent, au moins provisoirement, a l'emprise hu­
maine.
LA VEGETATION
Le tableau suivant fournit une vue d'ensemble de la
vegetation camerounaise, en s'effor�ant de mettre en
Acta Phytogeogr Suec 54
1 1 6 R. Letouzey
100
1
[TIIT]
2�
3�
, DIID
s nmJ
-�
7E22J
8
200
+ Foret dense humide sempervirente a
90
·· D
uQ
t2 ED
13 0
14 0
15 �
·· �
Gilbertiodendron
foret marecageuse du haut Nyong a Sterculia
subviolacea [7] ; foret inondee de la Sangha [6] ; prairies
aquatiques du haut Nyong; prairies sur schistes chloriteux.
30011m
dewevrei;
C. Domaine (?) congo-guineen de la foret dense humide
semi-decidue de moyenne altitude.
1 . Secteur de la foret dense humide semi-decidue de moyenne
altitude a Sterculiacees et Ulmacees [8].
+ Prairies marecageuses a Cyclosorus striatus et Mariscus
pseudopilosus; prairies sur cuirasses ferrugineuses a Bulbo ­
stylis laniceps; groupements saxicoles.
2. Secteur guineo-soudanien des savanes periforesW:res [9 ] .
+ Prairies marecageuses e t inondables; groupements saxi­
coles; r6neraies.
+ (pour A, B, C) Raphiales marecageuses et raphiales
ripicoles; groupements forestiers marecageux ou periodi­
quement inondes et ripicoles divers; prairies periodique­
ment inondees.
D. Domaine afro-montagnard.
1 . Secteur afro-submontagnard [ 1 5 ] .
a. Foret dense humide sempervirente d'altitude submonta­
gnarde (a Guttiferes?).
2. Secteur afro-montagnard [ 1 5 ] .
a. Foret dense humide sempervirente d'altitude montagnarde
a Podocarpus milanjianus et Olea hochstetteri.
+ Prairies patun!es de degradation.
Region soudano-zambezienne
A. Domaine soudanien.
1.
Republique Federale du Cameroun, secteurs phytogeo­
graphiques : 1 , Mangrove; 2, Fourres arbustifs littoraux; 3, Fo­
ret littorale; 4, Foret biafreenne; 5, Foret congolaise; 6 , Foret
inondee de la Sangha; 7, Foret marecageuse du haut Nyong; 8,
Foret semi-decidue; 9 , Savanes periforestif:res; 1 0, Savanes de
l' Adamaoua; 1 1 , Savanes plus ou moins boisees de la Benoue;
1 2, Monts Mandara a vegetation soudanienne; 1 3 , Steppes sa­
heliennes; 1 4, Prairies periodiquement inondees du Nord Came­
roun; 1 5 , Formations submontagnardes et montagnardes; 1 6,
Formations afro-subalpines. (R. Letouzey 1 965.)
Fig. 1.
2 . Secteur medio-soudanien des savanes boisees, voire forets
claires seches, a Jsoberlinia doka, Monotes kerstingii, Uapaca
togoensis, . . . de la falaise septentrionale du plateau de 1' Ada­
maoua [ 1 1 ] [ 1 2 ] .
+ Savanes arbustives d e degradation a Combretum e t Ter­
minalia.
3.
cause simultanement : facteurs ecologiques presents, passe
paleobotanique et flores actuelles, evolution possible des
groupements :
Region congo-guineenne
A. Domaine nigero-camerouno-gabonais.
1 . Secteur nigero-camerounais ou biafreen.
a. Foret dense humide sempervirente de basse et moyenne
altitude a Cesalpiniacees (Foret biafreenne) [4].
+ Groupements saxicoles.
b. Foret dense humide littorale de basse altitude a Sacoglottis
gabonensis et Lophira alata (Foret littorale) [3 ].
+ Mangrove [ 1 ] ; fourres arbustifs littoraux [2] .
B. Domaine camerouno-congolais.
1 . Secteur camerouno-congolais.
a. Foret dense humide sempervirente de moyenne altitude
(Foret congolaise) [5 ] .
Acta Phytogeogr Suec
54
Secteur soudano-guineen.
a. Savanes arbustives et arborees du plateau de 1' Adamaoua
a Daniellia oliveri et Lophira lanceolata [ 1 0] .
+ Prairies marecageuses e t periodiquement inondees;
prairies sur cuirasses ferrugineuses a Ctenium newtonii;
groupements saxicoles; vallons forestiers encaisses; syzyge
raies.
Secteur soudano-sahelien des savanes boisees, voire forets
claires seches, a Boswellia odorata, Sclerocarya birrea, Pro­
sopis africana, etc., du bassin camerounais de la Benoue [ 1 1 ] .
+ S avanes arbustives d e degradation a Combretum et Ter­
minalia.
B. Domaine sahelien.
1 . Secteur sahelo-soudanien.
a. Steppes sahelo-soudaniennes exondees du Nord Cameroun
(13].
b . Zones periodiquement inondees des abords d u Logone­
Chari et du lac Tchad [ 1 4].
b I. Vegetation des argiles noires a Acacia seyal et formes de
degradation d'origine anthropique.
b2. Vegetation des prairies gramineennes.
Region afro-alpine
A. Domaine afro-subalpin
1 . Fourres arbustifs subalpins « a Ericacees » [ 1 6] .
+ Prairies de degradation naturelle ou artificielle subal­
pines.
Cameroun
LA PROTECTION
Dans le domaine de la protection de la ftore et de la vege­
tation il est impossible de citer pour le Cameroun des
mesures legales et pratiques analogues a celles prises
dans les pays temperes. Cette situation s'explique fort
bien si l'on considere le contexte historique et l'etat pre­
sent des conceptions africaines sur de tels sujets.
Diverses croyances, reposant sur des bases mythiques,
magiques, religieuses, psychologiques, physiologiques,
etc. , incitent certainement les Camerounais, tout au
moins de certaines tribus et tout comme d'autres afri­
cains, a s'abstenir de toucher ou de detruire quelques
vegetaux, ou des parties de ces vegetaux. Une profonde
ignorance dans ce domaine de l'ethnobotanique came­
rounaise peut seule etre mentionnee ici.
De meme quelques « bois sacres » permettent la survie,
au moins partielle et provisoire, de lambeaux forestiers,
en pays bamih�ke par exemple ; la tradition remplace ici
avantageusement la contrainte legale mais cette protec­
tion de fragments de vegetation risque d'evoluer avec
la transformation spontanee des us et coutumes.
Dans le domaine legal, ne sont connues au Cameroun
que diverses regles concernant !'exploitation domestique
ou industrielle des arbres :
d'une part sont protegees, et ne peuvent ainsi etre
theoriquement abattues sans autorisation speciale, quel­
ques especes hautement utilitaires, telles Baillonella toxi­
sperma, Borassus aethiopum etc.;
d'autre part les essences de bois, faisant l'objet d'un
courant commercial, ne peuvent etre abattues au-dessous
d'une certaine taille (se traduisant par la notion de « dia­
metre minimum d'exploitabilite »), ceci afin d'assurer
leur regeneration naturelle. Cette regie repond en fait
a des exigences technologiques et se trouve pratiquement
respectee; cependant !'exploitation d'une essence donnee,
entreprise d'une maniere intensive, arnene incontestable­
rnent une rarefaction locale de l'espece, tel le cas des
Diopyros fournisseurs d'ebene, de 1'Afzelia bipindensis,
etc . ;
L a constitution theorique de « reserves forestieres »,
fermees temporairement a !'exploitation ou soumises a
celle-ci d'une maniere contr6Iee afin d'assurer la peren­
nite du capital forestier, ne joue qu'en faveur de !'exploi­
tation des bois car ces reserves restent en fait, sinon tou­
j ours en droit, accessibles a la hache du cultivateur;
dans le meme ordre d'idees, la rc!glementation des feux
annuels d'herbage, dans la zone des savanes perifores­
tieres et soudaniennes, est du domaine des reglements
administratifs sans consequences.
En 1 948 fut legalernent et pratiquernent instituee une
reserve botanique au sommet des monts Barnboutos,. a
proxirnite de Dschang en pays bamileke. D'une super­
fide voisine de 500 hectares, etagee de 2200 a 2700 m
1 17
environ, elle comportait des il6ts de foret de montagne,
des broussailles et des herbages anterieurement modeles
par action de l'homme, des stations rocheuses ou hu­
mides, etc., et put etre entouree d'une c16ture metallique,
d'un fosse, et etre protegee contre les feux pendant quel­
ques annees. Les incidents politiques et militaires, sur­
venus dans cette partie du Cameroun depuis l O ans, sont
h cause de !'abandon de cette reserve dont le sort
actuel, en zone d'insecurite, demeure ignore.
y a-t-il des especes ou des groupements vegetaux a
proteger au Cameroun? Une reponse affirmative peut
evidemment etre donnee, malgre la mauvaise connais­
sance de l'aire tant camerounaise qu'africaine des especes
et de leur dynanisme, malgre le manque d'information
sur l'equilibre des conditions ecologiques oil se trouvent
places les groupements en cause.
Quant aux rnesures pratiques a envisager pour realiser
une telle protection, elles exigeront beaucoup d'imagina­
tion et d'effort pour ne pas demeurer au stade des specu­
lations intellectuelles; dispositions legales, regles admi­
nistratives, education, propagande, . . . sont des necessi­
tes qui, en Afrique tropicale actuelle, ne s'appliquent pas
seulement aux plantes.
Sur le plan theorique done, et dans l'etat actuel des
connaissances, !'enumeration suivante peut etre tentee,
les chiffres entre parentheses indiquant les groupements,
ci-apres designes, qui pourraient avantageusement en­
glober certaines des especes a proteger.
Podocarpus milanjianus Rendle (PODOC.) - Protection inte­
grate, car cette espece ne se rencontre que par pieds isoles ou
par petits bouquets, sur toutes les montagnes.
Glossocalyx brevipes Benth. (MONIM.) - Foret du mont
Koupe (8).
Pararistolochia goldieana (Hook. f.) Hutch. et Dalz. (ARIST.)
- Zone des monts Roumpi.
Phyllobotryum soyauxianum Bail! . (FLACO.) - Foret biafreenne
(1).
Cylicomorpha solmsii (Urb.) Urb. (CARIC.) - Zone des mon­
tagnes de l'Ouest.
Crateranthus talbotii Bak. f. (LECYT.) - Zone littorale.
Tetraphyllaster rosaceum Gilg (MELAS.) - Mont Cameroun
( 1 5) .
Poga oleosa Pierre (RHIZO.) - Foret biafreenne ( 1 ) .
Endodesmia calophy/loides Benth. (HYPER.) - Foret biafreenne
(1).
Oldfieldia africana Benth. et Hook. f. (EUPHO.) - Foret congo­
laise (2).
Pentabrachion reticulatum Mull. Arg. (EUPHO.) - Foret du
moot Koupe (8).
Clutia kamerunica Pax (EUPHO.) - Monts Bamboutos ( 1 4).
Hamilcoa zenkeri Prain (EUPHO.) - Foret du mont Koupe (8) .
Tapura africana Oliv. (CHAIL.) - Zone Iittorale.
Zenkerella citrina Taub. (CAESA.) - Foret biafreenne ( 1 ) .
Eurypetalum unijugum Harms (CAESA.) - Fon�t d u moot Koupe
(8).
Microberlinia bisulcata A. Chev. (CAESA.) - Zone de Yabassi­
Edea.
Paraberlinia bifoliolata Pellegr. (CAESA.) - Zone de Yabassi- ·
E�L
Acta Phytogeogr Suec 54
1 18
R. Letouzey
Myrica arborea Hutch. (MYRIC.) - Mont Cameroun (1 5).
Scyphosyce manniana Baill. (MORAC.) - Foret biafreenne ( 1 ) .
Medusandra richardsiana Brenan (MEDUS.) - Foret du mont
Koupe (8) .
Okoubaka aubrevillei Pellegr. et Normand (OCTOK.) - Zone
.
de Deng Deng.
Melanodiscus africanus Radlk. (SAPIN.) - Foret biafreenne ( 1 ).
Alangium chinense (Lour.) Harms (ALANG.) - Mont Cameroun
( 1 5) .
Lefebvrea nigeriae Wolff (U MBEL.) - Monts Mandara ( 1 3).
Hop/estigma pierreanum Gilg (HOPLE.) - Mont Cameroun (1 5).
Afrostyrax kamerunensis Perkins et Gilg (STYRA.) - Mont
Cameroun (I 5) .
Rhynchostigma racemosum Benth. (ASCLE.) - Mont Cameroun
(1 5).
Neoschumannia kamerunensis Schltr. (ASCLE.) - Zone littorale.
Corynanthe dolichocarpa W. Brandt (RUBIA.) - Mont Came­
roun (1 5).
Calochone acuminata Keay (RUBIA.) - Foret du mont Koupe
(8).
Didymosalpinx parvif/ora Keay (RUBIA.) --:- Mont Cameroun
( 1 5) .
Atractogyne gabonii Pierre (RUBIA.) - Foret du mont Koupe
(8).
Anthospermum cameroonense Hutch. et Dalz. (RUBIA.) - Mont
Cameroun ( 1 5) .
Anthospermum asperuloides Hook. f . (RUBIA.) - Mont Came­
roun ( 1 5) .
Succisa trichotocephala Baksay (DIPSA.) - Mont Cameroun
( 1 5) .
Bafutia tenuicaulis C. D. Adams (COMPO.) - Monts Bam­
boutus ( 1 4) .
Crassocephalum mannii (Hook. f . ) Milne-Redh. (CO MPO.) Mont Cameroun ( 1 5) .
Helichrysum mannii Hook. f . (COMPO.) - Mont Cameroun
( 1 5).
Helichrysum cameroonense Hutch. et Da1z. (COMPO.) - Mont
Cameroun ( 1 5).
Helichrysum biafranum Hook. f. (COMPO.) - Mont Cameroun
( 1 5) .
Vernonia calvoana (Hook. f . ) Hook. f. (CO MPO.) - Mont
Cameroun ( 1 5) .
Vernonia insignis (Hook. f . ) Oliv. e t Hiern (CO MPO.) - Mont
Cameroun ( 1 5).
Vernonia myriantha Hook. f. (COMPO.) - Mont Cameroun ( l 5).
Vernonia chapmanii C . D. Adams (COMPO.) - Monts Bam­
boutos ( 1 4) .
Vernonia bamendae C. D. Adams (CO MPO.) - Monts Bam­
boutos ( 1 4).
Wahlenbe.ygia arguta Hook. f. (CAMPA.) - Mont Cameroun
( 1 5).
Wahlenbergia mannii Vatke (CAMPA.) - Mont Cameroun ( 1 5).
Lightfootia ramosissima (Hemsl.) E. Wimm. ex Hepper (CAMPA .)
Mont Cameroun ( 1 5) .
Lobelia columnaris Hook. f . (LOBEL.) - Mont Cameroun ( 1 5) .
Dielsantha galeopsoides (Engl. e t Diels) E . Wimm. (LOBEL .) Foret du mont Koupe (8).
Celsia densifolia Hook. f. (SCROP.) - Mont Cameroun ( 1 5) .
Celsia ledermannii Schltr. (SCROP.) - Monts Bamboutos ( 1 4) .
Veronica mannii Hook. f . (SCROP.) - Mont Cameroun ( 1 5) .
Bartsia mannii Hemsl. (SCROP.) - Mont Cameroun ( 1 5) .
Didymocarpus kamerunensis Engl . (GESNE.) - Foret du mont
Koupe (8).
Streptocarpus e/ongatus Engl. (GESNE.) - Mont Cameroun ( l 5) .
Acanthonema strigosum Hook. f. (GESNE.) - Mont Cameroun
(1 5).
Acta Phytogeogr Suec 54
Whitfieldia preussii (Lindau) C. B. Cl. (ACANT.) - Foret du
mont Koupe (8).
Mimulopsis solmsii Schweinf. (ACANT.) - Mont Cameroun
( 1 5) .
Filetia africana Lindau (ACANT.) - Foret du mont Koupe (8).
Afrofittonia silvestris Lindau (ACANT.) - Foret du mont Koupe
(8) .
Staurogyne kamerunensis (Engl.) Benoist (ACANT.) - Foret
biafreenne ( 1 ) .
Schaueria populifolia C. B . C l . (ACANT.) - Zone littorale.
Isoglossa nervosa C. B. Cl. (ACANT.) - Mont Cameroun ( 1 5).
Brachystephanus longif/.orus Lindau (ACANT.) - Mont Cameroun ( 1 5) .
Oreacanthus mannii Benth. (ACANT.) - Mont Cameroun ( 1 5) .
Pycnostachys pallidi-caerulea Perkins (LABIA.) - Monts Bam­
boutos ( 1 4) .
Sciaphila ledermannii Engl. (TRIUR.) - Zone littorale.
Forrestia preussii K. Sebum. (CO M MEL.) - Mont Cameroun
( 1 5) .
Notosceptrum ref/.exum Hutch. (LILIA.) - Monts Bamboutos
( 1 4).
Wurmbea tenuis Baker (LILIA.) - Mont Cameroun ( I 5).
Cynastrum cordifolium Oliv. (TECOP.) - Zone littorale.
Aristea mait/andii Hutch. (IRIDA.) - Mont Cameroun ( 1 5) .
Romu/ea camerooniana Baker (IRIDA.) - Mont Cameroun ( 1 5) .
Acidanthera divina Vaupel (IRIDA.) - Monts Bamboutos (14) .
Hesperantha a/pina Benth. e t Hook. f . (IRIDA.) - Mont Cameroun ( 1 5).
Podococcus barteri Mann et Wend!. (PALMA.) - Foret bia­
freenne ( 1 ) .
Raphia rega/is Becc. (PALMA.) - Foret congolaise (2).
Sc/erosperma mannii Wend!. (PALMA.) - Foret a Gilbertio­
dendron dewevrei (4).
Hypoxis recurva Nel (HYPOX.) - Mont Cameroun ( 1 5).
Hypoxis camerooniana Baker (HYPOX.) - Mont Cameroun
( 1 5) .
Gymnosiphon usambaricus Engl. (BUR MA.) - Foret congolaise
(2).
Afrothismia winkleri Schltr. (THIS M.) - Mont Cameroun ( 1 5 ) .
Afrothismia polyantha Schltr. (TH I S M.) - Mont Cameroun ( 1 5).
Oxygyne triandra Schltr. (THISM.) - Mont Cameroun ( 1 5) .
Holothrix tridentata Rchb. f. (ORCHI .) - Mont Cameroun ( 1 5) .
Deroemera ledermannii Schltr. (ORCHI.) - Monts Bamboutos
( 1 4) .
Cynorchis debilis Summ. (ORCHI.) - M o n t Cameroun (1 5).
Brownleea alpina N. E. Br. (ORCHI.) - Mont Cameroun ( 1 5) .
Sarcorrhynchus polyanthus Schltr. (ORCHI.) - Monts Bamboutos ( 1 4).
Barombia gracil/ima Schltr. (ORCHI.) - Foret du mont Koupe
(8).
Cephalangraecum braunii Summ. (ORCHI.) - Mont Cameroun
( 1 5).
Angraecopsis tridens Schltr. (ORCHI.) - Mont Cameroun ( 1 5) .
Angraecopsis ischnopus Schltr. (ORCHI.) - Mont Cameroun
( 1 5) .
Microdracoides squamosus H u a (CYPER.) - Zone de Yaounde.
Guaduella macrostachys Pilger (GRAMI.) - Foret biafreenne ( l ).
Guaduel/a ledermannii Pilger (GRAMI.) - Foret du mont Koupe
(8).
Puelia acuminata Pilger (GRAMI.) - Foret du mont Koupe (8) .
Isoetes biafrana Alston (ISO ET.) - Monts Bamboutos ( 1 4).
Oleandra annetii Tardieu (DAVAL.) - Zone littorale.
Antrophyum annetii (Jeanpert) Tardieu (VITTA.) - Zone littorale.
Vittaria schaeferi Hier. (VITTA.) - Zone littorale.
Cameroun
Athyrium ammifolium (Mett. ex Kiihn) C. Christensen (ATHYR.)
- Mont Cameroun ( 1 5) .
Hypodematium crenatum (Forsk.) Kiihn (ASPID.) - Monts
Mandara ( 1 3) .
Polystichum fuscopaleaceum Alston (ASPID.) - M o n t Cameroun ( 1 5).
Elaphoglossum isabelense Brause (LOMAR.) - Zone littorale.
Elaphoglossum preussii Hier. (LOMAR.) - Mont Cameroun ( 1. 5) .
Elaphoglossum cinnamomeum (Baker) Diels (LOMAR.) - Mont
Cameroun ( 1 5).
Ctenopteris zenkeri (Hier.) Tardieu (GRAMM.) - Zone de
Yaounde.
Stenochlaena mildbraedii Brause (POLYP.) - Foret congolaise
(2).
Il semble que la protection de groupements soit a
l'heure actuelle plus aisee a envisager que celle d'especes
determinees; les experiences, tentees en divers territoiresJ
conduisent a penser qu'il faudra ici encore beaucoup de
diplomatic psychologique, beaucoup d'efforts d'educa­
tion et de propagande pour obtenir !'application de dis­
positions legales et de regles administratives, si simples
et si peu astreignantes soient-eJles.
Le probleme depasse d'ailleurs pour le Cameroun la
protection de quelques groupements determines ; c'est
beaucoup plus la constitution systematique de reserves
botaniques, representant differentes formations, qui
s'impose, partout oil ces formations sont, d'une maniere
generale, plus ou moins menacees. Ces reserves bota­
niques pourraient englober aussi avantageusement la
plupart des especes ci-dessus mentionnees.
1 ) Foret biafreenne. Il est possible de trouver entre
Kribi et Campo un bloc de quelques milliers d'hectares
de foret dense humide sempervirente oil l'abondance des
grandes Cesalpiniacees et leur stabilite biologique con­
stituent la caracteristique de cette zone de « foret bia­
freenne ». Aspect de « belle foret primaire », absence ac­
tuelle de population, limites naturelles possibles, etc.,
incitent a la creation d'une telle reserve. La perennite
de celle-ci ne peut cependant etre assuree qu'en consti­
tuant simultanement a la peripherie un pare national de
plus grande etendue, source d'attrait et d'interet pour
le public, et protegeant ainsi, en droit et en fait, la reserve
botanique voisine.
2) Foret congolaise a Baillonella toxisperma. Dans la
boucle du Dja, a l'Ouest de Lomie, peut etre mise en
reserve une vaste superficie forestiere d'environ 1 000 km 2 •
Cette foret dense humide sempervirente, de type congo­
lais, renferme de remarquables Bail/one!la toxisperma et
constitue pour le Cameroun, avec ses sols argileux a
nappe phreatique rapprochee, un biotope assez particu­
lier. Cette zone est actuellement inhabitee et parait etre
d'un avenir economique assez faible; la presence de
Pygmees nomades ne pose pas de graves problemes
quant au projet envisage. L'ensemble de la boucle du
1 19
Dja constitue d'ailleurs depuis plusieurs annees une re­
serve theorique de faune.
3) Peuplement de Raphia regalis. Pourrait etre inclus
dans la reserve precedente (2), ce Raphia, vivant en sous­
bois sur sol sec, pouvant se rencontrer assez facilement.
4) Foret a Gilbertiodendron dewevrei. Peut aussi etre
incluse dans la reserve de foret congolaise ci-dessus (2).
Une autre possibilite consisterait a mettre en reserve un
ilot plus accessible, en dehors de la boucle du Dja vers
Bengbis-Sangmelima, de quelques centaines d'hectares ;
les peuplements purs a caractere relictuel de cette Ce­
salpiniacee sont ici endommages des a present, ou se
trouvent a la merci d'une population assez dense de cul­
tivateurs.
5) Prairie intraforestiere sur schistes ch/oriteux. Situee
dans la boucle forestiere du Dja, a 1 00 km au Sud-Est
d'Akonolinga, la colline du Nkoubar d'environ 1 00
hectares est couverte d'une prairie, actuellement brulee
periodiquement pour la chasse aux buffles, entouree
d'une lisiere broussailleuse xero-heliophile. Les con­
stituants de la prairie et de la lisiere representent une
vegetation originale qui ne se retrouve au Cameroun
que pour d'autres prairies plus petites voisines.
6) Prairie intraforestiere sur cuirasse ferrugineuse.
Situee a 25 km a l'Est de Y okadouma, la prairie sur cui­
rasse ferrugineuse dite de Mbolemba, s'etendant sur 250
hectares, represente un bon exemple de prairies intra­
forestieres sur ce substrat particulier, telles que l'on
en rencontre vers la peripherie du massif de foret dense
humide equatorial.
7) Roneraie. La protection des roneraies exige en pre­
mier lieu !'interdiction d'abattage et la lutte contre les
feux. La mise en reserve de quelq ues centaines d'hectares,
pres de Poli et dans la vallee du Lom pres de Betare Oya,
parait suffisante pour conserver au point de vue scien,.
tifique une espece qui, par ailleurs mais d'une maniere
plus dispersee, est assez repandue au Cameroun ainsi
qu'en bien d'autres territoires.
8) Foret afro-submontagnarde du mont Koupe. La foret
dense humide afro-submontagnarde camerounaise, de
1000-1200 a 1 600-1 800 m, est en realite fort mal connue
et la mise en reserve d'un echantillon de cette vegetation
s'impose d'urgence, car plantations de bananiers et de
cafeiers ou de cacaoyers font a l'heure actuelle disparai­
tre a vive allure les taches de cette foret qui, entre Douala
et Nkongsamba, couvrent encore les pentes inferieures
des montagnes de cette region. Le mont Koupe, pres de
Loum, s'eleve jusqu'a 2050 m et la reserve constituee
pourrait s'etendre avec profit jusqu'au sommet, engolActa Phytogeogr Suec 54
1 20
R. Letouzey
Fig. 2. Destruction, pour cul­
tures, de la foret submontag­
narde du mon t Cameroun (cf.
§ 1 5). Pres Buea, vers 1 200 m
(4°09'N-9 ° 1 4'E). Photo R. Le­
touzey 3 .2. 1 962.
bant ainsi la foret afro-montagnarde qui couronne ce
massif.
9) Prairie sur cuirasse ferrugineuse du plateau de l'Ada­
maoua. Le Sabal Haleo, a 60 km au Nord-Est de Tibati ,
represente le plus grand « bowal » du Cameroun puisqu'­
il mesure environ 1 500 hectares. La vegetation tres par­
ticuliere des « bowe » de 1' Afrique occidentale et centrale
soudano-guineenne pourrait etre ici conservee, a l'abri
du paturage de bovins assez facilement, plus difficilement
a l'abri des feux; il faut cependant noter que les feux,
sans doute depuis longtemps deja, constituent un fac­
teur ecologique participant activement a l'equilibre pre­
sent de ce biotope.
protection naturelle de cette vegetation parait assuree
mais la protection legale d'une colline determinee ren­
forcerait cette securite.
1 2) Karal a Acacia seyal. Dans le Nord Cameroun les
peuplements d'Acacia seyal installes sur argile noire tro­
picale ( « karal » ), inondes en saison des pluies, sont en
saison seche soumis aux degats du paturage et de la
recherche de bois ; la conservation d'un ilot a l'abri de
ces influences serait souhaitable. La surface protegee
pourrait etre assez reduite, quelques hectares, mais de­
vrait necessairement etre entouree d'une cloture artifi­
cielle.
1 3) Sommet des monts Mandara. S'elevant a pres de
1 0) Inselberg au Sud de l' Adamaoua. La mise en reserve
d'un inselberg granitique au Sud de Y oko permettrait
le maintien d'une vegetation saxicole extremement parti­
culiere ; celle-ci est en realite deja naturellement et effi­
cacement protegee centre les feux de brousse et les em­
prises humaines. Le choix d'un tel rocher, aussi volumi­
neux que possible, comme celui de Foui, ne pose pas de
problemes particuliers car des inselbergs sont extreme­
ment nombreux dans toute la zone des sa vanes perifores­
tieres au Sud de la falaise du plateau de l'Adamaoua.
1 1 ) Colline pres de Maroua. Les collines rocheuses des
alentours de Maroua sont formees de chaos d'enormes
eboulis granitiques ; elles abritent une flore de type sou­
danien primitive, formee d'especes d e diverses provenances chorologiques, particulierement est-africaine. La
Acta Phytogeogr Suec 54
1 500 m, les monts Mandara, par ailleurs couverts d'un
paysage vegetal domestique, offrent refuge, au voisinage
des sommets (hossere Oupay 1 442 m, hossere Ziver
1 425 m), parmi des chaos rocheux granitiques, a une
flore montagnarde soudanienne oil se rencontrent plu­
sieurs especes d'origine est-africaine. La protection na­
turelle de cette flore et de ces especes parait assuree mais
pourrait etre appuyee par des dispositions legales; il
faut cependant noter que ces dispositions seront certaine­
ment tres difficiles a faire admettre par les populations
autochtones, remarquablement peu accessibles a de tels
problemes; la delimitation materielle de cette reserve
posera aussi de serieuses difficultes. - Cf. Fig. 3 .
1 4) Sommet des monts Bamboutos. L a remise e n vi­
gueur des mesures de protection theoriques et pratiques
Ccngc-Kinshasa
121
concernant la reserve botanique des monts Bamboutos,
mentionnee ci-dessus, pourra sans doute etre envisagee
dans un proche avenir. 11 y aurait lieu d'etudier la pos­
sibilite de replacer cette reserve sur le mont Oku voisin
(3000 m au lieu de2740m), ou d'en creer ici une nouvelle,
si la vegetation naturelle, composee de foret afro-mon­
tagnarde, de fourres arbustifs afro-subalpins avec prai­
ries de degradation, peut y etre plus facilement protegee
contre les mefaits des incursions humaines, du paturage
et des feux d'herbage.
1 5) Secteur du mont Cameroun. Cette reserve devrait
englober toutes les formations vegetales se rencontrant
sur cette montagne, du niveau de la mer au sommet
(4070 m). 11 est certainement impossible de delimiter
un-secteur de ce cone volcanique repondant a cette exi­
gence et plusieurs reserves, aussi judicieusement placees
que possible, devront etre envisagees. L'exposition est
un facteur important et il sera:it interessant, au-dessous
de 2000 m, d'adopter le flanc Sud-Ouest Q.u massif, la
pluviosite y atteignant pres de 10 m; le Petit mont Came­
roun offre a lui seul un site accidente naturellement pro­
tege, peu degrade, mais favorable au maintien de la
foret afro-submontagnarde seulement car il n'atteint que
1 750 m. La foret afro-montagnarde bien exposee aux
i nfluences maritimes du Sud-Ouest se rencontre encore
aux alentours des Sources de Mann, mais c'est en fait
sur le versant Nord-Ouest que les formations forestieres
du mont Cameroun paraissent les mieux conservees. La
protection d'une reserve dans l'etage afro-subalpin,
avec fourres arbustifs a Ericacees et prairies de plus en
plus pauvres, voire terrains aphytotiques vers le sommet,
ne pose pas de problemes insolubles si l'on peut s'oppo­
ser aux degats eventuels des feux d'herbage allumes
volonta irement.
Fig.
3 . Sommet des monts Mandara a flore montagnarde
soudanienne avec especes d'origine est-africaine (cf. § 1 3). Hos­
sere Oupay, 1 442 m ( 1 0 ° 53 'N - 1 3 ° 47 'E), a 1 5 km au Nord­
Nord-Ouest de Mokolo, Cameroun. Photo R. Letouzey 3 .2.
1 962 .
CONGO-KINSHASA
R. Germain
PHYSIOGRAPHIE
Les territoires congolais qui s'etendent entre les latitudes
5° N et 1 3° S couvrent 2 344 000 km2 et presentent 3
paysages bien tranches : au centre, une depression de
900 000 km2 offre !'aspect d'une vaste peneplaine dont
!'altitude oscille entre 300 et 500 m. Cette « cuvette »
essentiellement forestiere est traversee d'Est en Ouest,
sur une longueur de 1 500 km, par le fleuve Congo.
En peripherie de cette enorme auge et l'enserrant sur
ses cotes N, E et S, s'etend une zone de plateaux dont
les plus eleves atteignent 1 500-1 700 m. C'est le domaine
des savanes entrecoupees de massifs forestiers et de
galeries.
A l'Est, un large fosse - portion du graben central
africain - renferme un chapelet de lacs ; les deux dor­
sales qui bordent cette depression sont jalonnees de
hauts reliefs (Ruwenzori, chaine des Virunga et divers
sommets s'etageant entre 2500 et 5000 m d'altitude). La
savane domine aux etages inferieurs ( 1 000-1 500 m) tan­
dis que la foret est mieux representee aux altitudes plus
elevees.
Acta Phytogeogr Suec 54
1 22
R. Germain
CLIMATOLOGIE
nent au groupe tropico-africain de la classification de
Th. Monod 1 et se subdivisent comme ci-apres :
Le climat du centre africain appartient aux types equa­
torial, subequatorial et tropical.
Sur la base des criteres de Koppen\ il apparait que
les climats du type A regnent sur une grande partie du
territoire tandis que les climats du type C sont relegues
sur les marges orientates et dans l'extreme Sud.
La pluviosite oscille entre 1 700 et 2000 mm dans la
Cuvette Centrale mais ne depasse pas 1 500 mm a la
lisiere Nord. Dans le Sud, les parties les plus seches du
Haut-Katanga ne re9oivent que 1 000 mm d'eau ; par
contre, les hauts reliefs de la dorsale orientate connais­
sent des pluies de 2500 mm et plus.
La duree de la saison seche s'allonge progressivement
en direction des Tropiques : elle depasse 6 mois a la
frontiere de la Zambie.
L'Est et le Sud relevent de 2 Regions phytogeographiques :
Region soudano-angolane [B .I. ] .
Types soudaniens [B.I.C.].
Sous-groupe Sud [B.I./C.a./].
Domaine oriental [B. I./C.a./6.].
Domaine angolo-zambezien [B. I./C.a./7. ] .
Region afro-alpine [B.III .].
Le Nord, - a !'exception d'une frange tres etroite qui appar­
tient au Domaine senegalo-nilotique [B .I. JC.a./ 5.] de la Region
soudano-angolane, -l'Ouest et la partie centrale au-dessus
du 6 e paralle l e Sud font partie de la Region guineo-congolaise
[B.II.]
Domaine atlantico-congolais [B.II. 1 .] .
On signalera en passant que les limites des unites
chorologiques de rang inferieur (Domaine et surtout
Secteur) restent a preciser en certains points.
LES SOLS
LA PROTECTION
Les terrains congolais comportent une gamme tres eten­
due de types de sols appartenant pour la plupart au
groupe des kaolisols. 11 s'agit de substrats arrives a ma­
turite, completement alteres ou presque et dont la fraction
argileuse contient de la kaolinite a cote de sesquioxydes ;
leur reserve minerale est quasi nulle. Dans l'Est, des
argiles noires tropicales et des sols bruns tropicaux sont
localement bien representes (regions volcaniques et
plaines fluvio-lacustres). Des franges de sols alluviaux
bordent par endroits les grands cours d'eau, tandis que
les sols hydromorphes dominent dans les parties les
plus deprimees de la Cuvette.
L' aspect du probleme
VEGETATION ET PHYTOGEOGRAPHIE
Physionomiquement, la vegetation congolaise se repartit
en 4 grands ensembles :
La foret equatoriale du type sempervirent et du type semi­
decidu.
Les peuplements savanicoles qui reunissent :
les savanes guineennes bordant la grande foret a ses lisieres
N et S ;
les savanes orientales planitiaires et submontagnardes du
graben et de ses dorsales;
Ies savanes zambeziennes qui relaient les savanes guineennes
vers le S.
Les forets decidues bien developpees aux confins meridionaux
(Haut-Katanga) mais reduites a de faibles surfaces aux Iisieres
septentrionales (Haut-Uele).
Les peuplements forestiers d'altitude.
Chorologiquement, les territoires congolais appartien-
1 Koppen, W., 1 936. Das Geographische System der Klimate in
Koppen, W. und Geiger, R. : Handbuch der Klimatologie. ­
Berlin.
Acta Phytogeogr Suec 54
·
Au Congo, en raison de la densite demographique peu
elevee en milieu rural, - population estimee : 1 2 000 000
ames soit 5 habitants par km2 avec des extremes de 1
(lac Leopold 11) a 50 (Kivu), - la destruction de la vege­
tation primitive ne revet pas le caractere alarmant qu'on
lui connait dans d'autres territoires africains densement
peuples. Le taux de boisement est fort eleve : les forets
denses humides, planitiaires et montagnardes, couvrent
environs 45 % de la surface.
Comme dans la plupart des regions tropicales, les
peuplements ligneux sont les plus menaces. Les savanes
par leur nature meme (groupements de substitution) ne
reclament generalement pas de mesures de protection ;
au demeurant, la mise en defens ne tarderait pas d'y
provoquer des modifications floristiques qui iraient a
l'encontre du but recherche; les feux courants assurent
la stabilite des groupements. Toutefois, le mesusage de
certains parcours herbeux peut entrainer des alterations
floristiques importantes qui se traduisent par la regres­
sion du couvert herbace et la proliferation des ligneux
buissonnants.
La protection de la vegetation et de ses especes im­
plique l'etablissement d'un inventaire des biocenoses. A
ce point de vue, les connaissances en phytosociologie
congolaise pour avancees qu'elles soient, - compte
tenu de l'etendue du territoire et de sa grande diversite
floristique, - sont encore fort modestes si on les com­
pare aux donnees que 1' on possede pour les regions tem­
perees. On conc;oit done qu'au stade actuel de l'etat
d'avancement des analyses phytosociologiques et des
1 Monod, Th. 1 957. Les grandes Divisions chorologiques de
1' Afrique. C.S.A. Publ. n° 24. - Londres.
Congo-Kinshasa
leves cartographiques, il soit malaise, en dehors de quel­
ques secteurs, de dresser la liste des associations prote­
gees ou a proteger et, plus difficile encore, de delimiter
avec precision les perimetres a soustraire a !'influence
humaine.
Bref historique de la Conservation de la Flore
au Congo
La plus ancienne ordonnance reglementant les coupes
d'arbres remonte a 1 887. Les premieres Reserves Fores­
tieres datent de 1 9 1 0 : elles portaient sur des perimetres
situes dans le Sankuru, le Kasai et le Nepoko, totalisant
environ 600 000 ha.
La mise en Reserve Integrale de certains biotopes
presentant un grand interet faunistique et floristique
date de plus de 40 ans. Des 1 925, le Pare National Albert
etait cree au Kivu ; limite d'abord a un secteur de 20 000
ha, celui-ci fut progressivement etendu et porte finale­
ment a plus de 800 000 ha.
A ce joyau de la Nature africaine, vinrent bientot
s'ajouter deux autres Pares : celui de la Garamba (Haut­
Uele) en 1 938 et celui de l'Upemba (Katanga) en 1 939.
L'ensemble de ces perimetres couvre environ 2 500 000
ha. Leur gestion est assuree par l'lnstitut des Pares
Nationaux du Congo et l'on ne peut faire allusion a cet
organisme mondialement connu sans evoquer la me­
moire de son premier President, le Professeur Victor
Van Straelen, homme d'une rare energie et d'une grande
clairvoyance, administrateur scientifique de talent en
qui la Nature congolaise trouva toujours un ardent de­
fenseur.
Les especes protegees
Deux especes congolaises figurent depuis 1 95 3 (3eme
Conference Internationale pour la Protection de la
Faune et de la Flore, Bukavu) sur la liste des plantes
africaines protegees : Encephalartos laurentianus De
Wild. (Kasai) et E. septentrionalis Schweinf. (vallee de
l'Uere et du Bomu).
Les biotopes proteges dans les diverses provinces1
Province orientate
a) Le Pare de la Garamba (492 000 ha) comporte, a
cote de galeries forestieres a dominance d'elements
guineens, diverses formations et principalement :
des groupements d'hydroseres largement distribues
en Afrique centrale;
des peuplements savanicoles qui couvrent la plus
grande partie de la surface ;
des forets decidues soudaniennes a Isoberlinia doka
et Uapaca somon.
L'aire en question represente un echantillon de grou­
pements vegetaux a caractere nettement soudanien.
1
L'ancienne division du Congo en six Provinces a ete conservee
pour des raisons de facilite.
1 23
b) La Reserve Integrale de Faune et de Flore des
monts Homas en territoire d'Irumu concerne essentielle­
ment des peuplements de l'etage inferieur de la foret
submontagnarde (ou de transition), vers 1 1 00-1 200 m
d'altitude.
c) La Reserve Integrale que constitue le Jardin bota­
nique de l'INEAC a Yangambi reunit des types forestiers
sempervirents (a Gilbertiodendron dewevrei - a Brachy­
stegia laurentii), semi-decidus (a Scorodophloeus zen­
keri principalement) et divers groupements forestiers
edaphiques (sur sols hydromorphes).
Province du Kivu
a) Le Pare National Albert (809 000 ha) englobe la vege­
tation du graben et des hauts reliefs de ses dorsales,
allant de 1 000 m (plaine des Rwindi-Rutshuru) a 5 1 1 9 m
(Ruwenzori). Ce vaste perimetre reunit de nombreuses
biocenoses dont les plus interessantes, a coup sur,
se succedent depuis l'etage superieur de la foret
de montagne jusqu'au pied des glaciers. Aux basses
altitudes, la plaine des Rwindi-Rutshuru qui represente
environ le cinquieme de la surface protegee, compte a
elle seule 27 associations. Dans les chaines des Virunga
(partie Sud), en dehors de la foret de montagne, 1 8
groupements ont ete reconnus sur le Nyiragongo.
b) La Reserve Integrale du mont Kahuzi vise avant
tout la protection de la bambusaie a Arundinaria alpina
qui remonte exceptionnellement haut (jusque 3000 m)
sur un ancien volcan.
c) La Reserve Integrale de l'ile ldjwi (lac Kivu) con­
cerne la foret submontagnarde.
d) La Reserve Integrale de la Lukele, sise en territoire
de Beni, reunit des types forestiers equatoriaux et sub­
montagnards.
Province du Katanga
Le Pare National de l'Upemba ( 1 1 73 000 ha) comprend
essentiellement des savanes et des forets decidues a ca­
ractere zambezien ainsi que d'importantes surfaces de
formations marecageuses et lacustres. Sur les hauts pla­
teaux, regne une savane basse d'allure steppique et loca­
lement se sont maintenus quelques ilots d'essences mon­
tagnardes (Podocarpus, Agauria, Philippia) bien repre­
sentees dans le Congo oriental.
La :flore et la vegetation de l' Upemba n'ont pas encore
ete etudiees en detail. L'importance des biotopes aqua­
tiques en fait un endroit privilegie pour l'etude des hy­
droseres.
Province de Leopoldville
Dans la partie occidentale de la province (Mayumbe),
le domaine forestier de Luki, gere par la station fores­
tiere de l'INEAC, porte sur 32 000 ha. Les peuplements
forestiers dominants dans cette Reserve sont surtout a
Acta Phytogeogr Suec 54
1 24
R. Germain
Terminalia superba et secondairement a Gossweileroden­
dron balsamiferum.
Province de l' Equateur
D'une fa90n generale, la protection de la vegetation ne
pose guere de problemes dans le Centre de la Cuvette
Congolaise. Les groupements sur sols hydromorphes se
protegent d'eux-memes; quant aux peuplements {ores­
tiers de terre ferme, ils n'ont guere ete entames en de­
hors de la peripherie des villages.
On signalera cependant que la creation d'un Pare
National avait ete envisagee dans les regions les moins
peuplees du bassin de la Busira.
Province du Kasai
Il n'existe aucune Reserve Integrale dans cette Province.
En dehors des Pares Nationaux et des Reserves Inte­
grales se situant dans 3 Provinces ( orientale, Kivu et
Katanga), il y a lieu de mentionner aussi les peuplements
forestiers qui ont fait l'objet d'une ordonnance de mise
en reserve. Dans ces derniers perimetres, la protection
vise avant tout le maintien de massifs boises et concerne
surtout les especes arborescentes.
Ces reserves forestieres, au nombre de 1 46, portent
sur une surface totale de 500 000 ha et se repartissent
comme suit :
Leopoldville Equateur Kasai Orientale Kivu Katanga
11
3
12
57
51
12
C'est naturellement dans les territoires fort peuples de
l'Est du Congo (Province du Kivu et District du Kibali­
Ituri en Province Orientale) que la surveillance des de­
boisements doit etre vigilante.
Les groupements qui demandent protection1
Rappelons d'abord que le Congo possede fort heureuse­
ment trois Pares Nationaux ftoristiquement tres riches
et phytogeographiquement bien repartis.
Le probleme de la « coexistence » Faune-Flore a ete
beaucoup discute. Le souci d'assurer aux Ongules des
paturages « appetissants » oil ils peuvent viander en toute
quietude, preoccupe les defenseurs de la Faune et du
Tourisme. Dans le cas des Pares Nationaux, il semble
desirable de pratiquer des feux controles dans les parties
les plus frequentees par les herbivores. Mis a part ces
« secteurs touristiques », les surfaces restantes devraient
etre integralement et surtout effectivement protegees.
Dans ce vaste territoire qu'est le Congo, il existe d'au­
tre part des groupements vegetaux qui, en raison des su­
perficies tres modestes qu'ils occupent et de l'interet
1
Ce paragraphe a ete redige avec la collaboration de M M . les
Professeurs C. Evrard (Kimuenza), A. Schmitz et J. J. Symoens
(Lubumbashi); l'auteur se plait a les remercier ici.
Acta Phytogeogr Suec 54
scientifique qu'ils representent, meritent de beneficier
d'une protection integrale sur !'ensemble ou sur une par­
tie de leur aire. Deux sites reclament des mesures ur­
gentes :
1 . La galerie forestiere de la Lukaya, pres de Kimu­
enza (Kinshasa-Zone annexe), montre des groupements.
de composition ftoristique tres particuliere ; de nombreux
taxa ne sont actuellement connus que par des echantil­
lons en provenance de cette vallee. Il s'agit d'un « locus
classicus » oil environ une centaine de specimens-types.
ont ete recoltes au debut du siecle par divers botanistes.
dont surtout Mildbraed. Une grande partie de ces der­
niers types ont ete detruits a Berlin et de nombreuses
especes ne sont plus connues actuellement que par leur
description.
La basse-vallee de la Lukaya, presqu'entierement
deboisee depuis cette epoque se voit presentement me­
nacee de destruction complete par !'extension rapide de
la ville de Kinshasa. La protection totale de la galerie
se heurterait a de grandes difficultes mais certaines tetes
de source et la haute-vallee, situees a l'ecart des voies
de communication, pourraient aisement etre reservees a
condition de prendre, sans tarder, les mesures neces­
saires.
La mise en reserve de quelques centaines d'hectares
constituerait un refuge pour de nombreuses especes qui,
sans cette mesure, risquent de disparaitre. A cote de
cet interet pratique indeniable, le site ainsi sauvegarde
constituera pour la taxonomie une source irrempla9able
de specimens de comparaison.
2. Un petit peuplement de Juniperus procera situe
pres de Kasiki, sur le plateau des Marungu (Katanga).
En dehors de ces deux endroits particulierement me­
naces, !'attention des Autorites gouvernementales et in­
ternationales meriterait d'etre attiree sur les points
suivants :
(a) Aux confins septentrionaux, dans les territoires
d'Ango et de Bondo (Uele), deux types de peuplements
demandent protection :
la foret decidue a Khaya-Afzelia- 0/ea-Anogeissus
dans la region au nord de Basape (Ango) ;
les ilots relictes a Triplochiton scleroxylon dans l a
region d e Lebo (Bondo). Ces peuplements menacent
disparition devant les defrichements culturaux.
(b) Dans le centre de la Cuvette, le projet d'etablisse­
ment du Pare National de la Salonga.
(c) Les forets du Mayumbe sont exploitees intensive­
ment depuis quelques annees. Les Reserves existantes
devraient faire l'objet d'une surveillance accrue.
(d) Dans le Sud, en zone de savanes et de forets deci­
dues zambeziennes, - territoires privilegies sous I' angle
de la speciation ftoristique, - il serait sage d'etendre
les mesures de conservation aux groupements ci-apres :
- a certaines forets du Haut-Katanga, notamment
Rwanda
aux « muhulu » (forets seches denses semi-decidues) des
environs de Tera (Territoire de Sakania) par exemple;
aux forets ripicoles et des tetes de source qui devraient,
tout au moins, etre soumises a certaines regles d'exploita­
tion ;
1 25
- aux peuplements de forets de montagne entourant
le barrage hydro-electrique de Bendera, au nord d'Al­
bertville.
RWANDA
P. Deuse
G EOGRAPHIE
Le Rwanda est un pays d'altitude e,levee aux confins de
Centrale sur le bord Est du grand graben. Le­
gerement au Sud de l'Equateur, il s'etend entre les paral­
leles 1 °04' et 2°50' de latitude Sud et entre les meridiens
28°50' et 30°53' de longitude Est.
La superficie est de 26 3 3 8 km2•
Le sous-sol du pays est forme de roches tres anciennes
des systemes du Burundien et du Ruzizien appartenant
a l'ere precambrienne. Un vaste massif granitique existe
au Nord de Butare. Au Nord le pays est domine par la
chaine des volcans eteints : Birunga dont le sommet le
plus important : le Karisimbi culmine a 4507 metres.
A l'Ouest la crete de partage des eaux du Congo et du
Nil s'etend du Nord au Sud le long du lac Kivu. Cette
crete a des sommets de 3000 metres. A l'Est de cette
crete existent des hauts plateaux inclines doucement en
gradins successifs et dont !'altitude passe de 1 800 a 1 400
metres, constituant les sources meridionales du Nil. La
riviere principale du Rwanda est l'Akagera qui se de­
verse dans le lac Victoria; elle est formee par 1'Akanyaru
et la Nyabarongo puis par la Ruvuvu venant du Bur­
undi.
Le Rwanda est un des pays les plus densement peuples
de l'Afrique Centrale. Sa population est actuellement
de plus de 3 millions d'habitants soit une moyenne d'en­
viron 1 00 habitants au km2• La population s'y repartit
avec une densite extremement variable sur des sols de
fertilite tres inegale.
1'Afrique
CLIMATOLOGIE
D'apres l'Esquisse climatologique du Rwanda par Van
Minnebruggen ( 1 965), trois types de climats peuvent
etre distingues au Rwanda :
1 °) climat tropical humide avec saison seche et tem­
perature moyenne du mois le plus froid superieur a 1 8°C
(indice de Koppen : AW).
2°) climat tempere avec saison seche et temperature
moyenne du mois le plus froid inferieure a 1 8°C (indice
de Koppen : CW).
3°) climat tempere sans saison seche avec hauteur
moyenne des precipitations du mois le plus sec supe­
rieur a 50 mm (indice de Koppen : CF).
Il est difficile de limiter ces trois zones. La premiere
(A W) couvre tout le pays jusqu'a une altitude d'environ
1 800 metres.
La deuxieme (CW) s'etend sur le reste du pays au
dessus de 1 800 metres.
La troisieme (CF) couvre la region des volcans :
!'extreme NW du pays.
La cote udometrique annuelle est voisine de 800 mm
dans la vallee de l'Akagera, de 1 200 mm a Butare, de
plus de 1 400 mm dans la dorsale montagneuse Congo­
Nil et sur les volcans.
La saison seche dure du 25 mai au 1 5 septembre a
!'extreme Sud Est du pays et du 20 juin au 1 0 aout dans
!'extreme Nord Ouest (moyennes sur 22 ans). Pour !'en­
semble du pays elle varie de 60 a 1 1 5 jours par an.
Le Rwanda est soumis a I' influence des vents alizes
du Sud Est pendant la majeure partie de l'annee. C'est
un pays a caractere nettement continental.
VEGETATION
D'apres Troupin ( 1 966), le Rwanda participe a deux
regions phytogeographiques bien definies : la region
soudano-zambezienne (domaine oriental) pour la plus
grande partie de son territoire et la region montagnarde
africaine pour les endroits attelgnant ou depassant 2000
m.
Region soudano-zambezienne domaine oriental
Le R wanda fait partie du secteur des lacs Edouard et
Kivu determine par Lebrun d'apres ses travaux et ceux
de Robyns et Germain.
Acta Phytogeogr Suec 54
126
P. Deuse
Plusieurs sous-districts y ont ete reconnus.
La vegetation est caracterisee par des forets xerophiles
souvent reduites a des petits bosquets reliques, des sa­
vanes de nombreux types : a Acacia, Combretum, Euphor­
bia candelabrum, des steppes boisees. Les graminees
principales des formations ouvertes sont : Themeda tri­
andra, Hyparrhenia div. sp., Loudetia simplex.
Region montagnarde africaine
Plusieurs etages peuvent y etre distingues :
Forets ombrophiles de montagne caracterisees par Po­
docarpus usambarensis, Symphonia globulifera, Carapa
grandifiora, Strombosia scheffieri, Syzygium parvifolium,
Galiniera coffeoides. Ces forets sont fortement degradees
et envahies par des especes secondaires telles que Poly­
scias fulva, Harungana madagascariensis, Bridelia bride­
liifolia ou meme Pteridium aquilinum.
Parmi ces forets, on trouve des peuplements a Hagenia
abyssinica ou des bambusaies a Arundinaria alpina.
Etage des bruyeres arborescentes (Erica, Philipia) entre
3200 et 3800 metres.
Etage afro-alpin entre 3 800 et 4500 m avec Senecio et
Lobelia arborescents parmi les Helichrysum et Alchemilla
La vegetation palustre
Cette vegetation occupe une grande partie du pays :
marais et tourbieres se succedent dans les fonds de vallee
entre les collines ou les montagnes :
tourbieres de moyenne altitude a Cladium jamaicense,
a Cyperus papyrus, a Miscanthidium violaceum, a Syzy­
gium cordatum et Myrica kandtiana;
tourbieres de haute altitude a Cyperus denudatus,
Xyris et Sphagnum, a Syzygium cordatum et Erica ruge­
gensis;
marais a Typha australis, Phragmites mauritianus,
Cyperus papyrus, Phoenix reclinata et Syzygium.
VEGETATION ET FLORE PROTEGEES
Au R wanda, la protection de la nature est organisee.
Deux Pares Nationaux ont ete crees :
Le Pare National de l'Akagera constitue par une re­
serve integrale de 1 79 000 hectares et un territoire annexe
de 7 1 000 hectares oil les habitants peuvent cultiver mais
ni chasser, ni pecher. Un domaine de chasse y est ad­
j oint ou l'abattage du gibier est reglemente. Ce domaine
de chasse est l 'agrandissement de la reserve de faune et
de flore etablie au Mutara par l'Institut pour la Re­
cherche Scientifique en Afrique Centrale.
Le Pare est situe au Nord-Est du pays le long des fron­
tieres de l'Uganda et de la Tanzanie. 11 possede des sa­
vanes herbeuses, arbustives, arborescentes, boisees, des
preforets et forets claires (Troupin) et des bosquets xero­
philes.
Acta Phytogeogr Suec 54
Dans cette immense reserve, on peut trouver tous les
stades de savanes. Leur protection est assuree sauf contre
le feu qui y est mis regulierement.
Le Pare National Albert (secteur Sud) abrite sur
25 000 hectares, tous les versants Sud des volcans eteints
de la chaine des Birunga. Ce n'est qu'une petite partie
du Pare National Albert qui s'etend au Congo depuis
les volcans jusqu'au massif du Ruwenzori.
Sur les pentes de ces volcans eteints au Rwanda on
peut trouver tous les facies de region montagnarde :
forets ombrophiles de montagne
forets de Hagenia abyssinica
bambusaies a Arundinaria alpina
forets ericoi:des a Philippia et Erica
Les pentes terminales des volcans et les cones sont
couverts d 'une vegetation extremement particuliere et
afro-alpine avec Senecio et Lobelia arborescents dans un
tapis d' Alchemilla et d' Helichrysum.
La foret de la crete Congo-Nil a ete completement
protegee lorsque le Rwanda etait sous la tutelle beige.
Malgre cette protection, il. ne reste plus que des lambeaux
de foret ombrophile de montagne et de belles formations
tourbeuses encore intactes.
Actuellement cette foret est exploitee et mise de plus
en plus en culture. Le jour n'est pas loin ou elle aura,
tout au moins dans ses facies primitifs, entierement dis­
paru.
ASSOCIATIONS ENCORE A PROTEGER
Le Rwanda avec ses deux Pares Nationaux a organise
la protection des differents types de vegetation et de
faune. A notre avis, deux regions devraient encore etre
reservees :
1 °) une partie des lacs de la Nyabarongo moyenne
avec les savanes boisees des rives et des collines les sepa­
rant.
2°) une partie de la foret de la crete Congo-Nil en­
globant la grande tourbiere du Kamiranzovu et son
cirque montagneux jusqu'au gite de l'INRS a Uwinka.
Ces deux regions devraient etre determinees avec pre­
cision.
Les autorites gouvernementales rwandaises devraient
etre appelees a decider la creation et !'organisation de
ces reserves.
BIBLIOGRAPHIE
Germain, 1 9 52. Les associations vegetates de la plaine de la
Ruzizi (Congo beige) en relation avec le milieu. INEAC, 52.
Bruxelles.
Koppen, 1 93 1 . Grundriss der Klimatkunde. Ed. 2. Leipzig.
Burundi
Lebrun, 1 947 . La vegetation de la plaine alluviale au Sud du
Lac Edouard. IPNCB, Expl. PNA. Bruxelles.
Robyns, 1947-48-55. Flore des Spermatophytes du Pare Natio­
nal Albert. Vol . I, 11, Ill ; IPNCB. Bruxelles.
1 27
Troupin, 1 966. Etude phytocenologique du Pare National de
l'Akagera et du Rwanda oriental. Publication INRS. Butare.
van Minnebruggen, 1 965. Bulletin climatologique annuel de la
Republique Rwandaise. Annee 1 964. ISAR. Rubona.
BURUNDI
J. Lewalle
APER<;U GEOGRAPHIQUE
Le Burundi, d'une superficie de 27 6 1 2 km\ s'c.�tend
entre les limites S 2°20' et S 4°28', E 29° et E 30°58'. Il
est separe du Congo par le lac Tanganyika et la vallee
de la Rusizi. Vers l'Est et le Sud, il rejoint la Tanzanie,
par deux vallees : celle de la Malagarasi (bassin du
Tanganyika) et celle de la Ruvubu (bassin du Nil).
Son niveau altitudinal inferieur est le Tanganyika
(780 m) ; ses points culminants s'echelonnent tout au
long de la crete de partage des eaux du Congo et du
Nil; cette ligne de faite orientee Nord-Sud, se prolonge
au Nord dans le Rwanda. Les sommets atteignent
2 600 m. Toute la partie orientale constitue un plateau
d'environ 1 600 m, descendant p ar paliers lents vers la
Malagarasi ( = le Mosso), la Ruvubu (
la Karusi) ou
les lacs rwandais ( = le Bugesera). A part les alluvions
de la plaine de la Rusizi et quelques pointements cal­
caires au Sud-Est, le substratum est constitue de roches
acides, metamorphiques.
=
CLIMATOLOGIE
1 o La crete Congo-Nil, indice de Koppen Cw ; la tempe­
rature dont la moyenne est de 14 a 1 9°, connait des
minima d'env. 0°C; precipitations tn!s variables, locale­
ment abondantes ( + 1 200 mm) et assez bien reparties.
2° Le plateau Nord-Est, prolongeant le Rwanda, et
la valtee de la Rusizi, indice de Koppen (Aw3) S ;
temperature toujours superieure a 1 8°C; regime a deux
saisons seches (janvier-fevrier et juin-aout).
3° Le plateau Sud-Est et les bords du lac, indice de
Koppen (Aw4)s; saisons seches plus marquees.
REGIONS NATURELLES
Les grandes regions naturelles correspondent aux etages
altitudinaux et aux divisions climatiques :
1° la crete Congo-Nil
2° le Burundi central et nord-oriental
3° le Burundi meridional et occidental
1 o La crete Congo-Nil est couverte par une foret
ombrophile de montagne. Celle-ci, reculant partout
devant les defrichements, est clairiairee et souvent
envahie par des .especes de forets secondaires ou meme
remplacee par une vegetation de prairie; par endroits,
elle fait place a des peuplements de bambous et a des
marais; la plupart des points culminants sont occupes
par une prairie afro-montagnarde. Cette foret de mon­
tagne qui prolonge celle du Rwanda, beaucoup plus
large, s'etend de fa9on discontinue, jusqti' a Bururi, oil
une foret claire la relaie.
2° Le Burundi central, en raison de sa tres forte
densite de population, est entierement sous cultures
vivrieres ou industrielles (cafe, the, tabac). Les regions
orientales (Bugesera), peu habitees, sont couvertes
d'une savane herbeuse entrecoupee de forets claires et
de groupements aquatiques. Les grandes vallees allu­
viales du Burundi central et oriental hebergent des
galeries forestieres, veritables relictes oil se melangent
des elements guineens et zambeziens; la papyraie
domine dans de nombreux marais.
3° Les abords du lac Tanganyika, de la Rusizi et des
lacs proches du Rwanda sont caracterises par une
vegetation palustre ou une phragmitaie. Dans le Mosso,
partie la plus meridionale du Burundi, les savanes
boisees et les savanes herbeuses dominent; cependant
on trouve localement une foret affine de certains types
forestiers periguineens mais a influence zambezienne
assez nette.
Chorologiquement, les territoires du Burundi appar­
tiennent au Domaine oriental (B.I.C.b.6 de la classi­
fication de. Monod) de la Region soudano-angolane.
ASSOCIATIONS DEJA PROTEGEES
Il n'existe pas de Pares Nationaux au sens strict, avec .
controle constant. Neanmoins, le Burundi a erige en
Reserve Naturelle toute la crete Congo-Nil, depuis la
frontiere rwa�daise au Nord, jusqu'a Bururi. La foret
domaniale n'a d'autres limites que sa lisiere naturelle,
« assez mouvante » du reste. L'administration de la
Acta Phytogeogr Suec 54
1 28
J. Lewalle
1. B urun d i , crete Conga­
Nil. Territoire de M u ramvy a,
Nyabigondo (plantation de
the), foret dense de m o ntagne.
Alt.
m. Photo : J. Le­
Fig.
2 1 00
walle.
·
tutelle avait tente de prectser les pourtours par une
rangee d'arbres (Eucalyptus) au dela de laquelle toute
exploitation etait, en principe, interdite.
Cette zone rassemble diverses associations tres
differentes et entremelees ; les lambeaux intacts y sont
tres rares et restreints, en raison de defrichements ou
d'exploitations forestieres anterieures. Pratiquement la
foret ombrophile de montagne ne se rencontre plus en
dessous de 2000 m; elle est constituee d'arbres semper­
virents, surmontant un sous-bois epais ; elle est riche en
epiphytes. Les essences les plus frequentes sont Podo­
carpus milanjianus, Ficalhoa laurifolia, Strombosia
scheffleri, Alangium chinense, Symphonia globulifera,
Syzygium parvifolium, Olea hochstetteri, Conopharyngia
johnstonii, Galiniera coffeoides, Xymalos monospora.
La secondarisation . y a introduit de nombreuses
especes a croissance rapide, notamment Neoboutonia
macrocalyx, Myrianthus holstii, Macaranga neomild­
breadiana, Polyscias fulva, Harungana madagascariensis,
Bridelia brideifolia. La degradation aboutit a une lande
a Pteridium aquilinum, ou a des formations a Lobelia
giberroa. Les marais et les forets de bambous occupent
des regions assez etendues. Certains sommets depassant
2300 m portent une prairie rase, sclerophylle, de type
afro-montagnard ou une lande ericolde a Philippia.
Les degradations de la foret progressent et sa surface
s'amenuise. Les essais de repeuplement ne compensent
pas l'effet des defrichements ou des exploitations.
ASSOCIATIONS QU'IL FAUDRAIT
PROTEGER
La protection effective la plus urgente concerne la
region de la crete Congo-Nil; la foret domaniale de la
Acta Phytogeogr Suec 54
crete, qui est en danger reel de disparition totale ne
pourra se maintenir qu'au prix d'une discipline tres
stricte et d'une surveillance renforcee. Peut-etre con­
viendra-t-il d'inclure dans la zone protegee des lambeaux
forestiers a caractere mesophylle; aux environs de
Bururi, ce type de peuplement passe progressivement a
une savane boisee.
A cote de cette Reserve, le Burundi a !'intention de
prendre des mesures de protection dans trois regions :
1 ) a l'Est, dans les vallees de la Malagarasi et de
Ruvubu;
2) au Nord-Est, aux abords des lacs (en accord avec
le Rwanda);
3) zone de la plaine de la Rusizi (en accord avec le
Congo).
1) L'isolement et la population clairsemee de certaines
zones du Mosso (Province Makamba, bassin de la
Malagarasi) et du Bugesera (Province Muyinga, bassin
de la Kagera) faciliteront l'etablissement de perime­
tres proteges.
L'etude du Mosso (Michel et Reed 1 955) a mis en
evidence la presence de savanes herbeuses (Hyparrhenia
cymbaria et Echinops amplexicaulis; Loudetia arundina­
cea et Themeda triandra; Oxytenanthera abyssinica;
Hyparrhenia filipendula et H. dissoluta; Andropogon
schirensis et Eriosema erici-rosenii; Loudetia simplex et
Striga asiatica; Elyonyrus argenteus et Lepidagathis
fischeri), de forets claires (Acacia caffra; Brachystegia
boehmii et Ritchiea quarei; Brachystegia microphylla et
Uvaria angolensis), de galeries forestieres a A lchornea
cordata et de forets a Newtonia buchananii et Albizia
Burundi
1 29
Fig. 2. Burundi, 1 5 km N de
Bujumbura. Plaine de la Ru­
sizi, savane Hyphaene ventri­
cosa et Euphorbia candelabrum.
Alt. 800 m. Photo : J. Lewalle.
zygia, tres particulieres et probablement en voie d'evo­
lution .
Les associations principales decrites dans le Bugesera
et qui se retrouvent au Rwanda (Liben 1 956) sont des
savanes herbeuses (Botriochloa insculpta et Themeda
triandra; Loudetia simplex et Heteropogon contortus),
des savanes arbustives (Pappea ugandensis, Dalbergia
nitidula, Ficus ripicola, Maytenus senegalensis; Com­
bretum binderianum, Albizia adianthifolia), des savanes
boisees (Acacia seyal et fanicum maximum; A cacia
sieberiana, A . cajfra, Blighia unijugata, Boerhaavia
plumbaginea, Crassocephalum bojeri, Setaria kagerensis,
Securinega virosa, Paullinia pinnata, Bridelia micrantha)
ou des forets sclerophylles d'extension reduite ( Carissa
oppositifolia; Apodytes dimidiata).
Des zones limitees de vegetation aquatique ou paludi­
cole y existent et sont d'ailleurs representees plus riche­
ment dans la zone suivante.
2) Les abords des lacs ·de la frontiere orientale du
Rwanda presentent un interet tout particulier pour la
faune, notamment les oiseaux; la flore beneficie ainsi
des mesures de protection edictees. Parmi les associa­
tions principales, la papyraie a Cyperus papyrus et Cy­
closorus gongylodes est bien representee sur de vastes
etendues. Les perimetres a proteger, fort limites en sur­
face, comprennent les rives, les iles et les marais inhabi­
tes. Le lac Rwihinda, appele « lac aux oiseaux », bien
qu'assez petit (4 a 5 km de long) est fort interessant;
aucune agglomeration importante ne l'avoisine.
I1 convient de signaler ici la menace que Lantana
9 - 6 8 1 557 Hedberg
camara fait peser sur les equilibres naturels des rives.
Cette Verbenacee ornithochore est deja en extension en
certains points du Rwanda (lac Mohasi). La oil elle s'im­
plante, sa progression est rapide et sa proliferation peut
avoir des consequences graves autant qu'inattendues
(extension rapide des glossines au Kenya). A l'interieur
des Reserves Naturelles, sa destruction s'impose.
3) L'etude de la plaine de la Rusizi (Germain 1 952)
a montre la mosaique d'associations qui se partagent
cette partie du graben. On y rencontre notamment des
marais (Phragmites mauritianus), des prairies mouilleuses
diverses, des savanes herbeuses floristiquement tres
riches ( Themedion afro-orientale; Beckeropsidetalia uni­
setea), des savanes boisees (Acacia sieberiana), des bos­
quets xerophiles ( Cadaba farinosa et Commiphora sub­
sessilifiora), des lambeaux de foret tropophile (Albzzia
grandibracteata et Strychnos potatorum). Certains grou­
pements qui regressent devant les cultures et l'elevage
meriteraient d'etre mis en defens. La zone proposee a
la protection couvre environ 500 ha et pourrait se pro­
longer par une surface de meme importance en territoire
congolais.
BIBLIOGRAPHIE
Germain, R . , 1 952. Les Associations vegetales de la plaine de l a
Ruzizi en relation avec l e milieu. Public. INEAC, Serie
Scient. n° 52.
- 1 9 55. Carte des sols et le vegetation du Congo Beige et du
Ruanda-Urundi; 3 , Vallee de l a Ruzizi. Public. INEAC.
Liben, L., 1 9 56. Carte des sols et de la vegetation du Congo
Acta Phytogeogr Suec 54
1 30
E. Guinea
Beige et du Ruanda-Urundi ; 7, Bugesera-Mayaga (Ruanda).
Public. INEAC.
- 1 9 6 1 . Les bosquets xerophiles du Bugesera. Bull. Soc. R. Bot.
Belg., 93, 93-1 1 1 .
Michel, G . et Reed, J., 1 9 5 5 . Carte des sols et de la vegetation
du Congo Beige et du Ruanda-Urundi; 5, Mosso (Urundi).
Public. INEAC.
Monod, T., 1 956. Les grandes divisions chorologiques de l'A­
frique. Rapport de la reunion des specialistes en phyto­
graphie, Yangambi, juil. 1 956.
FERNANDO PO .
E. Guinea
Scheme de la vegetation
La cliserie (climax-serie ou serie climacique) d'altitude
de la vegetation de l'ile, comprend trois etages bien
differents, mais delimites par des bandes diffuses de
transition, parce qu'il n'existe pas une coincidence ab­
solue des limites des especes vegetales. Pourtant des li­
mites de ces trois etages ne forment pas de lignes tran­
chantes mais des zones transitoires.
La cote volcanique (Baie de Venus)
La cote volcanique est plus ou moins escarpee, le deve­
loppement des plages est tres reduit, avec une tres
pauvre representation de cette vegetation (littori-des­
serta) avec des especes suivantes :
Ficus urceolaris Welw. ex Hiern. Ficus exasperata Vahl. Ficus
vogeliana (Miq.) Miq. Ficus ovata Vahl. Ficus natalensis Hochst.
Ficus ottoniaefo/ia (Miq.) Miq. Chrysophyl/um africanum A. DC.
Ricinodendron africanum Miill. Arg. Crotonogyne manniana
Miill. Arg. Antidesma /aciniatum Miill. Drypetes occidentalis
(Miill. Arg.) Hutch. Stipularia africana P. Beauv. Anchomanes
petiolatus (Hook.) Hutch. Peperomia pellucida (L.) H. B. & K.
Peperomiafernandopoiana C. DC. Rhektophyllum mirabile N. E.
Brown, Culcasia angolensis Welw. ex Schott. Polyspatha pani­
culata Benth. Piper guineense Sebum. & Thonn. Hybophrynium
braunianum K. Sebum. Piper umbellatum L. Chlorophora
excelsa (Welw.) Benth. Dicranolepis mannii Baill. Leea guineen­
sis G. Don. Dicellandra barteri Hook. f. Stipularia africana
P. Beauv. Ficus /eprieuri Miq. Ctenitis securidiformis (Hook.)
Copel. var. securidiformis, Bolbitis auriculata (Lam.) Alston,
Schizolegnia ensifolia (Sw.) Alston, Pol/ia condensata C. B.
Clarke, Pa/isota hirsuta K. Sebum.
Les restes de la foret vierge
Theoriquement la foret vierge occupe tout le contour
de l'ile ou elle atteint une profondeur de 5-1 0 km, et au
dessus, jusqu'a la cote de 600-900 m, ou commence
l'anneau de nuages qui entoure presque continuellement
les versants du Pie de S:te lsabel. Dans son limite supe­
rieure, vers les 600 m d'altitude, les conditions de culture
du cafe commencent a etre precaires, les fougeres arbo­
rescentes (Cyathea usambarensis) apparaissent, avec une
tres bon developpement entre les 1000- 1 500 m; au
dessus de cette ligne la foret vierge perds sa purete et
Acta Phytogeogr Suec 54
complexite et une foret plus uniforme, et moins diversi­
fiee, surgit.
Dans l'actualite la foret vierge est occupee par les
cultures et proprietes de cafe et cacaoyer, sur les sols les .
plus fertiles de l'ile. On trouve ici des especes suivantes :
Coccos nucifera L. Platycerium stemmaria Desv. Hibiscus tiliaceus
L. Caesalpinia crista L. Terminalia cattapa L. Laguncularia
racemosa Gaertn. A vicennia nitida Jacq. Acrostichum aureum L.
Sporo/obus robustus Kunth. Hydrocotyle bonariensis Lam. Tri­
stemma littorale Benth. Desmodium adscendens (Sw.) DC. Elyt­
raria acaulis Lindau. Eryngium foetidum L. Sida rhombifo/ia L.
Dissotis rotundifo/ia (Sm.) Triana. Panicum brevifo/ium L. Se­
suvium portulacastrum (L.) L. Stenothaphrum secundatum (Walt .)
Kuntze, Canavalia obtusifo/ia DC. Phyllanthus amarus Sebum.
& Thonn. Justicia tenella (Nees) T. Anders. Euphorbia hirta
L. Asystasia gangetica (L.) T. Anders. Ipomoea digitata L. Pas­
palum commersonii Lam. Triumfetta cord({o/ia A. Rich. OpUs­
menus hirtel/us Beauv.
La foret moyenne nephelophile
L'etage moyen est recouvert par l'anneau de nuages deja
cite, avec beaucoup de penet]ations des especes de l'etage
inferieur, et au dessus de 1 000 m se developpe une fon�t
plus uniforme d'Araliacees arborescentes avec des espe­
ces suivantes :
Po/yscias fulva (Hiern) Harms. Schejflera mannii (Hook. f.)
Harms. Lachnopy/is mannii (Gilg) Hutch. & Moss. Dicrano­
/epis vestita Engl. Hugonia planchonii Hook. f. Paul/inia pin­
nata L. Anthoc/eista scandens Hook. f. Alangium begoniifolium
(Roxb.) Harms. Dracaena fragrans Ker-Gawl. Lepicystis lanceo­
/ata (L.) Diels, Senecio mannii Hook. f. Lobelia columnaris
Hook. f. Vangueriopsis chlorantha (K. Sebum.) Robyns. Ma­
esa lanceolata Forsk. Stephania abyssinica (Dill. & Rich.) Walp.
Les prairies artificielles (Moka, 1 200-1400 m) avec
beaucoup d'herbacees :
Sebaea multinodis N. E. Br. C/ematis altissima Hutch. Hypericum
pep/idifolium A. Rich. Laggera alata (G. Don) Sch. Bip. ex Oliv.
Geranium simense Hochst. ex A. Rich. Ranunculus extensus
(Hook. f.) Schube ex Engl. Drynaria laurentii Hieron. Didymo­
carpus kamerunensis Engl. Impatiens sakeriana Hook. f. Calanthe
corymbosa Lindl. Struchium sparagonophora (L.) Kuntze, Lac­
tucaglandulifera Hook. f. Viola abyssinica Steud. ex Oliv. Alche­
milla tenuicaulis Hook. f. Cardamine africana L.
Fernando Po
131
·�1 P!ag�s
+
�
Avicennia-Laguncu/aria
Cultures tropi�f!l�s
• Cultures subtropica/es
- - - Limite inferieur
0
et prairies artificiel!es
ries fougeres arborescentes
Vig�tr.tion marecageuse
lm Foret subtropicale
:::: Foret des A ralioceae
�� Fore! m oussoni9ue (basse:T; haufe:!I)
� Broussailles et prairie naturelle
� Rest de la foret �ierge
..s
Fig. 1 . Carte phytogeographique de
Fernando Po.
Le refuge de Basile ( 1 900 m) est une tres bonne station
pour l'etude de la foret de brouillard avec des especes
suivantes :
Uragoga mannii (Hook. f.) Hutch. & Dalz. Uragoga peduncu­
laris (Salisb.) K. Schum. Antrophyum mannianum Hook . Lyco­
podium clavatum L. Lycopodium phlegmaria L. Micro/epia spe­
luncae Moore, Asplenium /aserpitifo/ium M'Ken. Asplenium
emilii-guineae Alston, Ouratea flava Hutch. & Dalziel ex Stapf.
Dorstenia subtriangularis Engl. Urophyllum paucinerve Hiern.
Hypoestes trif/ora (Forsk.) Roem. & Schult. Solanum torvum
Sw. Solanum indicum L. Pittosporum mannii Hook. f. Sauroma­
tum venosum (Ait.) Kunth (syn. Jaimenostia fernandopoana
Guinea & G. Moreno).
Au dessus de 2000 m apparaissent sur les arbres les
Lycopodii epiphytiques.
A partir de 2300-2400 m cette ligne de foret com­
mence a s'eteindre et la broussaille avec Hypericum lan­
ceolatum Lam., frequemment parasitee par Loranthus
nitidulus Sprague et L. incanus Schum. , surgit.
Brousailles et prairie naturelle
Vers le 2500 m apparaissent brusquement Agauria salici­
folia (Comm.) Hook f. ex Oliv. (resemblant a l'arbou-
sier) accompagne de Adenocarpus mannii (Hook f.)
Hook f., Blaeria mannii (Engl.) Engl. et diverses gra­
minees. Plus haut (2600-2700 m) commence Philippia
mannii (Hook f.) Alm & Fries jusqu'au sommet. Au
dessus de 2700-2800 m il y a des enclaves de �egetation
herbacee, avec des especes suivantes :
Sagina abyssinica Hochst. ex A. Rich. Cerastium africanum Oliv.
Micromeria biflora (Buch.-Ham.) Benth. Stachys aculeolata
Hook. f. Calamintha simensis Benth. Festuca simensis Hochst.
ex A. Rich. Festuca gigantea (L.) Vill. Festuca schimperiana A.
Rich. Limosel/a tenuifolia Nutt. Plantago palmata Hook. f.
Carex mannii E. A. Bruce, Cyperus mannii C. B. Clarke. Luzula
campestris DC. var. mannii Buchen. Wahlenbergia arguta Hook.
f. Wahlenbergia mannii Vatke. Trifolium simense Fres. Trifolium
subrotundum Steud. & Hochst. ex Hochst. Pimpinella oreophila
Hook. f. Galium spurium L. Sanicu/a elata Buch.-Ham. ex D.
Don. Peucedanum petitianum A. Rich. Helichrysum mannii
Hook. f.
La foret moussonique
Ce type de vegetation est presque inconnue.
BIBLIOGRAPHIE
Adams, C. D., 1957. Obs. Fern Fl. F. Po. - J. Ecol. 45 : 479494. Oxford.
Acta Phytogeogr Suec 54
1 32
A . W. Exell
Alston, A. H. G., 1 95 1 . Pterid. fernandop. - Bol. Real. Soc.
Erp. Hist. Nat. 49 : 1 89-99. Madrid.
Exell, A. W., 1 944. Cat. vase. pi. S . Tome. - Brit. Mus. (Nat.
Hist.) London.
Guinea, E. , 1 949 . En elpais de Ios Bubis. - Inst. Est. Afr.
Madrid.
- 1 95 1 . The Veget. of F. Po. Circular Paper of the IVth C.l.
A . O . , 62-66. - Santa Isabel.
Hooker, J. D., 1 864. On the plants of the temperate regions of
the Cameroons Mountains and islands in the Bight of Be­
nin; collected by Mr Gustav Mann . - Journ. Proc. Lion.
Soc. Bot. , 7, 1 7 1 -239. London.
Hutchinson, J. & Dalziel, J. M., 1 959-1968. Fl. W. Trop. Afr.
2 ed . London.
Mann, G., 1 862. Account of the ascent of Clarence Peak, Fer­
nando Po, altitude 1 0.700 ft. - Journ. Proc. Lino. Soc. Bot.,
6: 27-30. London.
P Rf N C I P E, S. T O M E A N D A N N O B O N
A . W. Exell
These three small islands in the Gulf of Guinea,
respectively north of, on and south of the equator,
are of greater botanical importance than might be
expected from their size and position and in one re­
spect they are almost unique. When they were discov­
ered by the Portuguese at the end of 1 470 and the
beginning of 14 7 1 they were uninhabited and apart
from the rather vague possibility of occasional
chance visits from the mainland everything indicates
that we have here three equatorial volcanic islands,
comparatively close to the mainland but whose vege­
tation was entirely virgin until the end of the 1 5th
century. It is very improbable that the islands were
ever joined to the continent. The remaining frag­
ments of this virgin vegetation are now unfortunately
small in area but such as they are, they still appear
to be almost devoid of species introduced by Man.
GEOGRAPHICAL SURVEY
Principe. This is a small irregularly rhomboid is­
land about 1 7 km long by 8 km broad and 1 26
sq. km in area, in Lat. 1 ° 30'N, Long. 7 ° 25'E, about
2 1 0 km SSW of Fernando Po and about the same
distance from the mainland (Rio Muni). This island
is a typically volcanic one with numerous sharply
contoured peaks, the Pico do Principe attaining 948
m and the Pico Papagaio 680 m. The northern half
of the island is flatter and almost entirely cultivated.
S. Tome. This irregularly pear-shaped island is
considerably larger, 47 km long by 27 km wide and
about 1 000 sq. km in area, in Lat. 0 ° , Long. 6 ° 30'E,
the equator passing through the small Ilheu das Rolas
off the south coast. It is 220 km from the mainland
(Cape Lopez, Gabon). The island is extremely moun­
tainous, culminating in a sharp ridge about 6 km
long stretching from Lagoa Amelia ( 1480 m) to the
Acta Phytogeogr Suec 54
Pico de S. Tome (2024 m). From the west coast the
land rises very steeply to this central mass but from
the east coast the ascent is more gradual providing a
greater area suitable for cultivation.
A nnobon. This, the smallest of the three islands,
7 km long by 2.5 km broad, lies in an isolated posi­
tion 1 o 26'S, 5 o 3 7'E, 1 80 km SSW of S. Tome and
340 km from the nearest mainland (Cape Lopez,
Gabon). There are three peaks of considerable
altitude-Santa Mina (655 m), Quioveo (63 1 m) and
Pico do Fogo ( 455 m). In the north, at an altitude of
about 270 m there is a considerable crater-lake some
600 m in diameter.
CLIMATICAL SURVEY
All three· islands have a typical equatorial climate but
with the extremes of temperature modified by their
insularity, especially in the case of Annobon which
has more of the characteristics of an oceanic island.
Although Principe lies north of the equator, it as well
as the other two islands has a southern type of cli­
mate with the driest period in June-July-August and
a shorter dry period, not so pronounced, in January­
February. The winds are predominantly from the
south and regions sheltered from these winds, espe­
cially the northern parts of the islands, have a much
smaller rainfall. The mean annual rainfall varies
from rather less than 1 000 mm to 5000 mm in . S.
Tome and from about 2000 mm to 4000 mm in
Principe. S. Tome has a comparatively small area in
the north with a mean annual rainfall of less than
1 000 mm. In both islands (and also in Annobon)
the rainfall increases and the temperature decreases
with altitude but there are considerable local varia­
tions due to the topography. Humidity is very high,
especially at the higher altitudes. In S. Tome the
Prfncipe, S. Tome and Annobon
mean temperature at the coast varies from just over
24 oc in August to nearly 27 ° C in March; at Monte
Cafe, alt. 640 m, the mean temperatures are 5 °-6 ° C
lower.
VEGETATION SURVEY
The islands were said to be densely covered with
forest when they were discovered but small areas in
the northern parts ,of the islands, especially in S.
Tome, are probably too arid to support forest. Al­
though it is now difficult to be certain in such a
small and rather densely populated island it does not
look as though evergreen forest extended right down
to the sea in Annobon, which gives the impression of
being comparatively arid except at the higher alti­
tudes. Principe and S. Tome undoubtedly supported
well-developed evergreen forest from 0-800 m over
most of their area, but this has been almost entirely
destroyed and now scarcely concerns us from the
point of view of conservation. From about 800 m to
1 400 m, in S. Tome, there is submontane evergreen
forest constituted largely of different species, rather
lower in height and characterized by a lower layer
composed very largely of rubiaceous shrubs. In Prin­
cipe this vegetation appears at a somewhat lower
level, probably about 600 m, but most of it has been
destroyed. From about 1 400 m upwards in S. Tome
and on the upper slopes of the peaks in Principe and
Annobon, where the temperatures are considerably
lower, there is mist-forest (the "Ob6 microtermico"
of Lains e Silva). On the summit of the Pica de S.
Tome there is a small area of a more montane type
characterized by Podocarpus and Philippia (the
"Mato subalpestre" of Lains e Silva). In addition
there are areas of sand-dunes and mangrove which
are unlikely to be destroyed by cultivation.
CONSERVATION
As far as I am aware no areas on these islands have
been officially conserved. The areas of natural vege­
tation which still exist have escaped destruction
through difficulty of cultivation. In this type of ever­
green forest vegetation well-marked associations of
species can scarcely be distinguished and what is
proposed is the conservation of certain comparatively
small areas containing most of the endemic species
and those of special interest. Endemism is compara­
tively high although it has perhaps been somewhat
reduced in recent years from the figures originally
given by the discovery on the mainland of some of
the species thought to be endemic. On the other hand
new, apparently endemic species are still being dis-
133
covered and the flora has b y no means been exhaus­
tively collected as yet. Quite a rich flora is clearly
in danger of extermination.
AREAS PROPOSED FOR CONSERVATION
Principe
The summits and higher slopes of Pico do Principe
and Pico Papagaio. Endemic species (some occurring
also on the other islands) and those of special interest
include
Hymenophyllum mildbraedii (Brause) Alston, Lomariopsis
nigrescens Holtt., Antrophyum immersum (Bory ex Willd .)
Mett., Selaginella mannii Bak., Impatiens manteroana Exell,
Ouratea nutans (Hiern) Exell, Lasiodiscus rozeirae Exell,
Calvoa henriquesii Cogn., Dissotis barteri Hook. f. ex Triana,
Schefflera mannii (Hook. f.) Harms, Lasianthus africanus
Hiern, Sacosperma paniculata (Benth.) G. Tayl., Chrysophyl­
lum calophyllum Exell, Anthocleista stenantha Philipson,
Utricularia mannii Oliv., Peperomia fernandopoana C. DC.,
Maesobotrya glabrata (Hutch.) Exell, Grossera elongata
Hutch., Brachycorythis basifoliata Summerh., Habenaria ste­
nochila Lindl., Diaphananthe papagayi (Reichb. f.) Schlech­
ter, Bulbophyllum mediocre Summerh. Hypolytrum grande
(Uitt.) Koyama .
This list would be considerably extended by inclu­
sion of endemics collected by Barter, Mann, Quintas
etc. based on unlocalized specimens. Many of these
species undoubtedly occur within the areas proposed
for conservation.
S. Tome
An area along the crest of the central mountain
ridge extending from (and including) the extinct vol­
cano, Lagoa Amelia, the Peak of · Calvaria and the
Pico de S. Tome. This area, difficult to estimate
exactly, is comparatively small, not very useful for
cultivation, and includes most of the remnants of the
virgin forest and the montane vegetation of the Pico.
It is approximately the region shown on the map
"Esbo9o da Carta da Vegeta9ao" by Lains e Silva
( 1 958) , coloured deep green (Ob6 microtermico) and
blue {Matos subalpestres). This area could be ad­
vantageously extended to a somewhat lower altitude
at Monte Cafe if any areas of virgin forest still exist
there. Endemic species {some occurring also on the
other islands) and those of special interest include:
Cyathea welwitschii Hook., Athyrium newtonii (Bak.)
Diels, Asplenium eurysorum Hieron., Asplenium exhaustum
(Chri st) Alston, Asplenium molleri Hieron., Cyclosorus op­
positifolius (Hook.) Tard., Pteris commutata Kuhn, Selagi­
nella mannii Bak., Selaginella molleri Hieron., Selaginella
thomensis Alston, Podocarpus mannii Hook. f., Stel/aria
manni Hook. f., Melchiora mannii (L.) Kobuski, Maytenus
mono,dii Exell, Impatiens buccinalis Hook. f., Cassipourea
mannii (Hook. f. ex Oliv.) Engl., Calvoa crassinoda Hook.
f. ex Tri an a, Calvoa molleri Gilg, Homalium henriquesii
Gil g ex Engl., Begonia baccata Hook. f., Begonia macambActa Phytogeogr Suec 54
1 34
A. Aubreville
rarensis Exell, Begonia molleri (C. DC.) Warb., Begonia
thomeana C. DC., Schefflera mannii (Hook. f.) Harms,
Urophyllum insulare Hiern, Sabicea cauliflora Hiem, Sabi­
cea ingrata K. Schum., Pavetta monticola Hiern, Bertiera
pedicellata (Hiern) Wernh., Craterispermum montanum
Hiern, Lasianthus africanus Hiern, Tarenna nitidu/oides G.
Tayl. Psychotria euchlora K. Schum., Psychotria guerkeana
K. Schum., Psychotria nubicola G. Tayl., Sacosperma pani­
·
culatum (Benth.) G. Tayl., Lobelia barnsii Exell, Philippia
thomensis Henriq., Rapanea thomensis Exell, Conopha­
ryngia stenosiphon (Stapf) Stapf, Marsdenia exellii Norman,
Anthocleista exelliana Monod, Utricularia mannii Oliv., He­
terodelphia paulowilhelmia Lindau, Peddiea thomensis Exell,
Helixanthera mannii (Oliv.) Danser, Erythrococca molleri
(Pax) Prain, Pilea manniana Wedd., Habenaria thomana
Reichb. f., Orestias stelidostachya (Reichb. f.) Summerh.,
Polystachya albescens Ridl., Polystachya expansa Ridl., Po­
lystachya ridleyi Rolfe, Polystachya thomensis Summerh.,
Rhipidoglossum brevifolium Summerh., Bulbophyllum resu­
pinatum Ridl., Bulbophyllum thomense Summerh., Costus
giganteus Welw., Palisota pe{iicellata K. Schum. and' Carex
leptocladus C. B. Clarke.
Many other interesting species recorded from
slightly lower altitudes (including the endemic Leea
tinctoria Lindl. ex Bak.) are probably also found in
the proposed area, especially if it can be extended
downwards to Monte Cafe.
A nnobon
The summits of the three peaks Santa Mina, Quioveo
and Pico do Fogo and, if possible, an area stretching
from the slopes of Pico do Fogo to the Crater Lake.
Endemic species (some occurring also on the other
islands) and those of special interest include:
Hymenophyllum mildbraedii (Brause) Alston, Fagara anno­
bonensis Mildbr. , Turraea glomeruliflora Harms, Maytenus
annobonensis (Loes. & Mildbr.) Exell, Agelaea ovalis Schel­
lenb., Cassipourea annobonensis Mildbr., Calvoa uropetala
Mildbr., Tristemma oreothamnus Mildbr., Pouchetia confer­
tiflora Mildbr., Sabicea insularis (Wernh.) G. Tayl., Pavetta
monticola Hiem, Bertiera annobonensis G. Tayl., Crateris­
permum
montanum
Hiern,
Lachnopylis
annobonensis
Mildbr., Peperomia hygrophila Engl., Thecacoris annobonae
Pax & K. Hoffm., Cavacoa quintasli (Pax & K. Hoffm.)
Leonard, Discoclaoxylon pubescens (Pax & K. Hoffm.) Exell,
Celtis prantlii Priemer ex Engl., Ficus annobonensis Mildbr.
& Hutch., Aerangis megaphylla Summerh., Cyrtorchis acu­
minata (Rolfe) . Schlechter, Costus giganteus Welw. ex Ridl.,
Palisota pedicelata K. Schum.
REFERENCES
Exell, A. W., 1944. Catalogue of the Vascular Plants of S.
Tome (with Principe and Annobon). - British Museum.
1956. Supplement to the Catalogue of the Vascular Plants
of S. Tome (with Principe and Annobon). - B ritish
Museum.
- 1 958. Aditamento a Flora gas Ilhas de S. Tome e do
Prfncipe. - Confer. Internacion, Afr. Oc., Sess. 6, 3: 779 1 , with A. Rozeira.
- 1 959. Additions to the Flora of S. Tome and Principe. Bull. Inst. Fran�. Afr. Noire 21, Ser. A, n. 2.
- 1 963. Angiosperms of the Cambridge Annobon Island
Expedition. - Bull. Brit. Mus. (Nat. Hist.) Bot. 3, 3 .
Lains e Silva, H . , 1 958. Sao Tome e Principe e a Cultura
do Cafe. - Lisbon.
SYNTHESE REGIONALE
A. Aubreville
D'apres les rapports etablis au Cameroun par M . Letouzey, au
Gabon par M. Halle et Mme Le Thomas, a Fernando Po par
M . Guinea, a la Republique democratique du Congo par M.
Germain, au Rwanda par M . Deuse, au Burundi par M . Le­
walle1.
Le vaste massif forestier guineo-congolais qui couvre de
grandes superficies au Cameroun, au Gabon et au Con­
go (Kinshasa) comprend encore de grandes parties de
foret demeurees intactes en raison de la tres faible den­
site demographique de ces pays. La vegetation et la
flore primitive sont done conservees, de ce fait, dans des
territoires que les botanistes, pendant longtemps encore,
pourront explorer. Ces forets peu degradees, souvent
1
Le rapport de la Republique centrafricaine (Bangui), de la
Republique du Congo Brazzaville, et de Principe, S. Tome et
Annobon ne nous sont pas parvenus.
Acta Phytogeogr Suec 54
vierges, ne se voient plus guere lorsque l'on circule sur
les routes aujourd'hui bordees de monotones brousses
secondaires, a la ftore banale, mais en avion on constate
qu'a quelques kilometres des routes et des villages, la
foret apparemment primaire est toujours presente. Cette
foret s'eloigne de plus en plus de celles des agglomera­
tions humaines qui deviennent importantes, et l'accrois­
sement de la population des villes tend a la faire dis­
paraitre dans de grands rayons autour d'elles. Le pro­
bleme essentiel qui est pose aujourd'hui aux botanistes
est d'en poursuivre !'exploration botanique, il reste
beaucoup a faire, et meme les especes endemiques ou
rares ne sont pas vraiment menacees d'extinction. Les
statistiques etablies par M. Halle et Mme Le Thomas
pour le Cameroun et le Gabon, la carte de M. Leonard
(La Carte A.E.T.F.A.T. du degre d'exploration floris-
Synthese regiona/e
tique de 1' Afrique) montrent bien !'importance de
!'effort qui reste a accomplir dans ce domaine primor­
dial.
Au Congo Kinshasa M. Germain estime que le taux
de boisement par la foret dense humide est d'environ
45 % (densite demographique moyenne, 5 habitants par
km2 avec des minima de 1). Au Cameroun la population
est plus dense, 9,7 habitants au km2 et tres i negalement
repartie; au Gabon 2 habitants seulement au km2• Peu
de mesures legales de conservation ont ete prises jusqu'a
present dans la foret dense humide de basse et moyenne
altitude de ces pays tres forestiers peu peuples sous
forme de creation de pares nationaux, reserves integrates
ou reserves de nature diverse. Il faut reconnaitre qu'elles
ne s'imposent pas d'urgence. Il serait certes tres facile
de delimiter sur les cartes des secteurs de protection,
portant meme parfois sur des superficies importantes,
mais de telles mesures seraient illusoires soit parce que
les forets ainsi classees choisies loin des zones habitees
ne sont pas attaquees par des defrichements et que les
mesures legales n'ajoutent rien a cette situation, soit
parce que si un jour la region s'ouvrait a la penetration
humaine et economique a la suite de la construction de
routes, de voies ferrees, de la decouverte de gisements
miniers, etc., le fragile paravent des reglementations
conservatoires serait ignore.
Je resume ainsi ce que je crois etre, d' apres les r apports,
!'opinion de leurs auteurs. Personnellement je ne la par­
tage pas entierement pour des raisons d'ordre psycho­
logique. Il est vrai que des barrieres legales de protec­
tion de la nature sont franchissables en pays africain nous avons fait !'experience de leur resistance - , mais
j e crois cependant utile d'etablir des a present, alors que
cela est tres facile en pays peu habite, des zones de pro­
tection suivant un plan rationnellement etabli de conser­
vation de temoins des diverses formations vegetates.
En effet, si devant la pression demographique et econo­
mique il y a lieu, par la suite, de declasser, le fait
acquis des mesures anterieurement prises de conserva­
tion, donne des arguments et laisse done des possibilites
psychologiques a une opinion publique ou a des services
publics eclaires en vue d'obtenir le maintien d'une partie
du secteur protege.
M. Letouzey pour le Cameroun esquisse le projet de
certaines aires a proteger dans ce qu'il appelle la foret
« biafreenne », la foret congolaise a Baillonella toxi­
sperma, la foret a Gilbertiodendron dewevrei, etc.
Dans toute 1'Afrique centrale, il y des forets de mon­
tagne ou parfois de haute altitude (Region afroaltimon­
taine), ou les considera_tions que nous venons de resu­
mer ne sont plus valables, c'est-a-dire que ces forets tres
instables sont vouees a une destruction tres rapide,
qu'elles sont aujourd'hui deja tres degradees, souvent
disparues, et qu'il y a done necessite de prendre des
1 35
mesures de protection d'urgence pour sauver certains
massifs. Soot visees specialement les forets de la haute
dorsale Congo-Nil, au Congo oriental, au Rwanda et
au Burundi, et celles de l'axe montagneux allant de Fer­
nando Po, au Mt Cameroun et aux Mts Mandara dans
le nord du Cameroun. Tous les auteurs signalent retat
avance de degradation de ces forets. Le danger es.t appa­
ru depuis longtemps, mais aussi depuis plus de 40 ans des
mesures de conservation ont ete prises dans !'ancien
Congo Beige sous !'inspiration de l'Institut des Pares
Nationaux du Congo. M . Germain n'a pas manque
de citer cette belle realisation du Pare National Albert
au Kivu (plus de 800 000 ha), a laquelle vinrent s'ajouter
plusieurs autres grands pares dans la Region soudano­
zambezienne. D'autres reserves integrates moins impor­
tantes conservent des fragments de types speciaux de
biocoenoses : reserve des Mts Homas (Irumu), de Yan­
gambi, du Mt Kahuzi (Kivu, bambuseraie de haute
altitude), de l'ile ldjwi (lac Kivu), de la Lukele (Beni),
domaine forestier de Luki (Mayombe).
M. Letouzey au Cameroun, indique aussi quelques
biotopes montagnards a proteger specialement : Mt
Koupe, inselbergs au sud de 1' Adamaoua, sommets
(hosseres) des Mts Mandara, sommet du Mt Bambouto,
biotopes divers du Mt Cameroun.
Certains pays montagnards sont plus menaces que
d'autres de la disparition de la vegetation primitive. Tel
est le Rwanda, un des pays les plus peuples de l'Afrique
tropicale avec 85 habitants au km2• La foret de la dor­
sale Congo-Nil ne porte plus que des lambeaux de l'an­
cienne foret de montagne en depit de !'existence de 2
pares nationaux. M . Deuse propose deux autres sec­
teurs a reserver.
Au-dela du grand massif forestier guineo-congolai�,
s'etendent les savanes boisees et les forets claires de la
Region soudano-zambezienne, au nord, a l'est et au sud
des lisieres de la foret. Elles constituent aussi des forma­
tions vegetales tres interessantes par leur flore et leur
faune dont il importe done au point de vue scientifique
de proteger certaines parties. Au Gabon je citerai per­
sonnellement une partie des savanes herbeuses littorales
avec des forets a Sacoglottis et Aucoumea (entre l'es­
tuaire du Gabon et le fieuve Ogooue), les savanes de la
boucle de l'Ogooue (Booue-projet de pare de l'Okanda),
qui n'appartiennent pas d'ailleurs a la Region soudano­
zambezienne. Mr. Letouzey au Cameroun indique un
certain nombre de biotopes a proteger pour leur interet
scientifique, ne couvrant que de petites superficies de
quelques centaines d'hectares chacun : prairies sur
schistes chlorites, sur cuirasse ferrugineuse, roneraies,
raphiales, etc.
Au Congo Kinshasa, au Rwanda et au Burundi, l'an­
cienne administration beige avait cree des pares natio­
naux et reserves dont plusieurs tres importantes : le pare
Acta Phytogeogr Suec 54
1 36
A . Aubreville
national de l'Upemba en 1 93 9 au Katanga ( 1 1 73 000
ha) ; le pare de la Garamba dans le Haut-Uele en 1 93 8 ;
l e pare national d e l a Kagera (250 000 ha) a u Rwanda.
M. Germain insiste pour que desrelictes de la vegetation
ancienne, menaces de destruction par les defrichements
et les feux, soient specialement proteges. 11 s'agit au
nord du Congo (Uele) de vestiges de foret seche a Khaya­
Afzelia-Olea-Anogeissus, de foret decidue a Triplochiton
scleroxylon ; dans le haut Katanga des « muulus », re­
lictes d'une foret seche dense semi-decidue; et de divers
peuplements de montagne (a Juniperus procera).
Un service de la protection de la nature, specialiste
de la flore et de la faune, aurait son champ d'activite
bien marque, en reconnaissant tous ces sites et biotopes
a proteger, a decrire, a signaler specialement a !'atten­
tion des naturalistes du monde entier et a la vigilance
des pouvoirs publics; autant que possible a les cartogra­
phier, les delimiter merne, et, dans certains cas de petites
superficies, a les cloturer.
Tous les auteurs s'accordent a dire que, s'il est parfois
possible et meme souvent necessaire et efficace de deli­
miter des secteurs, petits ou grands, oil une protection
de la flore et de la faune devrait etre assuree par les
Gouvernements, en revanche, la determination par voie
legale d'especes particulieres a proteger serait une me­
sure parfaitement illusoire dans ses effets. Une liste a
deja ete etablie pour l'Afrique depuis 1 95 3 , en Afrique
centrale; elle comprend les seules especes du genre En­
cephalartos. Vivant dans les savanes, ayant !'aspect de
palmiers, elles se signalent aisement a tous et il etait
bon de rappeler a tous les habitants qu'il etait interdit
de les detruire. 11 y a beaucoup d'especes rares ou ra­
rissimes dont la liste pourrait etre aisement dressee, M .
Letouzey en a deja donne une longue liste pour l e Ca­
meroun, mais l'assortir de mesures legales de protection
n'aurait aucune signification pratique.
Toutes les dispositions reglementaires existant deja
relatives a la protection de la nature sont-elles appli­
quees actuellement en Afrique centrale? Avec la situation
politique tres trouble qui existe dans ces pays depuis
quelques annees il est permis d'en douter. Aucun auteur
n ' a traite ce point de vue capital de la conservation de
la Nature, parce qu'il est delicat, et qu'il pose des pro­
blemes de moyens d'intervention qui depassent probab­
lement les possibilites des administrations en place. On
aurait grand tort de se decourager. Nous sommes devant
une tache qui demandera longtemps des efforts perseve­
rants de propagande.
D I S CU S S I O N
Monod rappelle qu'il a lui-meme publie en 1 960 (Bull.
I.F.A.N., Dakar) une carte des proprietes (ou ro�as) de
l'lle de Sao Tome, proprietes dont il sera necessaire de
tenir compte pour etablir une protection de la vegetation
d'altiude (parfois meme menacee par le feu en saison seche)
et pour mettre en place des propositions concernant les
limites qui pourraient etre choisies. La Conference inter­
nationale des Africanistes de l'Ouest, en 1 95 6, avait d'ailleurs
deja vote une resolution a ce sujet.
Aymonin: Dans !'esprit de l'actuel Congres de l'A.E.T.F.
AT. , oriente sur la Conservation de la Nature, il semblerait
plus souhaita:ble d'emettre un vreu relatif a l'appui de notre
Acta Phytogeogr Suec 54
Association aux projets d'explorations botaniques dans des
regions particulierement menacees (Le M asoala, par exemple,
Reserve integrale no II, recemment " declassee "• situee
d ans une zone non completement exploree de M adagascar,
etc.). D'autre part, en ce qui concerne le Gabon, l'avis de
M. N. Halle serait particulierement precieux en cette cir­
constance etant donne qu'il a dresse une carte des localites
de ce pays: une expedition internationale ne serait veritable­
ment rentable que si elle s'attachait a !'exploration de
nouveaux perimetres, hors de ceux actuellement relativement
bien quadrilles, mais les problemes d'organisation deviennent
alors beaucoup plus complexes.
East Africa
E T H I O PI A
E. W. Beals
GEOGRAPHY
Ethiopia has an area of about 900,000 sq km, be­
tween 3 ° and 1 8 ° N latitude, and from 1 1 5 m below
sea level to over 4600 m above. It is bordered on the
north by the Red Sea and elsewhere by the sub­
deserts of the Sudan, Kenya, and Somalia. The Great
Rift system is complex and not always clear cut in
the southwest but forms a distinct Rift Valley
through the center of Ethiopia, averaging 80 km
wide, and then fans out to form the wide Afar de­
pression in the northeast. This Rift separates two
great plateaus, much of whose land surface is over
2000 m, with high volcanic mountains and deep river
valleys. The southeastern plateau slopes south gently
into Somalia; the northwestern one slopes west but
is more abrupt due to faulting along the western
border of Ethiopia. Most of the area has volcanic
soils, except in the Rift, where alluvial soils occur,
and in the southeast, where Jurassic limestone pre­
dominates.
CLIMATE
The climate ranges from desert conditions, with less
than 5 cm annual rainfall in the northeast, to hot
wet conditions with over 200 cm annual rainfall in
the southwest, to the cold alpine climates on the tops
of mountains, where frost occurs on many nights the
year around. In the south two rainy seasons occur,
in spring and autumn. In central Ethiopia the spring
rainy season is irregular, and the longer summer
rainy season is amplified by moisture-laden winds
from the southwest. In the north there is a single,
summer rainy season, except along the coast, where
the rains come in winter. During rainy seasons, se­
vere hailstorms are frequent in the mountains, and
snow occurs occasionally from·3 800 m upwards.
VEGETATION SURVEY
True desert, where there is essentially no vegetation,
occurs only in the northeast. At low altitudes semi­
desert and bushland prevail. Acacia shrubs (A . mel-
lifera and A . nubica are most widespread) often
dominate, accompanied by Commiphora spp. The
latter may dominate on rocky soils in the south. The
most widespread grass is Chrysopogon aucheri. Open
grasslands occur l!nder certain drainage conditions.
Deciduous woodlands and savannas occur at
slightly higher elevations (generally above 1 000 m)
on the lower edges of the plateaus, in river valleys,
and in the Rift. Two kinds of such woodland are
common. The first is the A cacia type, where A .
tortilis,. A . seyal, and A . senegal are widespread.
More locally other Acacias may dominate, and above
about 2000 m are found savannas of A. etbaica and
others.
The second type, generally found on rockier soils,
is the combretaceous woodland, commonly domi­
nated by Combretum molle or Terminalia brownei.
Associated with this woodland type are the bamboo
thickets of Oxytenanthera abyssinica, which cover
large areas in western Ethiopia. The grasses in both
Acacia and Combretum woodland are many, but
Themeda triandra and Hyparrhenia spp. often
predominate.
In the southwest, at elevations from 1 200 to 2000
m, occurs broad-leaved evergreen rain forest, gener­
ally of two tree layers, both with many species. Rep­
resentative of the upper byer are A ningeria adolfi­
friderici, Ekebergia rueppelliana, Pygeum africanum,
and Syzygium guineense; of the lower layer, Teclea.
nobilis and Galiniera coffeoides. Lianas and epi­
phytes are abundant. Under slightly drier conditions,
mainly between 1 500 and 2200 m, Podocarpus
.gracilior occurs, often in nearly pure stands. Another
coniferous forest type, found in yet drier sites,
mainly between 2000 and 3200 m, is the Juniperus
procera forest. It may occur in pure stands or share
dominance with Olea chrysophylla. Both coniferous
forest types have mostly been replaced by degraded
montane scrub, dominated by Ca·rissa edulis, Euclea
schimperi, Dodonaea viscosa, etc. Also associated
with these coniferous forests are montane grasslands,
the cause of which is not clear.
Above these forests (between 2700 and 3 300 m)
Acta Phytogeogr Suec 54
1 38
E. W. Beals
35
t_}O IOO
45
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40
occurs subalpine forest, with Erica arborea, Hagenfa.
abyssinica, Hypericum lanceolatum, etc. The trees
are often festooned with lichens and mosses. In the
wettest sites bamboo forests of A rundinaria alpina
are found. Above this, beginning between 3 200 and
3 500 m, afro-alpine moorland occurs, with an abun­
dance of shrubby Erica arborea, Lobelia rhynco­
petalum, and many species of Helichrysum and A l­
chemilla.
VEGETATION NOW PROTECTED
Coniferous Forest. Menegasha National Park, the
only place in Ethiopia where vegetation is even no­
minally protected, is located on a mountain just west
of Addis Ababa. It was established in 1 9 5 8 and
consists of 3 500 hectares. Originally it was mostly
mixed Podocarpus-Juniperus forest, but now it is
largely pure Juniperus. Although it is a park, the area
is subject to cultivation, grazing, and "managed"
logging, and therefore protection of the flora is very
meager indeed.
There are also game reserves, e.g. near Awash
Station and around Lake Abiyata in the Rift, but no
attempt is made to reduce overgrazing by livestock
or cultivation in these areas. No species of plants in
Ethiopia have legal protection so far as I know.
Acta Phytogeogr Suec 54
SOO sq. km.
a�i
. .. . . .Q .,.. _ , . ,J
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f'
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Reserves of
r-./
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4
Reserves up to 499 sq. km.
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Fig. 1. Proposed reserves for Ethio­
pia .
PROPOSED AREAS FOR PROTECTION
I am grateful to Dr W. Burger for his suggestions for
Harar Province. I have also made use of personal observa­
tions related to me by Dr M. V. Prosser, Dr E. K. Urb an,
Mr L. H. Brown, and the late Dr H. F. Mooney.
Ethiopia is not well known floristically or ecologi­
cally and therefore the following suggestions are ten­
tative, limited by my experience and that of a few
others. I have proposed 24 areas for protection, some
of which are more urgent than others. For some,
precise locations are given; others are vague sugges­
tions. I believe that many of the areas can be pro­
tected in cooperation with game management au­
thorities, as the vegetation and wildlife are closely
interrdated.
Semidesert and Scrub
These do not need urgent protection at the moment
because of their widespread occurrence, but they are
being subjected to increased grazing.
1 . In the northeast depression, Guma Valley (on
the Assab road, 60 km east of Sardo), a preserve of
about 1 0 sq. km would protect some fine A cacia
ehrenbergia.na scrub on the alluvial flats and A. mel­
lifera scrub on the surrounding hillsides.
2. To the west is Dobi Valley, a remarkable and
Ethiopia
extensive salt flat, with interesting Tamarix-Suaeda
vegetation, which may need protection in the future.
3 . Although semidesert vegetation is not now
threatened, an area might be protected in conjunc­
tion with a game preserve for the rare wild ass, in
the area of Mt. Curub and the Sardo Plain, j ust west
of Sardo village. At least 1 00 sq km would be re­
quired.
4. In the southeast Rift, the east side of Lake
Abaya has almost luxuriant A cacia nubica and A. mel­
lifera scrub, with fine natural forests of Euphorbia
tirucalli and interesting swamps. This area is already
subject to heavy grazing. An area of at least 1 0 sq.
km ought to be protected, probably south of the road
to Dilla.
5. In the southeast, - the Commiphora scrub wood­
land is not at the moment in any danger, because it
is so inaccessible. Such areas are extensive from
about 50 km south of the Harar-Jijiga road south­
wards. They are especially interesting floristically be­
cause of many indigenous species and the great di­
versity of Commiphoras.
.
Open G rassland
The following grassland sites should be set aside in
conjunction with a game conservation program.
6. In an area about 1 00 km NNE of Awash Sta­
tion (in the Afar depression) is some of the finest
open grassland and savanna in Ethiopia. It is excel­
lent game country. Near water sources, the vegeta­
tion has become overgrazed by livestock. An area of
about -. 5.00 .sq . . km could be ·preserved, from Lake
Hirtale east to the Mulu River and north to Mt.
Ayelu, where there are hot springs.
7. Another possible grassland site, rich in game,
with somewhat different floristics, would be in south­
west Ethiopia, west of the Omo River where the Mwi
River joins it (50 km SE of Maji). This area is in
less danger of degradation than the Rift area.
Riverine Forest in the Desert
Human and livestock pressure on this is extremely
great, but there are some good examples near Aisaita
village in the Afar depression.
8. Around both Lake Aisaita and Lake Gargori,
there is still some relatively undisturbed forest of
large Tamarix and A cacia trees. At least 200 hec­
tares of this would be worth preserving.
A cacia Woodland
This type is rapidly deteriorating all over · Ethiopia
due to expanding human and livestock populations
and also increasing demand for charcoal in cities and
villages.
1 39
9. A very fine example in the southeast is in the
Dakata Valley between Harar and Jijiga. Just south
of the road between those towns is a grassy swamp,
and south of that is an extensive A cacia seyal wood­
land, with combretaceous woodland on rocky slopes.
There is a high game population, including ele­
phants.
10. In the Rift Valley, excellent woodland is
found just south of Lake Langano. An area of about
4 sq. km could include A cacia tortilis woodland on
old lake flats and the species-rich Acacia-Euphorbia
woodland on volcanic outcrops. A much larger area,
to include other vegetation types (see sites 1 1 , 1 8, 2 1
below), is recommended.
Combretaceous Woodland
This type is also deteriorating rapidly.
1 1 . A very good example of Combretum savanna
can be found south of Lake Langano, on the hills
east of the A cacia woodlands of site 1 0, and a sec­
tion could be set aside with it.
1 2. In northern Ethiopia from the Lake Tan a
region to Aksum, a long history of dense human po­
pulations has left an extremely degraded landscape.
The Tacazze Valley, west of the Aksum-Gondar
road, however, still has an interesting woodland of
A cacia spp., Combretum spp. , Terminalia spp. ,
Adansonia digitata, Boswellia papyri/era, and Stereo­
spermum kunthianum. There are also patches of the
bamboo Oxytenanthera. A section of thi� would be
worth preserving.
1 3 . A special type of woodland in the Rift (related
to combretaceous woodland) is found on bare lava
flows less than · 200 years old; it is dominated by
Pistacia chinensis. A section of this extremely · in­
teresting woodland, of at least 1 sq. km, shouid be
preserved, 60 km east of Nazareth along the road to
Awash Station. Such an area might be included in
the officially proposed National Park that includes
Mt. Fantale and Lake Metahara nearby. The park,
designed primarily for game protection, would in­
clude Combretum and A cacia woodland, open grass­
land, and Acacia scrub. The Pistacia woodland could
be preserved especially for its botanical interest.
Rain Forest
The forests of Ethiopia are all threatened because of
rapidly increasing commercial utilization of their
timber. Little if any rain forest remains in virgin con­
dition, but there are some patches of relatively
mature forest.
14. A remnant probably worth preserving is found
in southwest Ethiopia on the Jimma-Bonga Road 40
km WSW of Jimma (Belleta Forest).
Acta Phytogeogr Suec 54
140
B. Verdcourt
1 5. A more extensive area, but rapidly disappear­
ing, is found between Bonga and Gore (Sai Forest).
Tree ferns (Cyathea) are abundant here.
1 6. Forest areas between Adola and Neghelli in
south-central Ethiopia might be worth preserving,
but more investigation is needed.
Coniferous Forest
1 7. In eastern Ethiopia, along the Asba Taiari­
Harar road, 1 5 km east of the village Hirna, is a
Podocarpus-Juniperus-Olea forest on the mountain
Gara Ades. It is being haphazardly logged at present.
Most of the forest is north of the road, but a patch
of moss forest is found just south, on a small peak.
At least 4 sq. km should be preserved before it is
completely destroyed.
1 8. On the top edge of the Rift escarpment about
20 km ESE of Lake Langano is some Juniperus­
Podocarpus forest that is worth preserving in con­
junction with sites 1 0 and 1 1 .
1 9. Some of the finest Podocarpus forest, and
probably not immediately threatened, is to be found
in the Mendabo mountains, about 1 50 km ESE of
Shashamanne. An area should eventually be pre­
served on the eastern slope of this massif between
Goba and Masslo, when this region becomes more
accessible.
20. All the above areas are on the southeast
plateau. There may be some good areas of juniper
forest left on the northwest plateau, in addition to
Menegasha Park, in which case they should be pro­
tected.
Subalpine Forest and Ajro-alpine Moorland
The subalpine forest is suffering from encroaching
cultivation and increased burning to produce pasture.
Some of it may be preserved in conjunction with the
protection of the mountain nyala, an endemic
Ethiopian antelope.
2 1 . Mt. Boset, SSE of Lake Langano, has ex­
tremely fine subalpine forest of Hagenia, Hypericum,
and Erica, as well as extensive areas of moorland.
This might be protected in conjunction with sites 1 0,
1 1 , and 1 8.
22. The area about 1 0 to 20 km south of the
Dodola-Adaba track in the Mendabo mountains has
the least disturbed subalpine forest I know; especially
interesting are the vast stands of pure Hypericum
forest. Above this is fine moorland, rich in endemic
species. An area of at least 1 00 sq. km should be
preserved before it is degraded.
23 . Another fine example of afro-alpine vegeta­
tion is on Mt. Mulatta, 40 km south of Dire Dawa.
There are also small remnants of subalpine and
Podocarpus forests here. An area of 25 sq. km on
the southern and western slopes is suggested.
24. On the northwest plateau, the Simien moun­
tains contain excellent afro-alpine moorland with
somewhat different floristics, which might be pro­
tected in conjunction with preserves for the Walia
Ibex. The area certainly should include the highest
peak in Ethiopia, Ras Dashan (4620 m), but recom­
mendation of a precise area must await further in­
vestigation.
The Lake Langano-Mt. Boset area (incorporating
sites 1 0, 1 1 , 1 8, 2 1 ) might very well be made into one
large vegetation and game reserve, which would
probably cover at least 300 sq. km. It would extend
from the south shore of Langano south about 5 km,
and from the Mojjo-Shashamanne road east about
60 km to include Mt. Boset. This area is largely
government-owned land.
F R E N C H S O M A L I LA N D
B. Verdcourt
GEOGRAPHY
French Somaliland is situated on the N .E. coast of
Africa around the Gulf of Tadjoura and extends in­
land for some 80 miles ( 1 2 8 km). It is a small ter­
ritory of about 9000 square miles (23 , 000 sq. km)
and had a population of 70,000 at the beginning of
Acta Phytogeogr Suec 54
this decade. Mostly it is a forbidding mixture of bare
sandy plains, basalt plateaux, rhyolitic massifs and
rocky wadi valleys; the highest point in the territory
is the summit of Eigere-Aleita in the Goudah Range
(1 750 m) and the lowest L. Assal which is sur­
rounded by incrustations of salt ( 1 60 m below sea
level).
Somali Republic North
CLIMATE
The climate is mostly dry, the rainfall increasing
from the coast inland, the southern coastal strip re­
ceiving between 50 and 1 00 mm and the northern
under 50; the coastal regions of the actual gulf re­
ceive 1 00-200 mm. The area around Goudah to the
north-east of Tadjoura receives 200-500 mm, the
500 being an estimate for the Dai area. Near L. Assal
the estimated rainfall is about 50 mm. Rainfall is
erratic from year to year as the figures for
Djibouti indicate:
Mean
Number
of years
M aximu m
Minimum
130
52
3 00
10
Obviously mean figures based on very few years
are scarcely a reliable guide. The available informa­
tion is given in full by G riffiths and Hemming
(1963). The monthly distribution of rain is as fol­
lows-January-narrow strip of the north coast
bordering the Bab-el-Mandeb Straights and the whole
area south-east of the south coast of the Tadjoura
Gulf is wet; February-whole area dry; March­
coastal areas on either side of the gulf, except ex­
treme north, wet; April-extreme southern border in­
cluding Aeroleh Plateau wet; May-whole area dry;
June-tip around L. Abbe wet; July-western third
of territory wet; August-western two-thirds of ter­
ritory wet; September-western half of territory wet;
October-whole area dry; November-small area in
south-east including Djibouti wet; December-whole
north-east area north of gulf and east of Tadjoura
wet, also the coastal part around Djibouti.
141
with areas of Suaeda monoica, Tamarix and so forth.
Further inland, save in the north-east, there are ex­
tensive areas of grass steppe much of it very poor
and subdesertic with Eremopogon joveolatus, Tri­
cholaena, Eragrostis, Panicum and A ristida spp.
together with Heliotropium pterocarpum, Blepharis
edulis and Cassia shrublets. To the north-east this
is replaced by true desert. Around the mountains of
Moussa· Ali on the northern boundary and Goudah
and Mabla on the northern edge of the gulf, areas of
denser vegetation occur including broken xerophilous
open woodland (Acacia spp. etc.), subdesert trees and
succulent scrub (Dracaena, Euphorbia, A loe, San­
sevieria and Caralluma spp.) and on the tops of the
first two, montane evergreen thicket and scrub (in­
cluding Olea africana, Ficus populijolia, Buxus
hildebrandtii, Carissa edulis, A cokanthera schimperi
and Sideroxylon aubertii). In the Dai area of Goudah
the extensive mists enable montane dry evergreen
forest to exist even where the rainfall might be
thought insufficient and this part of the territory
undoubtedly enjoys the pleasantest climate. The Dai
Forest is characterised by its massive Juniperus pro­
cera and in no other area of the territory are such
conditions repeated.
I have not yet had replies to my queries as to
possible existing conserved areas. It appears that
there are interesting plants in all the formations but
particularly on the slopes of Dai and this one
remnant of forest already recognised as an amenity
should be preserved. The discovery on its slopes of a
species of Cistus not previously known in Africa
shows that many other plants are likely to be dis­
covered.
REFERENCES
VEGETATION
The vegetation is zoned in the usual way. Around
the coast there are patches of mangrove swamp
(mostly A vicennia) and a strip of coastal formations
Griffiths, J. F. and Hemming, C. F., 1 963. A Rainfall Map
of Eastern Africa and Southern Arabia. - Nairobi.
Pichi-Sermolli, R. E. G., 1957. Una Carta Geobotanica dell'
Africa Orientale (Eritrea, Etiopia, Somalia). - Webbia, 1 3,
1 5-132.
S O M A L I R E PU B LIC N O RT H
C. F. Hemming
GEOGRAPHICAL SURVEY
Somaliland can be divided into two main physio­
graphic regions, comprising a coastal plain and an
uplifted plateau separated by an escarpment of vary­
ing height.
The coastal plain varies in width from 60 km in
the west to less than 1 km in the east. The wide
Acta Phytogeogr Suec 54
·
142
C. F. Hemming
western section of the coastal plain is covered with
sandy soil whereas much of the narrower section to
the east consists of raised beach deposits.
The plateau to the south reaches a maximum
height of nearly 2400 m near Erigavo just at the top
of the escarpment. The whole plateau dips gently to
the south east, the lowest point being only 450 m
above sea level.
The escarpment separating the coastal plain from
the plateau is only to be seen in an impressive form
in the east, while in the west it is poorly developed
but there is a wide zone of deeply dissected country
between the coastal plain and the plateau. The line
of the escarpment is also the line of the main water­
shed.
The stratigraphy of the country is such that rocks
of the Basement complex, limestones and anhydrites
are to be found both above and below the escarp­
ment. In the south east of Somaliland on the lower
parts of the plateau there are vast deposits of anhy­
drite which has been altered to gypsum. Much of this
area has poor saline soils and over most of the coun­
try the soils are generally immature and clearly show
their geological origins.
CLIMATOLOGICAL SURVEY
The best recorded feature of the climate is the rain­
fall and there are records for periods varying from 1
to 44 years for 50 stations.
On the coastal littoral the mean annual rainfall
varies from 57 to 1 83 mm. There is no clearly de­
fined wet season and rain may occur in any month
but in a really wet year the wettest months are No­
vember and December.
The inland edge of the coastal plain and the
broken hilly country below the plateau is somewhat
wetter with a mean annual rainfall between 1 00-250
mm, but sites very close to the foot of the scarpface
receive considerably more rainfall as they benefit
from the rain produced by the high ground above
(e.g. Laliss-mean annual rainfall 648 mm).
The highest part of the plateau is its northern
edge overlooking the coastal plain and along the edge
the mean annual rainfall is 66Q-725 mm. To the
southeast at lower altitudes the rainfall decreases
gradually to less than 1 00 mm in the Nogal Valley.
On the plateau there are two rainy seasons. The
main rains (S.W. Monsoon) from April to June and
the short rains (N.E. Monsoon) from October to
November. The further south one goes across the
plateau the more clear is the separation between these
two seasons.
Temperatures vary with altitude and in the coastal
Acta Phytogeogr Suec 54
plain during the hottest summer months mean max­
ima reach 42 ° C and mean minima 3 2 ° C. In the
coldest month (January) the mean maximum is 28 ° C
and the mean minimum is 2 1 ° C . The highest station
for which regular temperature records are available
is Sheikh ( 1 430 m) where mean maxima and minima
for the hottest month (June) are 3 1 o and 1 8 °C, and
those in the coldest month (January) are 2 1 ° and
9 ° C. In the highest areas of Juniperus forest there is
occasional frost.
GENERAL VEGETATION
This section raises once again the extreme difficulty
of producing a unified system of vegetation classi­
fication based solely upon the physiognomy. I note
that the A.E.T.F.A.T. list of terms has already been
approved and that it will be employed in the 2nd
edition of the vegetation map of Africa. Knowing the
vegetation of Somaliland reasonably well I have con­
sidered which of the available terms is best suited to
describe each of the zones that I have recognised in
my own survey of the vegetation of the area:
Mine
(Black & White)
A.E.T.F.A.T.
(Coloured)
1. Coastal plains
2. Sub-coastal plain
3. Acacia bussei open woodland
4. A. etbaica open woodland
5. Evergreen scrub
6. Juniperus forest
7. Haud-type mixed bush
8. Gypseous areas
Desert plains with scattered veg.
Deciduous sub-desert shrublands
Grass steppe with trees
Grass steppe with trees
Tropical sub-montane thicket
Forest dry montane
Grass steppe with trees
See below
1 . Desert plain with scattered vegetation (XIV A 1).
coloured orange and marked 1 .
This includes the whole of the Somaliland lit­
toral and the vegetation is sparse and low being con-·
centrated particularly along drainage lines. The vege-·
tation makes a mosaic as it changes with the smallest
change in the soil or drainage pattern.
In the western area, where the coastal plain is at
its widest the dominant plants are grasses, Panicum
turgidum and Lasiurus hirsutus and could be de­
scribed as a sub-desert steppe (a term not on the list
but possibly IX A 1 b) but this does not seem to be
intended for such a desertic area. The term steppe
has no adequate innuendo of climate.
In the area to the south east also coloured orange·
but labelled 2 on the attached map the vegetation is.
similar both in appearance and often in species.
l-lalophytes which are typical of coastal areas are
common. It could be marked as Herbaceous halo­
philous formations (XII) but I do not know what the
Somali Republic North
143
440
G
F
L
u
0
A
D
E
N
I< E Y·
I
Coastal area
(Orange,t)
Sub-coastal
A. e t baie a
(Yellow)
(Claret)
Evergreen
Juniper
A. bussei
Haud t ype
Gypsum .
(Green)
(Black)
la t
Or ng Z )
(Claret)
(C re )
( a
e,
.M F.
.
o No sHo ·
Scol�.miln
H
A
U
(ETHIOPIA)
D
Fig. ]. Somali Republic North. Vegetation types. The original map accompanying Mr. Hemming's account was coloured to dis­
tinguish his vegetation classification from that of AETFAT but also allowing both to be used. It has not been possible to publish
a coloured map but the colour has been added to the key in words. The area marked "see note below" was not visited by Mr.
Hemming but should probably be coloured claret.
committee have in mind for this class. Is it designed
for coastal areas? The term Herbaceous makes it
seem unsuitable.
2. Deciduous sub-desert shrublands (VU A), col­
oured yellow.
This includes the area that might loosely be de­
scribed as the upper coastal plains lying between the
foot of the escarpment and the true littoral areas.
Here the dominant genera are A cacia and Commi­
phora. Their form is generally low and widespread
e.g. Acacia edgeworthii.
3 . Grass steppe with trees (IX A 1 b), coloured
claret.
This seems to be the best term in which to include
the 3 main open woodland/ bush communities that
are found on the plateau.
The most northern community within this broad
group of zones is dominated by A cacia etba,ica and
receives a mean annual rainfall of 300-5 50 mm. The
associated grass is, or was, Chrysopogon aucheri var.
quinqueplumis. The whole area is very heavily over­
grazed and A loe megalacantha is on the increase.
The next community is dominated by Acacia bus­
sei which is characteristic of extensive areas of flat
sandy soils. Much of the woodland has been killed
by overgrazing of the grass and dead trees on bare
soil is a common sight. It represents the most de­
vastated community in the country.
The third community that I have included is the
"Haud-type mixed bush" which is very variable in
form between thickets to low open scrub. It covers
a vast area extending southwards for over 1 000 km
to northern Kenya. This community is very rich in
species and new ones have been found in consider­
able numbers in the last 20 years.
The term "Grass steppe with trees" would seem
the only possible one on the approved list but the
term "Thorn woodland" (VI) could be used for
A cacia bussei and A . etbaica, but as there are no
explanatory notes it is not possible to know what the
map committee have in mind.
Acta Phytogeogr Suec 54
144
C. F. Hemming
5. Evergreen scr�:�b, coloured green.
This is my name for a zone which not only exists
in Somaliland but is important over much of the
Ethiopian highlands and Kenya. I simply do not
know where it could be included in this classification,
unless in submontane Tropical thickets (Ill A 2)
which would seem to agree best with the first edi­
tion of the map though the word "evergreen" would
be more descriptive than "thicket". It would also
be valuable as a concept.
6. Juniperus forest (Dry montane forest) (I A 2 b),
coloured black.
This is - the Juniperus forest that occurs as rem­
nants on the high ground along the N edge of the
upland plateau. This forest is open and mixed in
species and includes Olea africana, Barbeya oleoides,
Sideroxylon spp. and many others.
ASSOCIATIONS . AND SPECIES ALREADY
PROTECTED
As far as I know the only area in which any degree
of protection has been attempted is in the Juniper
forests. Some other limited areas have been enclosed
and- been protected against grazing or only subjected
to limited grazing. Initial examination of such areas
has indicated that considerable improvement in the
vegetation occurs within a year or two even in the
most unpromising rocky sites (C. F. Hemming in
press).
Under the previous British Administration (Ordi­
nance No. 7 of 1 944) a Forests Ordinance was issued
under which specified areas could be declared as
''forests" and gr.azing. and felling could be control­
led or prohibited. In fact the restrictions finally ap­
.
plied only to the felling .of live trees and the dead
Juniperus, previously killed by forest fires, was cut
and sawn and some�imes exported. The forests, how­
ever, remained open to grazing. To stop this
throughout the forest would be both expensive and
politically difficult. It has in fact proved difficult
even to keep grazing stock out of the experimental
plantation and nursery areas.
FUTURE PROTECTION
The present policy of protecting the J uniperus pro- .
cera forests against felling of live trees whilst permit­
ting uncontrolled grazing does nothing to protect
other species nor does it allow regeneration of Juni­
perus or any other species with edible seedlings. The
shade flora of the forest has been reduced to
Acta Phytogeogr Suec 54
Hypoestes hildebrandtii which is unpalatable to
stock. In general all the high ground, bearing both
evergreen scrub or Juniperus forest, receives heavy
grazing as the lower and hotter areas dry out after
the rains.
The most southerly type of mixed vegetation
which forms part of the "Grass steppe with trees"
described above extends far into the Ethiopian Oga­
den and adjacent parts of southern Somali Republic.
In restricted localities in both countries there grows
Cordeauxia edulis Hemsl. It is a 1-2 m shrub with
edible · nuts which are very palatable and sell well in
the market:: T�e nuts are collected for sale and any
that remain to germinate are quickly eaten by grazing
stock. This species is disappearing quite rapidly and
should b e protected.
There is one site on the main N .-S. road through
the Mudugh Province from Belet Wein to Bosaso
where there is a good patch of Cordeauxia. If money
could be found this area could be enclosed and to­
tally protected and seedlings produced for planting
elsewhere. It has already been suggested that North­
ern Nigeria is interested and other similar dry areas
might also be so. This could be a valuable project
but possibly outside the scope of a flora protection
scheme of the type A.E.T.F.A.T. might envisage. In
similar areas Cordyla somalensis Gillett is also found.
This too has edible nuts and may be a useful pos­
sible export but it does not require protection.
In Somaliland itself I consider that there is one
possibility of an interesting forest reserve. In 1 960 a
road was under construction from Las Koreh on the
coast at 48 ° 1 2'E to H ubera ( 10 40'N, 48 29'E)
with a view to opening up the forest on the Ahl
Medo. The forest rangers at Erigavo told me that it
is in this area that the best preserved and finest
Juniper forest is to be found. I have no recent in­
formation, but if this road has been completed and
exploitation has started it should be possible for the
supervising staff to control a nearby protected area.
If the road has not been completed I consider that
the area is too far out in the blue for any such sug­
gestion to be taken seriously. In fact grazing pressure
here is much less than in many other · forest areas
because the slopes to the south appear to be in some
kind of rain shadow which means that there are wide
rocky areas with practically no available grazing to
be crossed before one reaches the forest. For a forest
reserve to remain a viable unit in the face of local
exploitation all round I consider it should cover at
least one square mile.
I am not in a position to give a list of individual
species in need of protection but there are certainly
several plants, which have been collected in the past
o
o
Somali Republic South
particularly on the high ground in Somaliland, which
I have not been able to find, e.g. Jatropha phillipsiae
Rendle and J. palmatijida Baker.
The former species comes from the Wagger Mts.
and the latter from the Golis Range and both were
collected by Lort-Phillips. I do not quote these two
species because I consider them to be particularly
worthy of preservation but merely because I have
1 45
looked for them both and failed to find them. Finally
I would add that any suggestions that are eventually
made to African Governments about the protection
of the flora should be tied to some economic advan­
tage to them e.g. export of seedlings, catchment area
protection etc. I think it probable that requests for
the preservation of "wild flowers" for their own
intrinsic value will not be taken seriously.
S O M ALI R E P U B L I C S O UT H
P. R . 0 . Bally
GEOGRAPHY
Somalia-South is the easternmost strip of Africa,
bounded by the Gulf of Aden in the North, with
its main coast-line running South along the Indian
Ocean down to the Kenya border. In the North and
East it borders on the former British Somaliland,
now described as Somalia North, and on Ethiopia.
The geographical and vegetational characters are
much more uniform than those of Somalia-North
and it is for this reason treated as a separate unit
here. It Hes between 1 2 oN and 1 o 40'S and between
4 1 o and 5 1 ° l 5'E and covers an area of 1 8 7, 200 sq.
miles.
Only in the extreme North, between Cape Guarda­
fui and the Nogal are mountains rising to 1 200 m;
they can be considered as the Eastern extension of
the far more important Golis- and AI Madu Range
of Somalia North. From there the land slopes south­
ward through plateau-lands to low-lying semi-desert
country; little of it is over 600 m, and to the South
of 8 most of it is less than 300 m above sea level.
The South of the country is traversed by two im­
portant rivers, the Webi Shebeli and the Juba, both
descending from the Ethiopian Highlands. In the
interior their course is lined by a narrow belt of
vegetation, predominently of Hyphaene, otherwise
the two rivers have little effect on the surrounding
semi-desert vegetation.
o
In its lower course the Webi Shebeli flows parallel
to the coast and almost reaches the mouth of the
Juba, but its waters are eventually lost in the sand
dunes.
Both rivers flood the plains occasionally as they
are nearing the coast, where large-scale irrigation
schemes are maintained by Italian enterprise.
1 0 - 6 8 1 557 Hedberg
Other rivers, the Daror and the Nogal are less
important and flow only intermittently.
GEOLOGY
The mountains in the North consist of basement
complex, gneiss and granite.
They rise from alluvial plains, consisting mostly
of quartz sand, very little lime with only traces of
organic matter, coloured vivid red, the so-called
"Haud"-soil which is of very low fertility.
Further South calcareous rock and gypsum beds
cover much of the surface, often ·conside-rably eroded.
Along the coast there is a considerable dune for­
mation, up to several km inland, many of them are
shifting dunes.
CLIMATE
The rainfall in the greater part of the country does
not exceed 3-6 in. ; in the Mescat Hills in the North
up to 1 0 in. have been recorded. In the South and
especially along the coast the rainfall is again more
important, but records are scarce. Mogadiscio, the
capital and main port has an average rainfall of 1 5
in. The rains fall mainly during the S.-W.-Monsoon
between May and September, except around Cape
Guardafui where the N.-E.-Monsoon brings heavier
rainfall in the winter months.
Average minimum temperatures fall to 21 o Centi­
grade on the coast and to possibly 5 ° Centigrade on
the AI Mescat Hills in the North. Average maxima
are 40 ° Centigrade on the coast and 33 °C in the
interior plains.
Acta Phytogeogr Suec 54
1 46
P. R. 0. Bally
�1§ Montane communities, undifferentiat e d
ID Coastal
forest savanna mosaic
¥� wooded steppe, w.thicket dumps (A
�:m Subdesert steppe, tropi_cal
type
���i p hora)
�
Fig. 1. Somali Republic South. Vegetation map.
VEGETATION
In the AI Mescat Hills of the North the vegetation is
similar to that of the neigbouring AI Madu Range in
Somalia North, with Juniperus-Olea-Celtis associa­
tion, but it is much more reduced through more
intensive human interference, i.e. requirements for
firewood, timber and grazing of livestock. On the
lower slopes Moringa aptera, Euphorbia noxia,
Adenium somalensis are typical, besides Boswellia
carteriana the resin of which is an important item of
export. Although the collecting of Boswellia resin
(frankincense) dates back to antiquity, there is no
evident diminution of the stands. The trees are
owned individually by families and they are not tap­
ped to excess. To cut down a Boswellia for any pur­
pose whatsoever is considered a criminal action.
-
On the red alluvial "Haud"-soil Commiphora­
A cacia scrub with Sesamothamnus spp. and Jatropha
ferox are dominant, and here occurs also Cordeau­
xia edulis, the Yeheb nut tree, although the latter is
diminishing rapidly owing to thoughtless exploita­
tion.1
Acta Phytogeogr Suec 54
Other plants of this region which are becoming
rare are Euphorbia longispina ·whose fiber, "kabo"
is used for making the Somali-wickerwork milk­
gourds, also Euphorbia carteriana which serves the
same purpose.
In the central portion of the country, where cal­
careous rock and gypsum are frequently on the sur­
face, the subdesert steppe dominates with Acacia tor­
tilis, A cacia paradoxa, Euphorbia matabelensis, Ja...
tropha ferox, Cassia longeracemosa•, Salvadora per­
sica, Erythrina rotundato-obovata, Albizzia oga­
densis. Among the succulents Caralluma speciosa,
Caralluma russellii, Edithcolea grandis, Dorstenia
crispa are conspicuous.
In the South towards the Kenya border where the
rainfall is heavier the vegetation becomes denser, the
clumps are often fr�nged with the shrubby Aloe
microdonta and A loe rabaiensis and gradually
merge into a more continuous bush -savanna which is
known as the coastal savanna mosaic type. In this
Southern region Euphorbia robecchii, a large ar­
borescent succulent species which extends from the
Ogaden in Ethiopia throughout the Southern Somali
Republic and Kenya down to Northern Tanzania is
particularly common. It is by far the largest tree of
the coastal savanna and almost the only one with a
straight bole; its timber is soft and by no means
durable, but it is well suited for the manufacture of
crates in which the produce of the extensive banana
plantations in the irrigated flood plains of the Juba
are shipped to Italy. In consequence of this use which
has been going on for many years the tree has al­
ready become locally scarce over a wide area round
Chisimaio, where the sawmill was established. Re­
generation is slow in semi-desert regions and cannot
possibly keep pace with the demand.
The littoral and the dunes present again a differ­
ent aspect. Here we find several species of Salsola,
Cadaba, Grewia villosa, the rare endemic Euphorbia.
giumboensis, Pedalium m urex, the beautiful Sticto­
cardia macalusoi and-apparently only in the dunes
near Merca-the large, yellow-flowered Caralluma
somalica.
In his "Flora Somala" I, 1 929, E. Chiovenda has
listed the plants known at the time for the various
regions and though they could be considerably am­
plified today by the inclusion of results of later ex­
peditions, they give a fair picture of the typical plant­
communities; they are closely related to those of the
neighbouring countries; there are links with the
1
See report: "Enquiry into the occurrence of the yeheb nut
(Cordeauxia edulis Hemsl.) in the Horn of Mrica."-Can­
dollea 2 1 : 1, pp. 3-1 1 , 1 966.
Somali Republic South
Floras of Arabia and Socotra, but there is also a
relatively high percentage of endemics.
The general impression which four separate jour­
neys through the country left in my mind is that in
most parts the pressure of the increasing population
and of their livestock is steadily growing and far
exceeds nature's regenerative faculties. My last jour­
ney through Somalia-South was in 1 954 ; in the
intervening 12 years very considerable changes have
occurred there in the political field and with the
departure of the British administrative staff all my
previous contacts have gone. Efforts to make new
contacts have failed so far.
147
S O M AL I E
(ex ongloise)
- -.
-- - 7
/
Ogoden / /
E TH I O P I E
As to rare or threatened plants I can only enumer­
ate a few in which I was particularly interested at the
time:
Cordeauxia edulis, edible nut, important item of the So­
mal's diet.
·
Conocarpus lancifolius supplies a valuable timber, exported
to Arabia.
Euphorbia noxia, used for making arrow poison.
Euphorbia carteriana, Euphorbia longispina, "kabo" fiber
used for making milk gourds.
Pseudolithos sp., an edible succulent found in the Nogal
region.
Notonia sp. aff. pendula (syn. Monadenium subulijolium
illiiil
§
Tot a l R e s e rve of t h e
Bubasci
Simple Reserve
Partial Reserve:Eiephanl ,
Girafle,Rhinoceros only
Partial Reserve: Rhinoceros
and Dibatag
Partial Reserve: Ost.rich only
Fig. 2. Somali Republic South. Game Reserves.
Chiov.).
Euphorbia migiurtinorum, Euphorbia giumboensis, Mona­
denium stellatum, all very restricted endemics, apt to disap­
pear if human interference brings about ecological changes.
PROPOSAL FOR FUTURE CONSERVATION
There are five fairly extensive game reserves in the
Southern half of Somalia South, but unlike those of
Kenya, they serve solely for the protection of certain
species of Game such as Elephant, Girafe, Rhino and
Ostrich. They are not closed against the free move­
ments of the nomadic inhabitants and their stock.
The Somal would not take kindly to interference
with his grazing rights and in Somalia the incentive
of tourism as a source of the National Income does
not obtain. However, if an appeal to the Somalia
Government for a Vegetation Reserve were to be
made with special reference to the case of Cordeau­
xia edulis, the economic aspect may tip the balance
in favour of such a scheme.!
The recommendation should be
(a) to close a block completely for an indefinite
time to allow for regeneration of the entire vegeta­
tion in the block.
The World Wild Life Fund, Morges, Switzerland offers
financial aid to any project aimed at protecting the habitat
of Cordeauxia edulis a point which should add considerable
weight to an appeal to the Somalia Government in the mat­
ter.
1
(b) to attempt propagation of Cordeauxia agricul­
turally in its habitat and in other likely places.
Similar plant reserves are recommended for other
parts of the country, in suitable localities with a
characteristic vegetation i.e. in the neighbourhood of
Chisimaio, Mogadisho, Galkayo, Obbia, Eil on the
principle of the "grazing reserves" which the British
Administration had started in Somaliland Protector­
ate at Burao around 1 940 on the initiative of Major
E. Peck. After only a few years of strict protection
from grazing and browsing stock, from charcoal­
burning, wood-gathering etc., an astonishingly thick
vegetation cover was formed, in which hitherto un­
suspected & unknown species had a chance to grow
to maturity.
Such reserves need not be large; they need not
exceed a square mile, but they should be fenced in
and strictly policed.
Larger areas would be difficult to keep inviolate,
for in the dry season, when grazing is scarce, nothing
could stop the Somal when trying to find fodder for
his stock.
This was seen repeatedly in Somaliland Protector­
ate when the Juniper-and other tree nurseries were
invaded by the herdsmen with their goats and sheep
as soon as the forest officer turned his back on them.
Such an uncomprehending attitude towards long­
term planning in agriculture or forestry arises from
Acta Phytogeogr Suec 54
148
H. A . Osmaston
the extremely hard conditions of life with which the
population has to contend; the individual cannot af­
ford to consider anything but to keep himself and his
stock alive from day to day.
Those conditions may thus prove serious obstacles
to any project of nature-conservancy in Somaliland
and in all countries where similar marginal condi­
tions of life prevail.
U GA N D A
H. A . Osmaston
GEOGRAPHY
VEGETATION
Although a small country, Uganda includes wide va­
riations in landscape, climate and vegetation. The
oldest features of the landscape are the remnants,
some still flat-topped and thickly lateritised, of the
Tertiary surface which extended over most of tropi­
cal Mrica. Into this is incised a drainage system
which formerly flowed westwards into the Congo,
but which was then beheaded by the development
of the Western Rift Valley and by the accompanying
crustal warping which ponded back Lake Victoria
and the many broad swampy valleys which now sur­
round it, feeding the Nile which broke out to the
north. At this time too the massif of the Ruwenzori
(5 1 09 m) was faulted up at the side of the Rift, and
large volcanoes such as Mount Elgon (43 1 0 m)
erupted. Though lacking a seaboard the country has
many lakes and permanent rivers.
Floristically the country lies in an interesting posi­
tion at the junction of the East African region with
the Sudan-Guinea savannas and the Congo-West
African forests, besides having fine examples of the
Afro-alpine flora on three separate groups of moun­
tains over 4000 m. The forests are small and re­
stricted to the higher rainfall belts along the north­
west shore of L. Victoria, on the shoulder of the
Rift and on the mountains; most of the country is
covered with fire-climax savanna and cultivation,
though in the absence of fire and man at least half
of this would soon develop into some type of forest
or moist thicket, while in much of the rest, except
the seasonal swamps, the eventual climax would
probably be woodland or dry thicket.
Macrofossil and pollen evidence however shows
that there have been considerable changes in the
vegetation during the last 1 5 ,000 years, some due to
volcanic activity, others to changes in climate. There
is also historical evidence of important changes dur­
ing the last 80 years: some due to the growth of
human and cattle populations which have led respec­
tively to the development of forest/ savanna/ cultiva­
tion mosaics in place of forest in Buga·nda, and of
thorn woodland, thicket and succulent shrubland in
place of savanna in Karamoj a; others due to sleeping
sickness or rinderpest having driven out the humans
or cattle, with results of an opposite kind. Attempts
to pre�erve wild animals have in the Murchison Falls
National Park resulted in the rapid destruction, by
elephants and fire combined, of the trees in the
former Terminalia tree-savanna, and of the remnants
of Khaya-Cynometra forest; while in the Queen
Elizabeth Park the hordes of hippopotamus elimi­
nated the Themeda grassland, thus · preventing fires
and permitting the spread of thicket over the · bare
and eroding soil. Therefore when · the protection of
existing vegetation is proposed it is important to re­
member that it may not be the present climatic or
CLIMATE
Since the majority of the country lies at 1 000-1 500
m altitude (none is below 600 m), temperatures are
-moderate, and since the Equator passes through
Uganda the seasonal variation is slight; over most of
the country the annual mean lies between 1 6 ° and
24 ° C, decreasing on the mountains to 0 ° C at about
4300 m. There are glaciers on the Ruwenzori, be­
sides abundant traces both there and on Mt. Elgon of
more extensive Pleistocene glaciations. Rain is
brought mainly by winds from the east, and falls in
either one or two rainy seasons, the dry season
being severe only in the northeast where there are
five consecutive months with less than 25 mm of
rain in each, though much of Uganda has no month
with less than this. Mean annual rainfalls of 1 0001 500 mm are widespread, the minimum being 400
mm in the extreme northeast . and the maximum
about 2500 mm on the Ruwenzori and Mt. Elgon.
Acta Phytogeogr Suec 54
Uganda
Table 1 . Land cover in Uganda
Table 2. The national parks
Area km2
Well drained woodland and
savanna
Seasonally swampy savanna
Thicket, shrubland and steppe
Altimontane heath, moorland
and grassland
Forest, including Arundinaria
Permanent freshwater swamp
Cultivated crops and houses
14�
1 1 4, 000
20,000
1 9, 5 00
Km2
% of land
and swamp
57
10
9.75
Queen Elizabeth Park
Murchison Falls Park
Kidepo Park
1 ,900
3,600
1 ,200
Total
6,700
(or 3 . 3 % of the land and swamp area of Uganda)
500
8 , 000
1 0,000
28 ,000
Total lan d and swamp
Open water
200,000
36,000
Total
236,000
.25
4
5
14
1 00
edaphic climax. If it is seral after biotic, climatic or
.
geomorphological changes, or is a climax controlled
by fire or grazing, or is a relict, its maintenance and
regeneration may present considerable problems.
ASSOCIATIONS AND PLANTS ALREADY
PROTECTED
Some plant associations and species are already protected by the National Parks Ordinance and Bylaws,
by the Forests Ordinance and Rules and by tribal
tradition. The first only apply within the three Natio­
nal Parks which consist mainly of savanna and
woodland at 600-1 200 m, with some thicket and
semi-deciduous forest.
No vegetation may be damaged, burnt or removed
without the permission of the warden, and this is
adequately enforced on human visitors. The animal
residents however ignore it, and it was some years
before the evidence of gross changes in vegetation
and soil forced the Parks' Trustees and the public
into acceptance of planned control rather than mere
protection. Recently schemes for the reduction of
both elephant and hippo populations have been
started, and NUTAE (Nuffield Unit of Tropical
Animal Ecology, based in the Queen Elizabeth Park
and linked with Cambridge and Makerere Universi­
ties) is investigating the basic problems of scientific
management; the correct use of fire is accepted as a
powerful and economical tool for both the protection
of forest edges and the maintenance of grassland. It
is however inevitable that the continual need to at­
tract tourists and the local public, and to justify
economically, politically and scientifically the reten­
tion of these large areas, will always necessitate pri­
ority being given to the animals rather than the vege-
·
tation which serves to provide essential grazing and
browsing and a picturesque background. Unless
specially fenced botanical reserves are made, it is
possible that the more palatable plants will be exter­
minated even when the animal populations are more
strictly limited. Subject to this there are good pro­
spects for the preservation of several associations,
particularly:
Savanna: Hyparrhenia, Hyparrhenia-Combretum,
Hypa,rrhenia-Balanites, Hyparrhenia-Borassus, Hy­
parrhenia-A cacia, Themeda, Imperata.
The Lannea-Acacia shrub savanna in the Kidepo
Park is easily disturbed by overgrazing, becoming
shrubland and finally A cacia-Euphorbia thicket, so
that to maintain any balance between these existing
communities will be difficult.
Thicket: Euclea-Euphorbia dawei, Capparis to­
mentosa-Turraea robusta, Acacia-Harrisonia-Com­
bretum aculeatum.
Forest: The Maramagambo Forest (300 km2),
where Cynometra alexandri is locally dominant, is
likely to be maintained successfully, but the future of
the other small remnants such as the Rabongo Forest
and those on the dry Karamoja mountains hangs in
the balance, as does that of the Terminalia wood­
land.
Aquatic: Cyperus papyrus, A eschynomene, Pistia.
The Forests Ordinance and Rules apply both to
Forest Reserves and to unreserved public land (which
is practically all other land outside Buganda, the only
part where there are substantial areas of private
land).
Table 3. Analysis of forest reserves
Altimontane
Forest
Thicket, woodland and savanna
Total
500
6 , 5 00
7 , 5 00
1 4, 5 00
(or 7.2 % of the land and swamp area of Uganda)
Acta Phytogeogr Suec 54
1 50
H. A. Osmaston
Thus all the altimontane vegetation is reserved; all
the forest except 1 500 km2 on private land in Bu­
ganda; and widely distributed samples of most of the
other types of vegetation.
Protection is given in three ways: first by reserv­
ing certain species, normally the most valuable tim­
ber trees such as Chlorophora, Khaya, Entandro­
phragma, whi1c h may not be cut or damaged without
a licence in any reserve or on public land ; second by
forbidding commercial harvesting of forest produce
without a licence, though local inhabitants can take
unreserved forest produce for their own domestic
use and clear forest on public land; third by forbid­
ding unlicensed cultivation, burning or grazing within
forest reserves. These are enforced by a numerous
and well trained staff, though constant vigilance is
necessary to prevent encroachment by farmers into
the reserves, while outside them protection can only
be a delaying action to prevent wanton waste when
land is cleared for cultivation.
Although the reservation of individual species was
primarily intended for those of economic importance,
it has (in the absence of other legislation) been used
to protect Encephalartos spp. which occur in a few
very restricted localities in Uganda.
Outside the forest reserves the private forests of
Buganda are rapidly being cleared for coffee plant­
ing, while less conspicuous but more extensive areas
of savanna are being cleared and cultivated on ever­
shortening fallow rotations.
Within the forest reserves the vegetation, though
protected from the public, is subject to the efforts of
the Forest Department to make them more produc­
tive and meet the threatened timber shortage. This
involves first harvesting the existing timber, then
repeated weeding of the forest with hormonal arbori­
cides to free the natural or planted young crop from
competition by unwanted species. In the savanna fire
protection or controlled burning aims at densifying
the tree and shrub growth, while in both forest and
savanna small but increasing areas are being cleared
and replanted with exotic species. Although these
activities will eventually result in considerable modi­
fications to many of the forests, even the more pro­
ductive ones are only being worked on cycles of 3 080 years so there is no imminent danger of complete
loss in most associations, and in the less productive
ones, reserved mainly for river catchment protection,
no silvicultural work could be economically possible
for a long time. In recognition of these dangers how­
ever, particularly the risk of losing possibly useful
species, the Forest Department has already set aside
nature reserves varying in size from several ha to
several km2 within many of the larger forest reserves
Acta Phytogeogr Suec 54
for purposes of research, with the intention of pro­
tecting both the vegetation and the smaller animals
from all interference. Most of the principal associa­
tions of moist evergreen and semi-deciduous forest in
Uganda are represented, e.g. Parinari excelsa, Pipta­
deniastrum-Uapaca, Piptadeniastrum-A lbizzia-Celtis,
Celtis-Chrysophyllum, Cynometra-Celtis, but the
savanna and montane vegetation is less well covered.
In the past tribal tradition has given potent protec­
tion to individual trees, species and communities,
for example a magnificent specimen of Pterygota
mildbraedii, the Witch Tree of Mubende Hill; Chlo­
rophora excelsa, regeneration of which was tradi­
tionally encouraged in banana gardens in Busoga;
Butyrospermum which is left for the sake of its
oilseeds when savanna is cleared for farming; and
various sacred groves of forest species in savanna
country. Such traditions are fading, but if carefully
fostered and directed they could effect protection
in circumstances where legislation is unenforceable.
OTHER ASSOCIATIONS REQUIRING
PROTECTION
A good start has thus been made on establishing
nature reserves in the forests but more are needed to
cover other associations, particularly
Podocarpus-Baikiaea swamp forests on the Lake Victoria
shore;
Mitragyna swamp forest in Mengo;
Cynometra forest in the Seinl.iki valley in Bwamba;
Strychnos-Khaya forest in the Zoka;
Montane forests on Ruwenzori, Elgon and the Virunga Mts.
(including Arundinaria).
The outlook for savanna, woodland, thicket,
shrubland and steppe is less promising. Some types
are protected in the National Parks; representative
areas of many of the others occur within forest re­
serves, but the future of these, often comprising hilly
water-catchments, is uncertain, for their natural
wood productivity is so low that eventually they may
have to be afforested with exotic species such as pines
or assigned to some other controlled land use. In this
connection the growing evidence that African ante­
lopes can utilise the natural savanna grazing more ef­
ficiently than, and are more productive than do­
mestic cattle, suggests that extensive ranching under
semi-natural conditions may become important. De­
spite these uncertainties, nature reserves should be
selected now in forest reserves, in sufficient numbers
to allow for a few losses, and incluqing particularly
Terminalia glaucescens woodlands of Acholi;
Isoberlinia-Daniellia woodland's of West Nile;
Uganda
Vitex-Phyllanthus woodlands of Acholi;
Butyrospermum savanna;
Oxytenanthera thicket;
Vellozia-Euphorbia on inselbergs in Labwor;
Cyathea dregei in old mine workings on Oruha Hill, Mwenge.
The associations listed in "The vegetation
Uganda" provide a basic list to be covered.
of
Outside the Parks and forest reserves, cultivation,
overgrazing and tsetse clearing are making insidious
and increasing inroads upon the savanna, but grazing
is notoriously difficult to control, and the vast area
of savanna leads to misguided complacency; even in
Karamoja where overgrazing is ruining the country,
there is no prospect of effective control. Therefore
though the establishment of nature reserves in asso­
ciations not represented in parks or forest reserves
is urgent, it faces considerable difficulties, and the
creation of new forest reserves to cover them would
not be easy since the country's official Forest Policy
Statement makes no specific provision for such ac­
tivities. Fortunately some of the more interesting
communities such as the Sphagnum bogs of L. Na­
bugabo and the Syzygium bogs of Kigezi have so far
survived intact, but the ready accessibility of L. N a­
bugabo and the considerable amount of research al­
ready done there make this an obvious choice for the
first Uganda Nature Reserve outside the limits of
existing Forest Reserves and National Parks.
The desirable size of nature reserves is variable;
in grassland a few ha might suffice ; in mixed forest
1 km2 ; when it is desired to cover a number of re­
lated associations (e.g. the altitudinal zones on a
mountain, where there is also less competition from
productive forestry) an entire valley or ridge unit
amounting to tens of km2 should be reserved. Much
larger areas are of course useful but present problems
of protection and j ustification.
The management of associations known to be
seral is a difficult problem. For instance Maesopsis
often occurs as only a single generation in the suc­
cession from grassland to forest, so that if a nature
reserve with this species is to be left undisturbed as
a study in succession, then eventually it will contain
no Maesopsis. The aims of each reserve must there­
fore be clearly defined in a written plan at the outset,
and in savanna definite instructions must be given
1 51
as to the intensity of burning or grazing that is to be
permitted or effected.
If nature conservation is to endure it must ulti­
mately be based on popular consent and support; the
sooner this is encouraged and crystallised into the
form of tradition, the easier conservation will be. To
effect this two types of reserve are needed: first that
intended for research, where access is restricted ; sec­
ond that intended for educational and propaganda
purposes, where access is encouraged by paths and
labelled plants.
CONCLUSIONS
Uganda is fortunate in that most plant associatiOns
and species are represented on land already within
National Parks or Forest Reserves, though probably
in the former and certainly in the latter it will be
necessary to designate particular areas as Nature
Reserves for the preservation of the vegetation and
smaller animals. In the parks this presents no admi­
nistrative difficulties. In the forest reserves the Forest
Department already has the will, the organisation
and the technical skill to select and protect them (as
it has already started to do), with little expenditure,
administrative difficulty and political disturbance
compared with those involved in setting up a new
agency. An addition is however required to the
Forest Policy, formally laying this responsibility
upon the Forest Department, and then suitable minor
amendments to the Forests Ordinance and Rules to
permit further control of access and activities in
areas designated as Nature Reserves.
The establishment of an advisory committee is
also desirable to determine policy, to aid in the selec­
tion and management of the reserves, and to coordi­
nate research. It would include representatives of the
National Parks, the Forest Department, NUTAE,
Makerere College scientific departments, and perhaps
even AETFAT.
REFERENCES
Langdale-Brown, I., Osmaston, H. A. and Wilson, J. G., 1964.
The vegetation of Uganda. - Govt. of Uganda, 159 pp.
Osmaston, H. A, 1 962. The vegetation of the National Parks.
- In: Uganda National Parks Handbook, 120 pp.
Acta Phytogeogr Suec 54
K E N YA
G. Ll. Lucas
GEOGRAPHY
Kenya lies across the equator from approximately
5 ° N to 5 ° S at the coast, but only 1 ° S at Lake
Victoria, stretching from approximately 34 ° E to
41 °E and covering 2 1 9,789 sq. miles (569,258
km2). It is a land of contrasts due in the main to the
considerable altitudinal range which is from sea level
to the permanent snows of Mount Kenya at 5 1 94 m
a.s.l.
The country is divided north to south by the great
Eastern Rift Valley of Recent and Tertiary volcanic
origin. Its floor is often thousands of feet below the
rift walls which are about 50 miles (80 km) apart.
To the east of the rift lies a long mountain chain,
from the Mathews Range {2375 m) in the north
through Mount Kenya (5 1 94 m) and the Aberdare
Mountains (3994 m) to the Kitui Hills in the south.
Between this range and the sea lies a vast peneplain
dropping from about 1 200 m to the coastal strip
which is about 30 miles (48 km) wide and which
rises to about 250 m. This vast plain is broken up
here and there by inselbergs, hills and even moun­
tains. It consists mainly of Basement System rocks,
Palaeozoic and Mesozoic sediments, l ava plains and
a large eastern region of Quarternary sediments.
Along the western side of the Rift Valley lies a range
of mountains running southwards from the Suk
Mountains through the Mau es·carpment (both
around 3000 m) to the Tanzanian border. The grani­
tic Suk Mountains are surrounded by Basement Sy­
stem rocks, while the Mau is of Tertiary and recent
volcanic origin, as is Mount Elgon (43 2 1 m) on the
Uganda border. To the south of Mount Elgon and
west of the Mau escarpment lies another small rift
valley running E.N . E. to W.S.W. called the Kavi­
rondo Gulf an extension of Lake Victoria at 1 1 34 m.
On either side of this rift lies a mixture of Granites,
Bukoban, Nyanzian and Kavirondo rock systems.
Thus this chequer-board pattern created by the geo­
logy and allied soil types modifies some of climatic­
ally controlled vegetation belts.
CLIMATE
The weather patterns normally associated with the
convergence zone between the Trade Winds of both
hemispheres and its general mo·;e�r1e:-�. :.re highly
modified by the high mountains and Lake Victoria.
Acta Phytogeogr Suec 54
The south-east monsoons also influence coastal re­
gions. This gives a highly complex rainfall pattern
for the ·country as a whole and in fact the rainfall
varies between 5-1 00 in. ( 1 25-2540 mm) per year,
falling in one or two separate soosons. The amount
and duration also varies considerably year to year and
therefore rainfall probability maps are of most use
when considering aspects of vegetation. These maps
show that about 72 % of the country has less than
20 in. {508 mm) of rain a year, which is below
the limit for settled agriculture. Therefore only
2 8 % of Kenya's surface receives a reliable 20 in.
(508 mm) or more a year and this is where the 8 . 6
million population i s concentrated. It i s here that the
need for conservation is greatest. With the regions of
higher rainfall spread as they are over such a con­
siderable altitudinal range, many vegetation types
occur in what is a relatively small area. However,
these same areas contain the largest and most dense
concentrations of population, so one has to be parti­
cularly sure of the case for conservation.
Temperatures are a little more predictable
throughout the region being almost completely de­
pendent on altitude, with some modification on the
coast and lake shores by cooling breezes and a warm­
ing effect caused by air flowing from Ethiopia and
Sudan. Taking the temperature and rainfall patterns
and superimposing the main soil types, a very com­
plex pattern of opportunities for diverse vegetation
forms occurs. These are fully utilised in Kenya as
can be seen from the map (Fig. 1).
VEGETATION
As vegetation is a major topic in itself only a very
brief summary of types is given. This is based on a
modified form of Trapnell and Langdale-Brown's
system af vegetation types. The draft A.E.T.F.A.T.
sequence distributed to contributors does not really
cover in realistic terms some of the vegetation types
normally recognised in East Africa, although the
general sequence is followed as closely as is practic­
able.
I. Forest, and II. Forest-Grassland Mosaic. These
are shown together on the map as no large forest
patches now exist due to man's quest for timber, fire­
wood and agricultural land. The forest may be di­
vided into lcwland and montane forms with wetter
and drier types of each. The lowland moist forms are
Kenya
1 53
40
� forest & ForestpGrassland Mosaic
EJ IJushland&Thicket
fBl Mangrove
W Semidesert
[[[I]li] Wooded-Grassland &Grassland
11111 Altimontane Formations
- Fresh Water Swamp
Fig.
1 . Kenya. Vegetation types.
to be found in the coastal strip and Lake Victoria
region. It will be seen from the examples of Kakamega
and Shimba forests that the woody constituents are
very different, although covered by the same head­
ing. The lowland dry forests are semideciduous and
are to be found around Nairobi e.g. Karura Forest,
and include some of the coastal forests. Both are
dominated by Brachylaena hutchinsii, and sometimes
by species of Manilkara. Montane moist forests are
found in the Aberdare Mountains and Mount Kenya;
these are dominated by Ocotea usambarensis and Po­
docarpus milanjianus etc. The montane dry forests
are usually dominated by Juniperus procera and Po­
docarpus species associated with Olea. These are also
to be found on Mount Kenya, Mount Elgon, the
Mau escarpment, Masailand mountains and the
Chyulu hills etc.
Ill. Thicket and Bushland. The term thicket has
been expanded to cover bushland which is so char­
acteristic of large tracts of Kenya. A term in fact
used by Trapnell and Greenway, and as such i:J.-
J
Miles O
I I
50
100
I I I I I I I
eludes part of A.E.T.F.A.T. VII (sub-desert shrub­
lands).
Bushland consists of land covered by more than
50% shrubs and small trees growing closely together.
The trees are usually of bushy habit branching from
near the base with an average height between 1 0 to
30 ft (3-9 m). The ground cover is usually of grass
but this is severely limited by surface erosion. This.
region grades slowly into the semi-desert of Northern
Kenya as can be seen from Fig. 1 . Derived bushland
is to be found around many coastal and inland
forests.
Species of Acacia and Commiphora form the
dominants while Euphorbia species occur nearer the
coast. Typical bushland is a well known sight to all
those who travel the Nairobi-Mombasa road with
widely scattered A dansonia digitata in the basic
Acacia-Commiphora mixture. Many genera dominate
the derived forms, which occur from the coast to the
highlands.
IV. Mangrove. The coastal mangrove swamps of
Acta Phytogeogr Suec 54
G. Ll. Lucas
1 54
/
/'
/
'
I
...., ...,
I
'
'
- - ...... - ...... _ /
'
.,.\
I
I
'
I
/
/
/
/
/
/
�
,\
\
:::::t�:}
�
lliilliiiiil
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HH��ln�
National Parks
Forest Reserves
National
& Local Reserves
Areas of Dense Cultivation
...
Government Plan 1966-70
T
'Other Recomendations
Miles
0
I
I I I
50
100
I I ! I I I
Kenya form a very important forestry asset. They
are typical of the whole East African coast and a
general description will be found under the Conser­
vation proposals.
V. Woodlands, and VI. Thorn Woodlands. These
are small in comparison with Tanzania but being at
the northern limit of distribution are of particular
interest. The basic dominants are Brachystegia spi­
ciformis, with Afzelia quanzensis and Julbernardia
magnistipulata; they are coastal in distribution and
can be seen in the Shimba hills and patches parallel
to the coast to a point just north of Malindi.
The Thorn woodlands are made up of A cacia
species; at higher altitudes these are A . abyssinica
and A . lahai. These are probably derived from
forest. At lower and intermediate altitudes stands of
A. polyacantha subsp. campylacantha and A. xantho­
phloea and A . tortilis subsp. spirocarpa can be found,
to qualify in this section.
VII. Semi-desert (sub-desert shrublands can be
Acta Phytogeogr Suec 54
Fig.
2. Kenya . Existing and proposed
conservation areas. 8:1 = Mutomo Re­
serve (1 ° 50 ' S-3 8 ° 1 3 ' E; cp. p. 1 64).
found under this heading and under Ill which covers
the plants of taller stature). Semi-desert in Kenya is
where the woody species are dwarf shrubs and bushes
widely spaced from one to another with a non-exist­
ent ground cover except in the rainy season or
where water is available through drainage channels
and alluvial flats. Small Acacia mellifera, A. senega!
and A. tortilis subsp. spirocarpa are characteristic
along with species of Commiphora; many other
genera are represented including Euphorbia, Ja­
tropha, Boscia, Sansevieria, Balanites. As has been
pointed out already these regions grade slowly into
bushland.
IX. Grasslands and wooded grasslands. This term
is used by Greenway but is covered by Trapnell and
Langdale-Brown under savannas. In Kenya they are
divided into the coastal strip and the inland regions
surrounding the forests. Many types can be distin­
guished by their dominants. Good examples of Com­
bretum-Terminalia woodland are to be found at the
Kenya
coast, e.g. south of Kwale and Mida, species of
Hyparrhenia forming the grass layer. A cacia domi­
nated wooded grassland is to be found in the black
clay and flood plains as well as riverine alluvium.
A cacia drepanolobium, one of the galled species is
a typical dominant. Parts of southern Kenya come
into this section, the dominants are A cacia gerrardii,
A . seyal and A . nilotica subsp. subulata with The­
meda as the grass layer. Derived A cacia wooded
grassland can be found where some types of bush­
land have formerly existed, and patches can be found
throughout Kenya.
Grassland in Kenya is to be found in the upland
regions where it is dominated by Themeda triandra,
Exotheca abyssinica and Pennisetum schimperi.
Derived grassland may be found in most suitable
areas but is of little interest in the present context.
X. A ltimontane formations. These isolated com­
munities have attracted a great deal of phytogeogra­
phical interest, clearly described by Fries and Fries,
Hedberg etc. under the heading of Afro-alpine vege­
tation, they are only superficially described under the
Aberdare National Park conservation section. These
mountain top communities all over Africa hold so
many links with the past, and yet so little is docu­
mented comprehensively.
XI. Fresh water swamps. The swamps of Uganda
eclipse those of Kenya and although the Lorian
swamp is prominently shown on the map it is of a
seasonal nature worthy of research, as little is known
about it.
XIV. Desert. This remote little known area in
northern Kenya is a rock desert unique in East
Africa, grading with the semi-desert regions.
PLANT ASSOCIATIONS ALREADY
PROTECTED
Game conservation in Kenya is well over fifty years
old and although the approach was on a trial and
error basis, it laid a solid foundation for Kenya's
often enviable position in matters of African Conser­
vation. It is "game" to a large extent which has
served as the stimulus to create National Parks with
all the protection this implies. However, it is quite
remarkable that it is only in the last fifteen years or
so that the value of the habitat has been recognised
and only recently that research has begun into the
relationship of the animal with its habitat.
The conservation of plant associations or even
individual species can be proposed on aesthetic,
scientific and many other grounds. However, they
have most chance of success if they are commer-
1 55
cially attractive either in their own right as tourist
attractions e.g. the Mount Kenya and Aberdare Na­
tional Parks where the scenery is the attraction, or
luckily from our point of view as habitats for at­
tractive game animals. In this latter situation careful
control of both animals and habitat is vital, as will be
seen later.
Another factor now entering more and more into
consideration is the educational aspect of such re­
serves, from primary school level to fully fledged
research teams studying one of the many thousands
of field problems still outstanding.
Kenya's Government has been and is aware of the
tourist interest in its game and scenery, and has
created some very fine National Parks. More are
promised in the Government plan 1 966-1 970. The
latter will be dealt with both under this heading and
under proposed reserves.
Nairobi National Park (A)
This Park on the capital's outskirts at present covers
some 44 sq. miles ( 1 14 km2) but it is hoped that
this will be increased considerably so that all the
migrant game herds will be protected, more especially
their feeding and watering grounds. During drought
conditions the Park at present becomes heavily over­
stocked and the vegetation inevitably suffers. The
National Plan hopes for the purchase of a further
10 sq. miles approximately by 1 970. One hopes that
further areas will be added later.
As the oldest Park more work on the vegetation
etc. has been carried out and a reasonably compre­
hensive species list has been published. The vegeta­
tion which survives contains a rather poor, drier
semi-evergreen forest on the western border. The
dominants are Croton megalocarpus, Schrebera alata,
Brachylaena hutchinsii and Olea africana. The
riverine vegetation is usually dominated by Acacia
xanthophloea and some A. kiYkii as well as Ficus
sycomorus. There are areas called "groves" by
Verdcourt which are dominated by A cacia species.
Where water is not readily available in the rocky
valleys and gorges, Thicket has developed, the domi­
nants being Croton dichogamus, Acacia brevispica,
Lippia javanica, Haplocoelum foliolatum. The Bush­
land grades into Grassland with scattered remnant
shrubs and trees. The grass cover is very variable
dependent on the severity of grazing. Almost half the
Park has blackcotton soil with a characteristic grass
cover of Pennisetum mezianum, Themeda triandra,
Bothriochloa insculpta and Digitaria macroblephara
with scattered A cacia drepanolobium. Over.grazing
and burning has had an obvious effect on the basic
pattern and careful management must be maintained.
Acta Phytogeogr Suec 54
1 56
G. Ll. Lucas
Many small and interesting communities are also to
be found in the Park but cannot be dealt with here.
It is interesting but sad to note how with increas­
ing size of Park detailed knowledge diminishes; a
sign of nothing more than lack of funds and staff to
carry out this fundamental work.
Tsavo National Park (B)
This is the largest Park of over 8034 sq. miles
(20,808 km2), situated in the middle of the vast
A cacia-Commiphora bushland. The region supports
the most impornant game population in Kenya, par­
ticularly elephants. Problems of over-grazing and
browsing have occurred in recent years to the obvi­
ous detriment of the tree species, particularly Adan­
sonia digitata. The elephant-habitat relationship is to
be studied over the next three years with the aid of a
Ford Foundation grant. The Government in its de­
velopment plan notes the need for "basic research
into such questions as optimum population size, ef­
ficient means of control and economic techniques of
restoring and conserving the vegetative environ­
ment". It has, however, been unable to give this
statement financial support; one hopes that research
will be done in time! Although the vegetation is being
heavily attacked, and rainfall is low, many interesting
species are to be found. Besides the dominant Com­
miphora and A cacia species there are many less com­
mon and even new genera. The permanent water
sites in the Park support a rich and narrow riverine
forest characterised by Hyphaene coriacea.
A berdare National Park (C)
228 sq. miles (590 km2) in area, the Park at present
covers a large portion of the higher regions of this
mountain range. Its limitations have been recognised
and the Government Plan describes how it is to be
extended with other improvements particularly along
the northern border. - The development plan states
that this is to "include in the Pa_r:k a more repre­
sentative section of the indigenous flora".
For brevity Mount Kenya National Pa·rk (D) is
included in the following vegetation survey. Firstly
a little on the background of the Park. At present the
boundary is set at 1 1 ,000 ft (3 3 5 3 m) but the govern­
ment plan aims to reduce this to 1 0,500 ft (3200 m),
so making the area to about 268 sq. miles (694 km2).
Both Parks are renowned for their scenic beauty
and therefore their vegetation is of prime importance.
The Aberdare Park's boundary drops well below
8000 ft (2450 m) in some places. This means that
the Montane Forest belt with its Montane Rain
Forest zone, the Bamboo zone and Hagenia-Hyperi�
cum zone along with the "Alpine" belt and the
Acta Phytogeogr Suec 54
Ericaceous belt with the Ericaceous Shrub zone and
Moorland zone are all within the protection of the
boundary. This area has been discussed in various
works mainly from the phytogeographical aspect,
constituent species are not listed, but the whole re­
gion is in need of an authenticated list of plant
species.
The Mount Kenya National Park starting at
1 1 ,000 ft and rising to over 1 7,000 ft (5 1 8 1 m)
contains the spectacular "Alpine" belt with the
three zones recognised by Fries & Fries. This. covers
the Senecio brassica zone, the Senecio keniodendron
zone and the "Nivale" zone where only a few hardy
flowering plant species survive along with mosses and
lichens. The overall beauty with the strange giant
Senecios, Lobelias and giant heathers cannot fail to
impress and attract the tourist. Tourists mean money
for maintenance and one hopes research facilities.
PROPOSED AREAS FOR PROTECTION BY
NATIONAL PARK STATUS
Shimba Hills (E)
These are proposed as a National Park by the De­
velopment Plan so that it may become the counter­
part of the Nairobi National . Park for Mombasa
tourists. It is mainly proposed on account of its
faunal interest, notably Sable Antelope, but its vege­
tation is also of great importance. The Kwa Shimba
region is typical lowland rain forest with some of the
following dominant species, Sterculia appendiculata,
Chlorophora excelsa, and Memecylon verruculosum.
There are a considerable number of woody species
and those which have been authenticated are recorded
in check-list 1 (p. 1 60). This list also shows the un­
described species awaiting attention. The bio-geo­
graphic links are of the utmost importance and in­
terest to all biologists but the overall beauty and
richness of the vegetation will be the tourist's greatest
source of pleasure. The vegetation of the region has
been written up by both Dale and Moomaw and so
is not discussed further here. Howev.er, it must be
made clear that the open patches of A ndropogon­
Hyparrhenia grassland with what appears to be its
recolonisation by forest, as well as the Brachystegia­
Ajzelia woodland patches should also be included in
the proposed National Park boundary, in order to
preserve the whole fascinating ecological system.
Marine National Park (F)
The Government Plan includes a tentative proposal
for a Marine Park with perhaps the inclusion of
Kenya
some of the historical coastal monuments as well as
part of the coastal hinterland.
This is an ideal opportunity to cover two further
types of vegetation in need of National Park protec­
tion. Firstly a part (as large as possible) of the
Arabuko-Sokoke National Forest as this is lowland
evergreen dry forest, dominated by Cynometra web­
beri, Manilkara sulcata and Brachylaena hutchinsii.
The region also has the Brachystegia-Afzelia
woodland which could be included. Poor and rather
patchy rain forest dominated by Sterculia and
Chlorophora also occurs in the area surrounding
Mida Creek. A region in fact where a park would be
of greatest interest covering the various vegetation
types previously described as well as the Mida ar­
chaeological site.
The second type of vegetation that could be
brought within the same Park's boundary is that of
mangrove swamp. East African swamps have pro­
vided timber for local and Arab use for many cen­
turies and will continue to do so, but a region un­
cropped would provide a most interesting and valu­
able research area. The mangrove swamps have been
adequately described by Dale and so only a few of
the dominant species are listed here. They are Rhi­
zophora mucronata, Sonneratia alba, A vicennia
marina, Bruguiera gymnorrhiza, Ceriops tagal, Lum­
nitzera racemosa, Heritiera littoralis.
In this way it would be possible within one park
to show the Marine life, the Mangrove swamps, the
archeological interests and a most interesting cross­
section of forest-woodland types.
The Government Plan indicates an intention to
look into the possibility of establishing four further
National Parks, viz. :
1 . Marsabit Mountain, this th-ey say is a strong
candidate for conversion from National Reserve sta­
tus. The flora of the Marsabit region is only poorly
represented in Herbaria, but the isolation of this
mountain with its strong Ethiopian links is of par­
ticular importance. It affects the weather of the
whole countryside around and if a sector of this
countryside could be included, a complete range
from montane forest to desert would be covered
within one boundary.
2. Lake Rudolf. The north-east shores of the lake
have been proposed as a Park. This is a most in­
teresting area well suited to comparative ecological
surveys.
3. Ol-Donyo Sabuk. Rising from the plains to the
east of the rift valley, this attractive and interesting
reserve will provide an easily accessible research
facility near Nairobi, as well as being a scenic and
game animal attraction.
1 57
4. Maunt Elgon. At present a Nature Reserve it is
being considered for National Park status. This
would ensure the safety of the high mountain vegeta­
tion. As the second highest mountain in Kenya the
phytogeographical importance cannot be overstressed
as there is an unusual Angolan link, besides the ve­
getation belts already described for other regions. At
lower altitudes fine stands of Podocarpus gracilior
forest exist and should be included within the bound­
ary.
There are over 5240 sq. miles ( 1 3 ,562 km2) of
State Forests and Forests Reserves. Although the re­
serves are afforded some protection by the forest
statutes the Forest Department has not the powers
to protect them against all forms of depredation. The
aims of forestry are in the best interests of the main­
tainance of economic and financially productive
forests, on the one hand, and this necessitates con­
siderable disturbance from timber cutting and re­
planting etc . , but on the other hand there are re­
gions where the forests are maintained for water
catchment purposes, and here the aims of the conser­
vationist are served admirably, and some of these
attractive reserves exist in many parts of Kenya.
Game Reserves whether National or run locally
by the district council very often are not protected
sufficiently to conserve vegetation. Costs of main­
tenance are often high so that research is almost
unconsidered. All such areas are in need of basic
research before recommendations can be made on
conservation:, with a view to elevating them to Na­
tional Park status, or in suggesting the best support
that can be given.
In a paper of · this size it is impossible to give
either detailed information or discuss fully the im­
plications of reserving areas under National Park
status, but two main points must be made. Successful
National Parks, i.e. those which attract the tourist
must remain the first aim of the Park Trustees, but
allowance must be made in some cases for parks
which are not economic but are of the utmost scien­
tific or aesthetic importance. Secondly, to maintain
animal populations successfully it is vital to maintain
their habitats first and although this is a bitter lesson
well understood in Kenya, it must be emphasised for
the whole of Africa.
Many suggestions and recommendations made by
the Government Plan overlapped with draft sugges­
tions to be made in this paper and these have been
incorporated where appropriate, but three further
Parks are suggested for urgent consideration.
Mrima Hill Forest (G)
This fine coastal forest is typical Lowland Rain
Acta Phytogeogr Suec 54
1 58
Fig.
G. Ll. Lucas
3. Somewhere in Kenya the forest is being destroyed every day.
forest and is of a type once probably widespread in
the coastal strip and now nearly all destroyed. Some
of the dominants are Sterculia appendiculata, A ntia­
ris usambarensis and Newtonia paucijuga which may
be found elsewhere, but there are in addition many
new and as yet undescribed species to be found in­
cluding two Uvariodendron species and species of
Desmos, Drypetes and Diospyros. Verdcourt has
pointed out that there are three distinct floristic ele­
ments here-species of the East African coastal for­
ests (in relic patches all along the coast), a lowland
rain forest element linked to that of the Usambaras,
Ulugurus and Gazaland, e.g. Didymosalpinx norae,
and an endemic element. The appended list based on
collections at Kew with a few additions shows the
wealth of woody species present. These two major
points of interest alone make such a region of vital
importance to the biologist and not only the botanist.
Each new collection from this region seems to
turn up species not previously recorded from Kenya
and this in itself is a most telling indicator of the
Acta Phytogeogr Suec 54
state of original research in what are supposedly
well-known areas !
Kakamega Forest (H)
This forest is unique, from the Kenya viewpoint it is
the only remaining West African type Tropical Rain
Forest. On the continental scale it is the most east­
erly point of the West African-Congo type forest
with affinities not only in the plant kingdom but
with birds, mammals and insects. There are at least
ten species including such giants as Entandophragma
angolense, A ningeria altissima, and the smaller
Cordia millenii and Maesopsis eminii which are to be
found in this forest and no other in Kenya. The
dominant species include amongst others Olea wel­
witschii, Fagara macrophylla, Chrysophyllum albi­
dum and Celtis durandii. A list of woody species
authenticated by herbarium material is to be found in
check-list 2 (p. 1 63), it shows how incomplete our
information is.
The population pressure in this region is particu-
Kenya
larly severe but the need for this remarkable forest to
be conserved in its entirety so that it may remain a
viable unit is of prime importance for the future
understanding of plant populations in Kenya and
even Africa as a whole.
National Park status gives complete protection,
and for educational purposes it might be thought too
strong a measure, or a misuse of the term; this is an
administrative problem but whatever the term used to
cover the educational reserves _it must have written
into its terms of reference complete control over
human and, in fact, any form of activity within the
boundary.
Karura Forest (K)
This Crown Forest so near Nairobi's University Col­
lege recommends itself for research purposes from all
biological sciences. The fact that it still survives is a
great credit to the Forest Department, however, it
really needs the complete protection of National Park
status. The forest contains the remarkable Compos­
ite, Brachylaena h utchinsii as one of the dominant
trees along with Croton megalocarpus and Caloden­
drum capense etc. Although these may be found in
other lowland dry forests in Kenya there are ele­
ments of a moister riverine forest type such as New­
tonia buchananii and the unusual and rare Uvario­
dendron anisatum (type locality), which link this for­
est to some extent with parts of the Meru forests
and not other Nairobi relic patches.
In conclusion it must be said that if and when all
the Government Plans outlined here along with the
other suggestions incorporated are implemented and
made reality, there will be many small areas often
not more than a few acres that will merit complete
protection for one or other of their biological inter­
ests. Each time it will be based on that "funda­
mental", the habitat and its vegetation. One hopes
that enlightened opinion will always be present to
champion this most vital cause.
ACKNOWLEDGEMENTS
The introductory paragraphs on geography and climate are
based on the excellent papers in E. W. Russell's "The Na­
tural Resources of East Africa". The two maps are also adapted
from this work.
1 59
I am greatly indebted to my colleagues at Kew and in
Kenya for their most valu able assistance in the preparation
of this paper.
REFERENCES
Carcasson, R. H. A preliminary survey of the Zoogeography
of African Butterflies, E. M. Wildlife Journal Vol. 2, p. 1 22
(1 964).
Dale, I. R. and Greenway, P. J. Kenya Trees and Shrubs
(1961).
Dale, I. R. The Woody Vegetation of the Coast Province of
Kenya, I.F.I., Institute Paper 18 ( 1 9 39) .
Fries, R. E. and Fries, Th. C. E. Phytogeographical re­
searches on Mount Kenya & Mount Aberdare, Svenska
Vetensk.Akad. Handl. Ill, 25 ( 1 948).
Glover, P. E. An Ecological Survey of Kenya Masailand,
Roneo, no date.
Greenway, P. J. A Provisional Classification of East African
Vegetation, Typescript (1943).
Griffiths, J. F. Climatic Zones of East Africa, E. Af. Agri.
Journal, p. 179, Jan. (1 958).
He dbe rg, 0. Vegetation Belts of the East African Mountains,
Svensk. Bot. Tids. 45, p. 140-202 (195 1).
- Afroalpine Vascular Plants, Symbolae Bot. Upsalienses
15, 1 ( 1 957).
Huxley, J. The Conservation of Wildlife & natural hab:tats
in Central & East Africa, U.N.E.S.C.O. (1961).
I.U.C.N., Publications new series No. 1 , Conservation of
Nature & Natural Resources in modern African States,
Arusha Conference Report ( 1 963).
Kenya Government Development Plan 1 966-1970, paragraphs
3 1-35 (1966).
- Hunting Map 1 : 1 ( 1 965).
- National Parks (and formerly Royal National Parks of
Kenya) Annual Reports.
- Wild Life Resources and the National Parks, Trustees
National Parks of Kenya (1955).
- Wild Life Society. Annual Reports.
Moomaw, J. C. A Study of the Plant Ecology of the Coast
Region of Kenya ( 1 960).
Petrides, G. A. Kenya's wild-life resources and the National
Parks.
- A land use map of Kenya, E. Af. Ag. Journ. 23, p. 265
(1958).
Russell, E. W. Editor, The Natural Resources of East Africa
(1962).
Simon, N. and others. Nature Reserves, a letter to the Chief
Conservator of Forests, Kenya (1 958).
Simon, N. Between the Sunlight and the Thunder (1962).
Trapnell, C. G. and Griffiths, J. F. The Rainfall-Altitude
Relation, its Ecological significance in Kenya, E. Af. Agri.
Journal, Apr. p. 207 (1961).
Verdcourt, B . Notes from the East African Herbarium XI.
Kew Bull. 14, p. 348 ( 1 960).
Wild flowers in the Nairobi National Park, Vegetation by
B. Verdcourt; Plant list by E. African Herbarium (1 962).
Acta Phytogeogr Suec 54
1 60
G. Ll. Lucas
CHECK -LIST 1
Preliminary list of Woody Species to be found in the Kenya Coastal Forests. Key: A = Arabuko-Sokoke forest; M = Mrima Hill;
S = Shimba Hills. Occurrence marked by -.
Species
Sclerochiton boivinii C.B.CI.
Sclerochiton holstii (Lindau) C.B.Cl.
Whitfieldia elongata (Beauv.) C.B. Cl.
Dracaena steudneri Engl.
Lannea amaniensis Engl . & Krause
Lannea stuhlmannii (Engl.) Engl.
Ozoroa reticulata (Bak f.) R. & A. Fernandes
Sorindeia obtusifoliolata Engl.
Annona senegalensis Pers.
Artabotrys monteiroae Oliv.
Asteranthe asterias (S. Moore) Engl. & Diels
Desmos sp. nov.
Enneastemon fornicatus. (Baill.) Exell
Monodora grandidieri Baill.
Polyalthia sp. nov.
Popo wia t;ichoearpa Engl. & Diels
Uvaria acuminata Oliv.
Uvaria dielsii R. E. Fr.
Uvariastrum sp. nov.?
Uvariodendron sp. nov. 1 .
Uvariodendron sp. nov. 2.
Xylopia arenaria Engl.
Conopharyngia elegans (Stapf) Stapf
Conopharyngia holstii (K. Schum.) Stapf
Hunteria zeylanica Gard. ex Thw. var. africana (K. Schum.) M. Pichon
.Mascarenhasia variegata Britten & Rendle
Rauvolfia mombasiana Stapf
Saba fiorida (Benth.) Bullock
.Schizozygia coffaeoides Baill.
Cussonia zimmermannii Harms
Markhamia .zanzibarica (Boj. ex DC.) K. Schum. & Thonn.
Rhodognaphalon schumannianum A. Robyns
Ehretia bakeri Britten
Ehretia litoralis Giirke
Commiphora zimmermannii Engl.
Notobuxus obtusifolia Mildbr.
Afzelia quaf!zensis Welw.
Cassia afrofistula Brenan var. afrofistula
.Cassia singueana Del.
Cynometra webberi Baker
Dialium orientale Bak. f.
Erythrophleum guineense G. Don
Gigasiphon macrosiphon (Harms) Brenan
.Julbernardia magnistipulata (Harms) Troupin
Paramacrolobium coeruleum (Taub.) J. Leonard
Trachylobium verrucosum (Gaertn.) Oliv.
Maerua triphyl/a A. Rich. var. pubescens (Klotzsch) De Wolf
Cassine aet�iopica Thunb .
Cassine stuhlmannii (Loes.) Blakelock
Maytenus buchananii (Loes.) W i lczek
Maytenus mossambicensis (Klotzsch) Blakelock
var. ruber (Harv.) Blakelock
Maytenus ovatus (Wall. ex Wight & Arn.) Loes. var ovatus f. pubescens
(Schweinf.) Blakelock
Maytenus undatus (Thunb.) Blakelock
Pleurostylia africana Loes.
Combretum schumannii Engl.
Pteliopsis myrt(folia (Laws.) Engl. & Diels
Quisqualis littorea (Engl.) Exel l
Terminalia kilimandscharica Engl.
Brachylaena hutchinsii Hutch.
Byrsocarpus boivinianus (Baill.) Schellenb.
Byrsocarpus orientalis (Baill.) Bak.
Connarus sp.
Acta Phytogeogr Suec 54
A
M
s
Family
Acanthaceae
Acanthaceae
Acanthaceae
Agavaceae
Anacardiaceae
Anacardiaceae
Anacardiaceae
Anacardiaceae
Annonaceae
Annonaceae
Annonaceae
Annonaceae
Annonaceae
Annonaceae
Annonaceae
Annonaceae
Annonaceae
Annonaceae
Annonaceae
Annonaceae
Annonaceae
Annonaceae
Apocynaceae
Apocynaceae
Apocynaceae
Apocynaceae
Apocynaceae
Apocynaceae
Apocynaceae
Araliaceae
Bignoniaceae
Bombacaceae
Boraginaceae
Boraginaceae
Burseraceae
Buxaceae
Caesalpiniaceae
Caesalpiniaceae
Caesalpiniaceae
Caesalpiniaceae
Caesalpiniaceae
Caesalpiniaceae
Caesalpiniaceae
Caesalpiniaceae
Caesalpiniaceae
Caesalpiniaceae
Capparidaceae
Celastraceae
Celas traceae
Celastraceae
Celastraceae
Celastraceae
Celastraceae
Celastraceae
Combretaceae
Combretaceae
Combretaceae
Combretaceae
Compositae
Connaraceae
Connaraceae
Connaraceae
Kenya
Species
Santaloides splendida (Gilg) Schellenb. ex Engl.
Dichapetalum defiexum (Klotzsch) Engl.
Dichapetalum ruhlandii Engl.
Dichapetalum sp. nov.
Tetracera boiviniana Baill.
Tetracera litoralis Gilg
Diospyros mespiliformis Hochst. ex DC.
Diospyros· natalensis (Harv.) Brenan
Diospyros sp. nov.
Euclea fruticosa Hiern
Acalypha neptunica Muell. Arg. var. pubescens Hutch.
A lchornea laxiflora (Benth.) Pax & Hoffm.
Antidesma membranaceum Muell. Arg.
Cleistanthus holtzii Pax
Drypetes natalensis (Harv.) Hutch. var. leiogyne Brenan
Drypetes sp. nov.
Erythrococca kirkii (Muell. Arg.) Prain
Macaranga usambarica Pax & K. Hoffm.
Mallotus oppositifolius (Geisler) Muell. Arg.
Oldfieldia somalensis (Chiov.) Milne-Redhead
Phyllanthus discoideus (Baill.) Muell. Arg.
Phyllanthus stolzianus Pax & K. Hoffm.
Ricinodendron heudelotii (Baill.) Pierre ex Pax
Securinega virosa (Roxb. ex Willd.) Baill.
Suregada zanzibariensis Baill.
Grandidiera boivinii Jaub.
Ludia sessiliflora Lam.
Rawsonia lucida Harv. & Sond.
Scolopia stuhlmannii Warb. & Gilg
Garcinia livingstonei T. Anders.
Harungana madagascariensis Lam. ex Poir.
Psorospermum febrifugum Spach
Vismia orientalis Engl.
Apodytes dimidiata E. Mey. ex Arn.
Mostuea brunonis Didr. var. brunonis
Strychnos scheffieri Gilg ex Bak. f. var. scheffieri
Lawsonia inermis L.
Acridocarpus zanzibaricus, (Boj. ex Loud.) A. Juss.
Gossypioides kirkii (Mast.) Hutch.
Thespesia danis Oliv.
Memecylon amaniense (Gilg) A. & R. Fernandes
Memecylon melindense A. & R. Fernandes
Memeeylon mouririifolium Brenan
Memecylon verruculosum Brenan
Lo voa swynnertonii Bak. f.
Pseudobersama mossambicensis (Sim) Verdc.
Trichilia emetica Vahl
Turraea kaessneri Bak.f. (floribunda Hochst.)
Turraea mombassana Hiern ex C. DC.
Turraea nilotica Kotschy & Peyr.
Tric/isia sacleuxii (Pierre) Diets
Acacia adenocalyx Brenan & Exell
Acacia clavigera E. Mey. subsp. usambarensis (Taub.) Brenan
Acacia mellifera (Vahl) Benth. subsp. mellifera
Acacia senega/ (L.) var. senega/
Albizia adianthifolia (Schumach.) W. F. Wight
Albizia glaberrima (Schumach. & Thonn.) Benth. var. g/abrescens
(Oliv.) Brenan
Albizia versicolor Welw. ex Oliv.
Dichrostachys cinerea (L.) Wight & Arn.
Entada pursaetha DC.
Ne wtonia paucijuga (Harms) Brenan
Parkia jilicoidea Welw. ex Oliv.
Tetrapleura tetraptera (Sebum. & Thonn.) Taub.
Antiaris toxicaria (Rumph. ex Pers.) Lesch.
Bosqueia phoberos Baill.
Chlorophora excelsa (Welw.) Benth. & Hook.f.
Craterogyne kameruniana (Engl.) Lanjouw
Eugenia sp. nov. aff. E. aschersoniana
Syzygium guineense (Willd.) DC.
Brackenridgea zanguebarica Oliv.
1 1 - 68 1 557 Hedbery
A
M
s
161
Family
Connaraceae
Dichapetalaceae
Dichapetalaceae
Dichapetalaceae
Dilleniaceae
Dilleniaceae
Ebenaceae
Ebenaceae
Ebenaceae
Ebenaceae
Euphorbiaceae
Euphorbiaceae
Euphorbiaceae
Euphorbiaceae
Euphorbiaceae
Euphorbiaceae
Euphorbiaceae
Euphorbiaceae
Euphorbiaceae
Euphorbiaceae
Euphorbiaceae
Euphorbiaceae
Euphorbiaceae
Euphorbiaceae
Euphorbiaceae
Flacourtiaceae
Flacourtiaceae
Flacourtiaceae
Flacourtiaceae
Guttiferae
Hypericaceae
Hypericaceae
Hypericaceae
lcacinaceae
Loganiaceae
Loganiaceae
Lythraceae
Malpighiaceae
Malvaceae
Malvaceae
Melastomataceae
Melastomataceae
Melastomataceae
Melastomataceae
Meliaceae
Meliaceae
Meliaceae
Meliaceae
Meliaceae
Meliaceae
Menispermaceae
Mimosaceae
Mimosaceae
Mimosaceae
Mimosaceae
Mimosaceae
?
Mimosaceae
Mimosaceae
Mimosaceae
Mimosaceae
Mimosaceae
Mimosaceae
Mimosaceae
Moraceae
Moraceae
Moraceae
Moraceae
Myrtaceae
Myrtaceae
Ochnaceae
Acta Phytogeogr Suec 54
1 62
G. Ll. Lucas
Species
Ochna thomasiana Engl. & Gilg
Jasminum angustilobum Knobl.
Borassus aethiopum Mart.
Hyphaene parvula Becc.
Angylocalyx braunii Harms
Cordyla africana Lour.
Craibia brevicaudata (Vatke) Dunn subsp. brevicaudata
Dalbergia bracteolata Baker
Lonchocarpus bussei Harms
Millettia lasiantha Dunn.
Tephrosia vogelii Hook. f.
Carpolobia goetzei Giirke
Securidaca longepedunculata Fres.
Cassipourea euryoides Alston
Hirtella zanzibarica Oliv.
Parinari curatellifolia Plancb. ex Bentb. subsp. mobola (Oliv.)
R. A. Grabam
Canthium glaucum Hiern
Canthium guenzii Sond.
Canthium hispidum Bentb.
Canthium keniense Bullock
Canthium pallidum (K. Sebum.) Bullock
Canthium zanzibaricum Klotzscb
Chasa/ia umbraticola Vatke
Cremaspora trif/ora (Tbonn.) K. Sebum.
Crossopteryx febr!fuga (Afzel. ex G. Don) Bentb.
Didymosalpinx norae (Swynnerton) Keay
Gardenia posoquerioides S. Moore
Heinsenia diervilleoides K. Sebum.
Heinsia crinita (Afzel.) G. Taylor
Heinsia densiflora Hiern
Jxora sp. nr. odorata Hook. non Spreng.
Oxyanthus goetzei K. Sebum.
Pavetta mangallana K. Sebum. & K. Krause
Pavetta shimbensis Brem.
Pavetta tarennoides S. Moore
Pavetta trichosphaera Brem.
Pavetta uniflora Brem.
Polysphaeria parvifolia Hiern
Psychotria lauracea K. Sebum.
Psychotria holtzii (K. Sebum.) Petit
Psychotria amboniana K. Sebum.
Rothmannia fischeri (K. Sebum.) Bullock ex Oberm.
Rothmannia whitfieldii (Lindl.) Dandy
Rytigynia amaniensis (K. Krause) Bullock
Rytigynia oligacantha (K. Sebum.) Robyns
Tricalysia myrtifolia S. Moore
Uragoga macrophylla K. Krause
Xeromphis nilotica (Stapf) Keay
Xeromphis sp. nov.
Clausena anisata (Willd.) Hook. f. ex Bentb.
Tee/ea trichocarpa (Engl.) Engl.
Toddalia asiatica (L.) Lam.
Trimeria bakeri Gilg
A llophylus pervillei Blume
Blighia unijugata Baker
Chytranthus obliquinervis Radlk.
Deinbol!ia borbonica Sebeff. forma glabrata Radlk.
Lecaniodiscus fraxinifo/ius Baker
Majidea zanguebarica Kirk ex Oliv.
Melanodiscus oblongus Radlk.
Pancovia hildebrandtii Gilg
Inhambanella henriquesiana (Engl. & Warb. ex Engl.) Dubard
Malacantha alnifolia (Baker) Pierre
Manilkara sansibarensis (Engl.) Dubard
Manilkara sulcata (Engl.) Dubard
Mimusops aedificatoria Mildbr.
Mimusops fruticosa Bojer ex DC.
Pachystela brevipes (Bak.) Engl.
Odyendea zimmermannii Engl.
Solanum zanzibarense Vatke var. vagans (Wrigbt) Bitter
Acta Phytogeogr Suec 54
A
M
s
Family
Ochnaceae
0/eaceae
Palmae
Palmae
Papilionaceae
Papilionaceae
Papilionaceae
Papilionaceae
Papilionaceae
Papilionaceae
Papilionaceae
Polygalaceae
Polygalaceae
Rhizophoraceae
Rosaceae
Rosaceae
Rubiaceae
Rubiaceae
Rubiaceae
Rubiaceae
Rubiaceae
Rubiaceae
Rubiaceae
Rubiaceae
Rubiaceae
Rubiaceae
Rubiaceae
Rubiace(u
Rubiaceae
Rubiaceae
Rubiaceae
Rubiaceae
Rubiaceae
Rubiaceae
Rubiaceae
Rubiaceae
Rubiaceae
Rubiaceae
Rubiaceae
Rubiaceae
Rubiaceae
Rubiaceae
Rubiaceae
Rubiaceae
Rubiaceae
Rubiaceae
Rubiaceae
Rubiaceae
Rubiaceae
Rutaceae
Rutaceae
Rutaceae
Samydaceae
Sapindaceae
Sapindaceae
Sapindaceae
Sapindaceae
Sapindaceae
Sapindaceae
Sapindaceae
Sapindaceae
Sapotaceae
Sapotaceae
Sapotaceae
Sapotaceae
Sapotaceae
Sapo taceae
Sapotaceae
Simaroubaceae
Solanaceae
Kenya
A
Species
Cola clavata Mast.
Cola minor Brenan
Cola uloloma Brenan
Dombeya praetermissa Dunkley
Leptonychia usambarensis K. Schum.
Nesogordonia parvifolia (M. B. Moss) R. Capuron
Sterculia appendiculata K. Schum.
Gnidia latifolia (Oliv.) Gilg
Synaptolepis kirkii Oliv.
Grewia ca/ymmatosepala K. Schum.
Grewia truncata Mast.
Grewia vaughanii Exell
Celtis wightii Planch.
Trema orientale (L.) Bl.
Clerodendrum glabrum E. Mey.
Vitex mombassae Vatke
Rinorea elliptica (Oliv.) 0. Kuntze
Rinorea gazensis (Bak. f.) M. Brandt
CHECK-LIST 2
Preliminary list of woody species to be found in the Ka­
kamega Forest (Kenya).
Acanthaceae: Acanthopale pubescens (Lindau) C. B. Cl. ;
Acanthus arboreus Forsk.; Brillantaisia nyanzarum Burkill;
Macrorungia pubinervia (T. Anders.) C. B. Cl. Agavaceae:
Dracaena afromontana Mildbr. Alangiaceae: Alangium chi­
nense (Lour.) Harms. Annonaceae: Artabotrys nitidus Engl.;
Monodora myristica (Gaertn.) Dun.; Uvariopsis congensis
Robyns & Ghesq. Apocynaceae: Funtumia latifolia (Stapf)
Stapf ex Schlecht. Araliaceae: Cussonia arborea Hochst. ex
A. Rich.; Polyscias ferruginea (Hiern) Harms. Bignoniaceae:
Kigelia aethiopum (Fenzl) Dandy; K. moosa Sprague; Mark­
hamia platycalyx Sprague; Spathodea nilotica Seem.; Stereo­
spermum kunthianum Cham. Boraginaceae: Cordia abyssinica
R. Br.; C. millenii Baker ; Ehretia cymosa Thonn. Caesal­
piniaceae: Cassia (iidymobotrya Fres.; Piliostigma thonningii
(Schumach.) Milne-Redhead. Celastraceae: Maytenus senega­
lensis (Lam.) Exell. Combretaceae: Combretum molle R. Br.
ex G. Don. Compositae: Vernonia amygdalina Del . ; V. auri­
culifera Hiern. Ebenaceae: Diospyros abyssinica (Hiern) F.
White. Euphorbiaceae: Bridelia micrantha (Hochst.) Baill.;
Croton macrostachyus Hochst. ex Del.; C. megalocarpus
Hutch.; C. sylvaticus Hochst.; Drypetes gerrardii Hutch.;
Erythrococca atrovirens (Pax) Prain; E. bongensis Pax; Le­
pidoturus laxijlorus Benth.; Macaranga kilimandscharica
Pax; Neoboutonia macrocalyx Pax; N. melleri (Mi.ill. Arg.)
Prain; Sapium ellipticum (Hochst.) Pax; Securinega virosa
(Roxb. ex Willd.) Baill. Flacourtiaceae: Dovyalis macrocalyx
(Oliv.) Warb.; Oncoba spinosa Forsk. ; Rawsonia lucida Harv.
& Sond. Guttiferae: Garcinia livingstonei T. Anders. Hy­
pericaceae: Harungana madagascariensis Lam. ex Poir.
Icacinaceae: Apodytes dimidiata E. Mey. ex Arn. Labiatae:
Achyrospermum parviflorum S. Moore. Lauraceae: Beil­
schmiedia sp. Loganiaceae: Anthocleista vogelii Planch.;
Nuxia congesta R. Br. ex Fresen.; Strychnos usambarensis
Gilg. Meliaceae: Entandrophragma angolense (Welw.) C.
DC. ; Trichilia emetica Vahl; Trichilia strigulosa Welw. ex
C. DC.; Trichilia volkensii Gtirke; Turraea holstii Gtirke. Me­
lianthaceae: Bersama abyssinica Fres. subsp. paullinioides
(Planch.) Verdc. Mimosaceae: Acacia abyssinica Hochst. ex
Benth. subsp. calophylla Brenan; Acacia monticola Brenan
& Exell; Albizia grandibracteata Taub . ; A. gummifera (J. F.
M
s
163
Family
Sterculiaceae
Sterculiaceae
Sterculiaceae
Sterculiaceae
Sterculiaceae
Sterculiaceae
Sterculiaceae
Thymelaeaceae
Thymelaeaceae
Tiliaceae
Tiliaceae
Tiliaceae
Ulmaceae
Ulmaceae
Verbenaceae
Verbenaceae
Violaceae
Violaceae
Gmel.) C. A. Sm. ; Entada abyssinica Steud. ex A. Rich.
Moraceae: Antiaris toxicaria (Rumph. ex Pers.) Lesch.; Bos­
queia phoberos Baill.; Ficus capensis Thunb . ; F. exasperata
Vahl; F. natalensis Hochst . ; F. storthophylla Warb.; F.
thonningii Blume; Morus lactea (Sim) Mildbr. Myrsinaceae:
Embelia schimperi Vatke; Maesa lanceolata Forsk. Ochna­
ceae: Ouratea bukobensis Gilg; 0. densiflora De Wild. &
Dur. Olacaceae: Strombosia scheffleri Engl. Oleaceae: Olea
welwitschii (Knobl.) Gilg & Schellenb. Palmae: Raphia mon­
buttorum Drude. Papilionaceae: Craibia brownii Dunn;
Erythrina abyssinica Lam. ex DC. Proteaceae: Faurea spe­
ciosa Welw. Rhamnaceae: Maesopsis eminii Engl. Rhizopho­
raceae: Cassipourea ruwensorensis (Engl.) Alston. Rosaceae:
Pygeum africanum Hook. f. Rubiaceae: Canthium gueinzii
Sond.; C. venosum (Oliv.) Hiern; Chasalia cristata (Hiern)
Brem.; Coffea eugenioides S. Moore; Craterospermum lauri­
num (Poir.) Benth.; Heinsenia diervilleoides K. Schum.; Lep­
tactina platyphylla (Hiern) Wernham; Mussaenda erythro­
phylla Schum. & Thonn. ; Oxyanthus speciosus DC.; Pavetta
ternifolia (Hook. f. ex Oliv.) Hiern; Rothmannia urcellijormis
(Schweinf. ex Hiern) Bullock ex Robyns ; Rutidea smithii
Hiern; R. syringoides (Webb) Brem.; Rytigynia butaguensis
(De Wild.) Robyns; R. neglecta (Hiern) Robyns; Vangueria
apiculata K. Schum. ; V. linearisepala K. Schum. Rutaceae:
Clausena anisata (Willd.) Hook. f. ex Benth.; Fagara macro­
phylla Engl.; F. mildbraedii Engl.; Fagaropsis angolensis
(Engl.) Dale; Teclea nobilis Del.; Toddalia asiatica (L.) Lam.
Samydaceae: Casearia battiscombei R. E. Fries; Trimeria
bakeri Gilg. Sapindaceae: Allophylus macrobotrys Gilg;
Aphania senegalensis (Juss. ex Poir.) Radlk.; Blighia uniju­
gata Baker; Dodonaea viscosa (L.) Jacq. Sapotaceae: Aninge­
ria altissima (A. Chev.) Aubr. & Pellegr.; Bequaertiodendron
oblanceolatum (S. Moore) Heine & Hemsley; Chrysophyllum
albidum G. Don; Manilkara butugi Chiov. ; Pachystela brevi­
pes (Bak.) Engl. Solanaceae: Solanum aculeastrum Dunal; S.
giganteum Jacq. Thymelaeaceae: Englerodaphne subcordata
(Meissn.) Engl. Tiliaceae: Triumfetta macrophylla K. Schum.
var. ruwenzoriensis (Sprague) Sprague ex Hutch. Ulmaceae:
Celtis ajricana Burm. f.; C. durandii Engl.; C. mildbraedii
Engl.; Chaetacme aristata Planch. ; Trema orientale (L.) Bl.
Verbenaceae: Clerodendrum buchholzii Giirke; C. melano­
crater Gtirke; C. myricoides (Hochst.) R. Br. ex Vatke;
Lantana trifolia L.; Premna angolensis Gtirke; Vitex doniana
Sweet; Vitex jischeri Gtirke. Violaceae: Rinorea poggei Engl.
Acta Phytogeogr Suec 54
1 64
P. R. 0. Bally
THE MUTOMO HILL PLANT SANCTUARY
IN KENYA
P. R. 0. Bally
The numerous National Parks and Nature Reserves
in Kenya were created in the first place for the
preservation of its Fauna which is gravely threatened
in its survival by human expansion, as is the case in
many other countries.
The appeal of wild animal life to the general pub­
lic is such that it proved relatively easy to obtain
funds for game preservation, besides the National
Parks soon revealed themselves a most valuable eco­
nomic asset in Kenya, drawing tens of thousands of
tourists annually from all over the world, so much so
that the tourist trade has become one of the largest
single items of the national income.
In most of the Kenya Parks and Reserves the
vegetation too is more or less strictly protected, but
the fact has to be faced that outside their bound­
aries many plant-associations and individual plant
species are seriously threatened with destruction and
extermination through humanity's ever growing en­
croachments on virgin land.
The conservation of the indigenous vegetation is
in every way as important as that of wild animals:
not only does it give each region its own specific
character, but the existence of many smaller mam­
mals, birds and insects depends very largely on local
plant species.
Besides, the potentialities of indigenous plants for
our own needs are far from adequately known, be it
their medicinal, industrial (fibres, essential oils, re­
sins, gums etc.), agricultural (soil-binding, nitrogen­
forming etc.) or horticultural (ornamental plants,
succulents) value.
The loss in knowledge which we are apt to incur
with the destruction of the indigenous vegetation­
cover anywhere in Africa is the more incalculable as
it is bound to involve the disappearance of plants
yet unknown to science: statistics show that every
year several hundred new species are still discovered
on this continent alone.
Particularly threatened and at the same time of
outstanding botanical interest are the numerous
"Inselbergs" with too poor a woody vegetation to be
scheduled as forest reserves and often with little or
no value to agriculture because of their lack of arable
land.
Surrounded by" an expanding population, such iso­
lated hills are exposed to overgrazing by livestock,
especially the destructive goats, to continuous cutting
out of trees and shrubs for firewood, as well as to
Acta Phytogeogr Suec 54
frequent fires, mostly due to negligence by honey­
gatherers when smoking out bees. The result is a
progressive denudation and the eventual extermina­
tion of many endemic species.
Such damage occurs all over Africa, even in the
remotest districts, but it passes almost unnoticed.
The creation of plant sanctuaries in such localities
has therefore become an urgent necessity. A first
step towards this aim has now been made with the
Mutomo Hill Plant Sanctuary (cf. map p. 1 54).
It is the merit of Mr. George A. Classen, M.B.E. ,
A.I.M.M., F.G.S., Adviser on rural water supplies
to the Government of Kenya to have persuaded the
County Council of Kitui to set aside a small area in
the Kitui District for total protection of its vegeta­
tion.
Mr. Classen selected Mutomo Hill, a long ridge of
granitoid gneiss which rises abruptly from the sur­
rounding peneplain and is unsuitable for any form of
agriculture, although every part of it is subject to
individual ownership for grazing purposes.
The vegetation consists of pockets of evergreen
dry forest between the rocky outcrops. On the rocks
and in the crevices an unusual variety of succulent
plants-for which climate and altitude are particu­
larly well suited-have established themselves.
The object of the sanctuary is twofold: the pre­
servation in its natural state of the entire plant-com­
munity for the benefit of future generations, but also
to make it accessible for botanical study as well, for
those among the visitors to Kenya who are inter­
ested in the flora, which tends to be all too
easily overlooked in the Game Parks by the visitors
with their interest focussed predominantly on the
wild animal life.
The Kitui District is a relatively poor rural loca­
tion where every square yard of grazing is valued;
the Kitui County Council did not thus see its way to
excise more than an initial surface of some 12 acres
which has now been prohibited by the County Coun­
cil's by-laws. l
Small as the protected area may appear, it is
adequate for a start.
It remained to find the finance to ensure adequate
protection of the sanctuary by fencing it in and em­
ploying a guard, safeguarding it against destructive
interference, but also for opening up the area by
j udicious cutting of paths and for providing facilities
and accomodation for visitors similar to the rest­
camps in the Game Parks. Mutomo Hill is 1 25 miles
from Nairobi and 40 miles from Kibwezi in the
�
In March 1 968 the Kitui County Council agreed to extend
it to approximately 40 acres.
Kenya
1 65
Fig.
1. Part of Mutomo Hill Plant
Sanctuary.
Tsavo National Park; visitors must find a camp for
spending the night and a reliable water supply.
It was providential that at the time when Mr.
Classen informed me of his project the World
Wildlife Fund which had hitherto confined its activi­
ties to financial support for fauna-protection, de­
cided to expand them to include vegetation-protec­
tion and had asked my co-operation in the matter.
Having visited Mutomo Hill and collected there on
several occasions in the course of the past 24 years
I was well aquainted with this locality which I con­
sider most suitable for the purpose; besides, Mr.
Classen's standing, his wide knowledge of wild plants
and many years' experience in Kenya vouch for the
scheme to be well considered and basically sound.
I felt that I could recommend it without reserva­
tion.
An application to the World Wildlife Fund was
favourably considered by its board, and as a result
the Mutomo Hill Plant Sanctuary is the first plant­
sanctuary in Africa financed by that organisation.
Additional funds were obtained by the "Interna­
tional Organisation for the Study of Succulents", by
M. Julien Marnier-Lapostolle, owner of the Jardin
Botanique "Les Cedres" and by Mademoiselle Lucie
Vogt of Zumikon, Zurich.
PLANTS RECORDED ON MUTOMO HILL
Abutilon mauritianum (Jacq.) Medic.
Acacia mellifera (Vahl) Benth.
Acacia tortilis (Forsk.) Hayne
Achyrothalamus marginatus 0. Hoffm.
Adenia globosa Engl.
Aloe ukambensis Reynolds
Aspilia asperijo/ia 0. Hoffm.
Astripomoea hyoscyamoides (Vatke) Verdc.
Balanites aegyptiaca (L.) Del.
Barleria prionitis L.
Barleria sp.
Bidens hildebrandtii 0. Hoffm.
Blepharispermum zanguebaricum Oliv. et Hiern
Boscia sp.
Caralluma gracilipes K. Sebum.
Centaurea sp.
Cissus quadrangu/aris L.
Cissus rotundijo/ia (Forsk.) Vahl
Combretum exalatum Engl.
Commiphora sp. (B 1 5 8 3 )
Craibia (elliotii ) brownii Dunn
Crossandra subacaulis C. B . Clarke
Croton macrostachyus Hochst. ex Del.
Croton megalocarpus Hutch.
Croton pseudopulchellus Pax
Cucumis aculeatus Cogn.
Cucumis dipsaceus Ehrenb. ex Spach
Cyathula sp.
Cynanchum tetrapterum (Turcz) R. A. Dyer ex Bullock
Dorstenia schlechteri Engl.
=
Acta Phytogeogr Suec 54
1 66
R. M. Polhill
Dyschoriste thunbergiiflora (S. Moore) Lindau
Entada leptostachya Harms
Euphorbia candelabrum Trem. ex Kotschy
Euphorbia gossypina Pax
Euphorbia kibwezensis N. E. Br.
Euphorbia pseudograntii Pax
Euphorbia quinquecostata Volkens
Euphorbia uhligiana Pax var. saxatilis Bally & Carter ined.
Fagara chalybea (Engl.) Engl.
Ficus stuhlmannii Warb.
Ficus wakefieldii Hutch.
Ficus sp.
Gerrardanthus lobatus (Cogn.) C. Jeffrey
Grewia villosa Willd.
Heliotropium sp.
Hibiscus greenwayi Bak.f.
Indigo/era sp.
Ipomoea hartmannii Vatke
Ipomoea lapidosa Vatke
Kalanchoe mitejea Lebl. & R. Hamet
Lannea alata (Engl.) Engl.
Loranthus sp . (B 1 5 88)
Maerua edulis (Gilg et Bened.) De Wolf
Maerua kirkii (Oliv.) F. White
Melhania ferruginea A. Rich.
Melia volkensii Giirke
Monadenium invenustum N. E. Br. var. angustum Bally
Notonia hildebrandtii Vatke
Ochna sp.
Ormocarpum sp. (B 1 587)
Otomeria oculata S. Moore
Panicum maximum Jacq.
Pentas parvifolia Hiern
Peucedanum araliaceum (Hochst.) Benth. et Hook.£. ex Vatke
Plectranthus sp.
Polygala sphenoptera Fres.
Polystachya tayloriana Rendle (epiphytic on Vellozia)
Pterolobium stellatum (Forsk.) Brenan
Pycnostachys umbrosa {Vatke) Perkins
Rothmannia urcelliformis (Schweinf. ex Hiern) Bullock ex
Robyns
Ruttya fruticosa Lindau
Sansevieria sp. aff. kirkii Bak.
Sansevieria raffillii N. E. Br.
Sansevieria sp. nov. (Dwarf)
Sarcostemma sp. aff. andongense Hiern
Sclerocarya birrea (A. Rich.) Hochst. var.
Sclerocarya sp. (B 1 577)
Sesamum angustifolium (Oliv.) Engl.
Solanum indicum L.
Sphaeranthus cyathuloides 0. Hoffm.
Sterculia rhynchocarpa K. Schum.
Strychnos henningsii Gilg
Strychnos usambarensis Gilg
Synadenium compactum N. E. Br.
Tephrosia ehrenbergiana Schweinf.
Terminalia brownii Fres.
Terminalia spinosa Engl.
Thylachium ajricanum Lour.
Turbina stenosiphon (Hall. f.) Meeuse
Uvaria sp.
Vangueria apiculata K Schum.
Vellozia sp.
Small tree, unident. B 1579
TANZA N I A
R. M. Polhill
PHYSIOGRAPHY
Scenic features are arrayed on a grand scale with
ancient plateaux dominating nearly two-thirds of the
some 3 65,000 square miles (945,000 sq. km). The
Central Plateau comprises a seemingly endless ex­
panse of gently undulating country over much of the
western half at an elevation of ± 4000 ft ( 1 200 m).
Dissected highlands, up to some 7000 ft (2 1 00 m),
flank the deep trough of Lake Tanganyika to the
west and extend in an increasingly disrupted arc,
with isolated blocks of the Uluguru, Nguru, Usam­
bara and Pare Mts. continuing a line to the north­
east border. Plateaux at a rather lower elevation and
with more varied topography occur in the north-east
and in the south-east behind the narrow Coastal
Plain. Tectonic and volcanic activity have produced
spectacular effects in the Eastern Rift Zone, the
Acta Phytogeogr �uec 54
snow-capped dome of Kilimanjaro towering to
1 9, 3 40 ft (5 800 m), paired by the pinnacle-shaped
Mt. Meru. A whole host of peaks rise to the west
including the famous Ngorongoro Crater and the
still active 01 Doinyo Lengai. Lakes Natron, Eyasi
and Manyara lie in the valley floor and the Rift
Walls form precipitous scarps in places, but less fre­
quently conspicuous southwards. In the south, the
Poroto and Rungwe mountains are built up from a
smaller area of volcanic activity.
Very broadly speaking, the plateau soils are deep
rather acid and infertile sandy loams on the crests
grading to dark clay soils in the shallow valleys and
extensive interior basins, with more varied probably
slightly alkaline red-earths, sandy loams and clays
predominating in the north-east. These change to a
mosaic of sands, clays and coral along the Coastal
Plain and on the off-shore islands. Highland soils
Tanzania
matured under a forest climax are prized as agricul­
tural land, but where derived from basement complex
rocks rapidly deteriorate under anything less than
the most careful husbandry. Lacustrine and alluvial
soils are most extensive in the vicinity of Lake Vic­
toria.
CLIMATE
The mean annual rainfall varies widely from about
1 3-97 in. (32-240 cm) a year, with actual yearly
records ranging from 4.45 in. (1 1 cm) in 1 5 days
(at Mkomazi) to 1 30 in. (325 cm) in 1 53 days (at
Tukuyu). Although comparatively well watered as a
whole, there are, nevertheless, considerable annual
variations and most of the country has a long dry
season with rain practically restricted to November­
May, a bimodal distribution being characteristic only
of the north-east and substantial well distributed rain­
fall only in the vicinity of Lake Victoria. About half
the country receives less than a reasonably regular 30
in. (75 cm) a year, which is generally regarded in
East Africa as necessary for any intensive form of
agriculture. The predominant vegetation aspect is,
therefore, of a dry type with local often abrupt
changes to moist types in the highlands, parts of the
coastal belt and near Lake Victoria (particularly the
western part), also wherever ground-water is avail­
able.
Mean monthly temperatures so near the equator
vary little and mean annual maximum and minimum
temperatures are very closely correlated with altitude.
Mist formation ameliorates the climate at no more
than 2000 ft (600 m) in the east to 4000-7000 ft
( 1 200-2 1 00 m) inland in the north; it is also an im­
portant feature of the Umba Steppe and parts of the
Ruvu valley nearer the coast.
VEGETATION
The .flora of Tanzania is very rich and subdivision
into broad physiognomic types gives only some idea
of the floristic diversity. Indeed, more open forma­
tions (grassland-forest mosaic, grassland and wooded
grassland (savanna)) are often better associated with
more closed formations (forest, woodland, bushland
and thicket), which they may replace either in a
catena sequence (with local changes of topographic
and edaphic factors) or stages of seres or cycles
related to frequency and intensity of burning, grazing
and cultivation. A classification taking more account
of specific composition and determinative factors,
while liable to complexity particularly on a conti­
nental scale and posing problems of definition, is,
1 67
however, more amenable to the local worker and
would be particularly useful for a discussion of con­
servation problems. In the absence of any compre­
hensive published account of this nature, the broad
divisions adopted by this Association (with slight mo­
difications to bring it into line with Dr. Greenway's
well known system proposed in 1 943 and used for
the Flora of Tropical East Africa) are shown in Fig.
1 and discussed only briefly, with most emphasis on
floristic variants discussed in the conservation pro­
posals.
I. Forest covers only 2-3 % of the country and is
continually diminishing. Moist Lowland (Lowland
Rain-forest) types are to be found in considerable
extent only on the lower parts of the eastern high­
land arc (Usambara, Nguru and Uluguru Mts., also
parts of the Ulanga and Iringa Districts) and perhaps
in the extreme west along Lake Tanganyika and in
the Bukoba District (but see Semi-swamp Forest).
Such genera as Cephalosphaera, A llanblackia, lso­
berlinia, Macaranga, Newtonia, Parinari and Chryso­
phyllum (listed for the Usambara Mts.) may occur
amongst numerous eo-dominant trees. There is an
affinity with the more extensive Guinee--Congo for­
ests, but the species are frequently distinct (see Spe­
cies List, p. 1 77).
Moist Montane Forest (Upland Rain-forest), at
altitudes of above some 4000 ft (1 200 m), occurs in
areas of moderately high rainfall or where mist for­
mation is frequent. A ningeria, Parinari, Ocotea,
with Podocarpus, Chrysophyllum, Cassipourea, Po­
lyscia.s, Tabernaemontana (Conopharyngia), Maca­
ranga, and Neoboutonia are characteristic, with a
reduction in the number of dominants and with more
discrete shrub and herb layers. Myrica, Rapanea,
Nuxia and Hagenia (particularly on volcanic soils)
predominate near the upper limits. Where contiguous
with lowland types, as in the East Usambara Mts.,
there may be a fairly complex zonation.
Patches of ground-water, riverine and semi-swamp
forests may be found locally throughout, well known
in the foothills of the East Usambara Mts . , - Nguru
and Uluguru Mts., inland near Taveta and Moshi
(see conservation proposal No. 8) and in the Bukoba
District (see proposal No. 1 ) .
Dry Lowland Evergreen Forest (Lowland Ever­
green Forest), perhaps once of considerable extent in
the eastern coastal and low plateau regions and asso­
ciated with poorly distributed rainfall, is now frag­
mented and largely replaced by wooded grassland or
cultivation. Brachylaena, Manilkam, Cynometra for­
mations occur on deep soils overlying gneiss mostly
at the north end of the East Usambara Mts., in the
south-west Tanga and east Handeni Districts, while
Acta Phytogeogr Suec 54
1 68
R. M. Polhill
a
IIlW
C2J
[[I]]]
����
�
-
Fig.
Forest &Fo rest-Grassland Mosaic
Woodland
Bush land & Thicket
Wooded-Grassland & Grassland
A l t imontane
Formations
Mangrove
Fresh Water
Swamp
50
100
'=''
'�.lo=
' =l.ori:=:J'..
' "'...Io= .Id...!
MilesO
1 . Tanzania. Vegetation types.
Chlorophora, A lbizia and Pteleopsis, often with
Sclerocarya and Lannea stuhlmannii, are characteris­
tic of a type found along the coastal belt from be­
tween Tanga and Moa in the north-east to the pla­
teaux of the Lindi District in the south-east. The
endemic and monotypic genus Stuhlmannia is not­
able from dry evergreen and riverine forests of the
Pangani area.
Dry Montane Evergreen Forest (Upland Evergreen
Forest), with Juniperus, Olea, Ilex, Agauria, Cassi­
pourea, Nuxia and Ekebergia, occurs on the rain­
shadow aspect or exposed positions on the larger
mountains, e.g. north end of West Usambara Mts.,
Acta Phytogeogr Suec 54
parts of the Pare Mts., northern slopes of Kiliman­
jaro, eastern part of Mt. Meru, the Crater Highlands,
northern slopes of Mt. Hanang (relic), also the
Poroto and Livingstone Mts. in the south.
11. Forest-Grassland Mosaic, with relatively exten­
sive areas of Hyparrhenia, Exotheca', Themeda, Era­
grostis grassland and only relict patches of Moist
Montane Forest, is a feature of the Uluguru Mts. ,
Southern Highlands and Ufipa Plateau. Eleusine
jaegeri is locally dominant on parts of the Crater
Highlands, notably on Ngorongoro, and Eleusine
jaegeri, Sporobolus, Cymbopogon also recorded lo­
cally on the eastern part of Mt. Meru. Elsewhere old
Tanzania
forest land is mostly under cultivation or secondary
bushland.
Ill. Thickets are of only sporadic and local oc­
currence, but bushland, which is intermediate in
density between Thicket and IX, Shrub Savanna, is
more widespread and also included here. Many of
the associations so classed are floristically and eco­
logically quite unrelated; the following is a limited
sample of the most striking and best known.
Rocky hills and inselbergs of the Lake Victoria
region, Central and South-east Plateaux may support
a thicket of Dalbergia, Dombeya, Markhamia and
Lannea, with Strychnos, Teclea and Diospyros,
although wooded grassland (savanna) is often in­
duced in such sites by burning. Practically impene­
trable thornless deciduous thicket covering some 50
square miles (1 30 sq. km) comprises the ltigi Thicket
on the Central Plateau, dominated by Baphia, Pseu­
doprosopis and Bussea, with Combretum, Grewia
and Canthium. Commiphora, Cordyla thickets with
Croton, Hippocratea, Lannea and Strychnos are
found further east in parts of the Mpwapwa, Iringa
and Kilosa Districts. Thickets of lesser extent occur
in parts of the Handeni District (with Mansonia dia­
tomanthera and Burttdavya nyasica) and near the
Pu_su Hills (with Erythrophleum suaveolens and En­
tada pursaetha).
Commiphora, A cacia bushland, with many asso­
ciates including Adansonia, Delonix, Lannea and
Grewia, varying freely between thicket and wooded
grassland (savanna) density, is widespread in drier
areas with not too acid soils. It is most extensive in
the Eastern Rift Valley Zone, the eastern river val­
leys and coastal hinterland, also in the north-east as
a continuation of the much more extensive zone in
Kenya. Several types of thicket and bushland are a
conspicuous feature of the Lindi District, with nu­
merous species not found elsewhere in the country
(see list, p. 1 7 8). Coastal bushland of various compo­
sition and density, both on the mainland and on the
off-shore islands, often includes Sideroxylon, Mimu­
sops, Manilkara, Grewia, Terminalia, Thespesia,
Combretum and Ludia, or Elaeodendron, Maytenus,
Erythroxylum and Suregada on coral outcrops. Sec­
ondary bushland is also extensive, usually with
Thespesia, Haplocoelum, Grewia and Combretum
prominent.
A remarkable formation dominated by Philippia
mafiensis may be found on flat sandy expanses on
Mafia and of small extent (if not now extinct) on
Pemba. The Msua Thicket in the coastal sector west
of the Ruvu valley, composed of semi-thicket and
low trees, is an unusual association influenced by
mist formation, whereas the succulent Euphorbia
1 69
thicket on steep or rocky northern slopes of the
U sambara and Pare Mts. seems secondary to forest.
Bamboo Thicket comprising almost pure stands of
Arundina,ria alpina is found in patches between
7000-9000 ft (2400-2700 m) on Mt. Meru (but rare
on Kilimanjaro), also Oldeani in the Crater High­
lands and the Poroto and Rungwe Mts. in the south.
The plains bamboo, Oxytenanthera abyssinica, is
common in the south-east and extends north to
Kilosa and across to the west.
IV. Mangrove Swamp is extensive in the estuaries
of the Rufiji, Ruvuma and Wami Rivers, also in
numerous creeks along the coastline of the mainland
and the off-shore islands, particularly the west coast
of Pemba.
V and VI. Woodland (Deciduous Woodland) cov­
ers perhaps three quarters of the country, with many
interesting ecological and floristic variants, which are
in little danger and may be omitted from discus­
sion here. Brachystegia, Julbernardia woodlands
(miombo) dominate vast expanses of plateau in the
western, central and south-eastern parts, replaced in
the extreme south-east by woodlaJ)ds of similar form
dominated by other leguminous trees, e.g. Millettia,
Dalbergia and Lonchocarpus. Woodlands related to
and probably derived from the Dry Lowland Ever­
green Forests mentioned above may be found in the
eastern districts and include as additions Ostryoder­
ris, Pleurostylia, Sclerocarya, Dalbergia and Tamar­
indus. Small areas of Combretum, Terminalia wood­
land are found around Kilimanjaro as an extension
of its more widespread occurrence in Kenya and
Uganda. Acacia Woodland (VI) is of only sporadic
occurrence, grading into more extensive wooded
grassland or grassland formations.
IX. Wooded Grassland and Gra.ssland need be
mentioned only briefly in the present context, but
the transition from forest, woodland and thicket to
corresponding wooded grasslands is to be found at
least locally throughout the country, either with
changes of soil and water relations to edaphic grass­
lands or induced by burning, grazing and cultivation
to secondary grasslands. Edaphic grasslands of val­
leys, flood plains and pans are a conspicuous feature
and extensive in the Masai and Wembere Steppes,
the U sangu Plains, together with the Rukwa and
middle !vf alagarasi basins. Echinochloa pyramidalis
is characteristic of the main part of flood plains, with
Hyparrhenia ruja more frequent towards the margin,
in places wooded with mostly A cacia or with palm
stands (Hyphaene and Borassus). Alkaline flats, as­
sociated with past and present soda lakes of the Rift
Valley, are dominated by Sporobolus spicatus and
Cyperus laevigatus, sometimes with Sporobolus roActa Phytogeogr Suec 54
1 70
R. M. Polhil
hustus and S. marginatus. Upland grassland induced
from forest has been mentioned under II, Forest­
Grassland mosaic, but the greater part of the Se­
rengeti and Ardai plains, too, come under this head­
ing. Many often catholic species occur, with Them­
eda triandra, Panicum, Hyparrhenia, Digitaria and
Pennisetum prominent, and with Acacia wooded
patches peripherally. Very mixed associations of
grasses are also found in secondary wooded grass­
lands derived from Combretum, Terminalia, A cacia,
Erythrina, Ostryoderris woodlands near Lake Vic­
toria for example, the Protea, Dombeya, Combretum,
Faurea woodlands at higher altitudes throughout the
eastern highlands and also parts of the vast Brachy­
stegia, Julbernardia woodlands.
X. A ltimontane Formations. Ericaceous Heaths
with Erica arborea, Philippia and Blaeria, often as­
sociated with Agauria, Myrica, Rapanea and Myr­
sine, occur on exposed peaks of the higher moun­
tains. Moorland, with giant Senecio and Lobelia in
Deschampsia, Koeleria, Festuca, Exotheca grassland
and associated bogs, fringed by heath-like stands of
Helichrysum, Stoebe, A nthospermum and A denocar­
pus is only well developed on Kilimanjaro, but occurs
in incipient or modified form on many of the other
mountains. These isolated communities are, of
course, of great phytogeographical interest.
XI. Freshwater Swamp dominated by Papyrus or
Phragmites is extensive in places around Lakes Vic­
toria and Tanganyika, also in scattered riverine lo­
calities, notably the middle reaches of the Malagarasi
River (Usinge Swamps). Grassland Swamp, with
Leersia, Pennisetum glaucocladum, Vossia and
Echinochloa stagnina associated with Cyperaceae, is
well developed in some of the interior drainage ba­
sins, notably the Wembere, Bahi, Rukwa, Usangu
and Usinge depressions, also locally elsewhere.
PLANT CONSERVATION
The Present Situation
There are perhaps 1 0,000 species of higher plants
alone in Tanzania. Sufficient information has accu­
mulated to assess in general terms the survival ca­
pacity of major associations under pressures of cur­
rent land utilization. The distribution and status of
minor associations and individual species is clearly
beyond the scope of the present survey.
"Ninety-eight per cent of the 1 0 million inhabitants
depend on the land for their livelihood, but the
population is very unevenly distributed (Fig. 2). Ex­
cluding the off-shore islands, population is densest
around Lake Victoria, where alluvial soils and good
Acta Phytogeogr Suec 54
rainfall support an agricultural livelihood for some
2 1 I 4 million. Population is also clustered densely in
parts of the eastern highland arc, particularly the
southern slopes of Mt. Meru, Kilimanjaro and parts
of the Usambara and Uluguru Mts. to the east, the
Poroto, Kipengere and Livingstone ranges and Ma­
tengo Hills to the south and the Ujiji and Kigoma
areas east of Lake Tanganyika. Parts of the coastal
belt form the third major centre, the population
density in parts of Zanzibar being particularly high.
In the rest of the country population is sparse.
Tsetse fly infestation practically prohibits settlement
in vast areas of the western and southern parts (per­
haps 60% of the country), while low rainfall and
water supplies are limiting factors elsewhere.
Rapid and increasing population growth and the
pressing need for a much higher standard of living
have already put some strain on the natural resources
and increasing pressures will be directed not only on
these areas but also on marginal land and areas at
present set aside as forest and game reserves. These
problems are well appreciated and extensive research
has been undertaken in recent years by the Agricul­
ture, Forestry, Veterinary and Tsetse Research Or­
ganizations of the East African Common Services
Organization and by the Divisions of the Ministry of
Agriculture, Forests and Wildlife to assess more ac­
curately available natural resources and their most
effective utilization.
The policy of establishing Forest Reserves to pro­
tect the main catchment areas and watersheds, con­
trol logging and limit encroachment dates from the
beginning of the century and nearly 4000 square
miles ( 1 0,500 sq. km) of closed forest and another
40,000 square miles (105,000 sq. km) of dry forest
and woodland are now included (Fig. 2). Viable
stands of little disturbed forest are still to be found
in places difficult of access or where specially pre­
served for their protective effect on water supplies.
Elsewhere regeneration of some of the valuable in­
digenous hardwoods, notably Ocotea usambarensis
(East African camphorwood) on Kilimanjaro and the
West Usambara Mts. and Chlorophora excelsa
(mvule) on the Rondo Plateau has been carried out
to a considerable extent, but the indigenous soft­
woods (Podocarpus and Juniperus) are slow-growing
and seem best replaced by exotics. Some 46,000 acres
(1 8,500 hectares) of exotic softwoods have been
planted and increased annually by some 6000 acres
(2400 hectares), primarily on Mt. Kilimanjaro and
in areas of montane grassland (originally forest) in
the Southern Highlands. The principal exotic hard­
wood is teak, planted most extensively in the foot­
hills of the East Usambara Mts. and on the Rondo
Tanzania
30
171
40
(
J
I
(
10
§
V
I
National
Forest
Parks
Reserves
Areas 9f Dense
Areas
Proposed
Cult ivation
for Further
(Numbered
as
Protection
text)
MilesO
50
30
Fig. 2 . Tanzania. Existing and proposed conservation areas.
administrative independence, have j ustly attained
Plateau. Thus although good examples of most forest
associations could still be preserved, reafforestation world fame for their scenic splendour and magni­
must continue apace. Hydrological and ecological ficent assemblage of large mammals. As a tourist
studies of the East African Agriculture and Forestry attraction they already earn more than £ 1 million
Research Organization further suggest that it may annually and with an increase of facilities this figure
be possible to make more economic use of some is capable of considerable expansion, with a prospect
.
forest areas preserved solely for their protective role,
of growing popularity. A number of interesting and
even if long-term experiments must necessarily pre­ extensive research projects are being undertaken
cede any change in current forest policy.
here. These include comprehensive vegetation sur­
Within the relatively short period of their exist­ veys of the northern Parks by Dr. P. J. Greenway
ence, the National Parks (Fig. 2), run by a trustee­ and a broadly based programme of research into the
management of natural pastures, their ecology and
ship organization with considerable financial and
Acta Phytogeogr Suec 54
1 72
R. M. Polhill
the role of natural and induced burning, floods, field centre for research, and given information, di­
grazing habits of wild versus domestic ungulates and rection and financial assistance within some coherent
national framework, there is no doubt much poten­
related problems.
In the north, the Serengeti National Park covers tial support available from other educational bodies,
5000 square miles (1 3,000 sq. km) of upland grass­ societies, local authorities and individuals. It is sug­
land and A cacia wooded grassland, the much smal­ gested that a co-operative effort could be effected by
ler Manyara National Park includes a spectrum of the establishment of a series of Nature Reserves in
habitats from forest to plains on the Rift Wall, while carefully selected sites throughout the country. These
the Ngurdoto National Park is beautifully sited in could be linked with education programmes already
the montane forests near Mt. Meru (of which a established by the National Parks and University.
further part is scheduled for inclusion). In the south, The close collaboration already existing between the
the newly opened Ruaha National Park occupies Forest Division and National Parks might also be
extended along these lines, with the preservation of
some 2500 square miles (6500 sq. km), with A cacia,
Brachystegia woodland, . forest patches, which are relatively undisturbed be­
Commiphora bushland,
riverine and flood plain communities. In the east cause they are not readily accessible, economically
another new Park incorporates the ring of hills about valueless or vital catchment areas. Where requested,
financial and advisory aid available from interna­
Mikumi, with some 560 square miles (1450 sq. km)
tional sources might be most effectively channelled
of Brachystegia woodland, with riverine forest,
into such a development. At first, concern would be
Acacia wooded grassland and open pans. National
directed simply to the establishment and protection
Reserves include the higher parts of Kilimanjaro and
of such areas, but with a view to the ultimate devel­
Mt. Meru, also 25 square miles (65 sq. km) of I.ow­
opment in places of field centres with facilities for
land forest in the Gombe Stream Reserve, a chim­
teaching and research.
panzee habitat at the northern end of Lake Tangan­
With the above concept in mind, areas where Na­
yika. Further large areas of mostly uninhabited
Reserves might be profitably sited (or where
ture
country in the south are reserved as largely inviolate
protection may be given) are listed by divisions
other
animal sanctuaries, including several thousand square
Flora of Tropical East Africa (which coincide
the
of
miles of Brachystegia woodland and wooded grass­
land of the Rungwa Game Reserve and the 1 5,000 with the old Provinces now superseded by smaller
Regions) and mapped in Fig. 2, p. 1 7 1 .
square miles (39,000 sq. km) of the Selous Game
Reserve.
Lake Province (T 1 )
Proposals
As indicated above, good representatives of most
major plant formations are either within national
custody or in no immediate danger, but there are
a considerable number of places with vegetation of a
restricted and unusual type, of which it is particu­
larly desirable to further protect samples in a mini­
mally disturbed state because of their scientific inter­
est. Forest types predominate because they are highly
fragmented and often relics of previously wider dis­
tributions, separated for varying lengths of time with
corresponding degrees of divergence in the flora (and
fauna) from those most closely related. Further, the
intricate interdependence of the many species which
make up their complex structure renders a low tol­
erance to disturbance.
Optimal conservation is obtained in the National
Parks, but these are necessarily restricted to sub­
stantial areas in which all human rights can be justi­
fiably excluded and which can be self supporting as
a tourist attraction. The forest estate, too, must be
developed for maximum economic return possible
without endangering water supplies. The University
has already shown interest in developing at least one
Acta Phytogeogr Suec 54
1.
Minziro Forest
Location: Adjoining the Tanzania-Uganda border east of
the Bukob a-Kampala road.
Area: Under 1 00 square miles (265 sq. km).
Vegetation type: I, Semi-swamp Forest, with a variety of
associates having ranges primarily north-westwards and not or
rarely found in other parts of the country, e.g. Heywoodia
lucens, Podocarpus usambarensis var. dawei, Mussaenda
erythrophylla, Cassipourea ruwensorensis, Citropsis schwein­
furthii, Manilkara obovata, Baikiaea insignis, Uncaria afri­
cana.
Status: Central Government Forest Reserve. The timber of
commercial value, mainly Podocarpus, is being harvested, but
the forest remains essentially the same. The land is unlikely
to come under pressure for destructive development in the
near future.
2. Rubondo Island
Location: South-western part of Lake Victoria.
Area: Over 1 00 square miles (265 sq. km) .
Vegetation type: I, Forest, with some secondary thicket
and wooded grassland.
Status: Central Government Forest Reserve. At present
under some threat of development either as pine plantations
or possibly agriculture. It is probably the best example of the
typical forest vegetation of the Lake islands, many of which
have escaped the destruction which has been the fate of the
lake shore forests.
Tanzania
Northern Province (T2)
3. Mt. Meru
Area: About 50 square miles ( 1 30 sq. km).
Vegetation type: I, Moist Montane and Dry Montane For­
est, also X, Altimontane Formations.
Status: Much of the forest of Mt. Meru is Central Govern­
ment Forest Reserve, and most of the remainder, particularly
the part inside the crater, is about to become part of the
Meru-Ngurdoto National Park. Part of the Forest is being
re-developed as softwood plantations.
4. Kilimanjaro
Vegetation type: I, Moist Montane and Dry Montane For­
est, also X, Altimontane Formations, including. Ericaceous
Heaths and Moorland.
Status: Most of the Forest is Central Government Forest
Reserve, with the addition of a strip half a mile wide below
the main forest block on the south side of the mountain,
which belongs to the local authority, and is administered by
them with the assistance of the Forest Division. The area
above the tree-line is technically Forest Reserve, but also a
National Reserve and tentatively scheduled as a National
Park.
5. Masailand Mountains, e.g. Hanang, Kitumbeine, Lolkisale,
Longido, etc.
Location: Masailand, mainly near the Rift.
Area: Various.
Vegetation type: I, Forest, including Moist Montane For­
est and Dry Montane Forest, with degenerate derived types.
Status: Some of these mountains are Central Government
Forest Reserves, but are afforded no more than nominal
protection at the present time. They are valuable links in the
study of the African flora, fauna and climate. They are
threatened less by development than by disintegration from
uncontrolled cutting, fire and grazing.
6. Marang Forest
Location: Rift Wall, above Lake Manyara.
Area: About 30 square miles (80 sq. km).
Vegetation type: I, Moist Montane Forest.
Status: Central Government Forest Reserve in part, open
to same hazards as No. 5, and other parts to agricultural
development. Part might perhaps ultimately be included
within the Manyara National Park.
7. Lelatema Mts.
Location: South of Moshi, on the west side of the Ruvu
(Pangani) River.
Area: Over 1 00 sq. miles (260 sq. km).
Vegetation type: Probably some form of Dry Montane
Forest.
Status: This remote area is not under any form of formal
control, and is not threatened except by uncontrolled fire. It
is however an example of a mountain range lying wholly in
the rain shadow of another, probably receiving no more than
between 10 and 20 in. (25-50 cm) annually. It is believed to
have been very little studied botanically.
8. Rau Forest
Location: Near Moshi.
Area: About 10 square miles (25 sq. km).
Vegetation type: I, Forest, of a lowland ground-water type,
containing a number of extremely interesting associates, in­
cluding Oxystigma msoo (Leguminosae, Caesalpinioi:deae) un-
1 73
known elsewhere and the only East African representative
of the genus, which is otherwise restricted to the Guinee­
Congo forests. It occurs with Chlorophora, Diospyros, Ficus,
Lecaniodiscus, Acacia usambarensis and Tapura jischeri (rare
in East Mrica).
Status: Central Government Forest Reserve. A great deal
of cutting and small-scale planting has been done over the
years, and probably none of the forest is now in its "natural"
condition. The main function of the forest is to supply poles
and firewood to the adjoining Moshi township, the area
being insufficient to warrant full-scale development as a
timber-production forest. The future for Oxystigma is prob­
ably pretty bleak, unless the species should be discovered
elsewhere.
9. Bereku Ridge
Location: About 30 miles (48 km) north of Kondoa.
Area: Relatively small.
Vegetation type: V, Brachystegia woodland.
Status: Presumably under no formal control. Probably the
most magnificent accessible stand of Brachystegia micro­
phylla in existence. It was partly felled in the interests of
tsetse eradication about 10-15 years ago.
Tanga Province (f3)
10. Usambara Mts.
Vegetation type: I, Forest: full ra�ge from Moist Lowland
to Moist Montane, with associated heath and some Dry
Montane Forest. One aspect shown in Fig. 3. Flora very rich
with marked affinities to Guinee-Congo formations particularly
at generic level, many species distinct. A short list of woody
species of higher plants, restricted or practically restricted to
this area, is given on p. 177. Just these run to some 15 0
species and suggests that inclusion of ground herbs, epiphytes
and lower plants would increase these figures by a factor
of several. The fauna is of comparable outstanding interest.
Status: East Usambaras. A rather small proportion of the
East Usambara forests are Central Government Forest Re­
serves. A considerable proportion are under private tenure,
mainly by companies owning tea estates. The remaining small
proportion is under no formal control. Currently there is
keen interest in the preservation of these forests, and it is
probable that a forward-looking policy of research and con­
servation will emerge during the next year or two. The
Research Station at Amani founded in 1 902 and the main
centre for the country until the effective establishment of the
centralized East African Agriculture and Forestry Research
Organization in Kenya in 1950 still exists under that aegis,
until recently as a centre for research into insect borne
diseases. Its future development is pending, but interest has
been shown by the University. It comprises some 750 acres
(300 hectares), of which about one third remains under the
original Moist Lowland Forest, while a large part of the
remainder is occupied by permanent plantations of trees and
shrubs collected from all parts of the tropics, and each hav­
ing some economic interest�a collection (at one time Oif
+ 1 000 species tried) unique on the continent.
West Usambaras. Most of the best forest is included in
Central Government Forest Reserves, which at present are
managed for timber production, although their protective
function is acknowledged. Other areas are in private hands
on tea estates, the owner of one of which wishes to offer his
land as a nature reserve. Several areas in forest reserves
would apparently be suitable for research and conservation
work.
Acta Phytogeogr Suec 54
1 74
R. M. Polhill
Fig.
3. Intermediate evergreen forest,
East Usambara Mts. , NE. Tanzania.
Photo
P. J. Greenway. Reproduced
with the permission of the Academic
Press Ltd.
1 1.
Brachylaena forests of Tanga and east Handeni Districts
Location: Mainly south-west Tanga and east Handeni Dis­
Vegetation type: I, Dry Lowland Forest of a coastal type.
Status: Central Government Forest Reserve. An example
of the chain of relict patches of closed forest at no more
tricts.
of dry evergreen forest
than 1 000 ft (300 m), which extend through the coastal plain
covering some hundreds of square miles, rapidly diminishing
of Tanganyika, with the foothills of the East Usambara Mts.
Area : A highly dissected block
at one extreme, and the Rondo Plateau at the other. See
in area at the present time.
Status: Virtually no formal control. In recent years very
Nos. 23, 24 and 32 below.
large acreages have been cleared for sisal and maize planta­
tions. Apart from their great ecological interest, these forests
are the only source of the very valuable timber of
laena,
Brachy­
at present among the first dozen of Tanzania's timbers
in volume sawn annually, and in the top three in value of
exports. Unless urgent action is taken, this species is destined
to become a botanical curiosity.
1 2.
Msumbugwe Forest
Location: About
15 miles (24 km) south-west of Pangani.
Area: About 10 square miles (25 sq. km).
Acta Phytogeogr Suec 54
13.
Lake Manka and the Mkomazi area
Location: About
15
miles
(24
km)
radius
of
Mkomazi
Station on the Tanga-Arusha railway.
Vegetation type:
Ill, Acacia, Commiphora
bushland, with
alkaline grassland and palm stands.
Status: No formal status. This is probably the driest area
in Tanzania, being in the narrow valley between the West
Usambara and Pare Mts. It contains a small soda lake ex­
hibiting great seasonal fluctuations in level, fed by streams
from the Pare Mts. This affords a swamp habitat of con-
Tanzania
siderable interest, and is surrounded by a zone of alkaline
Vegetation
type: Ill,
type
locality
of
this
very
1 75
striking
grassland. The area is subjected to cattle grazing pressure and
thicket association found sporadically elsewhere only in parts
there is some erosion, but except near one or two villages,
of Zambia. See also vegetation survey above.
there has not so far been extensive removal of the woody
20.
Western Province (T4)
1 4.
Status:
No
formal
status.
Apparently
in no
immediate
danger.
cover.
Mbizi Forest
Rubeho Mts.
Location: About 40 miles (65 km) west of Kilosa.
Area: About 1 00 square miles (265 sq. km).
Location: About 8 miles ( 1 3 km) east of Sumbawanga.
Vegetation type: I,
Area: About 1 2 square miles (30 sq. km).
Moist Montane Forest, some derived
grassland and scrub.
Vegetation type: I, Moist Montane Forest.
Status : Central Government Forest Reserve. This is a small
Status: Central Government Forest
Reserve,
classified
as
relic forest of considerable interest both botanically and as
primarily protective forest. Forms good link in the Usam­
the habitat of several species of monkeys and many birds.
bara-Uluguru-Southern Highlands chain.
15.
Eastern Province (T6)
Mulele Hills '(also spelt on some maps Mlala Hills)
Location: About 60 miles (95 km) north of the north end
of Lake Rukwa.
21.
Nguru Mts.
Location: About 50 miles (80 km) north of Morogoro.
Area: Over 100 square miles (265 sq. km) are botanically
interesting.
Area: Under 1 00 square miles (265 sq. km).
Vegetation
Vegetation type: Forest-woodland or thicket-woodland mosaic.
Status: Contained
within
larger
Mulele
Lowland
grading
into
Moist
Forest
Status: At least partly under Central Government Forest
Reserve. The lowland forest is of a similar type to the East
Pterocarpus angolensis
Hills
Moist
Reserve, which was created as part of the programme for
ensuring the supply of
the
type: I,
Montane Forest.
timber.
The
mosaic of relic forest patches have only partly been explored
botanically, and evidently still contain much of interest.
1 6.
Usambara forests, but probably not quite as well developed.
The N guru Mts. form one of the most important links in
the chain of highland forests.
Kungwe Mt.
22.
Location: On the big peninsula halfway down the eastern
side of Lake Tanganyika.
Uluguru Mts.
Location : South of Morogoro.
Area: Over 1 00 square miles (265 sq. km).
Area: About 1 00 square miles (265 sq. km) are botanically
interesting.
Vegetation type: I, Moist Lowland grading into Montane
Forest; some montane grassland-thicket or bushland mosaic.
Vegetation type: I, Moist Montane Forest, with some sec­
ondary thicket and forest-grassland mosaic.
Status: No formal status.
Botanical exploration still very incomplete, but evidently iso­
lated for a long period with many species found only here
The forests are i n no
danger
from cultivation or cutting being too steep and inaccessible,
or rarely elsewhere-some 1 00 species of woody plants noted
on p. 1 7 8 .
and because the mountain is the abode of dangerous spirits.
Status: Partly under Central Government Forest Reserve.
Fires sweep up from 'miombo' to the east and are doubtless
Very little of the lowland forest now remains. The lower
the reason for the high and irregular eastern forest edge. This
slopes are very heavily populated, and the lower forest re­
is an extremely interesting
area both botanically
and zoo­
logically.
17.
serve boundary had to be established in many places higher
than was desirable. The remaining forest's protective function
is valued highly.
Mpanda Highlands
23.
Location: About 60 miles (95 km) south of Uvinza.
Area: Over 1 00 square miles (265 sq. km) are of interest.
Vegetation type: Thicket-woodland mosaic.
Status: No formal status.
Part of the
Pugu Hills, also Pande Hill
Location: 1 8 miles
(30
km) west and
15
miles
(25
km)
north-west of Dar es Salaam.
area has
recently
been opened up as a settlement scheme, thus ensuring the
Area: About 10 square miles (25 sq. km).
Vegetation type: I, Dry Lowland Forest of a coastal type
destruction of the remaining forest in that part. Some of the
and including amongst species little known or rarely found
larger forest patches are the habitat of Red Colobus monkeys.
elsewhere,
Area: Indefinite.
Xylopia arenaria Engl. (Annonaceae), Stephanos­
tema stenocarpum K. Sebum. (Apocynaceae), Diospyros eng­
leri Guerke (Ebenaceae), Alchornea engleri Pax (Euphorbia­
ceae), Sapium triloculare Pax (Euphorbiaceae), Casearia holt­
zii Gilg (Flacourtiaceae), Millettia puguensis Gillett (Legu­
minosae) and Nesogordonia holtzii (Engl.) Capuron (Ster­
Vegetation type: XI, Freshwater Swamp, also riverine for­
culiaceae).
At least some of these patches are dominated by
18.
Craibia.
Ugalla River
Location: About 1 00 miles ( 1 60 km) south-west of Tabora.
est.
Status: Central
Status: Central
Government
Forest
Reserve,
also
Game
Government
Forest
Reserve.
These
are
both good examples of coastal forest which now exists only
Controlled Area. An area of great ecological interest, but at
in a few restricted areas. Both these areas are likely to come
present in no danger of destructive development.
under pressure for destructive development. See also No. 1 2
above and Nos. 2 4 and 3 2 below.
Central Province (T5)
1 9.
ltigi Thicket
Location: A·round I.tigi Station on the Central Railway Line.
Area: About 50 square miles ( 1 30 sq. km) in all.
24.
Zaraninge Plateau
Location: About 1 5 miles (25 km) due west of the north­
ern mouth of the Wami River.
Acta Phytogeogr Suec 54
1 76
R. M. Polhill
Area: About 10 square miles (25 sq. km).
Vegetation type: I, Dry Lowland Forest of a coastal type.
Status: Partly Central Government Forest Reserve and may
come under pressure for development as softwood plantations
within the next decade. Extremely interesting botanically and
ecologically. See also Nos. 12 and 23 above and 32 below.
25 . Philippia mafiensis on Mafia Island
Location: Island lies east of Rufij i delta, from which it is
derived.
Area: Indefinite, but quite extensive stands of Philippia
reported by Greenway (typescript at East African Herbarium,
1 93 8).
Vegetation: Pure thickets in at one time shallow lagoons
or lake basins, sometimes in association with Syzygium and
Pandanus.
Status: No formal status. The occurrence at sea level of a
species of this genus, otherwise known in tropical Africa
only from altimontane formations, is a striking phytogeo­
graphical puzzle.
Southern Highlands Province (T7)
26. Kipembawe
Location: An indefinite area roughly 70 miles ( 1 1 0 km)
north of Chunya.
Vegetation type: Forest-woodland or thicket-woodland mo­
saic.
Status: Probably partly within the Rungwa Game and For­
est Reserve, but at least partly outside, with no formal
control, and subject to pressure from shifting cultivation and
other destructive agricultural development. This area is com­
parable with the Mulele Hills (see No. 1 5) and should at
least receive attention from botanists to establish its signifi­
cance.
27 . Kilombero Scarp-Uzungwa
Location: The north-west side of the Kilombero valley.
Area: Several hundred square miles.
Vegetation type: I, Moist Lowland and Moist Montane
Forest, etc.
Status: A large part of the area is Central Government
Forest Reserve, with protection as its main function. Much of
the . area is extremely remote, and even now accessible only
on foot. This area forms the main link between the north­
eastern group of montane forests and those in the Southern
Highlands. It is in no danger at present, but should figure in
any general conservation plan.
28. Image Forest
Location: About 43 miles (70 km) north-east of Iringa.
Area: About 25 square miles (65 sq. km).
Vegetation type: I, Moist Montane Forest, some montane
grassland and secondary thicket.
Status: Central Government Forest Reserve. Contains a
good stand of merchantable timber, but is very difficult of
access. Possibly increasing supplies of plantation-grown soft­
woods will leave the Image Podocarpus untouched. Image is
an exceptionally interesting wildlife habitat, being one of the
few relatively isolated forests with good populations of heavy
game, as well as an abundance of smaller species and birds.
Vegetation type: I, Dry Montane Forest and some montane
grassland.
Status: Central Government Forest Reserve. The southern­
most locality for Juniperus procera in Tanzania, and the
only good example of dry montane forest in the Southern
Highlands. It is located on ancient rocks, whereas all the
rest of the forest within a radius of 60 miles (95 km) are on
recent volcanic deposits. It is in some danger from fire.
30. Rungwe and Poroto Mts.
Location: About 15-20 miles (25-32 km) south and south­
east of Mbeya.
Area: Over 100 square miles (265 sq. km).
Vegetation type: I, Moist Montane Forest, some montane
grassland.
Status: Central Government Forest Reserves, with protec­
tion as their main function ; also some timber cutting. Eco­
logically recent because of the activity of Rungwe volcano.
No danger at present, and have a good potential for develop�
ment as a tourist attraction.
3 1 . Livingstone Mts.
Location: The eastern shore of the northern tip of Lake
Nyasa and extending north-westwards as far as Rungwe Mt.
Area: Some hundreds of square miles.
Vegetation type: Partly I, Moist Montane Forest, partly
derived thicket, bushland and grassland, largely unexplored
botanically.
Status: The northern part, near Rungwe Mt., is a Central
Government Forest Reserve, the remainder has no formal
status. Much of the country is extremely steep, b roken and
inaccessible.
Southern Province (T8)
32. The Rondo Plateau
Location: About 25 miles (40 km) south-west of Lindi.
Area: Under 1 00 square miles (265 sq. km).
Vegetation type: Partly I, Dry Lowland Forest of a coastal
type and partly V, Woodland, also with adjacent areas of
thicket and wooded grassland.
Status: Central Government Forest Reserve in part; part
has no formal status. This was the finest Chlorophora forest
in East Africa before it was cut over in the late forties
and early fifties. Part of the forest that was poor in Chlo­
rophora has been cleared and replanted with various exotics
including teak and pine, but a large part still retains its
original aspect. The Rond'o is by far the best representative
of a number of dissected plateaux carrying forest in the
coastal plain of southern Tanzania, and a part at least should
be preserved for study. It forms the final link in the chain of
coastal forest relics, d. Nos. 1 2, 23 and 24, and contains
many interesting plants some of which are listed on p. 178.
33. Lake Lutamba
Location: About 20 miles (30 km) west of Lindi.
Area: Indefinite.
Vegetation type: Ill, Coastal bushland and thicket.
Status: No formal status. The type-locality of many spe­
cies, but area as a whole little known and further botanical
exploration very desirable.
Zanzibar
29. Ndumbi Forest
Location: The north-west extremity of the Kipengere
Range, about 50 miles (80 km) south-east of Mbeya.
Area: About 10 square miles (25 sq. km).
Acta Phytogeogr Suec 54
34. Jozani Forest
Location: Waist
island.
between
main
part
and
south-east
of
Tanzania
Area: Limited.
Vegetation type: I, Semi-swamp Forest with
nix, Pandanus
and
Elaeis, Phoe­
Anthocleista.
Status: At one time a Forest Reserve, but present status
uncertain, probably much disturbed.
35. South-east Zanzibar
Area: Indefinite.
Vegetation type: Ill, Evergreen coastal bushland on coral
rag.
Status: No formal status. Little value in agricultural terms,
but may be exploited for charcoal. Not well known botanic­
ally, but notable to zoologists
as the habitat of the
Red
Colobus indigenous to Zanzibar.
NB. Zanzibar is highly populated and rarities in danger of
extinction may perhaps be preserved only by translocation to
Nature Reserves. In this context
Ipomoea zanzibarica (known
Vanilla zanzibarica (near
from Pangajuu and Ufufuma) and
Dole, rare in Pemba and on mainland) may be mentioned.
Pemba
36. Ngezi Forest
Location: North-west of island.
Area: Less than 10 square miles (26 sq. km).
Vegetation
type:
I,
Lowland
Semi-swamp
Forest,
with
Chrysalidocarpus, Phoenix, Elaeis, Tabernaemontana (Cono­
pharyngia) and Odyendea.
Status: Forest Reserve. Chrysalidocarpus pembanus is the
sole representative of this palm genus in East Africa. Ty­
phonodorum lindleyanum (Araceae), native of Madagascar,
but not on mainland, also occur5 in such habitats o n Pemba.
SOURCES AND ACKNOWLEDGEMENTS
The introductory sections
excellent
series
of papers
are largely summarized from an
i n E.
W.
Russell,
The Natural
Resources of East Africa (East African Literature Bureau,
1 962) and the maps are adapted from the same source.
Further
references
particularly
relevant
to
Tanzania
are
mostly listed there. Much background information is also to
be found in the Tanganyika Handbook,
ed. 2
( 1 95 8) and
Conservation of Nature and Natural Resources in modern
African States (International Union for the Conservation of
Nature and Natural Resources, Morges, Switzerland,
1 963).
The compilation of this paper would have been impossible
without the invaluable assistance of Mrs. H. Faulkner, Dr.
P. J. Greenway, O.B.E. (formerly Botanist in Charge, East
African
Forest
Herbarium),
Division,
Mr.
Lushoto)
J.
Procter
and
(Silviculture
Mr.
D.
Section,
Vesey-FitzGerald
(Tanzania National Parks, Arusha), all long resident in the
country and with a wide knowledge and a keen interest in
the flora and its conservation.
I
am also grateful to
my
colleagues at Kew for various information and assistance in
presentation.
SPECIES LISTS
Short list of trees and shrubs endemic to three of the areas
where
protection
urged.
Species
formations
of
with
elsewhere
representative
only
restricted
included
with
samples
is
particularly
distribution
an
asterisk
in
similar
C'),
and
imperfectly known species marked by single inverted commas
( ' ') .
1 2 - 6 8 1557 Hedberg
1 77
Usambara Mts.
Acanthaceae: Barleria amaniensis Lindau; 'Dyschoriste nobi­
lior C. B . Cl.'; lsoglossa candelabrum Lindau; 'Rhaphidos­
pora anisophylla Mildbr.'; 'Thunbergia amanensis Lindau';
T. usambarica Lindau. Ampelidaceae: 'Cissus allophyllo'ides
Gilg & Brandt'; 'C. braunii Gilg & Brandt'; C. njegerre
Gilg. Anacardiaceae: ':'Lannea amaniensis Engl. & Krause;
Sorindeia usambarensis Engl. Annonaceae: Anonidium usam­
barense R. E. Fries; Enantia kummeriae Engl. & Diels;
':'lsolona heinsenii Engl. & Diels; Polyceratocarpus scheffleri
Engl. & Diels; Uvaria dependens Engl. & Diels; Uvariodend­
ron pycnophyllum (Diels) R. E. Fries; ''' U. usambarense
R. E. Fries; ':'Xylopia holtzii Engl. Apocynaceae: Motandra
viridijlora K. Sebum.; 'Rauvolfia oreogiton Markgraf'.
Araliaceae: ':'Polyscias albersiana 'Harms. Celastraceae:
'Gymnosporia amaniensis Loes.'; Platypterocarpus tanganyi­
kensis Dunkley & Brenan. Chailletiaceae: ':'Dichapetalum
eickii Ruhl. Combretaceae: Combretum leiophyllum Diels.
Commelinaceae: Palisota orientalis K. Schum. Compositae:
Vernonia amaniensis Muschl.; Vernonia nuxio'ides 0. Hoffm.
& Muschl. Ebenaceae: Diospyros amaniensis Guerke. Euphor­
bi.tcee<e: Dryptes subdentata Mildbr.; Erythro�o;::·a po­
/yandra (Pax & K. Hoffm.) Prain; ':'Macaranga conglomerata
Brenan; *Meineckia jruticans (Pax) Webster; Pycnocoma
macrantha Pax; Thecacoris usambarensis Verdc. ; Zimmer­
mannia capillipes Pax. Flacourtiaceae: *Dasylepis integra
Warb . ; Homalium calodendron Gilg. lcacinaceae: lodes
usambarensis Sleumer. Labiatae: 'Coleus saxicola Guerke';
'C. subscandens Guerke'; 'Plectranthus pendulus Guerke'; 'P.
rupicola Guerke'; 'P. saxatilis Guerke'. Lauraceae: Beil­
schmiedia kweo (Mildbr.) Robyns & Wilczek; ':'Cryptocarya
liebertiana Engl. Leguminosae (Caesalpinio'ideae): Cynometr.1
brachyrrhachis Harms; C. engleri Harms; C. longipedicellata
Harms;
Englerodendron usam barense Harms; lsoberlinia
scheffleri (Harms) Greenway; Zenkerella grotei (Harms) J .
Lean. Leguminosae (Papiliono'ideae): Erythrina w.?rneckei
Bak. f.; Leptoderris harmsiana Dunn; Ptero;;arpus usamba­
rensis Verdc.; Schefflerodendron usambarense Harms. Lobe­
liaceae: Lobelia longisepala Engl. Malpighiaceae: Acridocar­
pus schejjleri Engl. Melastomataceae: ':'Memecylon amani­
ense (Gilg) A. & R. Fern . ; M. brenanii A. & R. Fern. ;
':'M. cogniauxii Gilg; ':'M. deminutum Brenan; M. erythran­
thum Gilg; M. greenwayi Brenan; M. erubescens Gilg; 'M.
heinsenii Gilg'; M. microphyllum Gilg. Menispermaceae:
Epinetrum apiculatum Troupin. Moraceae: 'Bosqueiopsis par­
vifolia Engl.' ; ':'Dorstenia holstii Engl.; Ficus scheffleri
Warb. ex Mildbr. & Burret; Ficus usambarensis Engl . ; ':'S/oe­
tiopsis usambarensis Engl. Myristicaceae: *Cephalosphaera
usambarensis (Warb.) Warb. Myrtaceae: 'Eu.genia schefjleri
Engl. & v. Brehm.'; ':'Syzygium sclerophyllum Brenan. Och­
naceae: Ouratea scheffleri Engl. & Gilg. Pandanaceae: 'Pan­
danus engleri Warb.' Rhizophoraceae: Anisophyllea obtusifo­
lia Engl. & v. Brehm. Rosaceae: '''Hirtella megacarpa R. Grab. ;
Parinari goetzeniana Engl. Rubiaceae: 'Canthium diplodiscus
(K. Sebum.) Bullock ' ; 'C. sclerocarpum (K. Sebum.) Bullock' ;
':'Chasalia albiflora K. Krause; ':'C. buchwaldii K. Sebum.;
':'C. disco/or K. Sebum.; Hutchinsonia xanthotrichct (K.
Sebum.) Robyns; lxora albersii K. Sebum.; 'I. narcissodora
K. Sebum.'; '1. schefjleri K. Sebum. & K. Krause'; ':'Lagynias
pallidijlom Bullock; *Morinda asteroscepa K. Sebum.;
Mussaenda holstii Wernh . ; Oxyanthus stenocarpus K.
Sebum.;
Pavetta amaniensis Bremek.; P. corethrogyne
Bremek.; ':'P. holstii K. Sebum.; P. olivaceo-nigra K. Sebum.;
.P. rufipila Bremek. ; P. stenosepala K . Sebum.; P. usambarica
Bremek.; *Pentas hindoio'ides K. Schum.; Polysphaeria macActa Phytogeogr Suec 54
1 78
R. M. Polhill
rantha Brenan; *Porterandia penduliflora (K. Sebum.) Keay;
Psychotria alsophila K. Schum.; P. brevicaulis K. Schum.;
P. coaetanea K. Sebum. & K. Krause; 'P. distegia K. Schum.';
P. eickii K. Schum. ; *P. faucicola K. Schum.; 'P. lampro­
phylla K. Schum.'; P. pandurata Verdc.; P. porphyroclada
K. Schum.; 'P. scheffleri K. Schum. & K. Krause'; *Ryti­
gynia amaniensis (K. Krause) Bullock; R. biflora Robyns;
R. eickii (K. Sohum. & K. Krause) Bullock; 'R. kidaria
(K. Schum. & K. Krause) Bullock'; R. undulata Robyns;
':' Uragoga macrophylla K. Krause. Rutaceae: Calodendrum
eickii Engl. ; 'Fagara amaniensis Engl.'; 'F. deremensis Engl.';
Teclea amaniensis Engl.; T. angustialata Engl.; Vepris
ngamensis Verdoorn. Sapindaceae: Allophylus melliodorus
Gilg; Placodiscus amaniensis Radlk. Sapotaceae: Vitel­
lariopsis cuneata (Engl.) Aubrev.; Gen. nov. aff. Sideroxylon.
Simaroubaceae: *Odyendea zimmermannii Engl. Solanaceae:
'Solanum eickii Dammer'; S. usambarense Bitter & Dammer.
Sterculiaceae: Byttneria fruticosa K. Schum.; Cola greenwayi
Brenan var. greenwayi; ':'C. scheffleri K. Schum.; C. usam­
barensis Engl.; *Dombeya amaniensis Engl.; 'D. malacoxy­
lon K. Schum.'; 'D. monticola K. Schum.'; 'D. schoenodoter
K. Schum.'; D. warneckei Engl.; ':'Leptonychia usambarensis
K. Sebum. Tiliaceae: *Grewia calymmatosepala K. Schum.
Turneraceae: Stapfiella usambarica J. Lewis. Verbenaceae:
'Clerodendrum dembianense Chiov.'; 'C. impensum Thomas';
'C. velutinum Thomas'; * Vitex amaniensis Pieper.
Uluguru and Nguru Mts.
Acanthaceae: Barleria lukwangulensis Mildbr.; Brillantaisia
ulugurica Lindau; 'Epiclastopelma glandulosum Lindau'; 'E.
macranthum Mildbr.'; Isoglossa ixodes Lindau; / oreacan­
tholdes Mildbr.'; Justicia beloperono"ides Lindau; ':'J. inter­
rupia (Lindau) C. B. Cl. ; 'J. ulugurica Lindau' ; 'Mimulopsis
longisepda Mildbr.'; 'Schliebenia salviiflora Mildbr.'; Tham­
no;usticia grandiflora Mildbr. Anacardiaceae: ':'Trichoscypha
ulugurensis Mildbr. Asclepiadaceae: '�Tylophora gracillima
Markgraf. Boraginaceae: 'Ehretia rosea Guerke'. Compositae:
'Vernonia ulugurensis 0. Hoffm.' Ebenaceae: 'Diospyros co­
rylicarpa Guerke'. Escalloniaceae: 'Choristylis ulugurensis
Mildbr.' Euphorbiaceae: Tetraorchidium ulugurense Verdc.;
Zimmermannia acuminata Verdc. Flacourtiaceae: Rawsonia
ulugurensis Sleumer. Guttiferae: ':'Allanblackia ulugurensis
Engl. Leguminosae (Caesalpinioi"deae): 'Cynometra ulugu­
rensis Harms'; Zenkerella capparidacea (Taub.) J. Leon.; Z.
schliebenii (Harms) J. Leon. Leguminosae (Papiliono'ideae):
Millettia semseii Gillett; M. sericantha Harms; Priotropis in­
opinata Harms. Lobeliaceae: Lobelia lukwangulensis Engl.
Loganiaceae: Adenoplusia ulugurensis Melch. Malpighiaceae:
Acridocarpus congestus Launert. Melastomataceae: Dissotis
polyantha Gilg; Memecylon myrtillo"ides Markgraf; Neope­
talonema pulchrum (Gilg) Brenan; 'Orthogoneuron dasyan­
thum Gilg'. Meliaceae: 'Turraea schliebenii Harms'. Myr­
taceae: Syzygium parvulum Mildbr. Oleaceae: 'Jasminum ro­
tundatum Knobl.'; Olea schliebenii Knobl.; Schrebera goet­
zeana Gilg. Pittosporaceae: Pittosporum goetzei Engl. Ru­
biaceae: Ancylanthus rufescens E. A. Bruce; Bertiera pauloi
Verdc.; Chasalia violacea K. Sebum.; *lxora ulugurensis
'
Acta Phytogeogr Suec 54
.
Bremek.; Lasianthus cereiflorus E. A. Bruce; L. glomeruli­
florus K. Sebum . ; L . grandifolius Verdc.; L . macrocalyx K.
Schum . ; L. microcalyx K. Schum.; L . pedunculatus E. A.
Bruce; L. wallacei E. A. Bruce; L. xanthospermus K. Schum.;
Mussaenda ulugurensis Wernh.; Pavetta axillipara Bremek.;
P. bruceana Bremek. ; P. coelophlebia Bremek . ; P. constipu­
lata Bremek.; *P. filistipulata Bremek.; P. kimbozensis
Bremek.; P. sparsipila Bremek. ; �'Pentas ionolaena K.
Schum.; P. pseudomagnifica M. R. F. Taylor; 'Psychotria
cephalidantha K. Schum.'; P. elachistantha (K. Schum.)
Petit; :::p. goetzei (K. Schum.) Petit; Rytigynia !entice/lata
Robyns; 'R. lichenoxenos (K. Schum.) Robyns'; 'R. nodulosa
(K. Schum.) Robyns'; Sabicea arborea K. Schum.; Tarenna
c,uadrangularis Bremek.; ':'T. ulugurensis (K. Schum.) Bre­
mek.; Tricalysia anomala E. A. Bruce. Rutaceae: 'Fagau
paracantha Mildbr. ' ; 'Vepris mildbraedianCI G. M. Schulze'.
Sapotaceae: Mimusops penduliflora Engl. Solanaceae: 'Sola­
num inaequiradians Werd.'; S. lignosum Werd.; S. schliebenii
Werd. Sterculiaceae: Cola microcarpa Brenan; C. stelecantha
Brenan; 'Dombeya macrotis K. Schum.' Theaceae: Tern­
stroemia polypetala Melch. Thymelaeaceae: 'Peddiea puberula
Domke'; P. subcordata Domke. Tiliaceae: Grewia schliebenii
Burret. Turneraceae: Stapfiella ulugurica Mildbr. Verbena­
ceae: 'C/erodendrum suffruticosum Guerke'; 'C. u!uguren:;e
Gu:rke'.
Lindi District, particularly Rondo and
Makonde Plateaux
Acanthaceae: 'Streptosiphon hirsutus Mildbr.' Annonaceae:
Xylopia collina Diels. Canellaceae: Warburgia ugandensis
Sprague subsp. longifolia Verdc. Chailletiaceae: ':'Dichapeta­
lum edule Engl.; D. macrocarpum Engl.; D. schliebenii
Mildbr. Combretaceae: 'Combretum lindense Exell & Mildbr.';
'C. schliebenii Exell & Mildbr.' Connaraceae: Vismianthus
punctatus Mildbr. Convolvulaceae: Ipomoea flavivillosa
Schulz-Menz. Ebenaceae: Diospyros eggelingii F. White. Eu­
phorbiaceae: Zimmermannia grandiflora Verdc. Flacourtiaceae:
Homalium elegamulum Sleumer. Hypericaceae: Vismia pauci­
flora Milne-Redh. Leguminosae (Caesalpinio'ideae): Bussea
eggelingii Verdc.; 'Caesalpinia insolita (Harms) Brenan &
Gillett'; 'Cynometra filifera Harms'; ':'Guibourtia schliebenii
(Harms) J. Leon. Leguminosae (Mimosoldeae): Mimosa bus­
seana Harms; *Pseudoprosopis euryphyl/a Harms; 'Xylia
schliebenii Harms'. Leguminosae (Papiliono'ideae): ':'Baphia
macrocalyx Harms; *B. punctulata Harms; *Crotalaria
pterocalyx Harms; *Dalbergia acariaeantha Harms; Eryth­
rina schliebenii Harms; Millettia makondensis Harms; M.
schliebenii Harms; *M. stuhlmannii Taub.; *Ormocarpum
schliebenii Harms. Passifloraceae: Paropsia schliebeniana
Sleumer. Rubiaceae: Cuviera semseii Verdc.; Heinsia bussei
Verdc.; H. parviflora K. Schum. & K. Krause; Leptactina
bussei K. Sebum. & K. Krause; Pavetta lutambensis Mildbr.
ex Bremek.; P. schliebenii Mildbr. ex Bremek.; 'Polysphaeria
squarrosa K. Krause'. Rutaceae: Vepris schliebenii Mildbr.
Solanaceae: Solanum lamprocarpum Bitter. Sterculiaceae:
Cola discoglypremnophylla Brenan & A. P. D. Jones; *Ster­
culia schliebenii Mildbr. Tiliaceae: Grewia meizophylla Bur­
ret.
S O C O T RA
M. D. Gwynne
TOPOGRAPHY AND GEOLOGY
The island of Socotra (centre 1 2 ° 30'N, 54° 00'E)
lies on a promontory of the African continental shelf
225 km east of Cape Guardafui, Somalia. It is
separated from the Arabian coast by the fault system
of the Gulf of Aden, while on the ·continental shelf
between Socotra and Somalia are the islands of Abd­
el-Kuri and The Brothers together with a number of
non-magnetic seamounts (Matthews 1 963).
Although imperfectly known it would appear that
its geological structure is simple and resembles that
of neighbouring parts of Africa and Arabia. Essen­
tially there is a mass of crystalline rocks with almost
undisturbed Cretaceous and Tertiary beds resting on
them. The island is probably part of a fault block
separated off from the mainland by t he same series
of dislocations which produced the Gulf of Aden in
late Tertiary times (Reed 1 921).
Socotra is 1 1 5 km in length from east to west and
35 km in width. It is bordered on the north and south
by wide alluvial plains of recent origin. The interior,
however, consists of a broad undulating, but deeply
dissected plateau of limestone averaging about 300
m in height above sea level and surrounding on the
west, south and east a small nucleus of granitic
mountains which rise to a height of over 1 500 m.
The rock formations may be detailed as follows:
A rchaean: These are exposed to form the main
massif of the Hagghier mountains near the north-east
coast. There are also two smaller exposures of the
same rock near the east and west ends of the island.
These ancient rocks can be divided into two groups.
(a) gneisses, generally granitoid, and granites
mostly of a pink-red colour. This group forms the
highest peaks of the island,
(b) dark green amphibolite schists similar to those
of the Archaean series of East Africa.
The basement rocks of Socotra are thus similar to
those of the East African massif.
Cretaceous: A series of fossil bearing Cretaceous
beds, nearly undisturbed, rests directly on the crys­
talline rocks. These run from quartzose sandstones,
marls and fine sandstones, through yellow or brown
Rudistid limestone to white chalk which ends the
series. The beds attain their maximum thickness of
3 00 m at the eastern end of Socotra (Gregory 1 899).
Eocene: The greater part of the plateau consists
.of Eocene limestones which occasionally repose di-
rectly on the Archaean basement. The beds are
mostly white limestones of about 400 m thickness
and are almost horizontal and virtually undisturbed.
The limestones are of a compact massive character
and are in places coarsely crystalline. Thus the beds
break off into steep cliffs along the coast and valleys.
Late Igneous rocks: In places the limestones are
pierced by dykes and masses of trachyte and basalt
and in the south-east there has been an eruption of
trachytic or rhyolitic lava. These resemble the Aden
volcanic series rather than those of East Africa.
Late Tertiary or recent conglomerates, grits and
breccias are found in the valleys and on the coastal
plains which largely consist of recent alluvial de­
posits.
SOILS
Apart from that given by Popov (1 957) there is very
little published information on the soils of Socotra.
As would be expected, however, they are related to
the three main topographic formations.
Hagghier massif: granite decomposition has led to
the formation of deep rich red soils in the mountains,
in places 2 m or more in depth. These have accu­
mulated in the valleys and have spread out over parts
of the Hadibo coastal plain in the north.
Limestone plateau: weathering has produced a
fine grey clay soil which builds up into black soil in
pockets and crevices in the smooth rock surface. In
some areas shallow soil deposits have accumulated in
extensive depressions of slight gradient and in such
areas the soil may be up to 75 cm deep, although
usually less.
Alluvial Plains: North coast: mainly packed gra­
vel, stones and coarse sand with an admixture of fine
grey clay soil. Fine soils from the uplands and high­
lands have become shallowly deposited at the estu­
aries to form areas which are the centre for local
agriculture. Shallow deposits of windblown sand oc­
cur throughout the area, particularly on the Goba
plain and on the Ras Houlaf promontory where they
have also become banked against the limestone to a
height of about 1 00 m.
Alluvial Plains: South coast: mainly packed gravels,
stones and coarse sand with loose sand on the sur­
face. Along the coast the sand is white and of shell
and coral origin. Parallel to the coast the belt of
yellow sand which builds extensive crescentic dunes
up to 7 m high is mostly of granitic origin. There
Acta Phytogeogr Suec 54
1 80
M. D. Gwynne
are also extensive shallow areas of grey clay and
fine silt particularly in depressions near water courses
and estuaries, but in these areas the soil is saline.
CLIMATE
The climatic factors exerting most influence on the
ecology of Socotra arise from its position with regard
to the seasonal monsoons of the Indian Ocean.
In the region of the island the wind circulation is
of the true monsoon type in that it involves the
alternate seasonal dominance of two opposing major
wind systems, each of them locally affected by the
relative position of large land and sea areas. The
reversal of wind direction at the change of seasons is
so marked that it is usually accompanied by a re­
versal of ocean currents in the north-western basin
of the Indian Ocean (MoMaster 1 9 66). The north­
east monsoon blows from November to M arch while
the south-west monsoon is the major influence from
M ay to September. The intervening periods of Sep­
tember-October and April-May are times of calm
or unsettled wind patterns between the monsoons.
During the north-east monsoon marine wind
speeds seldom exceed 25-35 km p.h. and gale force
winds (56 km p.h. and over) are generally under 1 %
of the total recordings. Around the coast of Somalia
and Socotra, however, the incidence of high winds is
thought to be greater. The north-east monsoon winds
are, therefore, strong without being violent and it is
these winds which bring the main rains to Socotra.
The south-west monsoon, however, .is very differ­
ent and both June and July are months of very high
winds. Observations of gale force and above make up
over 50% of all the records for the area around
Socotra where, on an average, there are 23 gale days
during July. On Socotra these winds which seldom
bring rain to most of the island are very dry causing
desiccation to plants and animals alike. The normal
pattern is for a strong daily wind with periods of
calm at dusk and dawn. During the daylight hours
the wind is often interspersed with gusts of extreme
violence and short runs of over 1 44 km p .h . have
been recorded.
Still the only reliable rainfall figures are those
measured at a Royal Airforce Station at Ras Karma
in the north of the island and which was occupied
from 1 943- 1 945. These showed that the annual rain­
fall for that particular area was from 1 2 5- 1 75 mm
during the three years that records were kept. These
figures are probably typical for most of the plateau
and plains areas although the local inhabitants say
that more rain falls in the east of the island
than does in the west. This is probably associated
Acta Phytogeogr Suec 54
with the higher ground in the east. The central
highlands, however, particularly on the north slopes
must have a much greater annual rainfall which,
judging from the vegetation, might be of the order of
3 80-500 (-625) mm. The present writer encountered
frequent rain during August and September in 1 956
at altitudes over 750 m on the northern slopes of the
Hagghier together with heavy mists and dew. Similar
mists and dew were reported by Popov ( 1 957) in the
same area at other times of the year.
Rainfall started moving down the valleys of the
northern slopes of the Hagghier during August and
by early September clouds had built up over the
northern plains and scattered showers were encoun­
tered. These showers were not met with on the
southern Hagghier slopes or on the southern plain
areas. Thus the southern half of the island is prob­
ably somewhat drier than the north.
May is said to be the hottest time of year when
both heat and humidity rise during the calm period
between the monsoons. For the same reason Septem­
ber is also an�ther period of high humidity.
Popov ( 1 957) records a mean of 25 ° C for Hadibo
on the north coast during the first three months of
1 953. In the highlands the temperature is appreciably
lower although as far as can be ascertained the local
inhabitants have no knowledge of frost.
Cloud cover is variable with the central peaks of
the Hagghier being in constant cloud for long periods
each year. Television cloud photographs taken from
Tiros satellites show that the whole island is fre­
quently obscured by complete cloud cover during the
monsoons, particularly during the period of the
north-east monsoon.
HYDROLOGY
The Hagghier massif forms the most important
watershed on the island and from this area of higher
rainfall and permanent springs, numerous water­
courses run both north and south. In their upper
reaches these streams, particularly on the northern
slopes, are permanent and the present writer has
seen them flowing in August at the end of a hot dry
season. They do not, however, survive the crossing
of the plains and soon disappear. Thus in the plains
the streams are sporadic carrying water only during
the rains and just after. These watercourses traverse
the plains along single well defined beds of boulders
with shallow banks not more than 1 m high. In the
north and west many of the river estuaries retain
water for most of the year so that the water table is
high allowing cultivation and enabling most houses
to have their own well. Along the north-east coast
Socotra
I l l I Montane g rassland
1:1 Submont a ne t hicket
�I�I!I!I S ubdesert succ u lent shrubland
181
I
7
;:::; Grass ste p p e with shrubs and t re>t"S
. ::: Subdesert shrubland (m a inly dw rf)
D Du n e area
' , , Proposed conservation area
Fig. ]. Tentative vegetation m a p o f Socotra. The map is based o n personal field observations, t h e published account o f Popov
( 1 957) and on topographic and vegetational detail obtained from a near vertical Ektachrome photograph taken from an altitude of
296 km ( 1 85 miles) by Astronaut Frank Borman during the flight of Gemini 7 in December 1 965 and supplied through the courtesy
of the United States National Aeronautical and Space Administration. This map does not show the Herbaceous Halophilous Plant
Formations of the coast, Mangrove, Lo wland Thicket and Fresh Water Swamp Formations.
there are two or three smaller catchments which
reach the sea through narrow gorges.
Much of the limestone plateau is dry particularly
during the south-west monsoon, but there are a num­
ber of rain pools and springs which last into the dry
season. The south coast, however, is very short of
water for there are only one or two springs and
seepages at the base of the limestone cliffs and sev­
eral wells of brackish water.
A large catchment of uncertain potential is that of
the Zahr watercourse which mostly arises in the high
ground in the west and sweeps through the central
area before reaching the sea along the north coast.
In the west there are also one or two other catch­
ments which reach the sea along the west coast, the
most notable being that of the Kalansiya area, and
that of the broad valley in the extreme south-west.
VEGETATION
General Features
Socotra is ringed by a narrow coral reef on which
are algae similar to those found on the coasts of the
African mainland and Arabia.
Along the white coastal sands fringing the island
are Herbac�ous Halophilous Plant Formations. These
are well developed on the coasts of the plains and less
well formed where the coast is immediately backed by
steep cliffs. In and along most estuaries small salt
marshes form.
Mangrove occurs as small narrow belts and
patches along inlets on the southwest coast and parts
of the western half of the north coast.
The band of yellow sand on the southern plain
contains many mobile crescentic dunes completely
lacking vegetation. Others, however, support a vary­
ing degree of plant cover some of which can be
quite dense. Where present the perennial vegetation
of these dunes is of the Sub-desert Dwarf Shrub/and
type similar to the Sub-desert Dwarf Shrubland of
the southern plain as a whole. According to Popov
( 1 957) a number of annuals and ephemerals grow on
these dunes in greater abundance than elsewhere.
Dune areas with different plant species composition
also occur on the Ras Houlaf promontory.
All the plains on the island contain large areas of
Barren Land. Those plains in the north contain a
band of Sub-desert Dwarf Shrubland on the seaward
side which extends inland in the Goba area for well
over 5 km and probably runs into the Zahr basin.
This type is almost entirely absent from the plains to
the east of Ras Houlaf.
Inland parts of the northern plains are covered
with Grass Steppe with Shrubs which in places runs
up to the foot of the limestone cliffs or merges into
a type intermediate between Grass Steppe with
Shrubs and Grass Steppe with Trees on the foothills
of the Hagghier and parts of the limestone plateau.
Parts of the smaller plains in the east of Socotra
and the surrounding limestone hills are covered with
Grass Steppe with Trees as is part of the watershed
Acta Phytogeogr Suec 54
1 82
M. D. Gwynne
between Kalansiya and the Goba plain. The re­
mainder of this watershed contains areas of Sub­
desert Shrubland.
The top of the main limestone plateau is very arid
and, during the south-west monsoon, shows little sign
of vegetation. It is, however, not true desert and
would best be termed Sub-desert Shrubland with large
areas of Barren Land. In hollows, ravines and on
sheltered ledges, patches of Lowland Thicket occur.
Similarly in the limestone hills at the eastern end of
the island the vegetation is mainly of the Sub-desert
Shrub type with extensive areas of Lowland Thicket.
The margins of the limestone plateau, including
the steep cliffs and valley slopes, and in particular,
the rough and rugged slopes and screes of the north,
contain an interesting Sub-desert Succulant Shrub­
land type with, soil and topography permitting,
patches of Grass Steppe with Shrubs and Grass
Steppe with Trees.
On the Hagghier massif, the lowland forms give
way to a band of evergreen Sub-montane Thicket
at about 800 m. Between 1 000 m and 1 200 m the
watershed is covered by open Montane Grassland
with patches of evergreen Sub-montane Thicket in
suitable localities. The higher peaks above 1 200 m
are bare rock covered with crustaceous lichens to­
gether with a few species of woody herbs, notably
Helichrysum.
The Zahr watercourse basin and the south-west
of the island are not sufficiently well known to be
able to definitely ascribe vegetation types to them. It
is likely, however, that the central part of the Zahr
basin is Sub-desert Shrubland with the higher regions
containing areas of Grass Steppe with Shrubs and
Grass Steppe with Trees. Similarly the south-west is
likely to be covered with Sub-desert Shrubland with
some Lowland Thicket on the hills and Sub-desert
Succulant Shrub/and along the cliffs and steeper
hills.
Throughout the plains and valleys there are small
Fresh Water Swamp Formations with both Cyper­
aceae and Gramineae. Various riverine communities
also exist where suitable conditions occur.
Protected Associations. Although geographically
closer to Somalia than to Arabia, Socotra is cultur­
ally and ethnically part of Arabia. Until recently the
island was part of the British controlled East Aden
Protectorate but now it forms part of the Peoples
Republic of South Yemen. It is ruled over by a
Sultan who is also Sultan of the Arabian mainland
State of Quishin. Sporadic visits of short duration
were made by colonial administrators and medical
officials in the past but there was never a Resident
Acta Phytogeogr Suec 54
and on the whole the i sland was virtually autonomous
during the period of the British protectorate. There
are, therefore, no conserved areas of any sort.
Areas in Need of Conservation
Approximately 3% of the plant genera and nearly
30% of the plant species found on Socotra are be­
lieved to be endemic to the island. In the future a
number of these species will undoubtedly be found
in Somalia and perhaps in South Arabia. There may,
however, be further botanical discoveries to be made
on Socotra itself as many areas have not yet been
examined botanically-particularly in the south-west
-so that the number of endemics might continue
near its present level. The whole vegetation of the
3640 sq. km of Socotra is thus worthy of conserva­
tion for, with the exception of the fringing coastal
areas, all the major vegetation types contain a num­
ber of interesting endemic species. Such a proposal,
however, would not be a practical proposition as the
island contains some 1 0,000- 1 2 ,000 inhabitants
whose agricultural and pastoral interests would not
make this feasible.
The most interesting areas worthy of conservation
are, in order of priority:
1 . Limestone plateau (comprising foothills, cliffs
and plateau top): This is undoubtedly the area of
greatest botanical interest on the island, particularly
in the north where the slopes contain a large number
of unusuai plants.1 Here the distinctive endemic
species Dendrosicyos socotrana, A denium sokotra­
num, Cissus subaphylla, Euphorbia arbuscula, E. spi­
ralis, Withania riebeckii and Cynanchum linifolum
dominate the scene on the lower slopes to produce a
landscape that is unmistakably Socotran. There is
also an abundance of annual and perennial herbs
among the commonest of which are the endemics
Pulicaria stephanocarpa, P. diversifolia, Corchorus
erodioides, Lactuca rhynchocarpa, Oldenlandia pul­
vinata, and the fern A diantum baijourii.
Higher up the slopes (above 500 m) this com­
munity is gradually replaced by one containing
Dorstenia gigas, Kleinia scottii, Ficus socotrana (a
stunted form), Euphorbia oblanceolata, Hibiscus
scottii, Tetragonia pentandra, and Boswellia spp.
Other endemics in this zone are Polycarpaea divari­
cata, Haya obovata and Pseudomussaenda capsuli­
jera which droop from the rock ledges. In areas
where the soil is very poor or limited in develop­
ment species such as Kalanchoe farinacea, K. ro­
busta, Aloe perryi, Teucrium sokotranum and the
1 Authorities
Popov ( 1 957).
for
plant
names
are
as given
by
Gillett in
Socotra
Fig. 2. Dendrosicyos socotrana growing on the
1 83
northern limestone cliffs. Photo M. D. Gwynne, July, 1 956.
Crucifer Diceratella incana become locally abundant.
In this region also is found the important horticul­
tural plant Begonia socotrana first brought off the
island in 1 880. It grows deep in rock crevices to­
gether with Exacum affine but never below 500 m.
B. socotrana reaches its best development, however,
on the sheer, bare rock faces of the peaks of the
Hagghier above 1 300 m.
On sheltered shelves and in depressions and gul­
leys dense thicket can become established in which
the following endemic trees and shrubs are among
the most common species: A cacia pennivenia, Croton
sulcifructus, R uellia insignis, Dicliptera effusa, Rhus
thyrsiflora, Psiadia schweinfurthii, A cridocarpus
socotranus and occasional Ficus socotrana. These
thickets are often entwined with the endemic creepers
Cissus paniculata, Tragia balfouriana and Dioscorea
lanata.
The top of the plateau is very arid so that the
vegetation is limited to small, scattered specimens of
Ficus socotrana, Croton socotranus, Jatropha unico­
stata, Dracaena cinnabari and A denium sokotranum
together with several species of annual grasses, a few
herbs and lots of bare ground.
The vegetation of all the steep limestone slopes
and cliffs is essentially the same throughout the is­
land except that it is probably more profuse in the
north than in the south. These limestone communi­
ties are best seen on the plateau promontory to the
west of the Hadibo plain.
la. A secondary area within the limestone which
is of interest is that of the Hamadera hills at Homhil
where there is an extensive Dracaena-Boswellia com­
munity. Dracaena cinnabari, Boswellia ameero, B.
elongata, B. socotrana, Adenium sokotranum and
Aloe perryi are the dominants with the Boswellia
spp. predominating on the level areas and the Dra­
caena on the slopes.
2. Hagghier massif:
Evergreen
Sub-montane
Thicket occupies the slopes of the Hagghier massif
between 800 m and 1 000 m. On the lower level it
merges into the Grass Steppe with Trees and Shrubs
of the plains or the Sub-desert Shrub/and of the
limestone. At the higher altitude it breaks off quite
sharply to give way between the peaks to open Mon­
tane Grassland which is the main grazing area for
cattle on Socotra. The Thicket is better developed
and more extensive on the . north of the Hagghier
than it is on the south.
Among the many species of this region the most
Acta Phytogeogr Suec 54
1 84 M. D. Gwynne
Fig.
3.
Adenium
sokotranum
growing in the Homhil area.
Photo M. D. Gwynne, August,
1956.
prominent endemics are Cephalocroton socotranus,
Ficus socotrana (here an extensive tree), Indigojera
sokotrana, Boswellia ameero, Euphorbia socotrana,
Hypoestes pubescens, A llophylus rhusiphyllus, He­
dyotis stellarioides, and the beautiful flowered Ruel­
lia insignis. These grow in a tangled, almost impene­
trable undergrowth of Cocculus balfourii and the
non-endemic Cissus quadrangularis, the whole being
frequently bound together by the endemics Tragia
balfouriana and Dioscorea lanata.
On the very steep, non-grass, stony slopes above
the Thicket, the vegetation gradually opens to give
an association of such species as Euryops socotranus,
Hypericum tortuosum, A erva revoluta, Pluchea obo­
vata, Pulicaria vieraeoides, Gnidia socotrana, Satu­
reja remota, Lotus ononopsis and Haemanthus gran­
difolius. Dracaena cinnabari and Commiphora plani­
frons are both conspicuous elements of this com­
munity.
2 a. The high peaks of the Hagghier may be
briefly mentioned here. They are of interest pri­
marily for their thick covering of lichen which ob­
scures the pink colour of the rock, and for several
species of endemic Helichrysum. Most of the other
plants which are found on the peaks occur elsewhere
on the island such as Kalanchoe farinacea, A loe
perryi, Exacum caeruleum and Begonia socotrana.
3. Plains and lower hill slopes: Nearest the coast
these are covered by a band of Sub-desert Dwarf
Shrubland in which among the many species present
a dwarf Commiphora, a new species of Indigo/era,
Campylanthus spinosus, Euphorhia spiralis, E. sepActa Phytogeogr Suec 54
temsulcata, Aloe perryi and the grasses Dactyloc­
tenium hackelii and Panicum rigidum are the most
interesting endemics. Large patches of Euphorbia
arbuscula occur in this area also.
Further inland in parts of the north this type is
replaced by Grass Steppe with Shrubs and in places
by Grass Steppe with Trees or an intermediate be­
tween the two. The dominant for this area is Croton
socotranus which often forms pure stands but is usu­
ally associated with Placopoda virgata, Justicia ri­
gida, Lycium sokotranum, Ballochia amoena, Tri­
chocalyx orbiculatus and A loe perryi all of which
are endemic species. The grasses of this association
are mainly the non-endemic A ristida adscencionis
and Melanocenchris abyssinica with some Panicum
rigidum on the more sandy areas. This association
has no real counterpart elsewhere.
On hillsides in some parts the Croton association
is gradually replaced at the higher levels above 1 00 m
by a community in which Commiphora parvijolia
and the endemic C. socotrana are the dominants
together with Barleria tetracanthera, Blepharis spi­
culifolia and Cissus subaphylla.
RECOMMENDATIONS
These three regions contain sizeable examples of all
the main plant associations on Socotra which are
worthy of conservation. The precise location for the
best examples of each association is difficult to de­
termine as so much of the island is still botanically
unexplored.
Socotra
Fig. 4.
1 85
Dracaena cinnabari.
Kishin valley, Hagghier moun­
tains. Photo M. D. Gwynne,
July, 1 956.
Socotra will not remain in its present backward
state for many more years. When development does
come it will undoubtedly spread first towards the
west along the plains because of the easier topo­
graphy. Thus any reserves created should not be in
this area as they will have little chance of survival.
It is for this reason that I would recommend that
the Reiged limestone plateau to the west of Hadibo
should not be made into a reserve even though it
contains the best examples of the limestone flora.
To the east of Hadibo the country is rough, rug­
ged and relatively unpopulated and by careful siting
of boundaries a single sizeable piece of Socotra could
be delineated into a Conservation Area which would
contain examples of all the interesting plant com­
munities on the island in sufficient quantity to en­
sure their continued survival. An example of such a
Conservation Area would be that contained by a
line drawn from a mid-point between the village of
Suk and the start of the Ras Houlaf sands south
through the Hagghier near Adho Demalus and on to
the southern limestone to a point 1 1 km in horizon­
tal distance from the start. The line would then tra­
vel almost due east for nearly 30 km when it would
meet a valley to the east of Homhil where it would
turn north and follow this valley to the sea.
Whether this particular area would be the most
suitable would depend entirely on the results of a
botanical survey of the whole island. Such a survey
is badly needed. When it is considered that, with very
few exceptions, all the species mentioned in this pa­
per are endemic to Socotra it can easily be seen how
worthwhile this project would be.
Socotra is equally interesting zoologically so that
final selection of the Conservation Area should also
be influenced by zoological considerations.
Further information on the biology, topography
and people is to be found in Balfour ( 1 888), Forbes
( 1 903), Popov ( 1 957), Botting ( 1 9 58) and Boxhall
( 1 966).
REFERENCES
Balfour, I. B., 1 888. Botany of Socotra. Trans. Roy. Soc.
Edin. 31 : 1-446.
Botting, D. S., 1958. Island of the Dragon's Blood. Hodder
and Stoughton, London.
Boxhall, P. G., 1966. Socotra: 'Island of Bliss'. Geogr. J. 132
(3): 2 1 3-222.
Forbes, H. 0., 1 903. Natural History of Sokotra and Abd-el­
Kuri. Bull. Liverpool Mus., pp. 598.
Gregory, J. W., 1 899. Note on the geology of Socotra and
Abd-el-Kuri. Geol. Mag. 6: 529-5 33.
McMaster, D. N., 1 966. The ocean-going dhow trade to East
Africa. E. Afr. Geogr. Rev. 4: 1 3-24.
Matthews, D. M., 1 963. A major fault scarp under the
Arabian Sea displacing the Carlsberg Ridge near Socotra.
Nature 198: 950-952.
Popov, G. B., 1957. The vegetation of Socotra. J. Linn. Soc.
London 55: 706-720.
Reed, F. R. C., 1 921. The Geology of the British Empire.
Edward Arnold, London.
Acta Phytogeogr Suec 54
R E G I O NA L S Y NT H E S I S
B. Verdcourt
The area dealt with in this report comprises five ba­
sic territorie3, Somaliland (including Socotra), Ethio­
pia, Uganda, Kenya and Tanzania. Ecologically the
variety of habitats could hardly be more diverse,
ranging from the most arid deserts to genuine dense
rain forest. The outlook for future conservation va­
ries just as much from country to country, being
quite encouraging in the south and distressingly dis­
couraging in the north-east. This is partly due to the
more marginal conditions of life in the arid areas,
partly to previous political history and undoubted�y
also to the differing mental outlooks of the various
race3. Owing to the wide range of habitats I venture
to think that the flora of East Africa is as rich if not
richer than any other area on the continent of simi­
lar size; in many areas there is a very high propor­
tion of endemic species, e.g. Usambaras (Tanzania),
Ogaden (Ethiopia-Somali border) and Socotra, to
mention only three outstanding regions.
We cannot hope to induce legislation to preserve
individual species save in very special circumstances
-it would in fact be almost impossible at this junc­
ture to draw up a list of genuinely threatened species
since the distributions of most are imperfectly
known. It is scarcely possible to point to an area and
say with any certainty that this is the last place where
X grows and must be protected. What is important
is to select as many habitats as possible from the wide
variety of different ecological areas and try to pro­
tect them. I have heard criticism of this idea on the
following lines-unless you give a firm reason i.e. the
name of a rare species, then nothing will be done.
I remember the attempt to preserve one species in
East Africa being more or less agreed on at minis­
terial level but it then became evident that the
government still thought they could thoroughly ex­
ploit the area provided they just left that species.
Only the idea of habitat preservation is of any im­
portance. The only alternative is to preserve in gar­
dens and zoos.
The Sornaliland flora is well known to be of par­
ticular interest because of the many strange endemic
species it contains. When I first had to name large
collections from this area from 1 952 onwards, I was
constantly surprised at the percentage of plants
which proved to be entirely new. This spate of new
species has continued but unfortunately few collec­
tors now have the opportunity to visit the area. The
island of Socotra is perhaps the most interesting part
Acta Phytogeogr Suec 54
of this floral region, containing as it does a very
high proportion of endemics (perhaps even 30%).
This striking flora was first made known as a result
of Balfour's expedition and the resulting volume is
one of botany's classic books. Several further expedi­
tions have added to our knowledge and many new
species remain undescribed owing to inadequate ma­
terial. Certain areas, particularly in the south-west,
have scarcely been examined and doubtless entirely
new plants remain to be discovered. Small islands
undoubtedly present the most difficult of all prob­
lems to conservationists and extinctions occur very
easily; frequently they are almost entirely dominated
by introduced species as in St. Helena, where much
of the indigenous fauna and flora disappeared cen­
turies ago; other depressing examples of extinctions
are many Mauritian birds and several trees in the
Seychelles. Species common in only very restricted
areas of such islands are rapidly eliminated as the
population increases, particularly if they are useful
or harmful species. The future chances of conserva­
tion on Socotra are not encouraging. There are no
areas protected at present and the native inhabitants
are unlikely ever to understand the use of conserva­
tion. The only cogent reason for conserving most
of the plants is the purely scientific one although
some of the species are of horticultural interest.
Tourist possibilities are negligible. The only hope I
see for the establishment of a · reserve is by direct
yearly compensation paid out of some international
fund. Since I believe that a thorough knowledge of
the Socotran flora may help in understanding the
history of the flora of Africa, it is important that
further expeditions1 consisting of professional bota­
nists should thoroughly comb the island at the right
time of year. Very general expeditions visiting the
island during the dry season are not likely to add
much to our knowledge. I agree with Dr. Gwynne
that this is a matter of some urgency. Among its
terms of reference this expedition should include the
collection of living material, pollen specimens and
tissues fixed for anatomical and cytological studies,
and also the selection of suitable conservation areas.
Perhaps A.E.T. F.A.T. could assist in this project.
From a botanical point of view the entire island is
worthy of national park status but the interests of
1 Since this was written
Mr. A. R. Smith of Kew has made
an excellent collection on Socotra and Abd al Kuri; there are,
however, still areas which no botanist has ever explored.
Regional synthesis
the local population render such a proposal entirely
impracticable. Certain areas in rough, rugged, rela­
tively uninhabited country east of Hadibo could be
designated conservation areas, but the plains, includ­
ing the exceedingly interesting limestone plateau at
Reiged are sure to be developed in a few years time.
I have no idea how this proposal could be made ac­
ceptable to the government, who would see no point
in it unless some financial gain were apparent. Al­
though nominally under British protection for a long
period, the people have virtually been autonomous
and there has never been a Resident. Although the
interest of this flora has not been underrated in the
past it has scarcely been in danger and conservation
has not been necessary. Even overgrazing has never
been a problem since domestic animals have always
been kept in check by nature's own methods without
interference from veterinarians.
The state of the territory of the Somali Republic
is perhaps the most distressing in our area both from
a botanical and an agricultural point of view. It is
certain that the whole Somali region has always
been dry, even during pluvial periods, else the char­
acteristic dry country flora much akin to that of
South West Mrica would hardly be so rich. Such a
dry area is of course always in a marginal condition
and the consequences of uncontrolled grazing and
browsing have been catastrophic. Added to this there
has been a drying out of the climate between 1 8 80
and 1 940, apparently recently reversed although
there is some doubt whether or not this is a perma­
nent reversal ; one can only hope so. Seventy years
ago many areas in the north had good grass cover
and herds of wild animals-elephant, hartebeest, wild
ass and even rhinoceros-now the same areas are
desert wastes devoid of nutritious grasses and trees,
and all the animals have gone, not primarily due - to
excessive hunting, but due to lack of suitable habi­
tats. Trees and bushes have been used for fodder,
fuel and building materials and overgrazing has de­
stroyed the grass. Permanent water supplies in the
forest areas have dried up. The herds of , domestic
animals have grown ever larger despite warnings
about the consequences, and it is pathetic to reflect
that some of the measures introduced by the Euro­
pean to help the Somali have only hastened the ruin.
To have extensive veterinary departments in a coun­
try grossly overstocked is clearly lunacy; to fine
miscreants so many hundred goats and then put them
up for sale again is clearly shortsighted. Provision of
permanent water supplies throughout the area has
meant that areas formerly having a seasonal respite
from grazing, thus allowing recovery, are now also
overgrazed. Orderly government, and the enforce-
187
ment of peace between the tribes has intensified the
problem. I am not unaware of the tremendous ad­
ministrative difficulties involved in dealing with a
people whose wealth and whole manner of life is
bound up with the number of stock that they actu­
ally possess. Moreover, the good will which the Brit­
ish administrative class has always had towards fine,
proud, nomadic people such as the Somali has para­
doxically complicated matters since their wishes were
more understood and respected. A firmer hand over
the problem of destocking would have been wiser and
lessened the serious problems now to be faced. It is
certain that a large part of the Somali populatio:1
could have been fed by cropping the game had con­
ditions continued as they were seventy years ago and
had this mode of life been acceptable to the Somali.
Even now it is not too late to save many areas;
enclosed areas protected from grazing show a re­
markable recovery and many inedible species disap­
pear. This is the first step and there are signs that the
Somali himself is now becoming worried. Unless im­
mediate action is taken the whole of the grass steppe
region can be written off as waste land. It has hap­
pened often enough in other parts of the world. In
the north there are still quite extensive areas of juni­
per forest and box scrub ; although nominally pro­
tected by a forest ordinance since 1 944, this only
protects living trees from felling. The forest remains
open to grazing and much damage has resulted from
erosion and lack of regeneration. Even succulents are
now suffering due either to direct grazing or lack of
sufficient root support due to wind erosion; succul­
ents of an unpalatable nature are greatly increasing
at the expense of other species. The answer to the
problem is basically to change the system of wealth
-drastic destocking with compensation followed by
reclamation and improvement of the grassland.
Fewer domestic animals of better types could then be
used and in many areas wild ungulates of good meat
quality reintroduced. In other parts of the world
similarly arid regions yield arable crops but such
schemes would involve extensive irrigation and use of
fertilisers ; the Somali government has no money for
such massive schemes but a quarter of the land used
properly could produce more than all of it does at
present. To discuss the possible preservation of spe­
cies and habitats interesting to botanists under the
present circumstances, with the exception of the
valuable food plant Cordeauxia, seems pointless and
any resolutions would scarcely be treated sympathe­
tically in Somaliland; but they will have to take heed
of more general measures. I well know that the So­
mali people have little reason to trust outside pro­
mises and have been subject to unjust acts of political
Acta Phytogeogr Suec 54
18 8
B. Verdcourt
In East Africa conservation is an idea now
expediency in the past which have engendered sus­
familiar
even to some of the nomadic tribesmen be­
picion. If the benefits of a new approach could be
cause
they
have actually had financial gain from its
demonstrated practically to the ordinary people by
education I think progress could be made. Mr. Hem­ practice. In twenty years there has been a complete
ming's first-class account of the vegetation of the change in outlook and national parks are accepted
northern region is a useful foundation for future features. It is even accepted that all of these need not
work. I have no knowledge of the present state of necessarily be self-supporting because together they
affairs in French Somaliland but certainly the tall are the only reason for the massive tourist industry
juniper forest at Dai should be rigorously preserved. which has developed and could well become the top
In Ethiopia the situation is different and somewhat money earner in Kenya. On the other hand, however,
more encouraging. The central government is at the average person still looks on a tree as fuel and an
least aware of the benefits of conservation and it is . animal as meat; this scarcely matters as long as the
quite likely that a valuable tourist trade could be government understands and has sufficient power to
developed. There are animals and birds which occur enforce rules. Without doubt it is the larger and more
nowhere else and also spectacular scenery with the exciting mammals that tourists come to see, and as
addition of many historical buildings of great inter­ man moves farther and farther from nature in other
est. In much of the country there are high moun­ parts of the world the number of people wishing to
tains and heavy rainfall in contrast with Somaliland, glimpse what life was like in the past will increase
but in many places, e.g. the Semien, cultivation ex­ yearly-back to nature for a week or so will become
a highlight of existence. East Africa· has a resource
tends up to 1 2,000 ft (3 650 m) on incredibly steep
slopes and little attempt at soil conservation is made. which will bring in a steady income for as long as
In the drier areas bordering Somaliland the problem man exists providing that it is looked after. That a
of overgrazing already stressed is becoming increas­ good deal of it will be looked after seems assured
ingly acute but none of the component species can be when a Kenya minister's Permanent Secretary (Mr.
said to be in serious danger. Woodland is deteriorat­ A. P. Achieng) can say "We aim at a non-exploitive
ing rapidly and forests are heavily exploited for their use of a natural resource. We sell something and it
timber; even the subalpine forest is endangered by is still there to sell again. All we, the salesmen, have
encroaching cultivation and burning to increase graz­ to do is to make it possible for the customer to see
the product." One might add that the customers
ing.
come
from the whole world. Fortunately the estab­
At present the only national park is that at Mene­
gasha, but since cultivation, grazing and logging con­ lishment of these parks, primarily for animals and
tinue there, it is hardly worthy of the name. Dr. Beals partly for scenic reasons, has conserved a wide range
suggests that twenty four conservation areas should of vegetation. Securely preserved are the Afroalpine
be set up covering the different types of habitat to be Flora, so ably monographed by our secretary, Dr.
found. Some of these reserves would basically be for Hedberg, and extensive areas of dry country vegeta­
rare mammals, e.g. the reserve near Mietgongo in the tion including the fascinating A cacia-Commiphora
Semien where the scenery is magnificent and the woodland around Tsavo, an extension of the Somali
rare Walia Ibex occurs. This area has been suggested flora which finally reaches north-east Tanzania. In
by several workers independently, e.g. L. Brown (see Uganda much interesting Acacia bushland and grass­
"The elusive Walia Ibex", Africana Vol. 1 , No. land is preserved in the Kidepo Park. It is true that
9 : 1 3- 1 5, 1 964). Much of the highland flora al so ex­ owing to the restriction in the areas suitable for
tends down into the East African highlands and migration, habitat damage is being caused by ele­
much of the dry country flora also occurs in the arid phant and hippopotamus but ecologists have been
eastern part of Kenya between Kibwezi and the employed and solutions to these problems will be
obtained. A College of Wildlife M anagement has
coast. There are, however, many e:x:ceedingly interest­
been set up and habitat conservation is naturally a
ing plants in the Ogaden which seem to occur no­
subject in the syllabus. Recently also an Education
where else and I would like to propose at least one
reserve in the Walwal-Wardere area. Many of the Centre has been established in the Nairobi National
areas proposed by Dr. Beals are rapidly deteriorating Park. Extensive areas of grassland and thicket are
and action needs to be taken quickly. It seems un­ preserved in the Serengeti area and adjacent M ara
likely that all these proposals will be taken up but Plains. In a.ll the areas occupied by nomadic tribes,
representations to the government might produce re­ e.g. Masai, Karamojong, Rendille, Turkana and
sults. Whether they would be able to enforce any Samburu to mention a few, the problems of over­
grazing are similar to those in Somaliland but the
resulting regulations is another matter.
Acta Phytogeogr Suec 54
Regional synthesis
outlook is brighter. Even these ultra-conservative
people whose cattle represent their whole way of life
have begun to benefit financially from such famous
game reserves as Amboseli, and are perceptibly
changing their ways. They are keen on education and
often highly intelligent. Amboseli reserve has fre­
quently been damaged by overgrazing but is develop­
ing rapidly and could bring in large sums. Gate fees
alone in 1 964 were £ 5750. It is basically thanks to
the philosophy of life of the Masai and their allies
during the past 350 years that large numbers of game
animals survive, but their prime interest in large
herds of cattle has led to serious overgrazing and
erosion. If they receive a substantial part of the
money accruing from the game reserves in their areas
their co-operation is likely to be gained. There are
large areas of marginal grassland in East Africa
where rainfall reliability is poor that could be given
over to game cropping schemes, since, bearing in
mind that the habitat is left undamaged, this is a
much more economical way of using the land than
allowing it to be overgrazed by stock or used for
marginal farming. In most countries similar land has
long ago been used and often depleted, so we are
fortunate to have the chance to put measures into
effect. For this chance we are chiefly indebted to the
tsetse fly but millions of wild animals have been
destroyed in an attempt to make land suitable for
stock, often to no avail.
In the dry areas, then, much vegetation is already
conserved, although there are some areas which
might be protected for their vegetation alone. One
such is a wide strip enclosing the road from Nairobi
to Lake Magadi, a scenic area with many interesting
plants; this would also safeguard the reservoir of
animals which makes the Nairobi National Park the
success it is. When I left Kenya farming activities
were already in operation which could ultimately
render this impossible. We must not be complacent
about the prospects of dry areas since sudden
changes in population and land use including radi­
cally ne\Y methods of farming could totally alter the
picture. If conservation areas were decided on before
the need became serious, it would obviate the sus­
picions of those who feel that conservationists often
seem to wait until a new scheme is under way before
they point out that an area is of exceptional biologi­
cal interest.
What of the forest? Only 5% of East Africa is
covered with forest and throughout British and Ger­
man rule firm policies of forest control were adhered
to, since it was obvious that it was an easily ex­
haustible resource. The Germans set up fourteen
major protection reserves in the then Deutsch Ost-
1 89
Afrika totalling some 2000 sq. miles (5 1 20 sq. km),
apart from a host of remnants. By 1 942 reserves
totalled 4000 sq. miles ( 1 0,240 sq. km). Now that
colonial influences have been removed there should
be no difficulty in maintaining these since no ulte­
rior motives can be suspected. The present forest
policies of Kenya, Uganda and Tanzania are similar
and their aims are clear. As much forest as possible
in high rainfall areas, and on hilltops and mountains
in arid areas, must be protected for perpetuity, in
order to conserve water supplies needed for irriga­
tion, hydro-electric power schemes and, of course,
ordinary human consumption; consistent with this
the forests must be managed to give the maximum
financial return possible. It is recognised that an
important secondary use is the provision of suitable
habitats for game, but a recent paper by Leggat,
Holloway and Gilchrist (in Jones 1 965) indicates that
the problem of damage by game when unnaturally
restricted can seriously interfere with forestry. No­
where in these policies is conservation for scientific
reasons considered really important, although there
are many agreements over certain selected areas as a
result of representations made over the years. As I
pointed out in my introductory talk, natural forest
can be replaced with more productive forest without
harming the water supplies. Once this happens most
plants and the associated fauna become extinct. En­
richment of a forest by the removal of weed trees is
less injurious. In general it is forest habitats that are
in most danger and immediate action must be taken.
It is difficult to decide which areas are most in need
but certain ones are of extreme interest.l The coastal
forests are small but contain numerous endemics,
some of which are even yet undescribed. It is fortun­
ate that, owing to bad roads, any forests are left
1
In 1 95 8 the workers at the Coryndon Memorial Museum
(now National Museum) and the East African Herbarium
drew up a list of forests which they considered needed' pre­
servation if a fair selection of Kenya's forest animals (in the
widest sense) and plants were to survive. It was not intended
that normal forestry should be interfered with but that
representative areas in as many of these forests as possible
should be declared nature reserves. The list was as follows:
Elgon, Kakamega, Kakalewa, Malaba, Kaptagat, Che­
rangani, Mt. Kenya, Upper Meru, Lower Meru, Nyambeni,
Mukogodo, Kikuyu Escarpment, Aberdares, South-west Mau,
Chepalungu, Karura, Ngong, Dagoretti, Kibwezi, Chyulu,
Kasigau, Boni, Witu, Utwani, Mambasasa, Sokoke-Arabuko,
Shimba Hills, Teita, Taveta, Bud'a Mafisini, Mrima Hill,
Gazi, Kulal, Mt. Nyiro, Marsabit, Mathews Range and the
Tana River gallery forest. Since then several of these have
been protected. Marsabit is a national park; the higher
reaches of the Mathews Range, parts of the Mt. Kenya and
Elgon Forests and a large area in the south-west Mau For­
est Reserve are now nature reserves, or soon will be.
Acta Phytogeogr Suec 54
1 90
B. Verdcourt
at all in this region which has been more or less
civilized for nearly 2000 years. At least the Arabuko­
Sokoke, Utwani and Mrima forests should be pre­
served in part. On the opposite side of Kenya,
Kakamega Forest is exceptionally interesting, being
the sole locality for many Kenya plants since it is
the eastern -limit for numerous West African species.
It is on the edge of densely populated country and
numerous requests have been made for its effective
protection. Most of the highland forests are much
poorer in species and less interesting. In Tanzania
the Usambaras, Ulugurus and Ngurus are covered
with ancient rain forest of exceptional interest; much
le3s explored are the pockets of forest on hills along
Lake Tanganyika. Numerous other areas are listed in
the detailed reports. In Uganda there are still exten­
sive areas of forest and the Forestry Department
there has always been very active and progressive;
in fact the outlook for savanna is less encouraging.
A good start has been made and many nature re­
serves have been established in the forests; a detailed
summary is given in Mr. Osmaston's paper.
I would like to close by mentioning two proposals
I put forward in 1 95 8 . It is still surprising how little
is known about the composition of many of the
forests, even the smaller ones. Foresters have indeed
collected a great deal and two generations of bota­
nists have combed the area; both have, however, been
too busy to devote the time needed, the forester
having much else to do and the botanist bent on
collecting as much in a day as possible. There is a
tendency to pass under many unknown trees, fre­
quently not in flower, with a shrug of the shoulders.
On several occasions when I have pondered beneath
a tree, determined to stay there until I had either
named it satisfactorily or obtained material, I have
been surprised to find that it has been . a new record
for the forest concerned and frequently for the ter­
ritory. On Mrima Hill I discovered that many of the
dominant trees were not recorded for Kenya-!
admit I spent a whole day moving only a few yards. I
believe there is a real need to appoint a field forest
botanist, one of whose tasks would be to make sur­
veys of areas threatened with clearance; there rarely
seems to be a botanist present when trees are being
felled. Many of the small forests near large towns are
in an unrivalled position to be used by educational
establishmen.t s for the teaching of ecology. Egerton
College, Njoro already has such a forest in use.
Very few large cities comparable to Nairobi have a
forest as interesting as the Karura right on their
boundary. All tropical forests are storehouses of
innuxtierable biological problems and every tropical
educational establishment should have access to a
Acta Phytogeogr Suec 54
forest area. Many smaller forests could be preserved
for this purpose.
The bibliography covers a range of papers giving
background information on many of the subjects
mentioned and also supplements the bibliographies
given by individual contributors to this section on
East Africa.
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1 96 1 . Report on the Narok District pilot game cropping
scheme. Typescript, reflex printed. Nairobi.
- 1 9 6 1 . Why shouldn't they go? (a case for conservation of
threatened species). Wild Life 3 ( 1 ) : 27-30.
Talbot, L. M., Ledger, H. P. and Payne, W. J . A., 1 9 6 1 . The
possibility of using wild animals for animal production in
the semi-arid tropics of East Africa. Trans. 8th Interna­
tional Congress of Animal Production. Hamburg.
- 1 9 6 1 . The possibility of using wild animals for animal
production on East Mrican rangeland, based on a com­
parison of ecological requirements and efficiency of
range utilization by domestic livestock and wild animals.
East African Agriculture and Forestry Research Organi­
zation, Lake Manyara Conference. (Mimeo)
Talbot, L. M. and Talbot M. H., 1 963. The wildebeest in
Western Masailand, East Africa. Wildlife Monographs
No. 1 2.
Talbot, L. M., Talbot, M. H. and Lamprey, H., 1961. An
introduction to the landscape. Guide prepared for the
I.U.C.N. JC.C.T.A. symposium held at Arusha, Sept. 1961.
Trapnell, C. G . and Griffiths, J . F . , 1 960. The rainfall­
altitude relation and its ecological significance in Kenya.
E. Afr. agric. J. 25: 207-2 1 3 .
Uganda Government, 1 966. Annual report o f the forest de­
partment 1 963-64. Entebbe (map of forests at end).
Acta Phytogeogr Suec 54
192
Discussion
Wild Life 1-3 , 1 959-196 1 . Nairobi.
Wildlife and conservation in Britain. Supplement to the
Times, Monday April 25th, 1966.
Wilson, J. G., 1962. The vegetation of Karamoja District,
Northern Province of Uganda. Uganda Dept. Agric. Me�
moirs of the Research Division, series 2: Vegetation,
No. 5.
Van Steenis, C. G. G. J., 1965. Man and plants in the tropics:
an appeal to Micronesians for the preservation of nature.
Micronesica 2: 61-65.
DISCUSSION
Kerfoot: The condition of forest reserves and the attitude of
forest departments to the land under their control is not
entirely an internal one. There is usually a strong profit
motive involved and I have no doubt that some forest depart­
ments would be very sympathetic towards conservation of a
natural resource simply as a natural resource, if they had
more valid reasons for so doing. Normally a forest has been
looked upon as a resource to be plundered or planted, or
re-settled by people if no profit motive can be allocated to
the area in question. A strong resolution from A.E.T.F.A.T.
would give a sympathetic forest department some ammuni­
tion with which to answer hostile pressure-groups. This may
be p articularly effective in areas not immediately required
for agriculture or land-settlement schemes in Kenya and
Tanzania. Other areas may be of value in maintaining water
supplies, not providing timber and do not require such
ammunition. A policy of laissez faire has, indeed, been the
rule rather than the exception in East Africa; now that
pressure is intense, this policy could be reversed by a strong
resolution from A.E.T.F.A.T. and other scientific bodies.
. Hepper: Mr. Kerfoot .indicated that although the forest de­
partments in East Africa are essentially for the exploitation
of the timber resources, the forestry staffs are sympathetic to
the idea of conserving an area for its scientific interest such
as the existence of an interesting species. This is excellent
confirmation of my hope mentioned in my summary on West
African vegetation concerning the value of the knowledge of
the occurrence of rare endemic species. They can be very
useful as a lever towards the conservation of an area of
natural vegetation which may not otherwise be preserved.
Pichi�Sermolli: In 1 963 a Mission of UNESCO, composed
of Sir Julian Huxley (head of the mission), Prof. T. Monad,
Mr. L. Swift, Dr. E. B. Worthington and Dr. A. Gille
visited Ethiopia in order to advise the Government of that
Country on the conservation of nature and natural resources.
This Mission recommended the creation of five National Parks
in: (1) Managasha, (2) Matahara, (3) Abijata lake, (4) Rift
Valley, (5) Source of the Blue Nile (see Report UNESCO/
NS/NR/47 ; 27 Dec. 1 963).
In 1 965 Ethiopia was visited by a second Mission of
UNESCO, composed by Mr. I. R. Grimwood and' Mr. L. H.
Brown. This Mission proposed to the Ethiopian Government
a triennial plan for the conservation of nature in which the
creation of three National Parks was strongly recommended:
the first at Matahara, the second in the High Sernien and
the third in the plains of the Omo River in the region of Maji.
(See L. H. Brown, Nature et Resources 2: 6-1 0, 1966.)
The Managasha forest is already under the Governmental
control for its conservation. I think that A.E.T.F.A.T. ought
to support the creation of these three national parks and
eventually to suggest the creation of a fourth park to protect
some forest areas of the Province of Kaffa and llubabor,
Acta Phytogeogr Suec 54
which are in danger of being destroyed in the very near
future.
Hepper commented on the participation of the horticultural
society in the formation of a local reserve for succulents in
Kenya. He pointed out that there remains a vast untapped
source of funds from horticulturalists everywhere for the
conservation of plants through such organizations as the
World Wildlife Fund. If only the members could feel to be
involved in the conservaLon of plants-probably through the
appeal of individual species-they would contribute a great
deal to the work of conservation in general.
Goodier: I should like to comment briefly on two very
important points of prillciple that are mentioned by Mr.
Osmaston in his paper on Uganda and which I think are
interrelated. These are ( 1 ) the size of Reserve, and (2) the
conservation of sera! stages.
In considering both these matters I think it is agreed that
it must be the aim, firstly, to conserve the whole environ­
ment and not just the vegetation element-thus, if at all
possible, the size of the Reserve should be larger than the
range of animals that may be dependent on the particular
habitat and contain sufficient of them to enable them to
survive. Secondly, the Reserve must, if possible, be large
enough to contain different seral stages and their associated
fauna so that a rotation can be obtained which will avoid the
extinction of any element through its habitat being totally
absent at one stage in time. This of course applies to the
herbaceous flora associated with woody communities as well
as to animals that are unable to move to alternative habitats.
In other words one should in the first place attempt to get
a reserve of sufficient size to be capable of being as near
as possible a self perpetuating system both as regards the
plant and animal components. I realize that this is perhaps
an unattainable ideal in relation to some of the larger animals
but should be realisable in some cases.
A reserve of course must also be useful in terms of provid�
ing facilities for scientific research. Research may involve
experimental interference so that if possible the reserve
should be large enough to accomodate this.
Milne�Redhead: I would like one site in Tanzania to be
added to the admirable list of conservation areas submitted
by Mr. Polhill. This is Liwiri Kiteza in the Matengo Hills
in the Songea District of the Southern Province (T8). The
upl and rainforest occupies about one square mile at 6000
ft altitude within sight of Lake Nyasa 4500 ft below. It is
(or was in 1956) unexploited and intact. I would like to see
this upland rainforest and the adjacent upland grassland and
rocky hilltops preserved as a whole. The forest is largely
unexplored botanically; the marginal zone contains plant spe­
cies of great interest, as does the rocky hilltop. Comparison
of this area with the much higher Nyika Plateau on the op­
posite side of the lake would be a worthwhile exercise.
South Tropical Africa
A N G O LA
J. Brito Teixeira
GEOGRAPHY
Angola, with 1 ,246, 700 km2 of extension, is situated
on the West African coast, between the Equator and
the Tropic of Capricorn. Except for Cabinda district,
at the N. of Zaire R., which is confined within the
borders of the Congo-Kinshasa and Congo-Brazza­
ville, the remaining territory is situated between 6°
and 1 8 ° S lat�tudes and 1 2 ° and 24 ° E longitudes.
The extension of the coast between the mouth of
Zaire and Cunene Rivers is about 1 300 km; the east­
ern border is at the same distance from the Atlantic.
The orographic system may be divided into three
zones or regions: coastal, mountainous, and the
highland plateau. The first one is a band of variable
breadth not exceeding 200 km and with altitudes
attaining 500 m; the broken topography of moun­
tainous region has altitudes superior to 500 m, some­
times surpassing 2000 m and is highest in Moco
Massif (2620 m). Beyond this "Marginal Chain of
Mountains", the third region (highland plateau) is the
most extensive (about 2 / 3 of the total area of
Angola). This vast and monotonous peneplain is
mostly undulated with altitudes from 1 000 to 1 700 m
and bows slightly from W-E.
There are three great geological units: the Ancient
Massif, the Continental Cover and the Coastal Sedi­
mentary Border. The Basement Complex, the
Western Congo System and the eruptive rocks belong
to the Ancient Massif (Pre-Cambrian). The Basement
Complex comprises gneisses, gneissic granites and
metamorphosed sedimentary rocks (schists and quart­
zites). The Western Congo System is composed of
schists, limestones, arkoses, and quartzites. The erup­
tive rocks, whicp are well represented, comprise
granites, granodiorites and quartzidiorites. About one
half of Angola is covered by sedimentary rocks of
the Karroo and Kalahari systems, from the Carbonif­
erous-Jurassic to the Pleistocene in age, the first
being characterized by the occurrence of gritty sand­
stones and the last by thick deposits of aeolian sands.
The Coastal Border is divided into four large sedi1 3 - 6 8 1 55 7 Hedberg
mentary basins, formed in the Mesozoic, Tertiary
and Quarternary eras with the following materials:.
conglomerates, sandstones, marly and dolomitic
limestones (Cretacous); marly formations (Eocene) ;
clay and gypsipherous marls (Oiigo-Miocene) ; sands
(Plio-Pleistocene).
CLIMATE
The Angolan climate is strongly affected by its
physiography, and by the Cold Stream of Benguela.
There are two main seasons: the rainy season and
the dry season (cacimbo). The first is the longest
(from the end of September to the beginning of
May); the second lasts from the middle of May until
the end of September, and is characterized by the
complete absence of rain. The average annual
temperature is generally high. The lowest values
(from 1 7 to 20 o C) occur either in the highest re­
gions (e.g. Sa da Bandeira, Nova Lisboa, Cuemba,
Andulo) or in the SW border area (Baia dos Tigres,
Porto Alexandre and Mo9amedes). The highest
values (from 27 to 3 5 ° C) are registered along the
river Zaire (Noqui and Santo Ant6nio do Zaire),
in the coastal border of the Northern region and in
the peneplain of the coastal region (Caxito, Onga­
Zanga, Dondo).
The coldest month is generally July; the warmest
is April as to the regions to the North of river
Cuanza and at altitudes inferior to 1 000 m; as to
altitudes of 1 000 m or more the warmest month is
October or November. The annual thermal ampli­
tude is always inferior to 1 0 ° C, and generally varies
between 4 ° and 7 ° C. In the highest regions, how­
ever, below zero temperatures are frequent in the
cold season (cacimbo). Frosts are also frequent. Rain
distribution throughout the year is rather variable,
the highest annual values belonging to the Northern
high regions ( 1 700 to 1 500 mm). In the Central
Plateau these values vary from 1 300 to 1 500 mm.
The lowest values occur in the coastal regions from
Luanda to the South (300 to 35 mm).
Acta Phytogeogr Suec 54
1 94
J. Brito Teixeira
In the coastal regions the average values of annual
relative humidity are generally high, equal or supe­
rior to 80% and constant throughout the year; in the
cold climates of the highland regions, the variability
is large with high values (75 to 8 5%) in the rainy
season, and low values (3 5 to 60%) in the dry season.
VEGETATION
In the Cabinda district begins, not far from the At­
lantic ocean, Gilbertiodendron dewevrei moist forest.
The coastal area lying between Santo Ant6nio do
Zaire and Benguela is characterized by a large area
of A dansonia digitata, which, then, turns to the E. ,
between the foot of Chela mountain and the sub­
desert formations of Mo9amedes district, extending
to the S. frontier. The A dansonia digitata forma­
tions adjoin moist semideciduous forest in the districts
of Zaire, Uige and Cuanza Norte, and with the
woodland and savanna-woodland of Brachystegia,
Julbernardia, lsoberlinia on the sub-highland pla­
teau of Cuanza Sui and Benguela districts and the
foothills of Chela mountain.
The most important types of this large phytosocio­
logical zone are Adansonia digitata with Sterculia
setigera and Euphorbia conspicua woodland and
savanna woodland, and sometimes tree savanna.
Intermixed with these formations there are thickets
(2-3 m high) of Strychnos welwitschii, S. ligust­
roides, Prevostea lucida and in the upper layer G ui­
bourtia carrissoana, G. gossweileri, Hymenostegia
laxiflora, Croton angolensis, Brachylaena sp. and
Pteleopsis diptera. In the black clayish soils (Catete
soils) there are more or less continuous dense patches
of Dichrostachys cinerea, groups of A cacia wel­
witschii, and large Setaria welwitschii savannas with
Clitoria ternatea and A loe zebrina. Near the sea there
are stands of Hyphaene guineensis. To the S. of
Benguela those formations give way to pure stands
of Colophospermum mopane and savanna-woodland
of this species with Spirostachys africana and Ptae­
roxylon obliquum. In the Cunene valley Colopho­
spermum mopane forms steppes ; species of A cacia,
Commiphora, Boscia, Combretum, Terminalia, etc. ,
are present there, and tree savannas of Hyphaene
ventricosa and Sclerocarya caffra appear as well.
The desert and semidesert formations of Namib
peneplain are represented by extensive A ristida pro­
digiosa steppes, with the famous Welwitschia mira­
bilis and Acacia mellifera, A. detinens, A canthosi­
cyos horrida, Commiphora, etc.
The moist semideciduous forest is mainly com­
posed of A lbizia gummifera, A. glaberrima var.
Acta Phytogeogr Suec 54
glaberrima, Ficus mucuso, F. exasperata, Celtis zen­
keri, C. soyauxii and Croton mubango, etc.
About 3 I 5 of the total area of Angola, at 9001 700 m of altitude, is covered by woodlands and
savanna-woodlands of Brachystegia spiciformis,
Isoberlinia angolensis, Julbernardia paniculata which
species are dominant in the western part of the
highland plateau. This formation is largely inter­
rupted and intermixed by semideciduous formations
of Marquesia macroura, Cryptosepalum pseudotaxus,
Guibourtia coleosperma and Brachystegia bakeriana
which cover large areas of the sandy soils of Kalahari
type and by steppes of Loudetia simplex with Cryp­
tosepalum curtisiorum, Brachystegia russelliae, Pro­
tea spp., Uapaca spp., Combretum viscosum etc.
Brachystegia-Julbernardia formations present, some­
times, several phases of degradation, giving place to
shrub savannas of Hymenocardia acida and Termi­
nalia sericea.
To the E. and S. of the Brachystegia-Julbernardia­
Isoberlinia savanna-woodland extensive "chanas" of
rubber (Gossweiler) or dwarf subshrub steppes of
Landolphia chylorrhiza, Carpodinus gossweileri, Pa­
rinari capense, Raphionacme utilis with very scattered
Loudetia simplex, are also frequent. The grass cover,
is almost always composed of species of Hyparrhenia,
Loudetia, Tristachya, A ristida, etc.
In the l arge physionomic formation of Brachyste­
gia-Julbernardia woodland, there are other types of
vegetation; but its description is not possible in this
abridged paper.
The forest-savanna mosaic of N. Angola (Zaire
and Uige districts) is well represented in the ecotone
zones of moist forest intermixed with Hyparrhenia
savannas with Sarcocephalus esculentus, Hymeno­
cardia acida and Piliostigma thonningii.
PROTECTION
Survey of Associations A lready Protected
There are in Angola 3 National Parks (Qui9ama,
Cameia and Iona) and 2 Nature Reserves (Mupa and
Luando). Besides these protected areas, 4 1 forest re­
serves and a number of game reserves were created
by law years ago; flora protection has also been duly
considered in these. Some forest reserves ::tre situated
in rather representative regions of :the Angolan flora,
but the enclosed map only represents the most im­
portant.
1. Alto Maiombe Forest Reserve (90,000 ha). Situated in
Alto Maiombe, in the Cabinda district, 275 km from Ca­
binda. It is representative of moist forest, characterized by
Gilbertiodendron dewevrei, Strombosia glaucecens, Parinari
nyangense, Librevillea klainei, Julbernardia seretii, Penta-
195
Angola
,.
12'
CABIN
14 '
p·?
D�
24'
21'
20'
18'
16'
E SCA L A
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50
�
+
+
+
c
• .J
0
+
100
150
200
Q U I LOM E T ROS
i-
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(LI�OPOLDVILLE)
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G
N
APROXIMADA
- · · · · · -··""'·--·�-·· · · · · · · --�----···
7'
+
+
7'
g•
t
+
9'
11'
t
13
'
11 '
t
+
13'
<r
+
+
17'
s
11'
u
D
1 4'
.
0
E
s
T
E
16'
� 1
�.
+
A
18'
11'
'oq"'
+
17
'
... .. ... ..... .. j,. ... ... .... � ... ... ... ... .. +
N
10'
+
�
�.
.... . ... �
F
� - - - · · -- - --· -
m
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·
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. . .. . -
--
24 '
Fig. 1. Angola. National parks and other protected areas. ( I ) Alto Maiombe Forest Reserve. (2) Beu Forest Reserve. (3) Golungo-
Alto Forest Reserve. (4) Quic;ama National Park. (5) Luando National Integral Reserve. (6) Cameia National Park. (7) L6vua
Forest Reserve. (8) Umpulo Reserve. (9) Mupa National Integral Reserve. ( 1 0) Iona National Park.
desma leptonema, etc., and the remarkable species Goss­
weilerodendron balsamiferum and Oxystigma oxyphyllum.
This type of forest, which was intensively surveyed by J.
Gossweiler, should receive the closest attention from the
Agricultural and Forestry Services.
2. Beu Forest Reserve (122,000 ha). Situated at 1 68 km
from Sao Salvador. Mixed formations of moist forest and of
:savannas of Hyparrhenia spp . and Loudetia spp. with Sarco­
..cephalus esculentus.
3. Golungo Alto Forest Reserve ( 105,000 ha). Situated at
the mountainous region of Cuanza Norte district near Go­
lungo Alto. The predominant formation is moist semidecid­
uous forest with Albizia gummifera, Albizia glaberrima var.
glaberrima, Celtis zenkeri, C. soyauxii, Premna angolensis,
Bombax reflexum, Ceiba pentandra, Zanha golungensis,
Canarium schweinfurthii, etc. Tree savannas and/or savanna­
woodland of Adansonia digitata, Sterculia setigera and Cochlo­
spermum angolense, etc., also occur.
Acta Phytogeogr Suec 54
1 96
J. Brito Teixeria
4. Qui9ama National Park (9 1 0,000 ha). Situated 80 km
from Luand'a and bounded by the Atlantic Ocean on the W.,
the left and right banks of the Cuanza R. and the Longa R.
respectively on the N. and S., and the road connecting
Muxima with Mumbondo and Capolo on the E. From W. to
E. we can see: typical sea-shore formations (Canava/ia mari­
tima, Ipomoea pes-caprae, Cyperus maritimus, Eragrostis
jascicularis, Chloris pubescens, Sporobolus virginicus, etc.)
and also Rhizophora mangle-Avicennia nitida mangrove.
Savanna-woodland and tree savanna of Adansonia digitata­
Sterculia setigera-Euphorbia conspicua; Hyphaene guineensis
tree savanna is frequent away from the sea in the lighter
sands. In the depressions of the undulations there are ex­
tensive savannas of Setaria welwitschii with scattered Maerua
angolensis and Capparis subglabra. In the drainage lines
there are Dichrostachys cinerea thickets and patches . of
Acacia welwitschii. Savannas and steppes of Schizachyrium
semiberbe var. hemileium and Digitaria milanjiana are found
in the higher sandy places in the intervals of the above
mentioned formations of Adansonia-Euphorbia-Sterculia.
More or less continuous Strychnos ligustroides-S. welwitschii­
Prevostea lucida-Combretum camporum thickets appear in
the red or reddish sandy soils of the plateau (muceque soils)
and little groups of Guibourtia gossweileri, Hymenostegia
laxiflora, Pteleopsis diptera, Brachylaena sp. and Croton an­
golensis are present in the upper layer of these thickets.
Combretum psidioides-Strychnos spinosa tree savannas or/
and shrub steppes are also frequent. At the E. of the Park,
near Muxima, in calcareous soils Ptaeroxylon obliquum and
Croton sp. are abundant, forming dense thickets.
5. Luando National Integral Reserve (950,000 ha). This
reserve, specially established to protect Giant Sable Antelope,
is situated at about 120 km to the S. of Malange. The vegeta­
tion presents several gradations of savanna-woodland where
Isoberlinia angolensis, Julbernardia paniculata and Brachys­
tegia spiciformis play an important part; Pterocarpus ango­
lensis, Guibourtia coleosperma, Parinari mobola, etc. are also
present. Hyparrhenia spp. savannas are represented as well
as tree and/or shrub savannas of Uapaca spp., Monotes
spp., Erythrophleum africanum, Afrormosia angolensis, Al­
bizia antunesiana and Burkea africana.
6. Cameia National Park (1 ,520,000 ha). This park is 90
km from Luso and is representative of the formations of the
highland plateaux, which is, generally speaking, covered by
Kalahari sand. The dominant vegetation is of Loudetia sim­
plex steppe with rhizomatous subshrubs of Landolphia thol­
lonii, Napo!eona gossweileri, Appunettia angolensis, Carpo­
dinus gracilis, etc.
7. L6vua Forest Reserve ( 1 3 8,000 ha). Consists of patches
of Brachystegia spiciformis-Julbernardia panicu!ata woodland
with, under special conditions, mist semi-deciduous forests of
Daniellia alsteeniana, Marquesta macroura, Anisophyl/ea
gossweileri, Canarium schweinjurthii, Syzygium guineense,
Parinari mobola and Klainedoxa lanceifolia.
8. Umpulo Reserve (750,000 ha). 1 40 km from Silva Porta.
Woodland and savanna-woo �lands of Isoberlinia angolensis,
Julbernardia paniculata, Brachystegia spiciformis and other
spp. of Brachystegia; Guibourtia coleosperma, Afrormosia
angolensis, Marquesia macroura, Cryptosepalum pseudotaxus,
Pterocarpus angolensis; rhizomatofruticeta of Cryptosepalum
curtisiorum, Brachystegia russel/iae and Loudetia simplex
steppe with Parinari capense and Brackenridgea arenaria.
9. Mupa National Integral Reserve (974,000 ha). Situated
90 km S. of Vila Artur de Paiva. Savanna of A dansonia
digitala, Sterculia quinqueloba, Acacia girajjae, Hyphaene
ventricosa, Terminalia prunioides. Savanna-woodland of lsoActa Phytogeogr Suec 54
berlinia-Brachystegia. Patches of Baikiaea plurijuga and Co­
/ophospermum mopane shrub savanna. The grass cover is
dominated by Aristida spp., Eragrostis spp ..
1 0. Iona National Park (1 ,500,000 ha). Situated near Vila
Porta Alexandre. Steppes of Aristida prodigiosa-A. gracilior
and Danthonia mossamedensis, including dwarf subshrubs,
Welwitschia and Euphorbia dinteri. Acacia-Boscia-Com­
miphora-Colophospermum shrub steppes are dominant on the
Eastern border of the Reserve. In the sand dunes Acantho­
sycios horrida is conspicuous.
Further Protection
In view of the above description of the main pro­
tected areas, in a region of more than 1 ,200,000 km2,
we can realize the existing difficulties and how much
w9rk must still be done before we can have an ade­
quate knowledge of the patterns of vegetation of
these areas. We are, however, optimistic in this
regard. Present legislation has protected, to a certain
extent, some areas which, otherwise, would have been
sacrificed to the consequences of the human influ­
ence. There are also species and floristic associations
which are naturally protected by the ecological con­
ditions surrounding them. A large proportion of
endemic species is found living in relatively inacces­
sible rocky places which are almost always without
economic interest. Others are found in scarcely popu­
lated areas because their edaphic conditions are
not favourable to agricultural or forest exploitation.
The Nature Protection Council (Conselho de Pro­
tec9ao da N atureza) created by the Decree 40,040
(1955), tries to reconcile scientific and cultural needs
with economic development, but it is not easy to find
the best solution to the several problems arising from
the necessity of protecting the fauna and vegetation
associations of Angola. As everywhere the education
of the people must be carried out at several levels
and it is sometimes difficult to make clear the main
objectives of such protection.
In Angola, as in other countries of Africa and
other continents it is probable that the natural land­
scape is already altered or even damaged in some
regions. However, this alteration is far from being
complete and regeneration is still possible. This prob­
lem has been and is being seriously studied by the
government and private organisations . and they
naturally profit from the experience of other count­
ries in this field.
For some associations, there is even, to a certain
extent, a danger of extinction, if efficient protection
measures are not followed in a near future. We refer
especially to the formations of Laurisilva type (mist
forest) in Cuanza-Norte district. Extensive Coffea
canephora cultivation, in this type of forest, has
given rise to an extensive removal of the inferior
strata and it is probable that the species of shrubby
Angola
undergrowth of these forests are seriously affected or
completely destroyed in large areas of their climax.
There are, however, some regions which have es··
caped destruction so far. Happily, Golungo Alto Re­
serve is still representative of this type of forest. In
the Experiment Station of Salazar (of the Agronomi­
cal Research Institute of Angola) there is, also, an
officially protected area (not very extensive, but sig­
nificant) of this type of forest. Other patches exist,
which are naturally protected by their topographic
situation, for example, in the ravines of mountainous
regions without agricultural or forestry interest. The
complete study and a detailed inventory of these
patches is a difficult but necessary task which still
remains to be undertaken.
In the case of woodland formations, the problem
of protection does not exist in spite of their occur­
rence in the most populated areas of Angola. The
existing protected areas are sufficiently extensive to
contain representatives of the various existing types
and subtypes.
The Mo�amedes desert, of course, supports a
natural collection of species famous all over the
world, which fortunately is not in danger. Iona Na­
tional Park in which is represented most of the for­
mations of desert and semidesert type is, like the
Mo�amedes desert, sufficiently protected by natural
conditions.
It will, however, perhaps be necessary to introduce
some new laws concerning the individual protection
of some species, such as Clematopsis scabiosifolia,
Leonotis leonurus, Leonotis nepetifolia. Cyathea an­
golensis and others which are much appreciated for
the ornamental effect of some of their organs, and
also Cissus ttter of Mo9amedes desert and Podo­
carpus milanjianus of the Chela escarpment.
In this connection it is hoped that the laws estab­
lished since 1 9 1 9 will be more adequately enforced
in the future for the benefit of the species of the
Angolan flora.
The intensification of education at different levels,
especially the training of university graduates, as well
as the increased activity of the botany departments
of scientific organisations, such as the Scientific
Research Institute (Luanda), the Agronomical Re­
search Institute (Nova Lisboa) and the University,
197
will certainly promote a more rapid diffusion
of protection ideals as recommended by law.
Adding to that, although the parks and reserves
are well selected and the laws rather clear, more ef­
ficient official measures should be taken in order to
provide these areas with enough qualified and trained
staff.
A Nature Protection Council directed by the Gov­
vernor-General of Angola, is already acting, and
should be assisted by the foundation of private socie­
ties such as the Angolan branch of the Nature Protec­
tion Society of Lisbon (Liga para a Protec�ao da
Natureza), which is soon to be initiated. The dis­
semination through publications, at different levels,
of botanical knowledge and of research results ob­
tained in Angola, will also enable the population to
have a better understanding of nature protection
problems.
ACKNOWLEDGEMENTS
Grateful acknowledgement is due to Eng. A. Castanheira
Diniz for his help in the geologic outline. Thanks are due to
Servi�os Geograticos e Cadastrais (Surveying and Carto­
graphy Services) for the delimitation of the reserves in the
enclosed map. Thanks are also expressed to my colleagues
Wand a Ferrao and M aria Jose Mace do, for their help in the
translation into English of this paper, and to the staff of the
Botany Division of the Agronomical Research Institute of
Angola. I am also obliged to .Prof. Dr. H. Wild, Prof. Dr.
A. Fernandes and wife, Dr. A. Mendon�a, Dr. E. Mendes
and Dr. A. Rocha da Torre, for their most valuable criti­
cism.
REFERENCES
Azevedo, Ario L. de., 1 954. Os solos de Angola e a agricul­
tura. Agronomia angolana, no. 9.
Gossweiler, J. and Mendonca, F. A., 1 939. Carta fitogeo­
grafica de Angola. Luanda: Governo Geral de Angola.
Protec�ao do solo, flora e fauna nas provincias Ultramari­
nas. Decreto no . 40,040 de 25 de Janeiro de 1955. Lisboa:
Agencia Geral do Ultramar, 1 955.
Regulamento florestal d a s provincias d e Angola, Mocam­
bique e Guine. Decreto no. 4453 1 de 21 de Agosto de
1 962. Luanda: lmprensa Nacional de Angola, 1 962.
Silveira, M. de Matos., 1 962. Climas de Angola. Luanda:
Servi<;:o Meteorol6gico de Angola.
Teixeira, J. Brito. A cartografia da vegeta<;:ao do distrito do
Bie. (In preparation.)
Teixeira, J. Brito. Apontamentos sobre a flora e a vegetacao
de Angola ( 1 950-1 965).
Acta Phytogeogr Suec 54
B E C H U A N A LA N D P R O T E CT O R AT E1
H. Wild
GEOGRAPHY
Bechuanaland extends from the Zambesi and Chobe
Rivers in the north through nine degrees of latitude
to the Molopo R. in the south. It lies between South
West Africa in the west and Rhodesia and the Trans­
vaal in the east, being 1 0 1 4 km across at its widest
point. The Tropic of Capricorn crosses the main
railway line about 48 km S. of Mahalapye. The
topography of the country is on the whole very flat
and almost all the country, except for an area lying
along both sides of the line of rail, is covered by
Kalahari sand. Altitudes vary between Ramaquabane
at over 1 2 1 9 m and the Central Kalahari at about
500 m.
Along the line of rail are Karroo system sand­
stones, granitic gneisses of the basement complex
towards the north and smaller areas of quartzites,
shales, conglomerates, banded ironstones, dolomitic
limestones, sandstones etc. towards the south. Except
for a broad band of quartzites, greywrackes and
limestones (Ghanzi Beds) running through Gha�zi to
south of Lake Ngami, the whole of the rest of the
country is composed of Kalahari sand often with
pans and, especially in the south, with scarcely any
surface water. In the north, however, we have one of
the world's most curious geographical features: the
Okavango R. comes down from the southern high­
lands of Angola, crosses the Caprivi Strip, by which
time it becomes a huge river approaching the size
of the Zambesi in Barotseland, then flows southwards
towards Maun and, in this distance of about 240
km, it spreads out into a delta and disappears into
the sands of the Kalahari. Some of its eventual chan­
nels may overflow at times into the Lake N gami and
Botletle R. systems and so find their way into Lake
Dow which can in turn feed or be fed by, according
to the scattered patterns of rainfall, the Makarikari
Pan system. This situation, together with the swamps
of the Chobe R. , has its effect particularly in the
formation of huge areas of brack or fresh pan grass­
lands. Elsewhere the Kalahari supports a vegetation
differing from the line of rail areas but changing
according to rainfall levels.
CLIMATE
Rainfall varies between more than 650 mm p.a. in
the Chobe area in the NE. to less than 225 mm p.a.
Acta Phytogeogr Suec 54
in the extreme SW. Relative humidity is low and
varies between about 4 1 % in October and 7 5% in
February. The mean annual maximum temperature
is about 25 ° C at Kanye and 3 0 ° C at Kasane. In the
hottest months temperatures frequently exceed 32.2 °
C, whilst the mean minimum temperature for the
coldest month (July) at Tshabong is 0.5 ° C. Frosts
can be very severe, therefore, especially in the south­
ern half of the country. Rainfall is erratic and falls
mostly between November and March.
VEGETATION
The following description has been taken from the unpublished
account and map by J. S. de Beer as modified by the writer
for inclusion in the as yet unpublished vegetation map of the
Flora Zambesiaca area by H. Wild and L. A. Grandvaux
Barbosa.
Broadly speaking the whole of the country is
covered by more or less open tree or bush savanna,
except that in the neighbourhood of pans there is
grassland. In addition, as the country gets drier from
NE. to SW. , the tree or bush savanna becomes more
and more open until at the extreme SW. in the Kala­
hari Gemsbok Park and at Bokpits the country ap­
proaches semi-desert steppe as defined in the Yang­
ambi system (Anon. 1 956).
In the NW. along the Rhodesian border a fairly
large area of Baikiaea woodland crosses over into
Bechuanaland. It is accompanied by Baikiaea - Dia­
lium - Burkea - Colophospermum savanna and areas
of Colophospermum savanna woodland. This is the
area with rainfalls above 635 mm p.a. Small areas of
similar vegetation but with no very pure stands of
Baikiaea occur between Sepopa and the SW. Afri­
can border in the NW. Apart from the Okavango
and Makarikari areas and the Ghanzi Beds, the re­
mainder of the line N. of Palapye-Ghanzi is covered
by huge tracts of Colophospermum tree savanna and
Terminalia savanna. In the Okavango area there are
large areas of Acacia giraffae or other A cacia spp.
savanna, Cymbopogon - Panicum repens - A ndro­
pogon eucomus swamp grassland and in the central
delta area Papyrus sudd. Around Lake Ngami we
have Cynodon dactylon - Cenchrus ciliaris - Aris­
tida congesta grassland and around Lake M akarikari
1
Since the 6th Plenary Meeting of A.E.T.F.A.T. Bechuana­
land Protectorate has become the independent territory of
Botswana.
Bechuanaland Protectorate
1 99
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Fig. 1. National parks and other protected areas in Bechuanaland Protectorate. 1, Chobe Game Reserve; 2, Central Kalahari Re­
serve; 3, Moremi Reserve; 4, Kalahari Gemsbok Park.
Acta Phytogeogr Suec 54
200
H. Wild
Aristida meridionalis - Heteropogon - Odyssea possible of different types of vegetation. In view of
grassland with a Sporobolus spicatus - Odyssea grass­ the fact that Bechuanaland has little material wealth
apart from its cattle, it would hardly be expected that
land fringing the actual salt lake. On the Ghanzi
Beds running NW. from the border W. of Ghanzi to large areas could be protected because of their vege­
S. of Lake Ngami, the main vegetation is an Acacia tation cover alone. Protection of vegetation must
mellifera subsp. detinens-Boscia albitrunca small tree · therefore be associated with other kinds of protec­
savanna. South of the Palapye-Ghanzi line on the tion, particularly of game animals, which form a
Kalahari we are dealing with a progressively drier sa­ potential if not actual source of tourist earnings.
In view of its low population and lack of natural
vanna type. This is the SW. Kalahari with no perma­
nent water except in a few pans. In a SW. direction wealth it is a matter for congratulation that Bechua­
we have first Acacia uncinata - Lonchocarpus nelsii naland has already made considerable efforts in this
tree savanna with widely spaced trees and a shrub direction. The areas concerned are as follows:
Chobe G ame Reserve- an area of approximately
growth of G rewia flava. Next is a similar tree sa­
1 hectares lying between latitude 1 9 ° S.
294,99
,
1
vanna with Acacia uncinata and A. giraffae domi­
R. Its vegetation cover includes Bai­
Chobe
the
and
area,
Park
Gemsbok
Kalahari
the
in
nant and finally,
a bush steppe or savanna characterised by Acacia kiaea woodland, approaching in places Baikiaea dry
semi-deciduous forest, Baikiaea-Dialium-Burkea-Co­
mellifera subsp. detinens, A. haematoxylon, A. sto­
lonifera, Grewia flava, Aristida spp. and Eragrostis lophospermum savanna, Colophospermum savanna­
spp. Throughout these southern Bechuanaland sa­ woodland, Terminalia sericea tree savanna, Cenchrus
ciliaris - Chloris ga,yana grassland in the M ababe De­
vannas A ristida spp., Eragrostis and Schmidtia spp.
predominate. There are also many Asclepiadaceae pression, surrounded by A cacia tree savanna and
some Cymbopogon - Panicum repens - A ndropogon
such as Raphionacme spp. with swollen tubers and
eucomus swamp and Papyrus sudd in the Chobe
Cucurbitaceae with succulent fruits which are used
by Bushmen as a source of water and food (Story swamps. It also contains interesting pans such as the
Tsotsoroga Pan, the type locality of Lagarosiphon
1 958).
Along the line of rail from S. to N. the vegeta­ tsotsorogensis (Bremekamp and Obermeyer, 1 9 3 5).
tibn pattern is more complicated because of a more This area is thus protected from cultivation and cat­
diverse topography and geology. From Lobatsi in the tle. I am also informed by the forest officer in
S. there is an Acacia nilotica - A. karroo - A. reh­ charge of this Chobe area that there is further hope
manniana tree savanna type followed by Terminalia that some of it may be more strictly preserved in
sericea tree savanna from S. of Gaberones, then future.
Moremi R eserve-1 8 1 ,299 hectares approx. on
Combretum imberbe savanna changing to Tennin­
the N. side of the Okavango swamps due N. of
alia tree savanna and, farther north still, Acacia
Maun. A game reserve run by the Batowana people
nigrescens-Combretum savanna around Mahalapye.
Around Palapye is an area of Terminalia tree sa­ of Ngamiland. Mostly Cymbopogon - Panicum re­
vanna followed by a large area of Colophospermum pens - Andropogon eucomus swamp grassland with
savanna N . to the Rhodesian border near Ramaqua­ Acacia or Colophospermum savanna and Papyrus
bane. This last type is often interrupted by Acacia sudd along the water courses. There exists a possibi­
lity that to this will be added Chief's Island nearby
savannas and Combretum - Terminalia savannas.
in the central Okavango. It is singularly difficult to
penetrate and has been traditionally reserved as a
hunting ground for the Chief of the Batowana. In
PROTECTION
practice, some local tribesmen do hunt on it also and
Survey of Associations Already Protected
in times of famine some hundreds of people may
move into it temporarily. Some 200 so-called "River
Discussions with agricultural officers, forest officers,
ecologists and the Administration in Bechuanaland Bushmen" also live permanently on the island. For
led me to believe that it would be difficult to decide these details I ·�m indebted to M r. J. van Riet Lowe,
what individual species one might try to protect by District Commissioner, Maun. It is pleasant to re­
legislation in such a flora as this where there· is cord this example of unusual foresight on the part of
uniformity over huge areas and it would be very the Batowana and the commendable desire of a
difficult to decide what were rare species in danger · cattleowning people to protect an area as large as this
of extinction; in any case there would be little chance for game preservation purposes. In this type of coun­
try even a large game population is not likely to upset
of efficient legislative control. The necessity here,
therefore, is to attempt to protect as large areas as the natural vegetation seriously.
Acta Phytogeogr Suec 54
Bechuana/and Protectorate
The Kalaha.ri Gemsbok Park-stretches along
some 1 93 km of the Nossop R. where it forms the
border with S.W. Africa. It is in the SW. corner of
Bechuanaland and on the Bechuanaland side of the
border is roughly 32 km wide. Half the reserve is
on the S.W. African side of the border. It lies in the
driest part of the country with a rainfall probably not
averaging much more than 1 27 mm p.a. Its vegeta­
tion is a bush savanna of Acacia mellifera subsp.
detinens - A. haematoxylon - A. stolonifera Grewia flava - Aristida spp.
Eragrostis spp. etc.
It might be called a steppe type of vegetation in
terms of the Yangambi ( 1 9 56) system.
Central Kalahari Reserve-a huge area of Kala­
hari roughly 3,600,000 hectares lying more or less
in the centre of the country with its N. boundary
j ust S. of Rakops, its W. boundary just E. of Tswane,
its S. boundary j ust N. of Letlhakeng and its E.
boundary somewhat to the W. of Lake Dow. Its ve. getation is mostly A cacia uncinata - Lonchocarpus
tree savanna with the trees widely spaced. It is roll­
ing country with deep sands. Boscia albitrunca is also
a common tree and low shrubs consist of Grewia
flava, Bauhinia macrantha etc. The principal grasses
are Eragrostis pallens, A ristida uniplumis, Schmidtia '
bulbos-a, Anthephora pubescens, Eragrostis lehman­
niana, A ristida meridionalis etc. The ridges of the
broad dunes carry the greater portion of the trees.
This is the natural home, together with the surround­
ing country, of the Bushmen and contains many of
their food plants such as Aloe zebrina, Bauhinia es­
culenta, B. macra.n tha, Boscia albitrunca, Brachys­
telma barberiae, Citrullus naudinianus. C. vulgaris,
Commiphora pyracanthoides, Cucumis metuliferus,
D uvalia polita, Grewia flava, Raphionacme burkei,
Ximenia caffra etc. (Silberbauer 1 965).
A tremendously interesting and quite admirable
scheme is now afoot to make this area available as a
reserved home for Bushmen who do not wish to live
in contact with the food-growing economy of the
Bechuana Bantu peoples and prefer to live their own
lives. The Bushmen, it is hoped, will be able to live
their own lives as hunter-food gatherers without inter­
ference or encroachment by other peoples and have
asked only that they be provided with drinking water.
Elsewhere, Bushmen will have the opportunity to
mingle with and absorb the way of life of the crop­
growing and cattle-keeping Bantu. This many of
them readily do. 3-5000 Bushmen at present live in
the reserve. Ecologically, the main danger will be that
boreholes sunk for water supplies could encourage
local overcrowding and upset the normal distribution
of the animal population. This, as Silberbauer (loc.
cit.) says, will have to be carefully watched. If this
-
20 1
scheme could be a success from a Bushman point of
view, there is little doubt it would also be so from a
vegetation point of view. Any imba1ance would up­
set all three parts of this biotic equation, i.e. men­
animals-vegetation. Since reading Dr. Silberbauers
fascinating report I hear in a letter from him that the
implementation of his recommendations is at present
making no headway. Perhaps this Association could
help by publicising their support for such a remark­
able scheme.
Further Protection
I would hesitate to say what further protection of
specific areas is necessary. As previously stated, there
is some prospect of further protection in the higher
rainfall area of the northwest. The protection of indi­
vidual species is quite impractical and the best pro­
spect lies in the encouragement of the survey. work
and research now being carried on by the Depart­
ment of Agriculture, the Forest Department and the
Game Department. The Bechuanaland pasture re­
search programme is designed to determine the op­
timum sustained utilisation of the various veld types
as well as defining these types in terms of floristic
composition, soil type and other environmental fac­
tors (A. McKay, personal communication). This
programme has of course to be carried into the field
in the form of recommendations on stock manage­
ment and particularly stock reduction and soil con­
servation. Stock reduction is particularly necessary
in Eastern Bechuanaland. The social problem in­
volved is tremendous and matters have already prog­
ressed to the stage, in the areas of more pronounced
relief and near rivers, where irreversible changes have
probably already occurred. Fortunately, from the
point of view of the preservation of natural vegeta­
tion, only a small proportion of land is under cultiva­
tion.
In addition to the serious position in Eastern Be­
chuanaland, Lake Ngami suffers from severe over­
grazing. In the SW. Kalahari the country is too
underpopulated for any serious degeneration of the
vegetation to have occurred, except in the Ghanzi
ranching area. The Southwestern Kalahari will only
be in danger if boreholes are made too numerous and
not adequately supervised. It is not a simple prob­
lem, however, as an isolated borehole is likely to
draw cattle, people and game from a very large area.
These concentrations can then result in deplorable
damage to the vegetation. This problem is being
tackled by the abandonment some four years ago of
the old system of communally-owned grazing bore­
holes and replacing them by a far more satisfactory
policy of drilling boreholes on a loan-repayment basis
Acta Phytogeogr Suec 54
202
H. Wild
for specific individuals who enter a contractual
agreement to limit the number of stock watering at
the borehole to a figure related both to the safe
grazing capacity and water-yield (J. van Riet Lowe,
personal communication).
In the northwestern corner of Bechuanaland pre­
servation of the natural vegetation appears to depend
primarily on the control of cattle density, game den­
sity or fire (G. Child, personal communication).
Overgrazing appears to have caused invasion of
Dichrostachys cinerea and Acacia spp. on the Puku
Flats around Serondellas. Elsewhere the super­
abundance of game lin the dry season causes some
species such as Combretum mossambicense and
Dichrostachys cinerea to benefit at the expense of
Combretum elaeagnoides and Baphia obovata. In
Baikiaea woodland fire is the chief danger and en­
courages invasion by Commiphora spp., Diplorhyn­
chus condylocarpon, Combretum spp., Terminalia
spp. This latter is perhaps the most widespread in­
vader of all. Fortunately, ecological research is at
present being concentrated on this area by both the
Game and Forestry Departments. With the consider­
able human population along the western side of the
Okavango the need for work in Northern Ngamiland
between the river and the S. W. African border is
probably equally necessary. Much of this problem
could probably be resolved if better use could be
made of the tremendous natural resources provided
by the Okavango R. which at present is almost en­
tirely wasted in the depths of the Kalahari sand.
Efforts have been made to investigate the fish poten­
tial, at present very neglected by the indigenous
population, and irrigation has immense possibilities
from such a huge source of water. However, this is
primarily a financial problem, particularly as the area
is remote and the country poor. Finally, the Bato­
wana are so wedded to a cattle economy that the
social problem of bringing about real change would
be considerable. In conclusion, nowhere is it more
obvious than in Bechuanaland that the possibility of
increased protection of vegetation lies almost exclu­
sively in the carrying out of ecological research to
decide how to control grazing by both cattle and
game at an optimum level and then to persuade the
inhabitants to practise these precepts.
ACKNOWLEDGEMENTS
I am most grateful for the assistance in the preparation of
this short account given me by Mr. Alistair McKay of the
Agricultural Department, Mahalapye, Mr. P. W. Henry of the
Forest Department, Kazungula, Dr. Graham Child, the Wild­
life Ecologist of the Game Department, Kasane, Mr. John
van Riet Lowe of Maun and Dr. Thane Riney of the Forestry
and Forest Products Division, F. A. 0., Rome.
REFERENCES
Anon., 1 956. Phyto-geography. C. S. A. Publ. No. 22, Yang­
ambi.
de Beer, J. S. (MS). Provisional Vegetalion Map of Bechua­
naland Protectorate.
Bremekamp, C. E. B. and Obermeyer, A. A., 1935. Scientific
Results of the Vernay-Lang Kalahari Exped. 1930: Sertum
Kalahariense, a list of plants collected. Ann. Transv. Mus.
1 6: 399-442.
Silberbauer, G. B., 1 965. Bushman Survey. Bechuanaland
Govt. Gaberones.
Story, R., 1 958. Some plants used by Bushmen in obtaining
food and water. Bot. Surv. Mem. No. 30, Pretoria.
Wild, H. and Grandvaux Barbosa, L. A. (MS). Flora Zam­
basiaca Vegetation Map.
R H O D E S IA
H. Wild
GEOGRAPHY
Rhodesia is situated in South Central Africa between
1 5 ° 40 ' and 22 ° 3 0 ' S latitudes and 25° 1 5 ' and 3 3 °
50' E longitudes, i.e. wholly within the tropics but
with its southern boundary near the Tropic of Capri­
corn and extending from the Zambesi R. to the
Limpopo R. on the one hand and the flat Bechua­
naland border to the Eastern Border mountain chain
lying along the border with Mozambique on the
Acta Phytogeogr Suec 54
other. Altitudes lie between 305 m, or just below, at
the junction of the Sabi and Lundi Rivers where they
pass in the SE. into Mozambique and in the Mazoe
valley where it crosses the border NE. of Mtoko on
its way to join the Zambesi near Tete, and just over
2390 m at Inyangani on the Eastern Border. Two­
thirds of the country is above 900 m.
The geology and the resultant soil pattern of Rho­
desia affects the vegetation in some degree and may
be broadly described as follows: to the E. of a line
Rhodesia
203
RHODESIA
10 0
25'
50
26'
f---�----+-1--,-- ��--f�--l--122"
'32'
27' 28' 29'
Fig. 1. National parks and other protected areas in Rhodesia. 1, Chimanimani National Park; 2, Ewanrigg National Park; 3, Man­
chester National Park; 4, Matopos National Park; 5, Mtarazi Falls National Park; 6, Mushandike National Park; 7, Ngesi National
Park; 8, Rhodes Inyanga National Park; 9, Robert Mcllwaine National Park; 10, Sebakwe National Park; 11, Sinoia Caves Natio­
nal Park; 12, Victoria Falls National Park; 13, Wankie National Park; 14, Zimbabwe National Park; 15, Chirinda Forest Reserve;
16, Kamwahuku Fossil Forest.
from roughly 65 km NW. of Plumtree to the Zam­
besi escarpment N. of Sinoia the rocks belong mainly
to the Basement Complex, i.e. granites w1ith smaller
dolerite or gabbro intrusions. These are overlain in
the Mazoe valley, for instance, by early Precambrian
basement schists. There are also late Precambrian
Umkondo sandstones and quartzites on the Eastern
Border. The serpentine of the 563 km long Great
Dyke running from near Sipolilo to near West Ni­
cholson also profoundly affects the vegetation. To
the west of the aforementioned line the country is
composed of younger rocks from the Late Precam­
brian Lomagundi dolomitic limestones to the Trias­
sic and Permian sandstones, shales and coals of the
Wankie and Sebungwe areas and the Tertiary Kala­
hari sand in the NW.
CLIMATE
Rhodesia has one summer rainy season extending
approximately from November to March. Average
rainfall varies between c. 305- 1 0 1 6 mm p.a., except
that the Eastern Border mountains may have from
1 524 mm or more. The main watershed area above
9 1 5 m has a mean annual temperature usually be­
low 1 9.4° C. In the Zambesi valley this reaches 26.6°
C approx., whilst on the Eastern Border it falls be­
low 1 5. 6 ° C. There is considerable diurnal variation
with cool nights, except at the lowest altitudes. Frosts
are usual in winter, although rare at lower altitudes.
Hail can occur in summer. Maximum temperatures
rarely exceed 32.2 °C on the watershed but occasion­
ally reach 43.3 °C in the Zambesi valley.
VEGETATION
This short description is largely based on the Vegetation
Map of Rhodesia by Wild, 1 965 b.
On the main watershed plateau above 1 200 m
the vegetation is Brachystegia spiciformis - Julber­
nardia globiflora savanna-woodland. In some parts
Uapaca kirkiana. becomes important locally and
where the water table is high it may be replaced by
Acta Phytogeogr Suec 54
204
H. Wild
Parinari curatellijolia tree savanna. Frequently as­
sociated woody species are Monotes glaber, Combre­
tum molle, A lbizia antunesiana, Strychnos spinosa,
Flacourtia indica, V angueria tomentosa, etc. The
grass cover is mainly of perennial species often domi­
nated by Hyparrhenia spp., Pogonarthria squarrosa,
Eragrostis spp. etc.
Between 9 1 5 m and 1 220 m the above is usu­
ally replaced by Brachystegia boehmii - B. allenii
(Zambesi escarpment) - Julbernardia globijlora es­
carpment savanna-woodland. Monotes engleri may
be common here, together with Pericopsis angolensis,
Ajzelia quanzensis etc. The grass cover is similar to
.
that in Brachystegia spicijormis - Julbernardia globi­
flora savanna-woodland.
From 300 to 900 m the vegetation is mainly com­
posed of various types of tree savanna or, less com­
monly, thicket formations, for example, Colophos­
permum mopane savanna (Zambesi and Sabi-Lim­
popo valleys); Commiphora - Combretum savanna
(Zambesi escarpment north of Wankie and stony ba­
salt areas of Limpopo valley) ; Terminalia sericea
savanna usually showing evidence of previous culti­
vations; Acacia nilotica - A. karroo - A . rehman­
nia.na - A lbizia - Bolusanthus speciosus savanna on
the valley bottoms, alluvial soils (Sabi valley) and
more fertile areas, often alternating with Colophos­
permum mopane savanna; A dansonia - Sterculia Kirkia - Acacia - Cordyla savanna in the valleys of
the Zambesi and Sabi with Hyphaene ventricosa sa­
vanna following the drainage lines; Acacia nigres­
cens - Combretum savanna on the black basalt soils
of the Sabi valley and Colophospermum mopane
. shrub savanna on the basalts of the Sabi-Limpopo
valley and where occasional frosts are severe. Map­
pable areas of thicket on a scale of 1 : 2,500,000
are confined to the Zambesi valley and Wankie area
and consist of Commiphora - Combretum - Ptero­
carpus antunesii thicket.
There are, however, important edaphic modifica­
tions of the above pattern caused firstly by the ex­
tensive area of Kalahari sand in the NW. The prin­
cipal formation here is Baikiaea woodland which
sometimes approaches semi-deciduous Baikiaea. for­
est such as is found .in Zambia on Kalahari sand.
Associated trees are Pterocarpus angolensis, G ui­
bourtia coleosperma and Ricinodendron rautanenii.
The grass cover is very sparse because of poor light
and consists of A ristida spp. , Triraphis schlechteri,
Tristachya rehmannii etc. Where the Baikiaea has
been exploited, or under somewhat poorer condi­
tions for Baikiaea, this type is replaced by Baikiaea Dialium - Burkea - Colophospermum tree savanna.
This grades into Baikiaea woodland and the dividing
Acta Phytogeogr Suec 54
·
line is not clear. In conditions somewhat less favour­
able still for Baikiaea but still on Kalahari sand, a
Brachystegia spicijormis Kalahari
woodland is
found. Under these conditions the Brachystegia spi­
ciformis tends to be better grown and with straighter
boles than in Brachystegia spiciformis - Julbernardia
globiflora savanna woodland on the watershed. Bra­
chystegia boehmii is also frequently present together
with G uibourtia coleosperma, Burkea ajricana, Ery­
throphleum africanum and Pterocarpus angolensis.
It also intergrades with Baikiaea woodland and Bai­
kiaea - Dialium - Burkea - Colophospermum sa­
vanna. Another striking edaphically induced vegeta­
tion is the Andropogon gayanus grassland confined
to the serpentines of the Great Dyke. This area,
534 km long and 5-1 1 km wide, lies in an ap­
proximately straight line tending about 17 ° of north.
The flora is a specialised one and there are at least
20 endemic species (Wild, 1 965a) . In the Mazoe val­
ley and elsewhere in the northern half of the country
the Shamvian basement schists, at least in the valley
bottoms, induce the development of a Pterocarpus Combretwn - Pericopsis - Acacia polyacantha tree
savanna instead of the Brachystegia spiciformis - Jul­
bernadia globiflora or B. boehmii savanna woodland
of the nearby granites.
On the Eastern Border mountains higher altitudes
and a therefore wetter cooler climate produce a
marked change in the vegetation. At the highest alti­
tudes there are patches of Widdringtonia - Podocar­
pus montane forest (i..e. Banti forest). Lianes are al­
most absent but epiphytic bryophyta and Streptocar­
pus spp., especially S. umta.Uensis, are common. At
similar altitudes above about 500 m forests not domi­
nated by gymnosperms also occur and in this case
the characteristic species are Macaranga mellifera,
Cussonia umbellijera, A lbizia gummifera, Rapanaea
melanophloeos and Ilex mitis, for example, the
Vumba Elephant forest and Chimanimani forest
patches.
At lower altitudes forest patches of differing types
occur. The best known of these is Chirinda Forest
(Swynnerton et al., 1 9 1 1), in which Khaya nyasica,
Lovoa swynnertonii, Strychnos mitis, Craibia brevi­
caudata, Diospyros abyssinica and Trichilia dregei
are all common. This is the richest forest floristic­
ally in Rhodesia and a lower story of Coffea ligust­
roides, Gardenia posoquerioides, Oxyanthus swyn­
nertonii, Conopharyngia usambarensis etc. is well de­
veloped. Lianes such as Landolphia kirkii, Clero­
dendrum swynnertonii, Dioscorea spp. are frequent.
Epiphytic ferns and orchids are also very common.
Occasionally at low altitudes below 1 000 m the rain­
fall is very high because of the proximity of high
Rhodesia
mountains such as in the eastern Inyangani foothills
and near the Haroni-Lusitu R. j unction at the south­
ern foot of the Chimanimani Mts. Erythrophleum
guineense, Xylopia aethiopica, Blighia unijugata, Fi­
licium decipiens and a Parinari sp. near P. polyandra
become important. This type is most unusual under
Rhodesian conditions because high rainfall at low
altitudes is normally non-existent. At the higher al­
titudes on the Eastern Border forest forms only a
small part of the area as a whole and scrub associa­
tions of Philippia spp . , Erica spp., Protea spp., and
mixed sclerophyllous vegetation on the more moun­
tainous and broken ground are usual (Goodier and
Phipps, 1 962). Elsewhere, with better soils and as a
result of fires, we have a Themeda - Exotheca Loudetia submontane grassland.
PROTECTION
Survey of Associations A lready Protected
In a part of Africa such as the Cape Province, and
particularly the Cape Peninsula, the development of
associated and highly civilised centres such as Cape
Town make the legal protection of individual species
quite feasible and indeed essential. In a country like
Rhodesia we have, on the whole, felt this approach
to be quite impossible. We cannot expect to have a
police force sufficiently acquainted with plant taxo­
nomy to enforce such regulations. On the other hand
there has always been, independently of the wish to
preserve vegetation, a strong urge to create national
parks etc. for general recreation and as part of the
tourist drive. This has no doubt been encouraged by
our lack of a coastline and perhaps principally
through the foresight of our founder, Cecil Rhodes.
In these national parks all forms of life, animals and
vegetation, are protected and this has allowed us to
develop a type of protection more suited to our cir­
cumstances. To illustrate the types of vegetation pro­
tected in this way it is simplest to give a list, with
appropriate �comments, of the national parks and
related areas.
1 . Chimanimani National Park (8085 hectares)
-establ.ished 1 950. This park adequately protects
the sclerophyllous montane and montane forest vege­
tation of this region. The wild animal population is
low and creates no problem in destroying vegetation.
There are no roads and, owing to the nature of the
terrain, not likely to be any. Visitors are relatively
few; human damage is therefore negligible. This is
fortunate since, apart from its beauty, the mountains
contain about 40 endemic species as well as many
other rarities (Wild, 1 9 64). Within the last year or so
205
the park has been extended southwards to include the
Makurupini / Haroni Forest near the Haroni-Lusitu
R. confluence. The unique low-altitude forest men­
tioned above is therefore permanently protected.
2. Ewanrigg National Park {283 hectares)-40
km E. of Salisbury and donated in 1 949 to the nation
by the wellknown authority on Aloe spp., H. B. Chris­
tian. The park is in the charge of a curator with
botanical garden training and contains a fine collec­
tion of living A loe species from Rhodesia, S. Africa,
E. Africa and Ethiopia. There is also a comprehen­
sive collection of African Cycadaceae. In addition,
the park includes natural Brachystegia spiciformis B. boehmii - Julbernardia globiflora savanna-wood­
land, which is thereby fully protected.
3. Manchester National Park ( 1 80 hectares)
-32 km from Umtali in the Vumba Mts.-estab­
lished in 1 958. 5 hectares of the park consist of a
garden of exotic species donated to the nation by its
previous owner, but the remainder consists of sub­
montane grassland and forest patches.
4. Matopos National Park (40,000 hectares)-left
to the nation by Cecil Rhodes, 48 km S. of Bula­
wayo. A huge area of very broken granite country
mostly covered by Julbernardia globiflora woodland
but because of locally higher rainfall and the protec­
tion from fire afforded by the granite kopjes, it has
a much richer flora than surrounding areas. Eastern
Border elements such as Erythrina lysistemon, Calo­
dendrum capense and unexpected higher rainfall
species such as Streptocarpus eylesii occur (Wild,
1 956). Scenically, it is of course most impressive.
5. Mtarazi Falls National Park ( 1 260 hectares).
Contains the 6 1 0 m high Mtarazi Falls and con­
·
sist of the area surrounding the falls. The vegetation
is submontane grassland and sclerophyllous scrub,
together with submontane forest. Previous cultivation
taking place at the foot of the fall, which had re­
sulted in the regular · burning back of the forest, has
now ceased.
6. Mushandike National Park ( 1 3 ,200 hectares)
-3 1 km from Fort Victoria. Mainly Brachystegia
spicijormis - Julbernardia globiflora but of a south­
erly type, i.e. it contains frequent examples of the
handsome Bolusanthus speciosus and Afzelia quan­
zensis, thus differing from this type of savanna­
woodland around Salisbury.
7. Ngesi National Park (9973 hectares). Includes
part of the Great Dyke but mostly in a part where
serpentine is replaced by pyroxenites. It is not here
therefore covered by Andropogon grasslands but by
Brachystegia boehmii savanna-woodland on the west­
ern slopes and a more mixed savanna woodland of
B. spiciformis, Faurea saligna, Combretum zeyheri,
Acta Phytogeogr Suec 54
206
H. Wild
etc. , on the west. The flatter granite sandveld to the
east is of Brachystegia spiciformis - Julbernardia glo­
biflora savanna-woodland, large grassy vleis or sea­
sonal swamps and a more mixed vegetation with
Sterculia, Kirkia acuminata and occasional Adan­
sonia on the granite ridges.
8. Rhodes Inyanga National Park (34,000 hec­
tares)-on the Eastern Border north of Umtali. Do­
nated to the nation by Cecil Rhodes. Contains all
types of Eastern Border vegetation from sclerophyl­
lous scrub with Ericaceae on Mt. lnyangani, The­
meda-Exotheca submontane grasslands, Cyathea spp.
along the water courses, patches of Widdringtonia
whytei and patches of submontane moist forest with
Ilex mitis, Rapanea melanophloeos, Grumilea kirkii
etc.
9. Robert Mcllwaine National Park (1 5,550 hec­
tares)-32 km SW. of Salisbury. Mainly granite
country with Brachystegia spiciformis - Julbernardia
globiflora savanna-woodland in the main. However,
Monotes glaber is locally very abundant and Brachy­
stegia glaucescens occurs on the frequent kopjes.
1 0. Sebakwe National Park (2480 hectares)­
some 48 km E. of Que Que. Includes a large area
of the Great Dyke which here consists of serpentine
and is covered by the bare A ndropogon grasslands
characteristic of this type of soil. Many of the un­
usual species of the southern half of the Dyke occur,
e.g. Argyrolobium eylesii, Acacia chariessa, Sutera
brunnea, Pearsonia metallifera, Lotononis serpentini­
cola, Sutera fodina etc. (Wild 1 9 65a). The remainder
of the park is Brachystegia spiciformis - B. boehmii ­
Julbernardia globiflora savanna-woodland on granite.
1 1 . Sinoia Caves National Park (282 hectares).
An area of dolomitic limestone with underground
caves and streams. The surrounding area is of
Brachystegia boehmii savanna-woodland but the
limestone induces a flora of lower altitude drier
country type, i.e. Commiphora spp. etc. are common.
12. Victoria Falls National Park (52,900 hec­
tares). Includes the "Rain Forest" of the Falls, Co­
lophospermu m mopane savanna-woodlands, a little
Baikiaea plurijuga woodland, Baikiaea-Dialium-Bur­
kea-Colophospermum tree savanna, Brachystegia spi­
ciformis on Kalahari sand and Hyphaene ventricosa
and Adansonia savanna near the Zambesi river
(Wild 1 952).
1 3. Wankie National Park ( 1 , 3 1 0,53 1 hectares)
-some 8 1 km S. of the Victoria Falls. Includes
large areas of Colophospermum mopane woodland
and some A cacia uncinata - Lonchocarpus nelsii sa­
vanna and pans. This park is designed for the ob­
servation and study of animals. However, the vegeta­
tion is protected from agricultural spoliation, alActa Phytogeogr Suec 54
though damag� by animals and especially elephant
occurs. Nevertheless, there is a constant endeavour
by ecologists of the National Parks and Wild Life
Department to control overgrazing and as this is
gradually achieved the vegetation will be more suc­
cessfully protected.
1 4. Zimbabwe National Park (7 1 4 hectares)27 km SE. of Fort Victoria. The park is primarily
for the protection and tourist exploitation of the Zim­
babwe Ruins; however, vegetation is also protected.
The surrounding vegetation is Brachystegia spicifor­
mis - Julbernardia globiflora savanna-woodland but
the hills of Zimbabwe induce a locally high rainfall
and such unusual species for this area as Albizia
adianthifolia, Crassocephalum mannii, Synaptolepis
alternifolia, Asparagus meleoloides (W1i ld 1 956) and
Sophora velutina subsp. zimbabweensis (Brummitt
1 9 66) are found and form an extension of our
Eastern Border floristic element (W1ild 1 95 6).
In addition to the above, a number of usually
smaller areas are protected in the name of the Com­
mission for the Preservation of National. and Histori­
cal Monuments and Relics, usually through the
Forest Act. The motive for protection is often arch­
aeological but there is incidental protection of vegeta­
tion at the same time. Beginning with the more im­
portant first we have:
Chirinda Forest {86 hectares) near Chipinga. The
best patch of moist evergreen forest in Rhodesia.
Very carefully preserved and protected by the For­
estry Commission. Contains a monument to C. F. M .
Swynnerton. The Big Tree o f Chirinda Forest
(Khaya nyasica c. 61 m tall) is also a national mo­
nument.
Bunga Forest (28 hectares) on Cloudlands Farm,
Vumba Mts. Sub-montane evergreen forest.
Van Niekerk and Nyahokwe Ruins, lnyanga ( 1 0 1 9
hectares). Brachystegia spiciformis - Julbernardia
globiflora savanna-woodland verging on Termina.Ua
sericea savanna with occasional Adansonia etc.
Nyahokwe Hill carries the only specim'en of Juni­
perus procera in Rhodesia. This was found very
recently and represents a 1 1 00 km southward exten­
sion of the distribution of the genus.
Several small areas of a few hectares each in the
vicinity of the Great Dyke north of the Mtoroshanga
Pass have now been declared protected areas to pre­
serve what is in Rhodesia the very rare palm Raphia .
farinifera.
Kamwahuku Fossil Forest ( 1 55 hectares)-1 45 km .
E. of Chirundu. Fossils consist of fossil Gymnos- .
perms (?Dadoxylon and Rhexoxylon spp.).
In addition, certain demarcated indigenous forestsh
Rhodesia
8 69 ,920 hectares in extent, are protected by the
Forest Act and an area in excess of 62,000 hectares
is protected by the Tribal Trust Land Forest Pro­
duce Act. These latter include areas in the Manyika,
Masembura, Victoria, Wedza, Chibi, Chikwanda,
Mangwendi, Chinamora, Tjolotjo, Wankie, Lupane,
Nkai and Holdenby Tribal Trust Lands.
Finally, the recently formed National Trust of
Rhodesia now administers and protects Murahwa's
Hill, 3 . 2 km N. of Umtali and 62 hectares in
extent. It is a very rich piece of dense woodland and
near forest containing (as enumerated by Mr. N. C.
Chase) 1 3 0 species of trees and shrubs ; 1 92 herbs,
small shrubs, lianes and ramblers; 23 ferns; 1 2
orchids ; in all 3 67 species. Zanha golungensis, Chae­
tacme aristata and Maerua cafra, all very rare in
Rhodesia, grow here.
Further Protection
From the above it will be seen that most associations
are already in some way protected in Rhodesia. Fur­
thermore, very large areas of granite kopje country,
as in the Chibi area for instance, are protected from
cultivation, and to a l arge extent grazing, by their
very broken topography. The same would apply to
large parts of the Eastern Border such as the parts
of the Chimanimani Mountains outside the Natiqnal
Park.
There has been some concern expressed in recent
years by the hawking, mainly in the towns, of indig­
enous plants dug up from the wild. These include
Gloriosa superba, Eulophia petersii, A nsellia nilo­
tica, Phoenix reclinata, Hyphaene ventricosa, Adian­
tum capillus-veneris, A loe spp. and Adenium obesum
var. multiflorum. None of these. plants are rare 'but
continued depredations could be harmful even to
large populations. Rather than introduce unworkable
legislation to protect individual species the Rhodesian
Natural Resources Board is asking for the coopera­
tion of Municipalities in preventing the issue of haw­
kers' licences for the sale of any plants from the wild.
It is the opinion of the writer that further protec­
tion of vegetation, including individual species, in
view of the wide spread of protected areas already
achieved, should not lie in the indefinitely prolonged
creation of new reserves but should now concentrate
on the ecological handling of the present reserves and
also on the country's vegetation as a whole. In those
207
reserves where animal life plays a large part, research
already goes on under the Department of National
Parks and Wild Life Management, aiming at recom­
mendations which will enable animal density and
proportions of species to allow a sensible stabilisa­
tion of the natural vegetation to take place. This
effort should be intensified. In parks like Inyanga
National Park protection may sometimes have been
too great in that indefinite fire control may have
harmed some vegetation types by making fires too
fierce when they do occur. This particularly applies
to Widdringtonia colonies.
Finally, there is one species, A ndrostachys john­
sonii, which in Rhodesia �s confined . to the extreme
SE. corner of the country. It forms small dry ever­
green forest patches and is of special interest owing
to the recent publication of the monogeneric family
A ndrostachydaceae (Airy Shaw 1 9 65). It is to some
extent protected in that it occurs in the very large
GoJ? a-re-Zhou game reserve which lies along the Mo­
zambique border south of the Sabi R. However, it
would be worth while to �boose a well grown forest
patch for special protection under the Forest Act.
ACKNOWLEDGEMEN'J1S
The author gratefully acknowledges the valuable assistance
of the Department of National Parks and Wild Life Manage­
ment, the Forestry Commission of Rhodesia, the Natural
Resources Board, the Historical Monuments Commission and
the National Trust of Rhodesia.
REFERENCES
Airy Shaw, H. K., 1 965. Diagnoses of New Families etc.
Kew Bull. 1 8, 2: 250.
Goodier, R. and Phipps, J. B., 1 962. A vegetation map of the
Chimanimani National Park. Kirkia 3 : 2-7 and map.
Swynnerton, C. F. M. et al., 1 9 1 1 . A contribution to the
'
Flora of Gazaland, Journ. Linn. Soc., Bot. 40: 1-245.
Wild, H., 1 952. A guide to the flora of the Victoria Falls.
The Victoria Falls: 121-160, ed. J. D. Clark. Comm. Pres.
N at. Hist. Mon. & Rei., Livingstone.
Wild, H, 1 956. The principal phytogeographic elements of
the S. Rhodesian flora. Proc. & Trans. Rhod. Sci. Ass. 44.
- 1964. The endemic species of the Chimanimani Mts. and
"their significance. Kirkia 4: 125-157.
- 1965 a. The flora of the Great Dyke of S. Rhodesia with
special reference to the serpentine soils. Kirkia 5, 1 : 49-86.
- 1965 b. Vegetation Map of Rhodesia. Rhodesia, · ifs natural
resources and economic development, ed. M. 0. Collins,
Salisbury.
Acta Phytogeogr Suec 54
ZAM B IA
F. White
In collaboration with W. R. Bainbridge, Department of Game
and Fisheries, Chilanga, Zambia, D. B. Fanshawe, Division
of Forest Research, Kitwe, Zambia, R. M. Lawton, Mount
Makulu Research Station, Zambia and E. Milne-Redhead,
Royal Botanic Gardens, Kew.
GEOGRAPHY
Zambia occupies an area of 285, 1 30 square miles
(729,933 sq. km) and lies on the plateau of Central
Africa between the longitudes 22 o E and 3 3 o 3 3 ' E
and the latitudes 8 ° 1 5 ' S and 1 8 ° S. Altitudes lie be­
tween just over 7000 ft (2 1 3 3 m) and 1 1 00 ft (335
m) at Feira where the Zambezi leaves the country.
In general the plateau which is believed to be part
of the great Miocene peneplain traceable over great
distances through Central and East Africa is gen.tly
undulating and rather monotonous. The average
general level is about 4000-4200 ft ( 1 220-1 280 m)
but locally this has been modified by warping. At
various places in the northern half of the territory
and along the eastern border there are small elevated
regions of more resistant rocks thought to be residu­
als from earlier cycles of erosion. The more import­
ant include:
The Nyika Plateau (6500-8557 ft, 1 98 0-2608 m),
mostly in Malawi but crossed for some miles by the
Zambia-Malawi boundary above the 7000 ft (2 1 3 3
m) level; the Mafinga Mountains (7 1 0 1 ft, 2 163 m),
the crest of which forms the boundary between Isoka
District of Zambia and Fort Hill District of Malawi;
the Abercorn Plateau (highest point Sunzu Hill,
6782 ft, 2066 m) and the Muchinga Escarpment
(6041 ft, 1 840 m).
In the east and south-east the continuity of the
plateau is interrupted by a series of relatively deep,
trough-like valleys of tectonic origin forming part of
the East African rift system; chief among them are
the Luangwa and its tributaries and the mid-Zambezi
valley between the Victoria Falls and Feira. These
eastern rifts and the highly dissected country border­
ing them .on the west form a backbone feature of the
country. To the west lie a series of depressions con­
taining many swamps formed partly by post-Miocene
erosion, partly by warping; they include the Lake
Bangweulu basin, Lake Mweru and Mweru Wantipa,
the Lukanga and Busango swamps west of Broken
Hill, the valleys of the Chambeshi and Chozi Riv.ers,
the flats along the Kafue River and the swampy
depressions in Barotseland.
Acta Phytogeogr Suec 54
As elsewhere in Central and East Africa the geolo­
gical foundation of Zambia is made up of the most
ancient crystalline rocks, consisting of sediments,
lavas and intrusives, intensely altered by repeated
metamorphism-the "Basement Complex", which is
exposed mainly along the eastern and south-eastern
side of the country and is flanked on the south-west,
west and north-west by successively younger groups
of sedimentary rocks. The oldest and most extensive
of these comprise the Katanga System and are of
considerable economic interest because of the copper,
lead and zinc they contain. The second main division
is composed of sediments and lavas referred to as the
Karroo System. Karroo rocks occur locally on the
plateau surface particularly in the west towards
Angola where they are mostly overlain by Kalahari
sands.
This system, however, is best represented in the
downfaulted valleys of the Luangwa and Zambezi
where they have been protected from erosion. The
youngest sediments, belonging to the Kalahari Sys­
tem, are almost confined to the broad shallow basin
of the Upper Zambezi. Much of this region is cov­
ered with unconsolidated sands.
Striking correlations exist between rock types, soils
and vegetation types. Duvigneaud and Denaeyer-de­
Smet (1 963) have described the vegetation associated
with copper outcrops in Katanga. A similar vegeta­
tion is found in Zambia, as at Solwezi dambo, but is
less extensive. The Kalahari sands together with the
adjacent sands of Karroo originl support distinctive
vegetation-types found nowhere else in the country
-Cryptosepalum 'mavunda'; Baikiaea 'mutemwa',
Brachystegia bakerana thicket and the dwarf shrub­
lands of the watershed plains. Many species are ende­
mic to the Kalahari and Karroo Sands (White 1 965).
Where parent material changes within a zone of
rapid climatic change abrupt changes of vegetation
occur. On the escarpment flanking the Zambezi Val­
ley below Choma Brachystegia-Julbernardia 'mi­
ombo' woodland occurs almost to the bottom, but is
suddenly replaced by other types where the Basement
Complex gives way to mudstone rocks of the Karroo
System.
CLIMATE
Zambia has a markedly continental climate. The rain
falls in summer between November and April aver1 In the following account the term "Kalahari sands" is
meant to include the adjacent sands of Karroo origin.
Zambia
aging between 25 and 3 5 inches (625-975 mm) p.a.
in the south and over 50 inches (1 250 mm) in the
north. Most rain falls as thunderstorms or heavy
showers with only rare periods of continuous rain
over several days. Even during the rainy season a
f;:tir amount of sunshine is recorded. During the win­
ter months-May to August-dry cool weather with
moderate breezes is the general rule. Night tem­
peratures are low and ground frost occurs occasion­
ally on the plateau, especially in the dambos, but is
unknown in the deep low-lying river valleys. In Oc­
tober and November temperatures and relative hu­
midity rise greatly, the former to 80-l 1 0 ° F (26.6°43.3 ° C) according to locality.
VEGETATION
A general picture of the vegetation can be obtained
from the Vegetation Map of the Federation of Rho­
desia and Nyasaland (Rattray and Wild 1 9 6 1 ) . The
following account provides further details, especially
of those types that are susceptible to fire or
liable to rapid change unless carefully managed.
Woodland and wooded grassland occur through­
out the territory except locally where the soil or
climate favours other types, such as herbaceous
swamp in lake basins and certain river valleys,
edaphic grassland along the drainage lines, dry ever­
green forest on deep water-retaining soils in the
higher rainfall areas, dry deciduous forest and thicket
on deep soils in the drier areas, evergreen fringing
forest on river banks and montane communities on
the uplands of the eastern border.
Woodland and Wooded Grassland
The most widespread type is more or less open
Brachystegia - Julbernardia woodland or 'miombo'
with a sparse to moderately dense grass cover. On
exceptionally favourable soils, where dry forest is
probably the climax, the canopy can be 9 0 ft (27 m)
high, but elsewhere in the northern half of the ter­
ritory well-grown stands usually form a light canopy
at a height of 40-50 ft ( 1 2- 1 5 m). Well defined
strata do not normally occur, but scattered smaller
trees up to 30 ft (9 m) high and many shrubby
species are well represented. Under the light canopy
the woodland grasses and herbs grow to a height of
2-3 feet (60-90 cm), but if the canopy is opened the
grasses grow much taller and consequently the dry
season fires are fierce. In drier regions the canopy
may be only 20-30 ft (6-9 m) high and in exposed
places at high altitudes the trees may be no more
than a few feet high. The canopy species are decidu1 4 - 6 8 1 557 Hedberg
209
ous for a few weeks in July and August but flush
at the .e nd of August or beginning of September
about two months before the rains begin. Miombo
woodland can withstand repeated early burning but
fierce fires late in the season destroy the new foliage
and eventually kill the tree (Trapnell 1 959). Al­
though 'miombo' is floristically poor it is far from
uniform since many of the dominants show definite
ecological preferences, e.g. Brachystegia utilis for
coarse shallow granitic soils and B. microphylla for
rocky outcrops ; a number of floristic variants can be
recognized. In recent years much miombo has been
felled to provide timber and fuel for the Copper
Mines. Elsewhere, outside the forest and game re­
serves, except on steep rocky s1opes, most miombo is
subjected to shifting cultivation of citemene and
related types and is undergoing progressive degrada­
tion. With increased population pressure, miombo on
steep slopes is now being cultivated, as in parts of
Isoka District.
Scattered across the high rainfall belt from Mwi­
nilunga to Abercorn, are small islands of closed dry
evergreen forest (described below) which occur in
places where the soils are deep and can provide an
ample supply of water throughout the dry season.
These forests are particularly vulnerable to fire and
in many places their area has been greatly dimin­
ished. The relict patches are often surrounded, as at
Mukabi (Lawton 1 9 64), by luxuriant and highly in­
flammable tall grass (Hyparrhenia), fern (Pteridium)
and herbs (Aframomun biauriculatum) more than
2 m tall-so called chipya vegetation ("chipya" in
the vernacular means "fierce fire") which may be
treeless or else have scattered or densely occurring
fire-resistant trees, especially Combretum spp .,
Erythrophleum africanum, Pterocarpus angolensis,
and Terminalia mollis. If the trees occur sufficiently
densely to suppress the grass layer, fire-sensitive ever­
green forest species may colonise and form patches
of evergreen thicket which could ultimately develop
into forest. In any area the precise pattern of the
mosaic of forest, grassland, woodland and thicket is
largely the outcome of the historic pattern of fires to
which it has been subjected, influenced by the avail­
ability of seed of the various species capable of grow­
ing on the site.
Elsewhere, as at the Ndola Sample Plots (Trapnell
1 959), the forest is surrounded by top quality
miombo woodland dominated by Brachystegia spi­
ciformis, B. longifolia and Isoberlinia angolensis. In
other places Marquesia macroum may also be pres­
ent. It is uncertain to what extent such top quality
miombo woodland represents a natural ecotone be­
tween dry evergreen forest and more typical miombo
Acta Phytogeogr Suec 54
210
F. White
woodland or is secondary, having replaced evergreen
forest destroyed by fire or cultivation but subse­
quently subjected to light rather than fierce fires.
The burning experiments at Ndola have shown that
when such woodland is subjected to fierce annual
late fires, the dominant 'miombo' species are soon
eliminated and only the fire-resistant 'chipya' species
survive. The results of complete protection experi­
ments are less concJusive. After 23 years of fire pro­
tection the top quality miombo woodland which orig­
inally had a few fire resistant shrubs and a well
developed grass layer, had changed to dense miombo
woodland with evergreen liane tangles and scattered
evergreen shrubs. Despite the occurrence of seedlings
of evergreen tree species, Trapnell, with commend­
able caution, did not think that there was sufficient
evidence to regard this type of woodland as a fire­
induced type except in respect of its understorey.
-"So long as the canopy remains unaltered the
term 'fire-sub climax' is regarded as inapplicable".
Four years later however (White, unpublished) many
of the miombo dominants were dead or dying and
were not being replaced by the saplings present,
which were obviously being suppressed by the vigor­
ous evergreen thicket growth. The impression ob­
tained was that the miombo species were unable to
hold their own in competition with the forest species.
In the drier southern half of Zambia floristically
poor, less luxuriant miombo woodland only 30 ft
(9 m) high clothes the rocky slopes of the steep
escarpment flanking the downfaulted rift valleys and
occurs on unrejuvenated plateau soils which are often
shallow and stony and in places seasonally waterlog­
ged in their lower horizons.
Elsewhere, where the land surface has been reju­
venated, and richer, heavier soils occur between 2000
and 4000 ft (6 1 0-1 220 m), miombo is replaced by
open woodland or wooded grassland with a com­
pletely different flora. The grass is tall and luxuriant
and the trees usually widely spaced, with forked and
twisted trunks and fire-trimmed crowns; characteris­
tic species include Acacia campylacantha, A . siebe­
rana, Afrormosia angolensis, A lbizia amara, A . ver­
sicolor, Borassus, Combretum mechowianum, C.
molle, Ficus sycomorus, Kigelia, Lonchocarpus ca­
passa, Ostryoderris, Piliostigma thonningii, Pterocar­
pus rotundifolius and Terminalia mollis though only
a few of these would normally occur in' any one
locality. Trapnell ( 1 937) designates this vegetation
as "Upper Valley" and White ( 1 965) refers its
species to the 'munga' ecological element. In many
places, especially on the less intensively cultivated
European farms small patches of fire-sensitive semi­
deciduous thicket, sometimes with emergent trees, are
Acta Phytogeogr Suec 54
associated with this type of open woodland and there
is little doubt that the thicket has been destroyed by
cultivation and fire and replaced by fire-cJimax open
woodland.
In the deep valleys occupied by the Zambezi and
Luangwa Rivers miombo is of restricted occurrence
and is confined to sandy soils derived from Karroo
Sandstone and small inliers of the Basements Com­
plex. On rocky slopes (usually of Karroo sandstone
and conglomerate) it is replaced by stunted open
'mopane' (Colophospermum mopane) woodland with
a sparse, often annual, grass layer. Elsewhere in the
valleys there is a mosaic of vegetation types, the
precise pattern depending on soil factors and recent
history of the site. Luxuriant mopane woodland up
to 70 ft {2 1 m) tall or more is found on heavy salt­
accumulating soils. On deep, coarse alluvium fring­
ing seasonal watercourses, especially where the
watercourse affords some fire protection, dense de­
ciduous thicket with emergent trees is still preserved.
Elsewhere on heavier alluvium most of the thicket
has been destroyed by fire or cultivation to be re­
placed by open woodland or wooded grassland of
the "Lower Valley" type of Trapnell, similar in
physiognomy to Upper Valley types but often with
taller trees and a different though overlapping floris­
tic composition. Characteristic species include:
Acacia spp., A dansonia, Afzelia, Balanites, Berche­
mia, Combretum imberbe, Kigelia, Ostryoderris,
Sclerocarya, Sterculia africana and Tamarindus
indica.
On deep Kalahari Sands in southern Barotseland a
dense closed deciduous thicket ('mutemwa') with an
emergent canopy chiefly of Baikiaea plurijuga and
Pterocarpus antunesii is the characteristic vegetation
type. On the northern Kalahari Sands it is replaced
by dense low evergreen forest dominated by Crypto­
sepalum pseudotaxus. Over large areas both types
have been greatly modified by fire and cultivation
and replaced by various woodland types. Both Bai­
kiaea and Cryptosepalum occur in Kalahari woodland
where fires are not too fierce, often with G uibourtia
coleosperma. Typical miombo species such as
Brachystegia spiciformis, B. longifolia and Julbernar­
dia paniculata are present in woodland on Kalahari
Sand along its eastern and northern borders, but,
except for the extremely widespread and tolerant B.
spiciformis and the thicket-forming B. bakerana, are
absent from the deep sands of central Barotseland
where Burkea africana is one of the commonest
woodland trees especially on the less fertile sands.
Both on the plateau and in Barotseland a narrow
zone of stunted, often frost-trimmed and usually
open woodland of characteristic floristic composi·
Zambia
tion is often found between well developed woo d­
land and the edaphic grassland of the drainage chan­
nels where the soils are less freely drained than the
woodland soils but less waterlogged than the grass­
land soils; characteristic species include: Uapaca spp. ,
Monotes spp., Protea spp . , Faurea speciosa, Syzygium
guineense subsp. macrocarpum.
ally present, the composition of this type of forest
varies greatly from patch to patch. Some of its
species are Guineo-Congolian in their main distri­
bution, others are Zambezian endemics with Guineo­
Congolian affinity and others are Afro-Montane.
The Siszya (meaning "burial place") Forest in
Abercorn District (Lawton 1 963), differs from the
type described above in being deciduous for a short
period at the end of the dry season and consisting
chiefly of Guineo-Congolian species, e.g. Celtis du­
randii, Aningeria altissima, Trichilia prieuriana etc:
Montane Communities
Montane communities (Montane Forest, Thicket,
Shrubland and Grassland) are confined to the Nyika
Plateau and Mafinga Mountains though very many
montane species, e.g. : Podocarpus milanjianus,
Ocotea usambarensis, Philippia benguelensis, Hyperi­
cum roeperanum, Delphinium dasycaulon, etc. oc­
cur in specialised habitats at 4000-5000 ft (1 2201 525 m) at various places on the plateau between
M winilunga and Abercorn. Most of the Zambian
Nyika is now grassland, with the forest largely con­
fined to the heads of river valleys; a few patches of
montane Philippia thicket occur on rocky Qutcrops
and scattered patches of montane and submontane
forest still survive. The best known patch of forest is
at about 7000 ft (2 1 3 3 m) at the headwaters of the
Chire River, a tributary of the Luangwa; it is es­
sentially submontane forest of the type described for
Malawi but, since it occurs towards the upper altitu­
dinal limit, it has a greater admixture of a true montane
species. Chrysophyllum gorungosanum submontane
forest with emergent Entandrophragma excelsum is
found in deep ravines in the Mafinga Mountains.
The intervening rocky slopes are clothed with
stunted shrubland.
Lowland Forest and Thicket
The distribution of dry evergreen forest and its rela­
tionship to various woodland types has already been
mentioned. This type is less luxuriant than moist tro­
pical evergreen forest and varies greatly in structure
according to the species present, degree of maturity
and previous interference. The canopy (Fanshawe
1 960) varies in height from 40-80 ft (1 2-24 m).
Beneath the canopy small trees, shrubs and climbers
of many species form a dense undergrowth. The
ground vegetation is usually sparse, often consisting
chiefly of moss and forest grasses. Typical canopy
trees include Parinari excelsa, Syzygium guineense
subsp. afromontanum (both widespread), Olea capen­
sis, Marquesia macroura, Cryptosepalum pseudo­
taxus (on Kalahari Sands) and Marquesia acuminata
(very local). Enta·ndrophragma delevoyi is often pres­
ent as an emergent up to 1 20 ft (40 m) high or
more. Unlike most of the canopy species it is briefly
deciduous. Although Syzygium and Parinari are usu-
21 1
·
In the drier half of the territory dense, deciduous
thickets are found on the deep Kalahari Sands of
southern Barotseland and adjacent regions, on deep
alluvial deposits and on deep sandy soils of Karroo
origin in the Zambezi and Luangwa Valleys and the
Mweru-Tanganyika lowlands and on certain plateau
soils avoided by miombo woodland, as well as on
large termite mounds in miombo woodland. Since
nearly all the constituent species are fire-tender the
area occupied by thicket has been greatly reduced by
fire and cultivation. The multiple-stemmed shrubs
and small trees which are often spiny form an almost
impenetrable barrier. True lianes are not plentiful
but many of the shrubs and small trees, e.g. Combre­
tum celastroides are facultative climbers. Emergent
trees up to 50-60 ft ( 1 5-1 8 m) high, sometimes
more, are usually present, and often form a more or
less open upper canopy. Emergents include Baikiaea
plurijuga (Kalahari), Ricinodendron rautanenii (espe­
cially in secondary types), Entandrophragma caudar
turn, Pterocarpus antunesii, A dansonia, Kirkia, Ost­
ryoderris, Sterculia africana and Acacia tortilis (in
Zambezi Valley). A very large number of shrub and
small tree species occur in these thickets. The fol­
lowing are particularly characteristic and widespread:
Byrsocarpus orientalis, Combretum celastroides, C.
elaeagnoides, Commiphora spp., Croton gratissimus,
Dalbergia martinii, Haplocoelum foliosum, Mark­
hamia acuminata and Popowia obovata.
c
Fringing Forest
Evergreen fringing forest ('mushitu') is widespread
in the wetter half of Zambia where the dambos usu­
ally have a swampy spring at their head and a slug­
gish, svampy water course running their length.
These sites are occupied by swamp forest in which
Mitragyna stipulosa, Syzygium owariense and Xylo­
pia aethiopica are the commonest trees. Lower down
the drainage lines, where the streams are bigger, the
nature and composition of the fringing forest varies
greatly and depends on the nature of the river bank
-rocky, sandy, silt or clay and the occurrence,
height and duration of flooding. The fringing forest
Acta Phytogeogr Suec 54
2 1 2 F. White
flora is very rich and includes many species more
characteristic of other regions. Many Guineo-Con­
golian species, not normally associated with water oc­
cur at their southern limit in Zambia in fringing
forest, e.g. Canarium schweinfurthii, Diospyros hoy­
leana, Maesopsis eminii :and Nauclea pobeguinii. Si­
milarly many characteristic species of submontane
and montane forest occur in Zambia in fringing
forest e.g. Podocarpus milanjianus, Ocotea usamba­
rensis, llex mitis, Ficalhoa. In the past fringing forest
has been much depleted by tree-felling, fire and culti­
vation.
Grassland
Most of the grassland types have been fully described
by Vesey-Fitzgerald ( 1 963). In addition to the true
grasslands, and similar types dominated by Cypera­
ceae, a distinctive mixture of sparse wiry grasses and
dwarf tufted or rhizomatous shrublets often occurs,
as a narrow zone between the grasslands of the
dambo and the woodlands and the dambo edge.
Many of the shrublets, e.g. Parinari capensis, are
closely related to, and except in habit are often
scarcely distinguishable from, tree species. A similar
type but v.ery rich in endemic shrubby species, oc­
cupies extensive "watershed" plains on Kalahari
Sands in the upper tributary region of the Zambezi.
They are waterlogged in the rains but waterless dur­
ing the dry season.
FLORISTIC RICHNESS, ENDEMISM AND
ECOLOGICAL PREFERENCE
White ( 1 965) has pointed out the richness of the
Zambezian savanna woodland tree flora compared
with the Sudanian, and recognized three well-defined
centres of endemism partly occurring in Zambia.
This is only one aspect of the richness and diversity
of the · Zambian flora. The Katanga, Barotse, and
Zambezi centres have many endemic shrubs and
herbs besides the trees listed in the paper mentioned.
Full figures are unlikely to be available for a long
time but Crotalaria provides an indication of this
richness. More than 70 endemic species are confined
to the Katanga centre (Polhill and Milne- Redhead,
personal communication), or nearly half as many
again as occur in the enormously greater area cov­
ered by the Flora of West Tropical Africa. Accord­
ing to Milne-Redhead the savanna of Mwinilunga
District, which lies inside the Katanga centre, is the
richest in Africa. Of the specimens he collected there
in 1 9 3 7-3 8, 1 0 % belonged to undescribed species.
He collected 90 species of epiphytic orchids, a group
Acta Phytogeogr Suec 54
of plants usually associated with forest regions rather
than savanna.
Besides endemics of restricted distribution and
others more widely distributed in the Zambezian Do­
main many species, more characteristic of other cli­
matic regions, reach the limits of their distribution
in Zambia. Guineo-Congolian and Afro-Montan,e
tree species occurring in Zambia in fringing forest
have already been mentioned. Many dry country
species of southern distribution, e.g. Azima tetra­
cantha, Rhigozum brevispinosum and Salvadora per­
sica j ust cross the Zambezi. Typical Cape genera
such as Moraea, Eriospermum, A nthericum, Hypo­
xis, Cyphia and Lapeyrousia have representatives in
Zambia, especially in sparse dambo grassland where
competition is diminished, and in rocky places.
The Cape Region is justly famous for the richness
of its flora, but a very high proportion of its species
are endemic to very small areas and have ecological
requirements similar to other endemics from other
small areas. So much is this so that in any one place
the total number of species present may be quite
small and well-defined ecological patterns are often
difficult to detect (White, unpublished). In the Zam­
bezian Domain the patterns of distribution and eco­
logy, and hence their interest and significance, are
quite different. Besides endemic species and the spe­
cies at the limits of their range which may help to
unravel the history of African vegetation, the major­
ity of widespread species in any one area in Zambia
usually show well-defined habitat preferences. In
other words they have a high 'indicator' value and
many can be used in site assessment. It is of the
utmost importance that representative patterns of ve­
getation types, not merely the types themselves
should be preserved both because of their intrinsic
scientific interest and practical application. Future
rational land-use in Zambia may suffer unless suf­
ficient natural vegetation is conserved so that by
future study its indicator value can be more fully
assessed.
PROTECTION
Survey of Communities A lready Protected
There is no body in Zambia with functions compar­
able to those of the Nature Conservancy in Britain.
Notwithstanding this, a very wide range of vegeta­
tion types are at the present time being effectively
conserved, especially in Forest Reserves, Game Re­
serves and National Parks, largely due to the efforts
of certain senior officers and their predecessors.
The Natural Resources Board, a statutory body
which co-ordinates the affairs of the Ministry of
Zambia
Lands, dealing inter alia with Water Supplies, For­
estry, Game and Fisheries with those of the Ministry
of Agriculture, has issued an ordinance protecting
fringing forest ('mushitu') which is legally defined as
"evergreen forest growing in a watercourse". For­
est field staff are conservation-minded and patrol and
protect mushitu directly under their control and are
able to enforce legislation. Elsewhere, especially
where there is pressure on the land, headwaters
mushitu are often destroyed; consequently dams built
to conserve water lower down the valleys silt up.
Certain of the larger trees, e.g. Erythrophleum guine­
ense, Entandrophragma delevoyi and Khaya nyasica
are protected by Native Authority ordinances and
may only be felled with permission of the Forest
Department, but outside the Forest Reserves this is
often difficult to enforce.
Forest reserves. Since the end of the war the For­
est Survey Units have made surveys of the forest
resources of all the administrative districts in Zambia
with the exception of Chinsali and Mpika. The re­
sult of these surveys together with recommendations
for the establishment of Forest Reserves and Pro­
tected Forest Areas are published ·i n a series of Dis­
trict Management Books. It has been the policy of
the Department, wherever possible, to schedule for
conservation any vegetation of real botanical interest
after the district has been surveyed. It may be years
however before such areas are gazetted. Since the
Forest Reserves are uninhabited and the grass inside
them is burnt early in the dry season, such interest­
ing vegetation as they contain is, at the present time,
reasonably well protected.
The following Forest Reserves have been con­
served because of their botanical interest:
Chichele Botanical Reserve. Just outside Ndola. About 30
acres of Chipya woodland and Parinari excelsa dry evergreen
forest. The protected area is now surrounded by plantations
of Pinus khasya and P. merkusii and so is safe from fire.
The Nyika Forest Reserve. Montane forest (Aningeria adol­
fi-friederici, Parinari excelsa, Podocarpus milanjianus) at head­
waters of Chire River c. 7000 ft (2 1 3 3 m).
South Mutundu Special Grant Reserve. Ndola District. Dry
evergreen forest with Erythrophleum guineense.
Muva Hills Protected Forest Area. Hillside miombo wood­
land on the Muva Quartzites.
Forest Reserves and Protected Forest Areas which
contain interesting vegetation types:
Balovale P. F. A. Balovale District. Baikiaea plurijuga dry,
semi-deciduous 'forest' (Zambezian type, northern facies).
Bombwe F. R. Kalomo District. Baikiaea plurijuga dry,
semideciduous 'forest' (Zambezian type, southern facies).
Chisamba F. R. Broken Hill District. Dry evergreen forest.
Chambezi Flats P. F. A. Kasama District. Edaphic grass­
land and termite mound vegetation.
213
Dome F . R. Ndola District. Fringing forest with Podocar­
pus mi/anjianus .
Kamenza F. R. Ndola District. Brachystegia microphylla
hillside miombo woodland.
Luano F. R. Ndola District. Miombo woodland on granite
soils with relic dry evergreen forest of Brachystegia micro­
phylla.
Lujubu North P. F. A. Ndola District, Isoberlinia 'transi­
tion woodland'.
Lunzua P. F. A. Abercorn District. Fringing forest.
Machili P. F. A. Sesheke District. Baikiaea plurijuga, dry,
semi-deciduous 'forest' (Zambezian type, southern facies).
Miengwe F. R. Ndola District. Dry evergreen forest.
Misaka F. R. Ndola District. Dry evergreen forest with
Entandrophragma delevoyi and Erythrophleum guineense.
Mpulungu P. F. A. Abercorn District (Siszya Forest). Dry
semi-deciduous forest (Guineo-Congolian type) with Celtis
duran,dii, Aningeria altissima and Trichilia prieuriana.
Mukabi P. F. A. Kawambwa District. Dry evergreen forest.
For a full account see Lawton (1964).
Mulenga P. F. A. Solwezi District. Chipya woodland on
limestone.
Mwomboshi F. R. Broken Hill District. Dry evergreen for­
est.
Nambala P. F. A. Mumbwa District. Dry deciduous forest
(Zambezian type).
Ndola F. R. Ndola District. Dry evergreen forest. The
important experimental burning plots are located here-see
Trapnell ( 1959).
Nkolenjumu P. F. A. Kasama District. Lake Basin chipya
woodland and related types.
Samfya P. F. A. Lake Bangweulu. Lake Basin chipya wood­
l and and related types.
Songe-we-lala. F. R. Broken Hill District. Hillside miombo
woodland.
Zambezi Source P. F. A. Mwinilunga District. Fringing for­
est.
The following areas protected by the Natural and
Historical Monuments Commission contain interest­
ing examples of fringing forest and related vegetation
types:
Chifubwa Gorge, Solwezi District; Chishimba Falls, Ka­
sama District; Kalambo Falls, Abercom District; Bell Point
at confluence of Mkushi and Lunsemfwa Rivers; Kundalila
Falls, Serenje District; Hippo Pool, Chingola; Lake Chi­
rengwa (Sunken Lake), Ndola District; Kundabwika Falls,
Mporokoso District; Chipoma Falls, Chinsali District; Lu­
mangwe Falls, Mporokoso District.
The Department of Agriculture does not hold re­
serves of land, but at its experimental stations there
are interesting examples of unstable, fire-induced ve­
getation types which are maintained for experimental
work and demonstration. This is particularly true of
'munga' open woodland types of the Mazabuka,
Chilanga, Chisamba and Mumbwa areas which are
late burnt every three years so that a satisfactory
balance between the tree and grass layers can be
maintained.
National parks and game reserves. Since most of
these, and particularly the Kafue National Park and
Acta Phytogeogr Suec 54
214
F. White
the Luangwa Valley Game Reserves, are more low­
lying, hotter and drier than most of the forest re­
serves mentioned above, they contain extensive areas
of vegetation types not well-represented in the forest
reserves, but there are also game reserves in higher,
wetter and cooler areas so that representative samples
of all the important vegetation types of Zambia are
included in reserves managed by the Department of
Game and Fisheries and at present are protected
from cultivation and uncontrolled burning.
The Department of Game and Fisheries, although
very small and understaffed, has abandoned an in­
flexible policy of game preservation and is now en­
tirely concerned with game management, one object
of which is to maintain the maximum number of
each species of animal which · can be supported by
each habitat without damage to those habitats. This
is known as the "carrying capacity" of the habitat.
For no vegetation type has the carrying capacity yet
been determined, but it is quite plain that in some
reserve�, e.g. the Luangwa South Game Reserve, the
carrying capacity has been exceeded with consequent
degrad�tion of the vegetation, soil erosion and pos­
sibly a permanent lowering of future carrying ca­
pacity.
It is the aim of the Department to draw up de­
tailed R:ange Management Plans for each of the
Game Reserves and National Reserves, based on a
detailed ecological evaluation of the habitat. The
first team, consisting of ecologists, is now working in
the Luangwa South Game Reserve. When these plans
are complete it should be possible to manage much of
the vegetation included in the reserves as stable
grazing and browsing climaxes, supporting a diversi­
fied fauna at full carrying capacity, but it is intended,
in the National Parks at least, to set aside certain
areas of vegetation in their wilderness state as botani­
cal reserves. The entire game estate is at present
being rationalised in connection with a new Fauna
Conservation and National Parks Ordinance and in
doing this it is hoped that some small but unique ve­
getation types will be protected, e.g. the Acacia
albida dry forest in the Luangwa Valley at Kakumbi
and a small area of virgin Baikiaea forest in N ac­
hitwe forest, Sichifulo Game Management Area,
Kalomo.
The Game Department manages three categories
of game estate. These are:
National Parks
Game Reserves
Controlled Hunting Areas
In the first two categories no habitation is allowed
and entry is restricted; it is illegal to light fires. The
Acta Phytogeogr Suec 54
vegetation in National Parks is totally protected from
cutting and other forms of exploitation. In the con­
trolled hunting areas there is no restriction on burn­
ing or utilisation of vegetation. The vegetation of
many of the smaller Game Reserves is very imper­
fectly known.
Luangwa Valley: Southern Section Game Reserve (3200 sq.
miles, 8 192 sq. km; 1 800-2000 ft, 549-61 0 m). Mostly river­
ine Acacia - Combretum woodland, mopane woodland and
various miombo woodland types, but locally Setaria grassland
occurs on Karroo marls. Some areas are heavily over-grazed.
The Setaria grassland Lundu plain and the Chifungwe plain
just north of the Game Reserve carry spectacularly large
numbers of elephant. Interesting species include all the Valley
Acacias, including A. tortilis and A. kirkii, although these
two and A. albida are much overeaten by elephant, and
Gyrocarpus, Entada chrysostachys etc.
Luangwa Valley: Northern Section Game Reserve ( 1790 sq.
miles, 4582 sq. km; 1 800-2000 ft, 549-61 0 m). Vegetation as
for above. It is proposed to amalgamate these two reserves
together with some smaller areas to form one large National
Park. This would ensure the preservation of many areas of
interesting and little-disturbed vegetation in their wilderness
state.
Lukusuzi Game Reserve (1050 sq. miles, 2688 sq. km,
2000-3000 ft, 6 1 0-9 1 4 m) escarpment and' plateau miombo.
Luambe and Nseju Game Sanctuaries ( 1 800 ft, 549 m).
Mopane woodland and Acacia-Combretum woodland.
lsango Game Reserve (325 sq. miles, 832 sq. km; 3000 ft,
9 1 4 m) . Mostly swamp and papyrus swamp; also Lake Basin
chipya vegetation and plateau miombo woodland.
Sumbu Game Reserve (780 sq. miles, 1 996 sq. km; 3000 ft,
9 1 4 m). Mostly plateau miombo woodland, also Bussea­
Combretum thicket.
Mweru Marsh Game Reserve ( 1 2 1 0 sq. miles, 3097 sq. km ;
3000 ft, 9 1 4 m). Mostly plateau miombo woodland and valley
and flood plain grassland; also Bussea-Combretum thicket.
Lusenga Plain Game Reserve (340 sq. miles, 870 sq. km;
3000 ft, 914 m). Mostly plateau miombo woodland; also
watershed grassland on Kalahari Sands.
Lavushi Manda Game Reserve (580 sq. miles, 1485 sq. km;
3500 ft, 1 067 m). Mostly plateau miombo woodland.
Kasanka Game Reserve ( 1 50 sq. miles, 384 sq. km; 3500 ft,
1 067 m). Mostly plateau miombo woodland.
Lunga Game Reserve (650 sq. miles, 1 664 sq. km; 4500 ft,
1 372 m). Mostly Cryptosepalum dry forest and Cryptosepa­
lum woodland on Kalahari Sands; also grass i and on plains
on Kalahari Sands.
Kajue National Park (8650 sq. miles, 22,144 sq. m ; 30004500 ft, 9 1 4-1 372 m) . A very wide range of vegetation types.
The Baikiaea forests are particularly interesting. Entandro­
phragma delevoyi and Parinari excelsa reach their southern
limits in the park.
Further Protection
Examples of most vegetation types are included in
the Forest Reserves, Game Reserves and National
Parks and at present are safely conserved. This may
not always be so. There is a danger that increased
pressure on the land may lead to political pressure
being brought to bear on Departments to liberate un­
productive land for food production. It is necessary
Malawi
to remember that the primary terms of reference of
both the Forest Department and the Game Depart­
ment concern production-of timber and other forest
produce and of animal life respectively, and that, at
present, production programmes almost totally ab­
sorb the energies of their staffs.
As a first step, one or more qualified officers
should be appointed to ensure that adequate samples
of vegetation types already included in reserved areas
are effectively protected.
As a long term measure it might be desirable to
set up a Commission of Enquiry, possibly sponsored
by an International Body, to produce a detailed and
comprehensive report on the status and management
of all biological reserves in Zambia, both those that
are intentionally reserved for their biological im­
portance and those that are accidentally or incident­
ally reserved, and to make recommendations con­
cerning their future management.
Protection from all outside influences without an
understanding of the origin, history and status of the
various vegetation types is not enough. The status of
many types, particularly in relation to fire, cultiva­
tion and grazing is still not fully understood. The
experimental plots of the Forest Department and
more recently of the Department of Agriculture have
shed much light on the effects of fire on vegetation.
More demonstration plots should be established espe­
cially near schools, and more effort should be made
to use them to instruct the people in methods of
wise land use.
The Departments of Biology at the new University
of Lusaka will need a Field Study Centre if they are
to function properly. Matonchi Farm in Mwinilunga
District comprising about 1 000 acres of freehold
215
land a t present owned by Mrs. Patterson, would b e
admirably suited t o this purpose. It lies a t the centre
of the floristically richest part of the great Sudano­
Zambezian savanna woodland Region and is the
type-locality of numerous species collected by Mr. E.
Milne-Redhe;ad. Zoologically it is also interesting and
has a diversified bird fauna.
ACKNOWLEDGEMENTS
I should like to thank Mr. R. M. Bennett, Mr. R. Polhill and
Mr. E. A. Robinson for kindly supplying useful information.
REFERENCES
Duvigneaud, P. and Denaeyer de Smet, S., 1963. Cuivre et
Vegetation au Katanga. Bull. Soc. Roy. Bot. Belg. 96 :
93-2 3 1 .
Fanshawe, D. B . , 1 960. Evergreen Forest Relics i n Northern
Rhodesia. Kirkia 1 : 20-24.
Lawton, R. M., 1 963. Palaeoecological and Ecological Studies
in the Northern Province of Northern Rhodesia. Kirkia
3: 46-77.
- 1964. The Ecology of the Marquesia acuminata (Gilg)
R. E. Fr. Forests and the Related Chipya Vegetation
Types of North-Eastern Rhodesia. Journ. Ecol. 52: 467479.
Rattray, J. M. and Wild, H., 1 9 6 1 . Vegetation Map of the
Federation of Rhodesia and Nyasaland. Kirkia 2: 94-104.
Trapnell, C. G . and Clothier, J. N., 1 9 37. The Soils, Vegeta­
tion and Agricultural Systems of North-Western Rhodesia.
Lusaka, Govt. Printer.
Trapnell, C. G., 1 959. Ecological Results of Woodland Burn­
ing Experiments in Northern Rhodesia. Journ. Ecol. 47 :
129- 1 68 . (1963).
Vesey-Fitzgerald, D . F., 1963. Central African Grasslands.
Journ. Ecol. 5 1 : 243-27 3 .
White, F., 1 965. The Savanna Woodlands of the Zambezian
and Sudanian Domains: an Ecological and Phytogeogra­
phical Comparison. Webbia 1 9 : 65 1-68 1 .
M A LA W I
J. D . Chapman
GEOGRAPHY
Malawi is situated in south-east central Africa be­
tween 9 ° 25 ' and 1 7 ° 08 ' S latitudes and 3 3 ° and 3 6 °
E and i s 520 miles (832 km) long and from 50 to
1 00 miles (80- 1 60 km) wide. Its total land area is
3 6,686 square miles (93 ,9 1 6 sq. km) and is entirely
landlocked, the nearest point to the sea being 1 3 0
miles (208 km) inland.
The dominant physical feature of Malawi is the
deep, trough-like depression, forming part of the
Great Rift Valley, which traverses it from north to
south and is occupied by Lake Malawi, the Lake
Shore Plains and the Shire River valley which drains
the Lake and joins the Zambezi in its lower reaches.
The Rift Valley plains lie at about 1 500 ft (457 m)
above sea-level and are sunk below a great peneplain
surface which covers much of Central Africa and is·
Acta Phytogeogr Suec 54
216
J. D. Chapman
believed to date from Miocene times. This surface is
now somewhat warped and generally slopes away
from the lips of the escarpment zones bounding each
side of the Rift Valley. Though normally around
4000 ft (1 220 m) elevation it varies from about 5000
ft (1 525 m) in the Dowa-Dedza part of the Central
Region to about 2000 ft (6 1 0 m) at the foot of Mt.
Mlanje. Rising up to several thousand feet above the
Miocene surface are the mountain plateau remnants
that occur on Mlanje (9 843 ft, 300 1 m), Zomba
(6846 ft, 2087 m) and Dedza (74 1 2 ft, 2260 m)
Mountains and, in the north, the high plateaux of the
Vipya (6830 ft, 2082 m), Nyika (855 1 ft, 2606 m)
and Misuku (6 1 96 ft, 1 859 m). These are all believed
to be remnants of the late Jurassic peneplain. The
otherwise flat and featureless Miocene surface is fre­
quently broken by smaller hills and mountains in
various parts of the country. The great physio­
graphic diversity of Malawi is well shown by the fact
that, on a clear day, one can stand at the lowest
point in the country at Nsanje (Port Herald) and see
the heights of Mlanje 70 miles ( 1 1 2 km) away and
9 500 ft (2896 m) higher.
Most of the Miocene land surface is underlain by
rocks of the Basement Complex. In southern Malawi
these are believed to be of Middle Pre-Cambrian age
and are schists, migmatites, gneisses and granulites
of the "Mozambique Belt". Intrusions of the harder
syenite form Dedza, Zomba and Mlanje Mountains.
Much of northern Malawi is covered by the some­
what younger, probably Upper Pre-Cambrian rocks
of the M afingi System, chiefly quartzites, schists and
phyllites with local intrusions of granite, syenite and
pyroxenite. In places the M afingi rocks have been
considerably hardened by metamorphosis and are
now represented by the garnetiferous schists and
gneisses which form the Misuku Hills and the Nyika
and Vipya plateaux. The Rift Valley floor is oc­
cupied by soft sedimentary rocks of Karroo and post­
Karroo age-shales, mudstones and sandstones-and
more recent alluvial deposits. It appears that the di­
verse rock types found in Malawi exert more of an
indirect influence on the vegetation through their
control of physiography rather than through the che­
mical nature of the soils to which they give rise. The
extensive bauxite deposits of Mlanje do not support
a distinct flora. In Malawi there is no evidence for
the occurrence of distinct vegetation types rich in
endemic species associated with metalliferous soils
such as occur in Katanga (Duvigneaud and Denaeyer
de Smet 1 9 63) and on serpentine soils in Rhodesia
(Wild 1 965). The more subtle differences that most
certainly exist between soils derived from different
rock types and their effect on vegetation have not
Acta Phytogeogr Suec 54
been studied in detail in Malawi, but in this connec­
tion it is interesting to note that as long ago as 1 928
Dixey pointed out that areas of graphitic gneiss and
crystalline limestone give rise to fertile red soils and
support a larger population than the pale, dry, sandy,
infertile soils derived from granite, granulites and
gneiss.
CLIMATE
The climate is continental in character with a large
seasonal variation in temperature. In contrast to
other East African territories situated nearer the
equator, there is only a single rainy season occur­
ring chiefly in the summer months from November
to March. The mean annual rainfall varies from 2045 0 (500- 1 1 2 5 mm) p.a. except where it is locally
augmented because of topographic features, as at
Nkhata Bay (70-90 / / , 1 750-2250 mm) and the Ka­
ronga Lake Shore Plain (45- 1 1 5 / / , 1 1 25-2875 mm)
and on the slopes of mountain massifs facing the
direction of rainbearing winds.
In general the climate of M alawi is less conti­
nental than that of Zambia because of dry season
invasions of moist maritime air from the Mozam­
bique Channel bringing periodic spells of mist, driz­
zle or even rain, so-called chiperone weather. On
higher ground, even where total precipitation may be
quite low, dry season mists are sufficiently prevalent
to bring about the replacement of the continental
Sudano-Zambezian flora by Afro-montane types.
The mean annual temperature of the Rift Valley
is over 7 5 ° F (24 ° C), that of the Miocene land surface
between 65 ° and 75 ° F (1 8. 3-24 ° C) and that of the
high plateaux below 65 ° F ( 1 8 . 3 ° C). Ground frosts
are frequent in June and July on the high plateaux,
less so at lower altitudes and are unknown from the
Rift Valley floor.
VEGETATION
When the first Europeans visited Malawi little over a
century ago they found the greater part of the coun­
try sparsely inhabited and well wooded. There can
be little doubt that much of the vegetation was then
woodland or savanna woodland and that over large
areas this has been degraded by fire and cultivation
to tree savanna and shrub savanna, locally to grass
savanna. Nevertheless, despite the dense population
today (believed to he as many as 42 per sq. km
compared with 6 per sq. km in Rhodesia and 2.3 in
Zambia) and consequent degradation of the vegeta­
tion, Malawi, in contrast to some other African ter­
ritories, e.g. Northern Nigeria, is still a country in
which a road journey from end to end leaves a domi-
Malawi
nating impression of trees in an open woodland
environment. A comparable journey by air however
shows how little woodland is left, especially in parts
of the Central and Southern Regions, since much of
the surviving woodland occurs as narrow strips adja,.
cent to the roads.
Woodland, and Wooded Grassland
The most widespread vegetation type is more or
less open Brachystegia/ Julbernardia woodland or
"miombo" ("dondo" in Chewa) with a moderately
dense grass cover. Depending on such factors as
depth of soil, degree of exposure and history of
human interference, this woodland varies greatly in
density and luxuriance and would accordingly be
designated as woodland, savanna woodland, tree
savanna and, in the case of some depauperate types,
even "grass steppe with trees" in the Yangambi
classification (Anon. 1 956). In varied form, Brachy­
stegia woodland covers thousands of square miles,
including most of the main watersheds of the coun­
try. It ranges in altitude from a few hundred feet
above sea level in the Lower Shire Valley to over
6000 ft ( 1 830 m) at the margins of montane grass­
land and forest patches on the high plateaux. Except
in dambos (seasonally waterlogged depressions where
grass is the climax)-or where the rainfall is excep­
tionally high or well distributed it is predominant
over most of the country between 2000 and 5000 ft
(6 1 0-1 525 m). Although generally absent from the
floor of the Rift Valley it locally descends far down
the escarpment and covers small rocky hills rising
from the valley floor.
Although much of the land occupied by Brachys­
tegia is too infertile for permanent agriculture or too
steep to be cultivated without causing accelerated
soil erosion, shifting cultivation has been widely
practised for centuries. Consequently extensive areas
must now be classed as savanna woodland or tree
savanna. Probably the only Brachystegia woodland
which approximates to the true climax, or at least
one which has not been much altered by human
influence, is on steep and rocky escarpments, tracts
of country too remote from domestic water supply,
or infested with tsetse fly, or areas too infertile to
attract settlement.
Locally on the Miocene land surface where the
soil is more fertile as in the Lilongwe area Brachys­
tegia woodland is replaced by other types. In Li­
longwe District most of the land has been cleared
for food crops or tobacco growing. The remaining
trees are usually scattered amongst cultivation and
except where fire protection is afforded, regrowth is
thin and the grass thick and tall. Various species of
217
Acacia are prominent, including A . campylacantha,
which is gregarious, and A . galpinii.
Many species of Combretum, Piliostigma thon­
ningii and Terminalia sericea also occur. In grave­
yards and other places where there is some protec­
tion from fire, fire-sensitive trees such as Bridelia
micrantha, Rauvolfia caffra and Trichilia emetica
may be found, indicating that here the climax vege­
tation might once have been dry forest.
At lower altitudes, in the Rift Valley and on the
Palombe Plain, the woody flora at least is richer and
more diversified and several types of woodland and
savanna as well as dry deciduous forest and thicket
are found. On the Palombe Plain most of the land
fit for cultivation has now been opened up for set­
tlement by the provision of bore-holes and, except in
graveyards, little if any undisturbed woodland re­
mains. However there are still plenty of scattered
trees and Acacia nigrescens, Combretum spp. (in­
cluding C. imberbe), Lonchocarpus capa.ssa and
Sclerocarya caffra are all widespread.
In the Rift Valley many of the commoner trees are
tall and of a most distinctive appearance, and several
woodland types are represented. On the better soils,
where most of the land is under cultivation and big
widely spaced trees of Adansonia, Acacia albida,
Cordyla. africana, Kigelia pinnata, Kirkia and Ster­
culia (S. appendiculata and S. africana) have been
left standing, the effect is park-like. Groves of the
palm Hyphaene often occur. There are several Aca­
cias. On colluvial soils, often with a high sand frac­
tion A cacia tortilis and A. nigrescens form, when
undisturbed, a tall woodland. So also does A . cam­
pylacantha, which is found on fertile soils. Pure
stands of A cacia seyal are characteristic of heavy
black soils subject to seasonal flooding, and A . xan­
thophloea can sometimes be seen near river banks
mainly on swampy clay alluvium. Extensive stands of
almost pure mopane (Colophospermum mopane) are
common below 2000 ft to as far north as Ntakataka,
at the foot of the Dedza escarpment, mostly on soils
not used for agriculture, and consequently little de­
graded by human interference. Most occurrences are
said to be associated with outcrops of crystalline
limestone usually uphill from the mopane (Watkin
Lewis, in litt.).
Terminalia sericea the trees tall and well grown,
is locally gregarious on sandy soils, for example on
the Lake Shore at Salima. Groves of Borassus palm
occupy swampy land little suited for agriculture in
the Kasitu valley, near Njakwa, and in the vicinity of
Rumpi, but the most extensive area is in the Lower
River, between Chikwawa and Chiromo. Pterocarpus
angolensis has a scattered distribution but it reaches
Acta Phytogeogr Suec 54
�·
..
218
J. D. Chapman
its best development towards the foot of the Rift es­
carpment, where it is frequently associated with the
presence of soft decomposing micaceous rock ("chi­
fomboti") not far below the soil surface.
Montane Communities (Montane Forest, Thicket,
Shrubland and Grassland)
The high plateaux and mountains support a flora
and vegetation which have little in common with the
"miombo" woodland surrounding them. Evergreen
forest occurs as relics, mostly confined to ravines and
the heads of streams, but sometimes also on slopes
and crests of ridges. Some of the forests are quite
extensive, as in the Misuku Hills, where they cover
several square miles. It is however more usual to find
small scattered patches of forest in a landscape domi­
nated by short grasses, mostly Exotheca abyssinica
with Loudetia simplex and Monocymbium ceresii­
forme on eroded slopes and with Themeda triandra
and A ndropogon schirensis on deeper soils. All these
species also occur at lower altitudes. Grasses con­
fined to high mountains, e.g. Danthonia davyi and
Eragrostis volkensii are very local.
The occasional occurrence in montane grassland
of the ·charred remains of large trees of Ocotea usam­
barensis, sometimes at a considerable distance from
the existing forest edge, indicates that most of them
are of secondary origin.
Conifer forest is confined to the Nyika Plateau
where there are several small patches dominated by
Juniperus procera and to Mt. Mlanj.e where Wid­
dringtonia whytei forms magnificent stands 140 ft.
(43 m) high over an understorey of broad-leaved
evergreen trees (Chapman 1 9 62). It is here, at the ex­
treme northern limits of its range, that the genus
Widdringtonia reaches its greatest luxuriance. On Mt.
Mlanje W. whytei occurs in several genetically di­
stinct variants (Chapman 1 9 6 1). Above the timber
line it behaves as a slow growing, multiple-stemmed
shrub only a few metres high. Both on the Nyika and
on Mt. Mlanje the area of conifer forest has been
greatly diminished by fire and the remaining patches,
though fire-protected, are still vulnerable. Paradoxi­
cally it appears that both Juniperus and Widdring­
tonia cannot regenerate in their own shade and need
the intervention of fire for their regeneration.
Broad-leaved evergreen forest occurs on moun­
tains and other upland areas where the effects of the
dry season are mitigated by frequent mists. There are
two distinct types (each with numerous variants) with
different ecological requirements, physiognomy and
floristic composition. Below 7000 ft. (2 1 34 m) where
rainfall is high (more than 50 in. , 1 250 mm), the soils
deep and exposure to wind not too great, luxuriant
Acta Phytogeogr Suec 54
forest with a canopy 70-90 ft. (2 1 -27 m) high and
emergents up to 1 60 ft. (50 m) high occurs. Most
species are endemic to the African mountains but
they belong to genera characteristic of the lowland
moist evergreen for�st of the Guineo-Congolian
Region and often are very closely related to Guineo­
Congolian species.
Above 7000 ft. (2 1 34 m), or at lower altitudes
where the rainfall is low (less than 50 in. , 1 250 mm)
and the soils shallow and exposure to wind consider­
able, much less luxuriant forest is found with a
canopy rarely more than 60 ft. ( 1 8.3 m). Other than
the extremely localised coniferous species, Juniperus
procera and Widdringtonia whytei, emergents are
absent. Most species belong to genera which are ab­
sent from the Guineo-Congolian Region but are well
represented in the North Temperate zone or in South
Africa or on tropical mountains.
In the past both types of forest have usually been
designated "montane" forest but since the former in
structure and floristics is very closely related to low­
land forest it seems better to refer to it as 'submon­
tane' forest and restrict the term 'montane' forest to
the less luxuriant type. Further details are given in a
forthcoming work (Chapman and White, in press).
Important canopy species of submontane forest
are
Chrysophyllum
gorungosanum,
Strombosia
scheffleri, Drypetes gerrardii and Celtis durandii.
Emergents include Aningeria adolfifriederici, En­
tandrophragma excelsum and Ocotea usambarensis.
Characteristic species of montane forest sensu stricto
are: flex mitis, Podocarpus milanjianus, Pygeum
(Prunus) africanum, Apodytes dimidiata, Afrocrania
(Cornus) volkensii and Rapanea melanophloeos.
With increasing exposure this type diminishes in sta­
ture until it merges into montane thicket in which
stunted shrubby trees a few metres high mingle with
large shrubs of Philippia benguelensis, Hypericum
revolutum etc. On the higher mountains exposed
rocky slopes support an open montane shrubland.
Lowland Forest (Moist and Dry) and Thicket
Lowland moist evergreen and semi-deciduous forest
is almost absent from south-central Africa since most
of the region is too high or too dry. Suitable condi­
tions occur at a few places in Malawi. At Nkhata
Bay on the Shore of Lake Nyasa the rainfall is ade­
quate for this vegetation type but no known examples
survive. However a number of lowland forest species
are known in Malawi only from this locality in al­
most closed Brachystegia spiciformis woodland with
evergreen understorey; this type appears to be sec­
ondary. Similarly, at the southern foot of Mt. Mlanje
in the "tea belt", a lowland forest climate occurs
Malawi
and relict forest species are found but no example of
undisturbed forest. Extensive areas of moist lowland
forest are only found in the extreme south of the
territory in the Malawi Hills which rise abruptly to
2000-3000 ft (6 1 0-9 1 5 m) from the surrounding
plain and intercept rain-bearing winds from the
south. This is the type locality of Burttdavya nya­
sica, the main emergent species, which is otherwise
only known from a few localities in Tanganyika. It
is closely related to the well-known West African
timber tree, 'Opepe', Nauclea diderichii, and because
of the high quality of its own timber it is particularly
vulnerable to illicit felling. Other emergents are
Khaya nyasica and Newtonia buchananii, which, in
common with other species from the Malawi Hills,
e.g. Chlorophora excelsa, Blighia unijugata and
Zanha golungensis, are otherwise confined to fringing
forest in south-central Africa. In Malawi Caloden­
drum capense, Cavacoa aurea and Wrightia nata.Zen­
sis are confined or almost confined to these forests.
A forest type transitional between lowland and
submontane with abundant Chrysophyllum gorungo­
sanum in the canopy and emergent Khaya nyasica is
found on some of the hills and smaller mountains
between 4500 and 5000 ft ( 1 370-1 525 m) in the
Shire Highlands (Chiradzulu, Soche Mt., Malabvi).
At various places in densely populated areas small
patches of dry semi-deciduous forest which are used
as burial groves indicate what the vegetation was
formerly like. They usually occur on deep soils
which retain moisture in the dry season and are
particularly plentiful in the Dedza area where they
are usually dominated by A lbizia schimperana and
Cordia abyssinica. This type is also transitional be­
tween lowland and submontane forest.
On suitable soils in the hot, dry, low-lying coun­
try deciduous forest occurs but being vulnerable to
fire few samples remain. One of these, on the Pa­
lombe Plain, is a Forest Reserve (Sambani). Char­
acteristic trees include Fernandoa magnifica, En­
tandrophragma caudatum, Kirkia acuminata, Ster­
culia appendiculata, Albizia tanganyikensis and can­
delabra Euphorbias over a tangled mass of deciduous
shrubs and climbers.
Dry deciduous lowland forest and deciduous
thicket grade into one another, the distinction de­
pending largely on the occurrence and density of
emergent trees. Both types occur in the Lower Shire
Valley, especially in the Mwabvi and Lengwe Game
Reserves, but little is known about them. Near
N sanje the 1 0-acre Nkhulubvi thicket, the home of
the god Mbona, the Rain Maker, is protected by
local custom. Scattered trees of Adansonia, Hy­
phaene, Parkia and Sterculia occur throughout.
219
Fringing Forest
Throughout Malawi perennial watercourses were
formerly fringed with forest, which was rich in spe­
cies and of astonishingly varied composition. Much
of this has been destroyed. Trees have been felled
for canoes or timber or the land cleared for cultiva­
tion right up to the river banks. Elsewhere fires have
been equally destructive. Outside the forest reserves
there is little fringing forest left except in graveyards
and on some of the tea estates. A few miles south
of Mt. Mlanje on a loop of the Lichenya River in a
naturally fire-protected situation a fine example of
Kha;ya N ewtonia forest is used as a grave-yard. An
unusually extensive example has been preserved on
the M walantunzi Estate near Cholo, due to the en­
lightened policy of the manager, Mr. T. Hayes.
A general picture of the vegetation can also be obtained
from the Vegetation Map of the Federation of Rhodesia and
Nyasaland (Rattray and Wild 1 961).
PROTECTION
Survey of Communities A lready Protected
Most of the main vegetation types are represented in
the existing Forest Reserves and Game Reserves and
in the Nyika Plateau National Park. Although the
statement of Forest Policy approved by the Minister
of Natural Resources in January 1 9 64 points out that
the forests of Malawi include areas of outstanding
botanical interest, their protection, at the present
time, though real, is only incidental, since only three
small forest reserves (Kurwirwi F. R., Sambani F. R. ,
and Nyika Juniper F. R. ; cp. below) have been
established primarily for their botanical interest. The
future fate of interesting vegetation in the other re­
serves must remain uncertain unless legislation is in­
troduced to protect it. Outside the reserves many scat­
tered patches of forest and woodland occur as relicts
in graveyards and on private estates but in most
places the natural vegetation has been destroyed or
greatly modified.
Woodland and wooded grassland. Miombo wood­
land covers extensive tracts of infertile country, steep
escarpments and other areas unsuited to agriculture
and is well represented in forest reserves and game
reserves throughout the country.
South Vipya: Mtangatanga and Perekezi Forest Reserves.
Along the western escarpment of the Vipya Plateau. Prin­
cipally Brachystegia taxifolia woodland with B. microphylla
(on rocky hills), B. spiciformis and lsoberlinia tomentosa.
Kasungu Game Reserve. Hundreds of square miles of
Brachystegia woodland on rather level sandy soils inter­
sected by miles of open grassy dambos.
Acta Phytogeogr Suec 54
220
J. D. Chapman
Kota-Kota Game Reserve. Escarpment miombo overlook�
ing Lake Malawi.
Dzalanyama Forest Reserve. Along Mozambique border
S.W. of Lilongwe. Mostly miombo; Julbemardia panicula,ta is
particularly common.
Chongoni Forest Reserve. Stunted miombo (B. floribunda,
B. longijolia and B. spiciformis) extends far up the slopes of
rocky hills and is sometimes only a few feet high.
Liwonde Forest Reserve. On Rift Valley Escarpment. B.
boehmii, B. bussei and B. manga. B. bussei forms stands
sufficiently dense to suppress grass.
Mkuwazi Hill and Kalwe Forest Reserves. Two small re­
serves in the high-rainfall belt of Nkhata Bay. Brachystegia
spiciformis, and locally B. microphylla, with evergreen trees
(Erythrophleum guineense, Afrosersalisia cerasifera, Sapium
ellipticum and Pterocarpus stolzii over an evergreen under­
storey (Landolphia etc.). This type probably occupies former
forest sites. It has been a good deal disturbed by the es­
tablishment of trial plots of various plantation species.
Pterocarpus woodland: the demand for the timber
of Pterocarpus angolensis is so great that except in
one or two inaccessible areas there are no large
sound trees left. Even in the forest reserves Ptero­
carpus has been exploited fairly intensively and most
of the best trees at Mua Livulezi Forest Reserve have
now been felled.
Kurwirwi Forest Reserve is an exception. This
small, practically unvisited forest reserve on the
steep, stony slopes of Kurwirwi Hill on the Lake
Shore south of Chinteche, was established many
years ago in order to safeguard the very fine Ptero­
carpus (and Terminalia sericea) which is found there.
Until quite recently this reserve was still sufficiently
remote for the trees to be safe from theft. Now how­
ever the main Lake Shore road, the Kamuzu High­
way, passes right beside it and strict control will be
necessary if the forest is not to be destroyed.
Mopane woodland. In the Rift Valley Mopane
woodland is found in:
Mua Tsanya Forest Reserve at Ntakataka in the
Utali area. "Tsanya" is the Nyanja name for
Mopane.
Mwabvi Game Reserve in the Lower Shire Valley.
The Mopane in the north, at the edge of the
Vwaza Marsh in Rumpi District (the northernmost
known occurrence) is probably included within the
boundary of the Vwaza Marsh Controlled Hunting
Area.
Other woodland types. The remammg woodland
types in the Rift Valley do not appear to be repre­
sented either in Game Reserve or Forest Reserves.
Montane communities. With the exception of
Zomba Mountain and the Misuku Hills the upland
regions which support montane vegetation have not
been settled by man except marginally and intermitActa Phytogeogr Suec 54
tently, but in the past dry season fires have brought
about extensive destruction of montane forest and
other fire-sensitive vegetation types. The largest up­
land area, the Nyika Plateau, has recently been made
a National Park. Most of the others are now forest
reserves in which the surviving fragments of montane
forest are protected to prevent erosion, flooding and
desiccation, and to maintain regular stream flow.
Details of the more important areas are given (from
north to south) below.
Misuku Hills Forest Reserves (c. 10 square miles,
25. 6 sq. km ; 5000-6250 ft, 1 525-1 905 m). In a
densely populated but inaccessible region. Mostly for­
est reserve (established 1 9 3 8) in three blocks (Matipa,
Mugesse, Wilindi) but there are also two lower-lying
interesting relics administered by the Native Autho­
rity-Kasumbi, a praying grove and Mughoma, a
burial place. These forests, dominated by Chryso­
phyllum gorungosanum with emergent Aningeria
adolfifriederici and Entandrophragma excelsum are
the best example of their kind in Malawi. Several
rare species of great phytogeographical importance
are not known from anywhere else in Malawi, e.g.
Cylicomorpha parviflora, Mitragyna rubrostipulata
and Podocarpus ensiculus.
The Nyika Plateau National Park (c. 325 sq.
miles, 832 sq. km; · 6000-8500 ft, 1 830-2590 m).
This, the largest and most striking upland area in
south-central Africa has the widest range of forest
types and was constituted as a National Park in
January 1 966. The forests include: Entandro­
phragma submontane forest on south-western border;
Ocotea usambarensis j Ficalhoa submontane forest on
eastern and south-eastern border; Juniperus procera
montane forest (the largest patch of which is now a
botanical forest reserve) and various stunted montane
forest types on the high plateau. The surviving
patches of forest occupy less than 5 % of the surface
and ar.e particularly vulnerable to fire. Hagenia abys­
sinica and Juniperus reach their southern limits here.
Ternstroemia polypetala is only known from the
Nyika in the Flora Zambesiaca area. The Nyika is
the type-locality of many species collected by Alexan­
der Whyte, McClounie and others more than 60
years ago.
North Vipya Plateau Forest Reserve. Uzumara
Hill (c. 2.5 sq. miles, 6.4 sq. km; 5000-6300 ft,
1 525-1 920 m). Most of the former forests of the
North Vipya have been destroyed by fierce annual
fires and only one of the remnants is a forest reserve.
Entandrophragma excelsum, Ficalhoa laurijolia and
Ocotea usambarensis are typical emergents.
The South Vipya. Recurrent fires have replaced
most of the forest by short montane grassland. The
Malawi
3 large relict forest patches, Chamambo, Kawan­
dama and Ntungwa (5000-6300 ft, 1 525- 1 920 m)
are inside the newly created South Vipya F. R. A
large part of the South Vipya is being planted by
the Forest Dept. with Pinus patula and other soft
woods. Some small patches of natural forest and a
few interesting relict trees known nowhere else in
Malawi, e.g. Ocotea kenyensis and Podocarpus fal­
catus are being protected inside the plantation areas.
Nchisi Mountain Forest Reserve (c. 30 sq. miles,
77 sq. km; 4500-5400 ft, 1 3 70-1 646 m). Small area
of evergreen forest (Chrysophyllum gorungosanum
with emergent A ningeria) on east and south slopes,
Brachystegia woodland on west and north slopes.
Dedza Mountain Forest Reserve (c. 12 sq miles,
3 1 sq. km. ; up to 74 1 2 ft, 2260 m) Brachystegia
woodland on lower slopes. The upper slopes receive
frequent dry season mists but the total precipitation
is low and stunted montane forest with Cassipourea
congoensis, Ekebergia capens�s, Ilex mitis, Podo­
carpus milanjianus and Pygeum africanum and mon­
tane thicket occur.
Chongoni Mountain Forest Reserve. Similar to
Dedza but with a patch of A lbizia schimperana, Cor­
dia abyssinica forest at about 4500 ft ( 1 370 m). This
type is otherwise almost confined to graveyards in
the Dedza region.
Zomba Mountain Forest Reserve (c. 1 8 sq. miles,
46 sq. km; 5000-6846 ft ; 1 525-2 1 30 m). Bounded
by precipitous rocky slopes. The lower plateau (c.
5 500 ft) was formerly cultivated and is now occupied
by 60-year old plantations of Widdringtonia whytei
which are being invaded by evergreen forest species.
The upper plateau is principally planted with Pinus
but varied natural vegetation survives including
edaphic and fire-climax montane grassland, Syzy­
gium owariense swamp forest, stunted montane for­
est, montane thicket and montane shrubland.
Cholo Mountain Forest Reserve (c. 1 8 sq. miles,
46 sq. km ; 4000-5000 ft, 1 220- 1 525 m). Chryso­
phyllum boivinianum forest but without emergents.
Mount Mlanje Forest Reserve (c. 1 3 5 sq. miles,
346 sq. km ; 3000-9 843 ft, 9 1 5-300 1 m). Mt. Mlanje
forms an isolated massif rising precipitously from the
surrounding plains 8000 ft (2440 m) below. At
6000-7000 ft (1 830-2 1 3 5 m) the plateaux form roll­
ing grassy uplands intersected by deep wooded rav­
ines and gulleys and are surmounted by rocky peaks
and ridges. Although Mlanje has never supported a
resident population it has always been vulnerable to
fierce dry-season fires which can ascend the precipi­
tous slopes by leaping from tuft to tuft of the highly
inflammable sedge Coleochloa setifera. The mag­
nificent forests of Widdringtonia whytei, with an
221
emergent canopy up to 1 40 ft high over an evergreen
understorey, have been greatly reduced by fire and
exploitation and replaced by montane grassland.
These forests are unique, since elsewhere in its re­
stricted range W. whytei is a much smaller and more
scattered tree. The more accessible grasslands have
been planted with Pinus patula which it is intended
to replace by Widdringtonia when the site has suf­
ficiently improved.
Although Mlanje has a rich and varied flora, there
are surprisingly few endemic species and only one
(Dasylepis burttdavyi) is known among the larger
woody plants, but several South African species
(Widdringtonia, Vaccinium exul etc.) reach their
northern limit there. Access to the mountain is diffi­
cult and visitors are few so that with adequate fire­
protection most of the vegetation is safe, but is
should be pointed out that some species, including
Widdringtonia are dependent on at least occasional
fires for their regeneration.
Lowland forest and thicket. Some types are well
represented in forest and game reserves but others
have been completely destroyed except for small re­
licts used as graveyards and praying groves.
Moist evergreen and semi-deciduous forest. Ma­
tandwe Forest Reserve near Nsanje, Malawi Hills
(c. 1 sq. mile, 2.6 sq. km, c. 2000 ft, 6 1 0 m). The
most extensive area of lowland moist evergreen forest
in Malawi. Principal emergents are Bu:ttdavya,
Khaya nyasica and N ewtonia buchananii.
Shire Highlands Forest Reserves (Lisau Saddle,
Chiradzulu; Soche Mt. ; Malabvi; c. 4500-5000 ft,
1 370- 1 525 m). Khaya nyasica emergent; associates
include Fernandoa and Zanha golungensis; Phoenix
reclinata common in understorey. These forests are
transitional to lower montane types.
Dry deciduous forest and thicket. These two types
often occur together and differ chiefly in the occur­
rence of emergent trees in the forest. Thicket without
emergents or with only scattered emergents is often
found on shallow soils.
Sambani Forest Reserve (c. 0.6 sq. miles, 1 . 5 sq.
km; 24 1 5 ft, 778 m). On the Palombe Plain a few
miles north of Mt. Mlanje. A good example of dry
deciduous forest. For botanical details see p. 2 1 9 .
Mwabvi and Lengwe Game Reserves (c. 6 0 and
50 sq. miles, 1 54 and 1 28 sq. km respectively; c. 300
ft, 92 m) . In the lower Shire Valley. Established to
safeguard the Nyala, a very rare antelope, and other
game animals. There are extensive areas of decid­
uous forest and thicket which have not yet been
botanically explored. But see Mitchell ( 1 953). Some
of this vegetation is threatened by the new Lonrho
sugar scheme.
Acta Phytogeogr Suec 54
222
J. D. Chapman
Nkhulubvi thicket (c. 1 0 acres). Near Nsanje. See
p. 2 1 9.
Fringing, seepage and groundwater forest. Outside
the forest reserves these types have been nearly
everywhere destroyed or degraded. Within forest re­
serves a wide range of types are preserved, e.g. South
Vipya F. R. (Adina, Uapaca, Pterocarpus stolzii,
Treculia, Khaya nyasica; also Syzygium seepage for­
est) ; Dzalanyama and Nchisi F. R. (Uapaca) ; Nami­
lombwa F. R. (Ekebergia capensis, Diospyros mespi­
liformis, Mimusops zeyheri) ; Chongoni F. R. (Acacia
abyssinica) ; Mua-Livulezi F. R. (Adina, Chloro­
phora, Cola mossambicensis, Khaya, Parkia) ; Nami­
zimu F. R. (Platycerium angolense abundantly epi­
phytic on Parkia) ; Cholomwani F. R. on the Cholo
Escarpment (Adina, Anthocleista, Cordia etc.) ; lower
slopes of Mt. Mlanje (Magnificent Newtonia fringing
forest); Massenjere and Kalulu Hills F. R. (Burtt­
davya, Chlorophora).
Groundwater forest which is never swampy but
has a permanently high water table is not represented
in forest reserves. There are however two interesting
occurrences. Both are graveyards. See p . 223.
Further Protection
Within existing reserves: Unless special steps are
'
taken to manage parts of the larger and more inter­
esting forest reserves as if they were botanical re­
serves, their vegetation will be constantly threatened
by· fires, encroachment, illicit felling and the removal
of saplings for house poles and other purposes. If it
is to be done effectively this work must be given
priority and made the responsibility of an experi­
enced senior officer. Some forests are particularly
interesting or especially vulnerable. Such are the Mi­
suku Forests, though here the population is so high
that it is essential to establish Eucalyptus and Cypress
plantations on a scale sufficient to meet the demand
for poles. Otherwise it will be impossible to prevent
,
the theft of saplings and young trees, leading eventu­
ally to the destruction of the forests. Mkuwadzi Hill
on the Nkhata Bay Lake Shore is a small but very
interesting forest reserve, not only on account of the
luxuriant Brachystegia woodland, in places verging
on forest, but also because of the many rare butter­
flies which are restricted to this habitat (Gifford,
1 965). The upper montane forests on Dedza and
Chongoni Mts. need more effective protection.
Mangoche requires further protection. Not only is
there an interesting evergreen forest on the top of
the mountain, but this is the home of a small herd
of elephants. They divide their time between
M angoche and the rugged hills of the N amizimu
Acta Phytogeogr Suec 54
Forest Reserve nearby. They do little harm and every
effort should be made to protect them. The urgent
need to intensify protection of the Malawi Hills
forests has already been stressed.
M any forest species are excessively rare in Malawi
and are only known (and probably only occur) in a
single locality, sometimes represented by only a few
individuals. An attempt to protect these by legisla­
tion would probably be ineffective but the co-opera­
tion of the local people might easily be gained if
they could be told both of their rarity and scientific
interest.
Outside the reserves: Some vegetation types outside
the reserves will have to be brought under the control
of the Department of Forestry & Game, or protected
in some other way, if they are not to disappear.
Apart from mopane and dry deciduous forest and
thicket, none of the Rift Valley vegetation types is
satisfactorily represented in the reserves, and it is
essential that representative areas be set aside before
it is too late. In certain areas, Palms (Hyphaene sp.)
have practically vanished in areas where until a few
years ago there were extensive stands. This is entirely
due to the primitive form of tapping, which kills the
tree, but special measures have been put into force
during the last few months to prohibit all tapping of
palms in the Fort Johnston District at the request of
local chiefs and Members of Parliament. Swamp vege­
tation is not protected, and it is likely that much of
it (e. g. the Elephant Marsh in the Lower River) will
disappear within the next few years. Some of the
reed beds, those at the margin of Lake Chilwa for
example, form an important wildfowl habitat and
this should be kept well in mind when considering
which areas might be reserved.
Outside the forest reserves and especially in
densely populated areas there are many small patches
of forest often used as graveyards or for religious
purposes. Although they are protected by local cus­
tom many are particularly vulnerable to fire. Perhaps
the Malawi Young Pioneers could help here. A list
of "ulnerable forest patches is given in Table 1 .
ACKNOWLEDGEMENTS
The first draft of this account was written a few days before
I took up my present employment. I am greatly indebted to
Mr. F. White, Curator of the Forest Herbarium, University of
Oxford, who checked many facts and arranged it in its present
form. I also wish to thank Mr. W. E. Lewis, Chief Conservator
of Forests and Game, who kindly read' the typescript and
made a number of valuable comments and Mr. I. J. M. Rob·
ertson, formerly Assistant Conservator of Forests, who con·
tributed some helpful suggestions.
Malawi
223
Table 1 . Vulnerable forest patches in need of protection from fire.
Locality
Remarks
Northern Region
Graveyard
at
Misuku
Court, called Mughoma,
where the ancestors of
the former chief are
buried.
Submont�me forest-Bosquiea, Ficus spp., Sapium, Trichilia, etc.
Sacred grove called Kasumbi, in the same area.
As above but much more vulnerable to damage by fire.
Mafinga Mountains,
the Zambia border.
on
Ravine forest with Entandrophragma and Ficalhoa-interesting
montane shrubland on rocky upper slopes. Stunted B. taxifolia
woodland on lower slopes. Source of many of the tributaries of
the Lufira River. Lower slopes fast being denuded for "cite­
mene" millet cultivation.
Pirewombe Hill, the pla­
teau of the upper Lu­
fira, near the Zambia
border some 10 miles
south-south-west of
Chisenga.
Submontane forest, Chrysophyllum with Entandrophragma emer­
gent, in montane grassland. One block about 4 sq. km. Existence
unsuspected until recently.
North
Hill
Tall Ocotea forest, as extensive as the Uzumara forest, but fast
being burnt away.
Vipya,
Chimaliro
North Vipya, Ntunje
Very like the Chimaliro forest.
North Vipya, Choma
A much smaller patch, mainly Chrysophyllum forest, only a few
miles from Mzuzu.
Rumpi-Njakwa area
Palm stands (Borassus) to be selected.
Central Region
Masamba-imfa graveyard
at the foot of Dedza Mt.
just below the Reserve boundary.
Lengwe Estate, on the
edge of the Dedza es­
carpment near Mulun­
duni Mt.
Ntunda Forest, Mphepo­
zinai, a few miles from
Ncheu Boma. A big
grove, part of it used at
one time as a burial
ground.
Small patch of very fine Cordia f Albizia schimperiana forest.
Respected until recently but unless protected it will very soon
disappear.
Bosquieaf Ficus fCordiaf Albizia forest, much like Masamba-imfa.
Protected until a few years ago by the then owner of the estate,
Mr. Dowdell. Present status not known, but it is unlikely that
it is protected now.
Groundwater forest-Khaya, Parkia, Ekebergia, Ficus exasperata.
A very nice forest, surrounded by gardens, and respected by the
local people.
Southern Region
Chaone Hill, in a culti­
vated enclave in
Liwonde Forest Re­
serve.
Tall KhayafNewtonia groundwat�r forest with submontane canopy
trees. Needs to be protected from fire.
Shire Highlands-Nan­
zadi Forest, near Na­
rninkweya Estate, round
the bead of the Nanzadi
Stream.
Unusually extensive fringing forest, up to 0.5 km across-Khaya
with submontane forest species. Bird population particularly in­
teresting. Formerly property of B. C. A. Co., now belonging to
Govt., and fast being destroyed.
Shire Highlands-Bangwe
Hill.
Khaya forest, transitional to lower montane-exploitation probably
stopped, but no protection from fire.
'Acta Phytogeogr Suec 54
224
L. A. Grandvaux Barbosa
Machemba Hill, near Mt.
Mlanje.
Khaya forest-formerly a protected hill.
Mauze Hill, near Mt.
Mlanje
Very fine Khaya/Newtonia lowland forest with Chrysophyllum.
Formerly a protected hill. Greatly in need of protection from
fire.
Sumbu area, west of
Chikwawa
This is a most interesting area, on sandstone, near the border of
Mozambique. Pterocarpus ango/ensis/ Afzelia quanzensis wood­
land occurs and is being worked for timber by contractors. The
trees are very large, and of excellent form-there is no compar­
able area elsewhere; It is essential that a representative area be
set aside while there is still time.
REFERENCES
Dixey, F., 1 928. The Distribution of Population in Nyasaland.
Anon., 1 956. Phytogeography. C. S. A. Pub!. No. 22, Yan­
gambi.
Chapman, J. D., 1 961. Some Notes on the Taxonomy, Distri­
bution, Ecology and Economic Importance of Widdring­
tonia with Particular Reference to W. whytei. Kirkia, 1 :
Duvigneaud, P. and Denaeyer-de Smet, S., 1963. Cuivre et Ve­
getation au Katanga. Bull. Soc. Roy. Bot. Be/g. 96: 9 3-2 3 1 .
Gifford, D . , 1965. The Butterflies o f Malawi.-Society of
Malawi (Historical and Scientific).
Mitchell, B. L., 1953. Game Preservation in Nyasaland. Nyasa­
1 3 8-1 54.
- 1 962. The Vegetation of the Mlanje Mountains, Nyasaland.
Govt. Printer, Zomba.
Cbapman, J. D. and White, F. (in press). The Evergreen For­
ests of Malawi.
Rattray, J . M. and Wild, H . , 196 1 . Vegetation Map o f the
Federation of Rhodesia and Nyasaland, Kirkia 2: 94-104.
Wild, H., 1 965. The Flora of the Great Dyke of S. Rhodesia
with Special Reference to the Serpentine Soils. Kirkia 5 :
Geog. Rev. 1 8 : 274-290.
land Journal 6 (2): 37-5 1 .
49-86.
M O <;A M B I Q U E
L. A . Gmndvaux Barbosa
GEOGRAPHY
The territory of Mo9ambique is located between
1 0 ° 27 / (R. Rovuma) and 26 ° 52 / (Ponta do Ouro)
Lat. S. , and between 30° 1 2 / (R. Luangua) to 40 °
50' (Ponta Janga) Long. E. and covers an area of
77 1 , 1 25 km2• Using the geographical division of the
"Flora Zambesiaca" territory (Map, p. 225), Mo9ambique is divided into four areas, from N. to S. :
Niassa (N), Zambezia (Z), Tete (T) and Manica and
Sofal a (MS), South of Save (SS) and Louren90
Marques (LM) (including Maputoland). They cover
respectively: Niassa 36%, Zambezia 1 3 % , Tete and
Manica and Sofala 30% , South of Save and Lou­
ren9o Marques 2 1 % of the total area. The tropic of
Capricorn crosses Mo9ambique near lnhambane,
and the Louren9o Marques area is outside the tropi­
cal region. With special importance to the vegetation,
the following altitudinal zones may be considered:
low from 0 to 200 m; subplanaltic (low planaltic)
from 200 to 500 m; median altitude from 500 to
Acta Phytogeogr Suec 54·
1 000 m; submontane 1 000 to 1 500 m and montane
above 1 500 m corresponding respec-tively to approxi­
mately 40 % , 30 % , 25 % , 4 % and 0.2 % of the tota{
area. The highest mountains in Mo9ambique are
near the Rhodesian Border in the Chimanimani Mts.
and the highest point is Binga Mt. 2436 m.
GEOLOGY
The identified systems are: the Primitive (Precam­
brian), Umkondo (Predevonian), Karroo (between
the Upper Carboniferous and the base of Jurassic),
Cretaceous, Tertiary and Quaternary. Nearly two­
thirds of the country belongs to the system composed
of granites and gneisses dominant to the North of the
River Save.
The Umkondo is located North of the Chimani­
mani and Espungabera, and the Karroo is frequent
in the Tete and Manica and Sofala areas.
The Creataceous and Tertiary cover large areas
Mo�ambique
Fig. 1.
225
Mo<;ambique. Nature
reserves . 1, Maputo; 2, Pafuri;
3,
Gorongosa;
4, Niassa; 5,
Marromeu; 6, Bobole; 7, Gile.
at low altitudes as does the Quaternary in the littoral
areas of Zambezia and South of Save.
Soil and geology affect the vegetation in a greater
degree in the large plains.
CLIMATE
The climate may be considered as tropical, although
influenced in the extreme South by the transition to
a moderate climate, since here we are outside the
tropics. This influence is attenuated by the warm
stream off the Mo!rambique coast.
There are three climatic zones: Northern zone15 - 6 8 1557 Hedberg
with a tropical monsoon climate influenced by the
Indian monsoon; Central zone-between the Rivers
Ligonha and Pungue with a high amount of rainfall
due to the influence of the superposed regimes of
North and South; Southern z one-South of River
Pungue influenced by the anticyclonic regime and
the medium latitude depressions.
The mean annual temperature is between 22 ° and
26 ° C at the lowest altitudes and between 1 8 ° and
21
at the highest altitudes. In November in the
Zambezi valley the mean temperature is 3 0 ° C and
the average of the maximum temperatures is 40 ° C.
The mean annual amount of rainfall varies beo
Acta Phytogeogr Suec 54
226
L. A. Grandvaux Barbosa
tween 320 mm (Pafuri) inland in the South of Save,
and above 2000 mm at the_ high _ altitudes of the
Central zone, as at Milange (2053 mm) .
VEGETATION
(This description is based on the explanatory notes of the
new "Vegetation M ap of Mo�ambique", prepared by G.
Barbosa, ined. Numbers in brackets correspond to the vegeta­
tion types in the "Vegetation Map of the Flora Zambesiaca
a rea"; for letters in brackets see p. 224).
Forests. ( 1 ) Moist evergreen submontane: In very
restricted localities, less than 0. 1 % of the Mo9am­
bique area, usually between 1 200 m to 1 500 m con­
sisting of: Aphloia theiformis, Parinari polyandra,
Maesa lanceolata, Macaranga kilimandscharica, etc.
(2) Moist Semi-deciduous (Lowland): At lower and
more extensive mesoplanaltic areas between 500 to
1 200 m with higher temperatures, including: Pte­
leopsis myrtifolia, Erythrophleum suaveolens, or New­
tonia buchananii and Millettia stuhlmannii. Very
often, when secondary, the tree layer is sparse and
the sh.rub layer more dense. (5) Dry Semi-deciduous
(Sublittoral lowland): In the "cromopsamic" regions of
old dunes, especially in the South consisting of: Afze­
lia, Sideroxylon inerme, Ficus, Balanites, Morus,
Garcinia, etc. Finally, at very low altitudes, may
occur: (6) Dry Deciduous (Lowland) with: Adan­
sonia, Cordyla, Xylia, in the (MS) area or Bombax
in the (N) region with a dense and tall understory of
Landolphia, Dalbergia, Fernandoa magnifica, etc.
At higher altitudes in the Chimanimani Mts., in
the Gorongosa Mt. in Gurue etc. there occurs (8)
Dry-Conifer (Montane) forest with Widdringtonia or
with Podocarpus milanjianus.
Forest-woodland mosaic (9, 1 0). Occurs in the
sublittoral zone on both sides of the Zambezi delta.
This forest-woodland mosaic consists of: Brachys­
tegia spiciformis - Ju'zbernardia globiflora woodlands
(of high stature) and patches of Moist Semi-decidu­
ous (low-land) Forest of Pteleopsis myrtifolia - Ery­
throphleum suaveolens or also these same woodlands
with Dry Deciduous Forests.
Thickets. There are two principal types. One be­
tween the rivers Save and Pungue of secondary
woodlands and patches of Dry Deciduous Forest
(Lowland) with abundance of ( 1 3) thickets with Lan­
dolphia, Dalbergia, Combretum, Fernandoa, Markha­
mia, etc. The other type in the sublittoral Northern
zones (N) with: Guibourtia schliebenii, Pseudoproso­
pis euryphylla, etc.
Mangrove. Abundant in the Mo9ambique coast in
juvenile soils on fluvio-marine alluvium. There are
Acta Phytogeogr Suec 54
two principal species, Rhizophora mucronata (red
mangrove) and A vicennia marina (white mangrove).
Thickets and forests of coastal dunes (see p. 230).
Pioneers of the saline sands: Sesuvium portula­
castrum, Cyperus maritimus, Scaevola plumieri,
Tephrosia canescens, Sporobolus virginicus, etc. As
well as these there are median woodlands of: Gre­
wia occidentalis var. litoralis, Diospyros rotundifolia,
Euclea spp. Thickets or forest with: Mimusops caf­
fra, or Brexia madagascariensis or Sideroxylon iner­
me or Trachylobium verrucosum. The first abundant
towards the South and the latter ones to the North.
Woodland. The principal types are the following:
( 1 7) Bra�hystegia floribunda - Julbernardia pani­
culata. Tnis type of miombo exists in Mo9ambique
in the highest areas of the Tete (T) zone and oc­
cupies a relatively small area.
(1 8) Brachystegia floribunda - Julbernardia globi­
flora, surrounding the Tete area and also on the Vila
Cabral plateau (N) area. It occurs over a greater area
than the preceding.
(20) Brachystegia spiciformis, in the sublittoral to
the South of Save (SS). In sands: secondary forma­
tions, almost pure, sometimes with Julbernardia glo­
biflora but without Brachystegia boehmii. It stretches
from the River Save to the River Limpopo, with a
small area S. of the Limpopo.
(2 1) Brachystegia spiciformis in areas with high
rainfall and including Brachystegia boehmii, Julber­
nardia globiflora, A lbizia adianthifolia, Pterocarpus
rotundifolius or Pterocarpus polyanthus and elements
of the moist forest interspersed in the miombo such
as: Erythrophleum suaveolens, Pteleopsis myrtifolia.,
Schrebera alata, Harungana madagascariensis, Bau­
hinia petersiana, etc.
In some localities: Uapaca kirkiana and V. sanzi­
barica or Pericopsis angolensis and Pterocarpus an­
golensis may occur with great abundance and be­
come dominant. The patches near Vila Pery (MS)
and on hiJh ground near Gurue (Z), are the most
important representatives of type 22. In secondary
savannas Parinari curatellifolia is sometimes domi­
nant.
(23) Brachystegia spiciformis - Julberna.rdia globi­
flora. The most common miombo in Mo9arnbique
is Brachystegia spiciformis - Julbernardia globiflora
- Brachystegia boehmii, abundant in the areas (MS),
(Z) and in the South of (N).
(25 and 33) Brachystegia spiciformis - Adansonia
digita·ta. In sublittoral lowlands Brachystegia spicifor­
mis - Julbernardia may appear interspersed with (25)
A dansonia-Millettia-Xylia-Brachystegia sp. nov. in
red calcareous soils (Urrongas region) in (SS).
In the North of Mo9ambique, also generally in
Morambique
227
Fig. 2. Podocarpus falcatus at Bela
Vista near R. Maputo, a species re­
quiring protection in Moc;:ambique.
Photo: L. A. Grandvaux Barbosa.
calcareous areas Brachystegia spiciformis - Brachys­
tegia boehmii (or B. allenii) mixed with formations of
Adansonia - Sterculia appendiculata or Bombax (33).
(26) Brachystegia boehmii - Hirtella zanzibarica
occurs in a restricted area near the Zambezi delta,
with light sandy, badly drained soils. Often with
patches of Philippia simii thickets, and savann as,
with scattered trees such as: Parinari, Protea and
Uapaca nitida.
(28) Brachystegia x longifolia, B. utilis, B. spicifor­
mis, B. boehmii, and local Brachystegia spp. (B.
manga, B. microphylla, etc.) in the plateau of the
Northern part of Mo9ambique (N).
(29) Brachystegia boehmii associated with Julber­
nardia globiflora and sometimes Brachystegia manga
or Brachystegia allenii in the subplanaltic areas of
medium altitude of (MS), (f) and (N).
(30 and 3 1 ) The areas where Julbernardia globi­
flora or Brachystegia boehmii are dominant, with
elements of the transition to the lowlands or with
elements from the Adansonia digitata - Sterculia ap­
pendiculata domain. In the zones bordering the great
Rivers of the (SS) and (MS) Julbernardia occurs with
more abundance, and in the North, in the river val-
leys of (N) Brachystegia boehmii becomes predomi­
nant.
(32) Thickets with Berlinia orientalis - Brachyste­
gia spiciformis in sublittoral sands between Macomia
and Palma, and Cabo Delgado (N).
(34) Woodland more or less reduced to secondary
savanna or "wild orchards" in the suburbs of Lou­
ren9o Marques, with: Garcinia livingstonei, Sclero­
carya caffra, Strychnos spinosa, Trichilia emetica,
Anacardium occidentale (subspontaneous) very abun­
dant, A lbizia adianthifolia and Afzelia quanzensis.
(35 and 5 1 ) Two large patches of (3 5) Colopho­
spermum mopane, in the Zambezi valley and its tri­
butaries, rather dense and approaching woodland
(with an amount of rainfall varying between 500 and
700 mm) interspersed with patches of tree-savanna,
of small trees and shrubs with (5 1 ) Pterocarpus bre­
nanii and Diplorhynchus condylocarpon.
Tree Savanna. The more important communities
of this physiognomic group are the following:
(3 6) Julbernardia globiflora, with A ndrostachys
gregarious woodlands, near the mopane area in (SS)
or (49) A dansonia digitata - Sterculia-Millettia-Lon­
chocarpus, especially on the banks of the Zambezi
Acta Phytogeogr Suec 54
228
L. A. Grandvaux Barbosa
and Save Rivers, at medium and low altitudes; in (SS)
towards the interior there is a predominance of (50)
Colophospermum mopane tree savanna, and patches
of other dominants such as: Guibourtia conjugata,
A cacia spp. or (47) Terminalia sericea. On the slopes
of the Buzi, Revue and Urema R. valleys, at low
altitudes, on basalt, "gravinigra", shallow and gener­
ally calcareous soils (52) A cacia nigrescens, Ostryoder­
ris, Combretum, A lbizia harveyi, etc. ; (53) Acacia nig­
rescens mixed with Adansonia - Sterculia in the sub­
littoral North; alluvial vegetation is important in the
Zambezi, Pungue and generally in the big river-val­
leys.
Shrub Savanna. Halophilous formations, inland, in
the Changane River valley.
Grasslands. The genera concerned are: Papyrus
(sudd), Loudetia, Andropogon, Hyparrhenia., The­
meda - Exotheca, Themeda - Ipomoea, A ristida Heteropogon, etc.
PRESENT PROTECTION
The first Portuguese legislation established to pro­
tect animals and vegetation is relatively old. There
were already, legal regulations existing in 1 89 3 and
the preservation of Gorongosa has already existed
for 45 years.
For the Portuguese overseas Provinces in Africa
there is a Decree-Law no. 40:040 dated 20th Janu­
ary, 1 955, establishing the legal protection of the soil,
flora and fauna. This law includes all the former
legislation already established and introduces in the
general rules, a subordination to the unity and inter­
dependence between the soil, vegetation and wild
animals. The "Conselho de Protec9ao a Natureza"
was created to protect the soil, flora and fauna, and
consists of the Governor General as president and all
the heads of the Departments connected with any of
these items. Besides the function of proposing legisla­
tive and administrative measures it lays down that the
protection of the soil, flora and fauna is part of the
duty of all the Departments as well as of the general
public.
The following kinds of reserves have been created:
National Parks where all forms of life, wild ani­
mals and vegetation are protected and some elements
of geologic and prehistoric interest are preserved.
These Parks are in the charge of an authority re­
sponsible for their control. Visitors are allowed.
Integral Nature Reserves-in which any disturb­
ance is strictly forbidden, even the introduction of
imported species. Only scientists and people with spe­
cial interests are allowed entry.
-
Acta Phytogeogr Suec 54
-
Partial Reserves Similar to National Parks but
visitors are not allowed.
Special Reserves-Partial Reserves aiming at the
protection of particular species.
The National Parks are in general surrounded by
the other kinds of Reserves as mentioned above.
Special Reserve of Maputo (750 km2). Between the
River Futi, Natal and the sea, in the extreme SE. of
Mo9ambique. Only a few kilometres from Lou­
ren9o Marques. It was created to protect the sa­
vanna elephant Loxodonta africana. The vegetation
includes grassland savanna with: Hyparrhenia dis­
soluta, Cymbopogon excavatus, Urelytrum squar­
rosum, Trachypogon spicatus, etc., or savanna with
scattered trees and shrubs such as: Syzygium cor­
datum, Garcinia livingstonei, Trichilia emetica,
Afzelia quanzensis, Sclerocarya caffra, Dialium
schlechteri, Strychnos spinosa, etc. Great abundance
of pools with Phragmites communis; badly drained
zones with Imperata cylindrica. It is possible that
Podocarpus falcatus also occurs in this Reserve since
it is found very near. The annual amount of rainfall
is between 800 and 1 000 mm.
Partial reserve of Pafuri (1 0,860 km2). Between
the River Limpopo and its tributary the Olifant River
and the border with the Transvaal (South Africa)
near the Kruger National Park. Savanna woodland
consisting of Colophospermum mopa·ne with Xi mc­
nia americana, Salvadora angustifolia var. australis,
Azima tetracantha, Adenium obesum, Boscia albi­
trunca, etc. Sometimes woodlands of A ndrostachys
johnsonii or communities of G uibourtia conjugata
or even Terminalia sericea. Grass layer with: En­
neapogon cenchroides, Aristida gracilior, A. meri­
dionalis, Eragrostis, Schmidtia bulbosa, Sporobolus
smutsii, etc. It covers an arid area with an amount
of rainfall between 200 and 400 mm. To the North
of this Reserve there is a belt of Partial Reserve,
which lies along the right bank of the Limpopo
River.
National Park of Gorongosa (5530 km2). Estab­
lished in March, 1 9 2 1 and its area increased in 1 9 66.
It is situated a few hundred km from Beira, near
Vila Paiva. Includes a high mountain with the Go­
gogo Mt. of 1 863 m and an extensive area of more
or less swampy lowland. The mountain is mainly a
botanical reserve, where different layers of vegetation
may be studied, from the Lowland savanna to the
Moist Semi-Deciduous Forests (Lowland), the Ever­
green submontane at medium altitudes, the Dry Con­
ifer Montane Forest of Podocarpus milanjianus at
the highest altitudes, etc. At very low seasonally
swampy altitudes, with pools, there is an exceptional
and very rich fauna with a great number and variety
Mo�ambique
of animals where in speaking of the Gorongosa
someone said: it "is situated in a region where na­
ture reigns in all her glory".
Includes a very large open valley with a great
number of pools, extensive "tandos" (lowland
grasslands generally in alluvium or "gravinigra" soils).
Surrounding the "tandos" is a belt of savanna grass­
land with Hyphaene - A cacia xanthophloea - A cacia
spp. There is also another savanna on the elevations
of conglomerates, sandstones and calcareous soils
from the Cretaceous to the Neogene with woodlands
of dense, semi-deciduous to deciduous forest of
Adansonia - Sterculia appendiculata - Millettia, in­
tergrading with communities of Ostryoderris - Scle­
rocarya - Lonchocarpus. On the drier slopes of the
valley is a tree-savanna of Acacia nigrescens. This
complex mosaic of valley and mountain merging to­
gether allows the development of all the splendid
fauna with a truly rich flora in surroundings where
nature has capriciously interlaced wide stretches of
plain with forests, has supplied abundant water and
warmth for both the needs of animal and plant life.
Partial Reserve of Niassa ( 1 5, 000 km2). Includes
the Mecula region, in the extreme North of Mo­
�ambique. It is bordered by the Rovuma River and
its tributaries Lugenda and Licombe _{37 ° 40' long
G.). It is still an almost unknown region from the
botanical point of view. We may define the vegeta­
tion ·O f this area as an association of the open forma­
tions of: Adansonia - Steirculia appendiculata - Ki­
gelia pinnata, common at low altitudes, intergrading
with the plateau vegetation, with predominance of
Brachystegia boehmii - Julbernardia globiflora or
sometimes B. allenii or B. manga. Other floristic
elements may be abundant in restricted localities
such as: communities of Oxytenanthera abyssinica,
Hyphaene, A cacia nigrescens or A . polyacantha.
Tree savanna with: Lonchocarpus capassa, A lbizia
harveyi, Dalbergia melanoxylon, Commiphora spp.,
Boscia salicifolia, Tama,rindus, Millettia bussei, Ster­
culia africana, etc.
Special Reserve of Marromeu. On the right bank
of the Zambezi delta, there are extensive plains near
Marromeu, consisting of savannas and grasslands
with good grazing areas in more or less clayey, al­
luvial soils known as "Marromeu tandos" where
there are great herds of buffalos. This Reserve was
created for the protection of Synceros caffer caffer,
and therefore has more zoological than botanical in­
terest. The vegetation is, as mentioned above, pre­
dominantly grass savanna or tree savanna and grass­
lands. Extensive grasslands in badly drained areas, in
dark soils, with: Setaria spp. , lschaemum spp.,
Urochloa, Panicum, Bothriochloa, et:c. Sometimes
229
Pennisetum purpureum or Themeda. Patches with
predominance of Andropogoneae such as Hyparrhe­
nia spp. , Heteropogon, etc. Tree savanna with Hy­
phaene crinita, Phoenix, Acacia spp. (A. polyacantha
subsp. campylacantha, A. nilotica, etc.) sometimes
also Kigelia, Lonchocarpus, Combretum spp., etc.
Areas with pools surrounded by Phragmites, Typha,
Mimosa; etc. High termitaria with a typical flora
such as: Ficus, Sideroxylon, Tamarindus, Euphorbia,
etc.
Special Reserve of Bobole ( 1 2 hectares). Mainly a
botanical Reserve designed to prevent the imminent
destruction of . the moist dense formations, of the
dark hydromorphic (peaty) soils ("machongos") of
South of Save. This Reserve was established on the
swampy banks of the small slow flowing River Bo­
bole which is a tributary of the Incomati River, a
few kilometres N. of Vila Luiza, Louren�o Mar­
ques suburbs. It is a small area and was in danger of
destruction by intensive banana cultivation. It is un­
der the control of the Direc�ao dos Servi�os de
Agricultura (Agricultural Department). The vegeta­
tion is as follows: Raphia palms with abundant Pter­
idophyta such as Pteris vittata, Dryopteris gongylo­
des, Lygodium scandens, etc. The following species
are important too: Ficus verruculosa, Myrica coni­
fera, Pandanus livingstonianus and Voacanga dregei.
In the ecotone of this forest are: Turraea wakefieldii,
Erythroxylum delagoense, Casearia gladiijormis, Cis­
sampelos torulosa, Artabotrys brachypetalus, Taber­
naemontana elegans, Vangueria tomentosa, Bridelia
cathartica, Ochna arborea, 0. barbosae, 0. natalitia,
Landolphia spp., Ozoroa obovata, Strychnos spinosa,
etc.
Partial Reserve of Gile (2 1 00 km2). Created in
1 960, situated at medium altitudes in the district of
Zambesia in the Gile region. It was created mainly
for the preservation of the local fauna. The vegeta­
tion consists of Brachystegia spiciformis, B. boeh­
mii, Julbernardia globiflora woodlands.
In addition to the above Reserves there are also
Forestry Reserves under the control of the Forestry
Department:
In the (LM) region: Liquati (3300 ha.) : Afzelia
quanzensis; Goba: A ndrostachys johnsonii; in the
(MS) region: Inhaminga ( 1 607 ha.): Millettia stuhl­
mannii; Maronga (8300 ha.) ; Zomba (3 1 00 ha.) ; Mo­
ribane (53 00 ha.) ; Mucheve (9057 ha.); Amatongas
(4275 ha.) ; Nhapacue (1 7,000 ha.) more or less moist
semi-deciduous forests (Newtonia or Millettia) ; in the
(Z) region: Derre ( 1 7 0, 000 ha.) : Pterocarpus angolen­
sis; and in the (N) region: Mepalue (5 1 00 ha.) ;
Ribaue (5200 ha.); Mecuburi (230,600 ha.); Baixo
Pinda ( 1 9,600 ha.) ; Matibane (5 1 ,200 ha.) : semiActa Phytogeogr Suec 54
230
L. A. Grand"·aux Barbosa
deciduous or deciduous forests. (Information from
"Repart. de Florestas de Mo9ambique".)
SUGGESTED PROTECTION
The main problem consists in the education of the
population so that everyone will feel the need of pre­
serving as much as possible of the rarer wild species
which are nearly extinct, and to reinforce control of
the larger areas of general vegetation types.
Every year some new wild animal or plant species
is in danger of extinction in the world. The contin­
ued and wise protection of Reserves and Parks must
be enforced. Small Reserves, which we may call
"micro-parks", should be created at once, and also
the preservation of more of the principal vegetation
communities, which are the indispensable habitats
for many other forms of life. These "micro-parks"
would not interfere with economic development and
they would be complementary to the National Parks
and large Reserves already existing.
For .M o9ambique we would suggest the followin