Download local and regional diversity in some aegean land snail faunas

J. Moll. Stud. (2000), 66, 131–142
© The Malacological Society of London 2000
LOCAL AND REGIONAL DIVERSITY IN SOME AEGEAN
LAND SNAIL FAUNAS
R. A. D. CAMERON 1 , M. MYLONAS 2 and K. VARDINOYANNIS 2
1
Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN. UK.
Natural History Museum of Crete, University of Crete, P.O. Box 2208, 71409 Irakleio, Greece
(Received 5 May 1999; accepted 1 July 1999)
2
ABSTRACT
Land snail faunas from maquis and phrygana sites on
the islands of Naxos and Crete, and from the eastern
Peloponnese were sampled to determine the relationships between local (site) and regional diversities.
Mean site diversities are similar in each region. In
both the Peloponnese and Crete, however, these
represent a much lower proportion of total diversity
than is the case for forest faunas from more northerly
parts of Europe. The small island of Naxos has more
uniform faunas. Some of this between-site diversity
is a product of habitat heterogeneity, but most is a
product of small-scale biogeographical differentiation. Despite the short (c. 250km) distances between
regions, the faunas of each region differ far more than
do faunas from forests in northern Europe spread
over much greater distances. Nearly 80% of species
recorded were found in only one region. These results
are compared with those from elsewhere, and discussed in the context of the high diversity of snail
faunas in the mediterranean area generally.
INTRODUCTION
The relationships between local and regional
species diversities for any group of animals or
plants has both theoretical and practical (conservation) implications (Cornwell and Lawton,
1992; Srivastava, 1999). Comparisons within a
single habitat-type ( diversity, Cody, 1986) are
particularly fruitful, exposing small-scale biogeographical differentiation, and contributing
to understanding of the role of interspecific
competition in limiting local diversity (Srivastava, 1999).
In a review of species diversity in local and
regional land mollusc faunas, Cameron (1995)
showed that there were regional differences in
the relationship between the two, which could
be related to the environmental histories of
each region and to the ecological tolerances and
powers of dispersal of the species concerned.
Thus in northern temperate regions, where
mollusc faunas are a product of immigration
since the last glaciation, regional diversities are
low, even though some site diversities are high
by world standards (Solem, 1984). In contrast,
there are some tropical and subtropical regions
where climatic fluctuations have not removed
whole faunas, but have caused contractions and
expansions of local refugia with opportunities
for allopatric speciation, especially in stenotypic
and poorly dispersing species: the non-adaptive
radiation of Gittenberger (1991).
No data sets from Mediterranean habitats
were available for that review. The high regional
diversities of land molluscs in Mediterranean
countries are well-documented, despite incomplete accounts of many faunas (Bank, Falkner,
Gittenberger, Hausdorf, Proschwitz and Ripken,
1998), but their relationship to local diversities
has not been formally addressed. We report
here on a survey in the Aegean area, involving
three regions within it: the islands of Naxos and
Crete, and the south-eastern part of the Peloponnese (Figure 1). Sampling concentrated on
the major semi-natural habitat complex of the
area, maquis and phrygana. The investigation
was prompted by the occurrence of a spectacular non-adaptive radiation in the area, that of
the genus Albinaria (Clausiliidae) (Gittenberger, 1991; Douris, Cameron, Rodakis and
Lecanidou, 1998).
THE HABITATS AND THE REGIONS
Outside of cultivated areas, maquis and phrygana
today constitute the predominant vegetation types of
the Aegean area below the subalpine zone (c. 1500m).
Maquis is dominated by shrubs: woody plants generally capable of growing into trees if not prevented by
fire or grazing. Phrygana is dominated by undershrubs:
132
R.A.D. CAMERON, M. MYLONAS & K. VARDINOYANNIS
Figure 1. A sketch map of the area studied. The approximate positions of sample sites on Crete and in the Eastern Peloponnese are shown on the main map; those
on Naxos are shown enlarged.
AEGEAN LAND SNAILS
woody species which are always small, usually unpalatable and relatively short-lived (Rackham and Moody,
1996). The two habitats frequently intermingle in
small-scale mosaics determined mainly by soil properties and moisture regime, and there are intergradations between them. Fire and changing grazing
pressures create irregular cycles of vegetational
change in maquis, so that at one extreme, cover may
be less than in most phrygana, while at the other it
becomes scrub woodland with a closed canopy. Phrygana is more stable, but can be destroyed by burning
(Rackham and Moody, 1996).
Sampling in each region included both maquis and
phrygana. A few scrub woodland sites were sampled
at the extreme of the maquis range, and one subalpine site was sampled on Crete. Data from the last
are excluded from most analyses. In all regions,
sampling was restricted to sites on hard limestone,
which provides calcium for snails and a relative abundance of shelter under rocks. Some sites included
abandoned cultivations; maquis has spread, and
become more mature over the last 150 years as a
result of the abandonment of marginal land (Rackham and Moody, 1996).
There is an ongoing debate about the nature of the
vegetation in the Aegean area before the start of agriculture. Pre-Minoan Crete held significantly more
woodland than it does today, but remains of plants
typical of maquis and phrygana are found in interstadials of the last glaciation (Friedrich, 1978). The
pattern of climatic change over the Quaternary and
late Tertiary is not entirely clear, but there were no
extremes sufficient to extinguish the molluscan fauna,
which includes many restricted endemics now found
in maquis and phrygana (Vardinoyannis, 1994). Glacial
maxima are associated with significantly lower winter
temperatures than today (Gittenberger and Goodfriend, 1993; McCoy, 1980; Por, 1989), but some elements of modern Mediterranean vegetation can be
found in the late Pliocene, when dry summers replaced
a moister subtropical climate (Suc, 1984).
Figure 1 shows the area of study, and the approximate location of sample sites. While the area is now
extensively fragmented by the sea, it was part of a
continuous land-mass in the early Miocene. Marine
transgressions (11–9 My ago) established a midAegean channel which separated all three study
regions from Asia Minor and the Dodecanese
(Creutzberg, 1963; Verginis, 1976; Meulenkamp,
1985). While the Peloponnese was only intermittently
separated from the rest of the mainland thereafter,
Crete has been isolated from other regions since the
end of the Messinian salinity crisis (c. 5.5 My ago),
and effectively for longer. It was broken up into a
number of smaller islands during the Pliocene, but
tectonic uplift of more than 700m gave it approximately its present form in the Pleistocene (Dermitzakis, 1987; summary in Vardinoyannis, 1994). Naxos
has been intermittently connected to other Cycladan
islands during the Pleistocene, and certainly separated from the mainland far more recently than did
Crete (Dermitzakis, 1987; Mylonas, 1982).
133
METHODS AND MATERIAL
At each site, an area of c. 1 hectare was delimited, and
within it three people searched for molluscs for about
one hour. At least one person searching had extensive
experience of collecting in this environment. In addition, c. 5 litres of litter and soil were collected from at
least five locations within the site for examination in
the laboratory. Samples were made in late April and
early May 1993. Although some slugs were found,
they are excluded from analysis as this method of
sampling is inefficient; several visits would be needed
to find a high proportion of those present.
This sampling protocol involves a larger area and
more effort than has been used in many comparable
studies (Cameron 1973), to compensate for the patchy
distributions and good concealment of many species
in this habitat. At each site, notes were made on the
availability of refuges (judged by the disposition and
quantity of boulders and crevices in rocks), on the
habitat type (forest, maquis, phrygana), and on signs
of previous cultivation, especially evidence of terracing and of relict cultivated olive-trees.
Species identifications were made by M. Mylonas
and K. Vardinoyannis. These include as yet undescribed or unassigned forms which were clearly distinct from all other species found in the survey.
A conservative classification has been used; a number
of genera need reassessment, which will probably
increase the number of species involved here. Nomenclature follows Vardinoyannis (1994), and designation of species as anthropophile follows Mylonas
(1982 and 1984). All material collected is held in the
Natural History Museum of Crete.
RESULTS
The Appendix gives details of site locations and
characteristics, and the matrix of sites and
species for each region. 90 species were found,
of which three occurred only in the subalpine
site on Crete. Amongst the maquis/phrygana
series the range of species per site is 8–18. Table
1 shows for each region, and overall, the total
number of species found (S), the mean number
of species per site (), and two indicators of
the relationship between local and regional
diversity: Whittaker’s I (S/) (Cody, 1986;
Cameron, 1995), and the proportion of species
occurring in at least half the sites in each region
and in at least 30% overall. It also shows the
effect of separating anthropophilic species from
the rest (see below).
Amongst regions, there are only small differences in mean number of species per site, and
much overlap between regions in individual site
diversities. Naxos has a much smaller total array
(S) than the other two regions, and therefore
a lower value for Whittaker’s I and a higher
134
R.A.D. CAMERON, M. MYLONAS & K. VARDINOYANNIS
Table 1. Number of species found per region (S), mean number per site (), Whittaker’s
Index (I), and the percentage of species occurring in at least 50% (regions) or 30% (overall) of
sites examined, by region and in total, and distinguishing between native and anthropophilic
species. The lower percentage occurrence for the overall comparisons takes account of the
marked regional differentiation.
S
I
% in 50%
NAXOS n 12
Native
Anthropophilic
TOTAL
21
6
27
8.50
3.25
11.75
2.5
1.8
2.3
28
67
37
CRETE n 12
Native
Anthropophilic
TOTAL
37
9
46
10.00
3.86
13.86
3.7
2.3
3.3
14
44
20
E. PELOPONNESE n 11
Native
Anthropophilic
TOTAL
37
6
43
11.00
1.36
12.36
3.4
4.4
3.5
19
17
19
OVERALL n 35
Native
Anthropophilic
TOTAL
77
10
87
9.80
2.87
12.67
7.9
3.5
6.9
8
60
14
Table 2. Distribution of species by regions both overall and after separating into native and
anthropophilic categories. Percentages given in brackets.
Region
No of Species
No in Region only
Anthropophilic
Naxos
Crete
E. Peloponnese
Overall
6
9
6
10
0 (0)
2 (22)
1 (18)
3 (30)
2
3
1
3 (40)
4
4
4
4 (40)
Native
Naxos
Crete
E. Peloponnese
Overall
21
37
37
77
11 (52)
28 (76)
25 (68)
64 (83)
5
4
7
8 (11)
5
5
5
5 (6)
All species
Naxos
Crete
E. Peloponnese
Overall
27
46
43
87
11 (41)
30 (65)
26 (60)
67 (77)
7
7
8
11 (13)
9
9
9
9 (10)
proportion of frequent species. The overall
value of I is much higher than for any region on
its own, and Table 2 shows that nearly 80% of
all species found were found in only one region,
and only 10% in all three. Table 3 presents
these data differently, giving Jaccard Indices of
similarity between the faunas of each region,
contrasting them with values of the same index
obtained by comparing the fauna of some Scottish forests with those from similar forests at
varying distances across northern Europe. Despite the shorter distances, the Aegean faunas
No in 2 Regions
No in 3 Regions
show a much greater degree of differentation.
Some species of snail survive well in cultivated areas and are spread passively by agricultural activity (Mylonas, 1984). Tables 1 and 2
show that such anthropophilic species are more
widely distributed, and reduce differences
between sites both overall and within Crete and
Naxos. Although the anthropophilic species
found in Peloponnesan samples are, with one
exception, also found in at least one of the other
regions, they are infrequent in the sites, and
contribute to difference rather than diminishing
AEGEAN LAND SNAILS
it. There are no significant relationships between
the number of anthropophilic species and
others at each site (the very weak relationships
are all positive). Overall, the presence of
anthropophilic species makes only marginal
differences to estimates of between site and
region diversity.
Of the various recorded features of each site,
only altitude and presence of past cultivation
appear to have consistent effects on diversity
(Table 4). Sites above 700m are poorer than
those below (the subalpine site, not included,
Table 3. Jaccard Indices of similarity for the
recorded faunas in this study (maquis/phrygana),
and for sets of deciduous forest faunas from
northern Europe compared with one such set
from eastern Scotland (Cameron and Greenwood, 1992).
Index
Median
distance km
NAXOS WITH:
CRETE
E. PELOPONNESE
0.20
0.23
250
250
CRETE WITH:
E. PELOPONNESE
0.17
250
EASTERN SCOTLAND WITH:
DERBYSHIRE, ENGLAND
0.77
SUSSEX, ENGLAND
0.56
S. SWEDEN
0.59
N. GERMANY
0.57
N. ITALY
0.27
400
650
1000
1000
1500
135
was the poorest of all). On Naxos and Crete,
sites with previous cultivations are poorer in
non-anthropophilic species than those without.
There are no consistent differences between
sites from maquis and phrygana, nor with our
estimates of the abundance of refuges. A few
species appear to be confined to the highest
sites in the main series on Crete. Removing the
highest site reduces the value of Whittaker’s I
for non-anthropophilic species to 3.2.
The levels of similarity between the three
regions are much greater at generic level than
at that of species (Table 5). On Crete, over half
the genera encountered are represented by
more than one species in our samples, and by
10 species in the case of Albinaria. On Naxos,
only a third of genera are so represented, and
there is only one species of Albinaria. The Peloponnesan samples do not repeat this pattern;
although Albinaria is represented by six species,
only a fifth of all genera found have more than
one species in the samples, and there are more
genera present than on Crete (28 to 22). The
restricted number of sites exaggerates the
generic differences between regions: thus of
fourteen genera found on Naxos or the Peloponnese but not in our samples on Crete, eight
are known to occur on the island (Vardinoyannis, 1994).
DISCUSSION
The primary aim of this study was to establish
the levels of diversity, variation in species
composition within a single habitat (Cody,
Table 4. The effect of previous cultivation and altitude on mean number of
species. No sites on Naxos were above 600m, and only one site on the Peloponnese showed signs of previous cultivation.
Mean no of species per site
No of sites
‘Native’
Anthropophilic
All Species
NAXOS
Cultivated
Uncultivated
4
8
6.5
9.5
3.25
3.25
9.75
12.75
CRETE
Cultivated
Uncultivated
Above 700m
Below 600m
4
8
3
9
8.75
10.63
7.60
10.78
4.50
3.5
2.33
4.33
13.25
14.13
10.00
15.11
PELOPONNESE
Above 700m
Below 600m
3
8
8.67
12.12
1.00
1.50
9.67
13.62
136
R.A.D. CAMERON, M. MYLONAS & K. VARDINOYANNIS
Table 5. Distribution of numbers of genera by regions, and the Jaccard Indices of Similarity
for genera between regions.
Region
NAXOS
CRETE
PELOPONNESE
OVERALL
JACCARD BETWEEN
PELOPONNESE
CRETE
No. of Genera
19
22
28
36
NAXOS
0.52
0.46
In one region
1
5
8
14
In two regions
7
6
9
11
In three regions
11
11
11
11
PELOPONNESE
–
0.42
1986), both within and between the regions
concerned. With the exception of within Naxos
variation, indices of diversity are substantially
higher than those obtained in comparable studies in the northern half of Europe, or at the
same latitudes in N. America (Cameron 1995).
Site diversities do not vary much between areas,
and it is the variation in S which accounts for
varying values of I within and between regions.
As in other studies (Cameron 1995), differences between recorded faunas can arise in
many ways. Sampling error, the failure to find all
species in a site, will inflate differences between
sites. Although the habitats studied here do
present particular sampling problems, these
were compensated for by increasing size of area
and sampling effort. A conservative approach
has been taken on classification. In some genera
there may be more species in our samples than
we have recognised, as for example in Mastus
on Crete (Maassen, 1995). Our classification
will tend to minimise I.
Besides these procedural issues, using I to
estimate diversity depends on the uniformity
of the habitat between sites. Any differences
introduce an element of diversity (differences
between habitats, Cody, 1986). There are slight
effects of altitude and previous cultivation, but
no evidence of consistent effects related to the
specific vegetation type. At least on Crete, altitudinal changes in maquis vegetation are not
apparent below 1000m (Rackham and Moody,
1996), and the maquis habitat goes through
cyclical changes. Its fauna must be those species
which can survive all stages of these cycles,
some of which resemble phrygana. There are no
areas of more stable and favourable habitats
around from which species can invade maquis
entering more favourable phases.
The habitats studied are affected by human
activity. Although data are scarce it appears
that this activity has caused very few extinctions
of snail species (Mylonas, unpublished). Human
activity has spread a number of species, however, including many which are now abundant
and conspicuous (Mylonas, 1984). This is clearly
reflected in the low I values for anthropophilic
species on Crete and Naxos. Data from the
Peloponnese does not fit this pattern: Anthropophilic species were rarely encountered, and
more detailed study is needed. It is a reasonable, but unproven conclusion that differences
between sites and regions were greater before
the start of agriculture.
Although there are not modern systematic
accounts for the whole area, it is known that
countries bordering the northern shore of the
Mediterranean have richer faunas than countries further north. Thus Italy has at least 400
species (Cossignani and Cossignani, 1995), and
a recent estimate, probably conservative, gives
Greece 825 species and subspecies, of which
threequarters are endemic (Bank et al 1998).
This contrasts with 126 species in the British
Isles, or 116 in Norway and Sweden combined
(von Proschwitz, 1994). This greater diversity
is partly due to the greater range of habitable
environments available, with great altitudinal
gradients and marked local contrasts in rainfall
regimes. The evidence from this study, and from
the occurrence of large numbers of restricted
endemics (Bank et al 1998) shows that microgeographical differentiation within single habitat
types also makes a very substantial contribution
to this diversity.
In the Aegean area, some of this differentiation can be attributed to the long-term fragmentation of land-masses caused by Tertiary
tectonics (Mylonas 1982, Vardinoyannis 1994).
It does not account for all of it. Detailed studies
on the speciose genus Albinaria for example,
reveal patterns on a much smaller scale, and
phylogeographical analysis suggests that this is
a more recent process (Douris et al 1998).
Retreats into, and expansions from numerous
local refugia in response to Plio-Pleistocene
AEGEAN LAND SNAILS
climatic fluctuations provide a plausible explanation, which has a parallel in semi-arid northwest Australia (Cameron, 1992) and perhaps
more widely in the seasonal tropics (Stanisic,
1994; Tattersfield, 1998). Mountain zones sufficiently far from the blanket ice sheets of glacial
maxima also show such microallopatric effects,
as for example in Pyrenean Chondrinidae (Gittenberger 1984).
In his review of global land snail diversity,
Solem (1984) showed that there was no general
trend for site diversities () to increase towards
the tropics. Later work (de Winter and Gittenberger, 1998) has demonstrated that very high
local diversities can be found in the tropics, but
many estimates in good habitats are much lower,
and not higher than those of more temperate
regions (eg. Tattersfield 1998). The site diversities recorded here are in the middle range by
world standards, and they are not as high as
those recorded for many forests in areas wiped
clean by Pleistocene glaciations (Cameron,
1995). They probably represent the most
favourable environment of any size available to
snails in our regions. At first sight, this lack of
correlation between local and regional diversities appears to suggest that local diversity may
be limited by competition (Srivastava, 1999). In
the context of land molluscs, however, such a
conclusion may be premature: other evidence
for competition is sparse, and the lack of any
negative effect on the number of other species
of the presence of anthropophiles does not
suggest that it is strong. Critically, caution is
needed in determining what is regionally available in a group with poor powers of dispersal;
a species present at one end of Crete may not
be available at the other in the sense intended
by Srivastava. Species/area curves for land molluscs in mediterranean environments may be a
lot steeper than those normally found in withinprovince studies (Rosenzweig, 1995; Cameron,
in preparation).
Two of the regions studied here are presently
islands, and the third, in the Peloponnese, is
nearly so. Theory suggests that small islands
will have reduced faunas relative to comparable
areas of mainland (MacArthur and Wilson,
1967), and that the niche-breadths of the species
present on them may be greater (Rosenzweig,
1995). There is little sign of this in our study:
sites on Naxos have a slightly lower mean
number of species per site, but there is great
overlap with sites in the other regions. Naxos
appears to lack microgeographical differentiation in its snail fauna; although the smallest of
our regions it is much larger than the much
137
more isolated island of Porto Santo in the
Madeiran archipelago, which has both microgeographical differentiation between parts of
the island and levels of species diversity in
phrygana-like habitats very similar to those
found here (Cameron, Cook and Hollows,
1996). Island size may have to be very small
before the effects of extinction rates become
significant. Nevertheless, there are particular
cases where the islands lack a species found on
the mainland, and appear to have no remotely
plausible ecological equivalent: the very large
Helicid Codringtonia codringtoni occurs in the
Peloponnese, but not in the islands.
Maquis and phrygana/garrigue habitats are
widespread throughout the mediterranean
region. Carefully collated data from different
parts of it could provide valuable evidence as to
how mollusc faunas are structured (Srivastava,
1999).
ACKNOWLEDGEMENTS
We would like to thank Drs S. Giokas and J. Botsaris
for help with collecting and identification. R.A.D.C.
was supported by a Royal Society Travel Grant.
REFERENCES
BANK, R.A., FALKNER, G., GITTENBERGER, E., HAUSDORF, B., PROSCHWITZ, T VON, & RIPKEN, T.E.J.
1998. Biodiversity of the western palaeactic region
as exemplified by continental Mollusca. In:
Abstracts, World Congress of Malacology, Washington DC (R. Bieler and P.M. Mikkelsen, eds.), 25.
Unitas Malacologica, Chicago.
CAMERON, R.A.D. 1973. Some woodland mollusc
faunas from southern England. Malacologia, 14:
355-370.
CAMERON, R.A.D. 1992. Land snail faunas of the
Napier and Oscar Ranges, Western Australia:
Diversity, distribution and speciation. Biological
Journal of the Linnean Society, 45: 271-286.
CAMERON, R.A.D. 1995. Patterns of diversity in land
snails: The effects of environmental history. In:
Biodiversity and Conservation of the Mollusca,
(A.C. van Bruggen, S.M. Wells and Th. C.M.
Kemperman, eds.), 187-200. Backhuys, Leiden.
CAMERON, R.A.D., COOK, L.M. & HALLOWS, J.D.
1996. Land snails on Porto Santo: adaptive and
non-adaptive radiation. Philosophical Transactions
of the Royal Society of London, B, 361: 309-327.
CAMERON, R.A.D. & GREENWOOD, J.J.D. 1992. Some
montane and forest molluscan faunas from eastern
Scotland: Effects of altitude, disturbance and isolation. In: Proceedings of the tenth International
138
R.A.D. CAMERON, M. MYLONAS & K. VARDINOYANNIS
Malacological Congress, Tübingen, (C. MeierBrook, ed.), 437-442. Unitas Malacologica, Tübingen.
CODY, M.L. 1986. Diversity, rarity and conservation
in Mediterranean climate regions. In: Conservation
Biology, (M.E. Soulée, ed.), 123-153. Sinauer,
Sunderland, Mass.
CORNELL, H.V. & LAWTON, J.H. 1992. Species interactions, local and regional processes, and limits to
the richness of ecological communities: a theoretical perspective. Journal of Animal Ecology, 61:
1-12.
COSSIGNANI, T. & COSSIGNANI, V. 1995. Atlante delle
Conchiglie terrestre e dulciaquicole Italiane. L’Informatore Piceno, Ancona.
CREUTZBERG, N. 1963. Die paläogeographische
Entwicklung der Insel Kreta von Miozän bis heute.
Kretische Zeitschrift, 15: 336-342.
DERMITZAKIS, M.D. 1987. General introduction to the
geology of Crete. Institute of Palaeontology, University of Vienna.
DOURIS, V., CAMERON, R.A.D., RODAKIS, G.C. &
LECANIDOU, R. 1998. Mitochondrial phylogeography of the land snail Albinaria in Crete: Longterm geological and short-term vicariance effects.
Evolution, 52: 116-125.
FRIEDRICH, W.L. 1978. Fossil plants from Weichselian
interstadials, Santorini. In: Thera and the Aegean
World, 1, (C. Doumas, ed.), 741-745. Thera Foundation, London.
GITTENBERGER, E. 1984. Vicariantists and dispersalists among the Chondrininae (Gastropoda: Pulmonata: Chondrinidae). In: World-wide Snails,
(A. Solem and A.C. van Bruggen, eds.), 56-69. E.J.
Brill, Leiden.
GITTENBERGER, E. 1991. What about non-adaptive
radiation? Biological Journal of the Linnean
Society, 43, 263-272.
GITTENBERGER, E. & GOODFRIEND, G.A. 1993. Land
snails from the last glacial maximum on Andikithira, southern Greece, and their palaeoclimatic
implications. Journal of Quaternary Science, 8: 109116.
MAASSEN, W.J.M. 1995. Observations on the genus
Mastus from Crete (Greece) with descriptions of
twelve new species (Gastropoda: Pulmonata:
Bulimulidae). Basteria, 59: 31-64.
MACARTHUR, R.H. & WILSON, E.O. 1967. The Theory
of Island Biogeography. Princeton University
Press, Princeton, NJ.
MCCOY, F. 1980. Climatic change in the eastern
Mediterranean area during the past 240,000 years.
In: Thera and the Aegean World, 2, (C. Doumas,
ed.). 79-100. Thera Foundation, London.
MEULENKAMP, J. E. 1985. Aspects of the late
Cenozoic evolution of the Aegean region. In:
Geological Evolution of the Mediterranean Basin,
(J.D. Stanley and F.C. Wezel, eds.), 307-321.
Springer, Berlin.
MYLONAS, M. 1982. The zoogeography and ecology of
the terrestrial molluscs of the Cyclades. Unpublished Ph.D. Thesis, University of Athens. (Greek
with English summary).
MYLONAS, M. 1984. The influence of man: a special
problem in the study of the zoogeography of terrestrial molluscs on the Aegean islands, Greece. In:
World-wide Snails, (A. Solem and A.C. van
Bruggen, eds.), 249-260. E.J. Brill, Leiden.
POR, F.D. 1989. The legacy of Tethys: an aquatic
biogeography of the Levant. Kluwer, Dordrecht.
PROSCHWITZ, T. VON. 1994. Zoogeographical studies
on the land Mollusca of the province of Dalsland
(S.W. Sweden). Acta Regiae Societatis Scientarum
et Litterarum Gothoburgensis, Zoologia, 15: 1-152.
RACKHAM, O. & MOODY, J. 1996. The making of the
Cretan landscape. Manchester University Press,
Manchester.
ROSENZWEIG, M.L. 1995. Species diversity in space
and time. Cambridge University Press, Cambridge.
SOLEM, A. 1984. A world model of land snail diversity
and abundance. In: World-wide Snails, (A. Solem,
and A.C. van bruggen, eds.), 6-24. E.J. Brill,
Leiden.
SRIVASTAVA, D.S. 1999. Using local-regional richness
plots to test for species saturation: pitfalls and
potentials. Journal of Animal Ecology, 68: 1-16.
STANISTIC, J. 1994. The distribution and patterns of
species diversity of land snails in eastern Australia.
Memoirs of the Queensland Museum, 36: 207-214.
SUC, J-P. 1984. Origin and evolution of the Mediterranean vegetation and climate in Europe. Nature,
307: 429-432.
TATTERSFIELD, P. 1998. Patterns of diversity and
endemism in East African land snails, and the
implications for conservation. In: Molluscan conservation: A strategy for the 21st Century; Journal of
Conchology Special Publication No. 2, (I.J. Killeen,
M.B. Seddon and A.M. Holmes, eds.), 77-86. Conchological Society of Great Britain and Ireland,
Cardiff.
VARDINOYANNIS, K. 1994. Biogeography of land snails
in the south Aegean island archipelago. Unpublished Ph.D. Thesis, University of Athens. (Greek
with English summary).
VERGINIS, S. 1976. Die paläogeographische Entwicklung des Kykladischen Massivs (Alte Egeide), und
ein Vergleich mit den Alpinem Raum. Etairia
Kikladikon Meleton, 1974-76: 1-35.
WINTER, A.J. DE & GITTENBERGER, E. 1998. Land
snail diversity of a square kilometer of rainforest
in southwestern Cameroon. In: Abstracts, World
Congress of Malacology, Washington, DC. (R. Bieler
and P.M. Mikkelsen, eds.), 84. Unitas Malacologica, Chicago.
AEGEAN LAND SNAILS
APPENDIX
Section (a) gives details of sites. For refuges, M many, E enough/intermediate, F few. For habitats, M maquis, P phrygana, F forest, SA subalpine. For cultivation, no sign of cultivation,
evidence of previous cultivation, R ruins on
139
site. Altitudes were not recorded on Naxos, but all
sites were below 600m.
Section (b) lists the species found at each site, tabulated by region. Asterisks indicate anthropophilic
species. Nomenclature and the sequence of names follows Vardinoyannis (1994). Note that Site 13 on Crete,
in the subalpine zone, is excluded from most analyses.
(a) Site Details
NAXOS
Sample No
Location
11
12
13
14
15
16
17
18
19
10
11
12
Avionitsa
Avionitsa
Agiasos
Agiasos
Agia
Apollonas
Mesi
Moutsouna
Kinidaros
Danakos
Chimaru
Kalanto
Refuges
M
E
E
E
E
M
M
M
E
M
E
M
Habitat
M
P
M
P
M
P
M
P
M
m
M
M
Cultivation
CRETE
Sample No
Location
1 1
1 2
1 3
1 4
1 5
1 6
1 7
1 8
19
10
11
12
*13
Stalida-Mohos
Katohori-Thrypti
Anogia
Kritsa-Katharo
Spinalonga
Giouhtas
Amoudara
Mt Skloka
Krousounas
Orne
below Omalos
Matala
above Omalos
Refuges
Habitat
Cultivation
E
E
M
E
E
E
E
M
M
F
E
E
E
M
P
P
M
M
M
M
P
M
P
F
M
SA
Refuges
Habitat
Cultivation
E
M
E
E
F
E
F
F
F
E
E
M
M
F
M
M
F/M
M
P
P
M
F
R
Altitude m
500
500
100
800
0
400
0
100
800
500
1000
50
1600
EASTERN PELOPONNESE
Sample No
Location
11
12
13
14a
14b
15
16
17
18
19
10
Xeropidago
Leonidio-Kosmas
Kosmas
Loggastra
Loggastra
Parori
Apidea
11 km Monemvasia
Monemvasia
Sparti Tripolis
Agios Petros
Altitude m
100
100
1100
550
550
300
100
100
50
700
900
140
R.A.D. CAMERON, M. MYLONAS & K. VARDINOYANNIS
(b) Species Records
NAXOS
Samples
Species
1
2
3
4
5
6
7
8
9
10
11
12
*Helix aspersa
Helix figulina
Helix godetiana
*Eobania vermiculata
Helicigona bacchica
Helicigona amorgia
*Monacha rothi
Monacha sp
Cernuella ionica
Cernuella syrensis
*Trochoidea cretica
Trochoidea didyma
Zonites pergranulata
*Vitrea contracta
Vitrea clessini
*Oxychilus hydatinus
Oxychilus samius
Albinaria coerulea
Mastus turgidus
Granopupa granum
Rupestrella philippii
Pyramidula chorismenostoma
Cecilioides acicula
Pagodulina sparsa
Truncatellina sp
Orculella critica
Lauria cylindracea
Number of species
17
11
15
11
8
9
9
10
14
13
10
15
AEGEAN LAND SNAILS
141
CRETE
Samples
Species
1
2
3
4
5
6
7
8
9
10
11
12
13
*Helix aspersa
*Helix aperta
*Eobania vermiculata
Lindholmiola barbata
Metafruticola lecta
Metafruticola noverca
Metafruticola nicosiana
Metafruticola pellita
*Monacha rothi
Monacha syriaca
Trochoidea mesostena
Trochoidea sp
Helicopsis bathytera
Helicopsis sp
Carpathica cretica
*Eopolita protensa
Vitrea clessini
*Vitrea contracta
*Oxychilus hydatinus
Oxychilus spratti
Oxychilus superfluus
Lindbergia orbicularis
Lindbergia pageti
Lindbergia pseudoillyrica
Poiretia dilatata
Cecilioides acicula
*Rumina decollata
Albinaria cretensis
Albinaria eburnea
Albinaria hippolyti
Albinaria idaea
Albinaria corrugata
Albinaria maltzani
Albinaria moreletiana
Albinaria praeclara
Albinaria terebra
Albinaria teres
Mastus turgidus
Mastus olivaceus
Mastus cretensis
Pleurodiscus sudensis
Granopupa granum
Rupestrella philippii
Rupestrella rhodia
Orculella critica
Orculella sp
Truncatellina rothi
Cochlostoma cretense
Number of species
12
18
16
11
15
18
11
16
8
14
11
12
5
142
R.A.D. CAMERON, M. MYLONAS & K. VARDINOYANNIS
EASTERN PELOPONNESE
Samples
Species
1
2
3
4a
4b
5
6
7
8
9
10
*Helix aspersa
Helix cincta
Helix figulina
Codringtonia codringtoni
*Eobania vermiculata
Lindholmiola lens
Helicigona sphaeriostoma
Monacha messenica
*Caracollina lenticula
Chilostoma sp
Cernuella syrensis
Candidula sp
Helicopsis sp
Poiretia dilatata
Punctum pygmaeum
Cecilioides acicula
Daudebardia rufa
Zonites parnonensis
Zonites graecus
*Vitrea contracta
Vitrea demiobasis
Vitrea shuetti
*Oxychilus hydatinus
Oxychilus samius
*Rumina decollata
Albinaria discolor
Albinaria schuchi
Albinaria messenica
Albinaria voithi
Albinaria grisea
Albinaria arcadica
Mastus turgidus
Mastus pupa
Chondrula bergeri
Granopupa granum
Rupestrella rhodia
Rupestrella philippii
Orculella critica
Pogodulina sp
Pyramidula chorismenostoma
Acanthinula aculeata
Truncatellina rothi
Cochlostoma tesselatum
Number of species
12
16
11
14
11
14
13
12
15
8
9