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Point Journal of Agriculture and Biotechnology Research, 1(1): 001-012 June, 2015.
Available online at http://www.pjournals.org/PJABR
ISSN 2467-8805 @ 2015 Point Journals International
Received 07 May, 2015 Accepted 04 June, 2015, Published 24 June, 2015
Review
Environmental degradation and its effect on terrestrial
and aquatic diversity in the Abijata-Shala Lakes
National Park, Ethiopia
Getaneh Gebeyehu, Temesgen Gashaw* and Damena Edae
Center for Environmental Science, Addis Ababa University, Ethiopia.
*Corresponding author. Email: [email protected]
Abijata-Shalla Lakes National Park has immense natural resources which comprises two types of
2
2
2
ecosystems: aquatic (482 km ) and terrestrial (405 km ) ecosystems covering a surface area of 887 km .
These ecosystem types favor more of diverse species of birds, mammals and plants. Diversity of birds
accounted 52.5% of the country of which one endemic, five near endemic and one threatened species
are found in the park. The park is also home to 76 mammal species including six endemic species.
However, reptiles, fish, amphibians and invertebrates species are not well recorded in the area. In case
of plants, 97 plant species are identified in the Acacia-Commiphora woodland ecosystem type
comprising of the acacia woodland, acacia bush land, scrubland and grassland vegetation. However,
there was an expansion of cultivated and grazing land by 4.1% and 8.6% respectively between 1973 and
2000 at the expense of protected/dense woodland, water bodies and wetlands, grazed woodland and
shrub land, barren land and broad-leaved forest. As a result, the park is highly affected by
environmental degradation. The main activities those adversely affecting the park ecosystem and its
biodiversity includes: expansion of settlement and cultivated land, overgrazing, deforestation,
increased irrigation, overfishing and soda ash mining. The decline of water capacity in the aquatic
habitat has affected the abundance of bird species as result of its impact on the edge of lakes which
has diversity of phytoplankton. The degradation of terrestrial habitat affected the diversity and
abundance of birds and mammalian in the park due to its change to vegetation community structure
and composition. Therefore, this paper aims to assess environmental degradation and its effect on
terrestrial and aquatic diversity in Abijata-Shala Lakes National Park, and propose technologies and
practices for ecosystem restoration.
Key words: Aquatic ecosystem, Environmental degradation, Species diversity, Species interaction, Terrestrial
ecosystem
Citation: Getaneh, G., Temesgen, G. and Damena, E. (2015). Environmental degradation and its effect on Terrestrial and Aquatic
diversity in the Abijata-Shala Lakes National Park, Ethiopia. Point J. Agric. Biotechnol. Res. 1( 1): 001-012
INTRODUCTION
Background
Ethiopia has a long history of conservation. The first
recorded indigenous conservation-oriented activity took
place during the reign of Emperor Zerea Yacob (14341468). The country has a very diverse set of ecosystems
ranging from humid forest and extensive wetlands to the
desert (Melaku, 2011). Representative examples of
Ethiopia's remaining ecosystems are conserved through
a network of effectively managed protected areas.
Protected area of the country covers approximately
16.4% of the land including 20 national parks, 3 wildlife
sanctuaries, 2 wildlife reserves and 17 controlled and 7
open hunting area and 3 community conserved area
(EWCA, 2014).
Abijata-Shalla Lakes National Park (ASLNP) is one of
protected area found in the country which was
established in 1963. Its primary objective of establishment was to conserve bird species (EWCA, 2014). The
park comprises two ecosystems which cover aquatic
Getaneh et al.
2
2
(482 km ) and terrestrial (405 km ) ecosystems. These
ecosystems dominated and characterized by presence of
large diversity of migratory and resident birds of which
52.5% of bird species of the country are founded in the
area. Comparatively, the park host less number of
mammalian species because of disturbance, habitat loss
and interactions with domestic livestock. According to
Ethiopian ecosystems types, the terrestrial part of park is
characterized by Acacia-commiphora type. However,
Ethiopia’s protected areas are increasingly degraded
(Young, 2012). Land is being converted for subsistence
and commercial agriculture, timber used for fuel wood
and construction, protected grasslands used for livestock
grazing. The loss of forests and other protected land is
underpinned by a growing population, unsustainable
natural resource management, poor enforcement of
existing legislation, uncertain land tenure and very low
public awareness of the impact of climate change and the
importance of biodiversity and ecosystems.
ASLNP is under serious treats due to water abstraction
for Soda Ash enterprise, increased irrigation, expansion
of settlement, cultivated land and grazing land, deforestation and over grazing (Flower, 2011, Temesgen et al.,
2013). As a result, the aquatic habitat has confronted
problem of water resource exploitation and decline of
lake water capacity. The source of these problems is both
internal that is, limited into the park boundary and also
some others are external in their origin. Similarly, the
terrestrial habitats faced degradation and fragmentation
due to major agricultural activities which compete with
wildlife for food, cover and space. Subsequently, the
biodiversity of both terrestrial and aquatic habitats are
under great challenge (Tafesse, 2008).
Objectives
The overall objective of this review is to assess
environmental degradation and its effect on terrestrial
and aquatic diversity in the Abijata-Shala Lakes National
Park.
Specific objectives include:
i. To characterize the park ecosystem in terms of species
diversity and species interactions
ii. To assess the type and extent of environmental
degradation including land use/ land cover changes and
loss of habitat
iii. To assess the impact of degradation on the aquatic
and terrestrial biodiversity resources
iv. To propose technologies and practices for ecosystem
restoration
MATERIALS AND METHODS
Study area
ASLNP is located within the central portion of the Great
002
Rift Valley, in Oromia Region, 207Km south of the capital
(Addis Ababa) between 7°15’–7°45´N and 38°30´–
38∘45´E at elevation of between 1,540 and 2075m a.s.l.
The entire park falls within the ecological-climate zone III
semi-arid. The main rainy season generally occurs
between late June and September. The annual rainfall is
on average between 500-600mm. Temperature normally
range between 16°C and 24°C with the highest
temperature occurring in March and the lowest in
2
December. The ASLNP encompass an area of 887 km ,
2
of which 482 km is aquatic ecosystem (it include lake
Abijata, Shalla and Chitu and their shorelines) and 405
2
km is land or terrestrial ecosystem, which comprise the
acacia woodland, acacia bush land, scrubland and
grassland vegetation and the rocky outcrops (Rezenom,
2012; Fekadu and Fekadu, 2014).
Data collection and analysis
The data was collected from published journals,
proceedings, thesis and workshops. Species diversity
and interaction, type and extent of environmental
degradation with its causes, and effects of environmental
degradation on terrestrial and aquatic ecosystem was
assessed in detail. The data were analyzed using excel
spread sheet and the results were displayed by graphs.
After an in-depth analysis, technologies and practices for
ecosystem restoration was proposed.
RESULTS AND DISCUSSION
Species diversity and their interaction
Species diversity
ASLNP comprises two types of ecosystems: aquatic (482
2
2
km ) and terrestrial (405 km ) ecosystems covering a
2
surface area of 887 km (Fekadu and Fekadu, 2014).
According to WWF eco-regions division, ASLNP
vegetation is Acacia-Commiphora woodland ecosystem
type within Somali Masai biome (Tafese, 2008).
Terrestrial ecosystem favors savanna vegetation zone
and small diversity of species compared to others. While,
aquatic ecosystem favors more on bird species. Species
diversity in ASLNP is well documented in the taxonomic
groups of mammals, birds and plant species (Figure 1).
The park also provides protection to six endemic
mammal species (EWCA, 2014), five near endemic and
one endemic bird species (Rezenom, 2012). The park
also accommodates four vulnerable and four threatened
of which the Lesser Flamingo is considered to be a
globally threatened species, finds a home in the waters of
Abijatta. The Great White Pelican has a breeding colony
on the islands of Shalla and this colony is considered to
be one of the most important aggregations on the
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Point J. Agric. Biotechnol. Res.
Taxonomic groups
Vascular plants
Butterflies
Endemic and near endemic spp.at
ASLNP
Amphibinas
Endemic and near endemic spp.at
Country level
Fish
Reptiles
No. of species at ASLNP
Birds
Mammals
No. of species at country level
0
2000
4000
6000
8000
Number of species
Figure 1. Comparative Statistics for major groups of species recorded to date in Ethiopia and ASLNP.
Source: Authors’ compilation.
continent. One reason that the park plays an important
role in protecting such a unique assemblage of species
can be related to its vulnerable but equally life
maintaining waters. The waters are full of productivity and
this has in turn enhanced the life forms that depend upon
it. However, fish, reptiles, amphibians and other
invertebrate species are not recorded and further
investigation need for justification. The most notable
taxonomic groups are discussed as:
Mammals
Large animal diversity found in the national park of the
world comprises five major classes of vertebrates.
According to Vreugdenhil et al. (2011), about 320 species
of mammals recorded in Ethiopia. This is one of Africa's
most diverse countries for mammals, most of the medium
and large sized species are severely depleted and
difficult to see, as they suffer from habitat loss and
hunting pressure almost everywhere, even in many
protected areas. Similarly, ASLNP hosts less diverse
number of mammals due to the disturbance, habitat loss
and competition with domestic animals for forage. Thus,
the acacia woodland favors few mammals which have
decreased in number (Tafese, 2008).
According to the Park document cited in Tafess (2008),
a total of 76 mammal species have been recorded so far,
of which the most commonly potted are Grant’s gazelle,
Oribi, Warthog and the Golden Jackal. About 31 species
from large mammals are endemic in the country level
(Melaku, 2011). Out of these, ASLNP hosts six endemic
mammal species such as Scott’s Hairy Bat (Myotis
scotti), White toothed shrew (Crocidura sp.), Mahomet’s
mouse (Mus Mahomet), White toothed rat (Berylmys sp.),
Ethiopian grass Rat (Arvicanthis sp.) and Harrington’s
Scrub rat.
Birds
The Ethiopian avifauna represents an interesting mixture
of African, Palearctic and some strikingly unusual
endemic components, that in recent years has caught the
interest of the international birding community, making
Ethiopia one of Africa’s fastest growing destinations for
bird watching (Vreugdenhil et al., 2012).
The ASLNP contains diverse avifauna compared to
mammals’ diversity including six endemic bird species.
ASLNP in Ethiopia is established primarily to conserve
the diverse bird life of the area (EWNSH, 2010).
The scientific investigation of bird species diversity
recorded shows different numbers of bird species in
different time. For example, a total of 436 bird species
were recorded of which, 114 species are wetland birds
while 282 species are terrestrial (Melaku and Rezenom,
2002). More study on bird species in the ASLNP is also
indicated, their presence include 453 bird species
(representing 52.5% of the country total) representing 73
Families and 22 Orders (Rezenom, 2012). Thus, the
values of Abijatta-Shalla from a conservation point of
view are one of the sites of highest wetland bird diversity
in Ethiopia. Legesse et al. (2005) stated that Park
provides wintering and maintenance station for such a
large number of terrestrial and aquatic birds, which
include Southern African, Sub-Saharan and Palaearctic
species.
According to Rezenom (2012) studies, the park
accommodates interims of geographical occurrence 305
(67%) species are resident and (including one endemic
and five near endemic). The endemic bird species in the
park include Yellow-fronted Parrot (Pocicphalus flavifrns)
and five Near-endemic bird species of Wattled Ibis
(Bostrychia carunculata), Black-winged Love Bird
(Agapornis taranta), Banded Barbet (Lybius undatus),
White-winged Cliff Chat (Mytmecocichala semirufas),
Getaneh et al.
004
Abyssinian
Black-headed
Oriole
(Onychognathus
albirosris) and Thick-billed Raven (Corvus crassirosris).
A total of 148 (33%) species are migratory of which
(99) Northern migrants; (7) African migrant; (20) Intra
African migrant; (8) Intra African –northern migrant and
(14) Northern migrants with resident sub species.
Besides, 18 and 25 species were found Afro tropical
Highland Biome Species and Sommali-massi Biome
Species respectively. Based on habitat classification 317
(70%) species are terrestrial and 136 (30%) are wetland
(of which106 species are wetland specialist and 30
species are generalist).
The park is also home of four nearly threatened bird
species such as Lesser Flamingo (Phoeniconaios minor),
Pallied Harrier (Circus macrourus), Basra Reed Warbler
(Acrocephalus
griseldis),
Black-winged
Pranticole
(Glareole nordmanni) and four vulnerable bird species
such as Imperial Eagle (Aquila heliaca), Lesser Kestrel
(Faco naumanni), Wattled Crane (Grus carunculatus) and
Ferruginous Duck (Aythya nyroca) (Rezenom Almaw,
2012).
species of legumes and 179 species of browse trees are
known (http://etflora.net/). In terrestrial ecosystems,
plants form the basis of all communities, in terms of both
structure and function. The abiotic environment sets the
particular form of structure, with cold and dry climates
often having slow and intermittent growth. Thus, plants
determine the niche possibilities for animals.
Vegetation zone is identified to be savannah and the
habitats surrounding the lakes are largely Acacia and
Euphorbia woodlands with few Ficus trees. Small areas
of riverine forest and open scrub on the rocky slopes are
also important habitats. Lakeshores around Lake Abijata
have short grasslands comprising of Cynodon and
Sporobolus spp. that are important for stabilizing the
fragile soils. Other key Gramminae species include
various spp. of Hyparrhenia. The dominant tree species
in the park are Acacia tortilis, A. senegal, A seyal,
Agerrardi, Balanites aegptiaca, Ficus sycomorus and
Mytenus senegalensis. Other species include Acacia
ethbaica, Grewia sp., Ziziphus macronata, Calpurnia
subdecandara and Croton macrostachys from the park.
Herptofuana
Species interaction
Of the approximately 240 reptile species recorded from
Ethiopia, 15 are endemic. Most of the endemic species
have been recorded in protected areas. With a total of 71
amphibians for the country, the amphibian herpetofauna
of Ethiopia is rather poor and probably insufficiently
studied. Nevertheless, with 30 endemic species, it has a
high degree of endemism (Vreugdenhil et al., 2012). Most
species are probably protected in the existing protected
areas. However, reptiles species of the ASLNP has not
been documented and they will be further studied on the
occurrence of species.
The park was created for many species of aquatic birds,
particularly great white pelicans and greater and lesser
Flamingoes. Lake’s islands are used as breeding sites by
many birds including pelicans; and Lake Abijata is their
feeding sanctuary. Other birds in the area include white
necked cormorant, African fish eagle, Egyptian geeze,
various plover species and herons (EWCA, 2014).
The dependence of species habitat relationship on
factors ranging from local vegetation structural features
suggests that several processes operate simultaneously
at different scales of influence. For example, strong
interaction between the habitat type and helmeted guinea
fowls indicates that certain habitat is very important for
the survival of birds (Tewodros Kumssa and Afework
Bekele, 2013). Due to these biological characteristics the
lake is the major feeding site for aquatic and terrestrial
bird including both migratory and resident ones.
Flamingos and White Pelicans are among the water birds
that depend on the Lake. In the past, the lake was fished
by the local population but now it is rarely reported.
The ecosystem destruction affects the different
ecological processes and components of ASLNP
(Tafese, 2008). Mammal species in the area include
Grants Gazelle, Jackals, Oribi, Warthog, and others. But
the majority of the mammal species have been reduced
or eliminated because of habitat disturbance and severe
competition with livestock for forage.
The mammalian herbivores are important components
of terrestrial ecosystem in maintaining the diversity and
composition of mammalian carnivore populations.
However, insensitive domestic animal grazing is causing
major changes in composition diversity and abundance of
Ichthyofauna
With 150 species generated from Fish base
(http://www.fishbase.com), the ichthyofauna of Ethiopia
does not seem all that numerous, considering the size of
the country, but with about 40 endemic species,
endemism is proportionately high. The fish fauna of the
Abijata and Shala lakes has not been studied well and it
is recommended that they will be surveyed on the
occurrence of new species.
Plant diversity
A total of 97 plant species were recorded distributing in
28 families of which Poaceae (40 species (41.2%) and
Fabaceae (19.6%) were largest diversity (Tolcha
Regassa et al., 2005). A large number species is adapted
to grazing and browsing: 736 species of grasses, 358
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Point J. Agric. Biotechnol. Res.
Table 1. Distribution of land use/land cover in 1973, 1986 and 2000.
Land use/land cover type
Broad-leaved forest
Protected/dense woodland
Grazed woodland and shrubland
Cultivated land
Grazing land
Barren land
Water bodies and wetlands
1973
Area
(ha)
379
7696
16 906
2023
12 713
4293
19 855
(%)
0.6
12
26
3
20
7
31
1986
Area
(ha)
755
10 962
19 488
2538
11 210
2560
16 232
(%)
1.2
17
31
4
18
4
25
2000
Area
(ha)
302
4183
15 822
4602
18 156
4180
16 506
LUCC(%)
(%)
19731986
19862000
19732000
0.5
7
25
7
28
7
a
26
+0.6
+5.2
+4.1
+0.8
-2.3
-2.7
-5.6
-0.7
-10.6
-5.8
+3.2
+10.9
+2.5
+0.4
-0.1
-5.5
-1.7
+4.1
+8.6
-0.2
-5.2
a
Including three small reservoirs existing at Alage
Source: Temesgen et al. (2013)
herbivore wildlife assemblages.
An increase in complexity of vegetation structure,
floristic composition and heterogeneity can increase
niche diversity of birds and vice versa (Leito et al., 2006).
Both natural and human induced disturbances such as
floods, drought, deforestation change in land use, natural
resources and seasonal climatic changes affect
vegetation
and
bird
community
structures
(Rahayuninagsih et al., 2007). The change in vegetation
community structure alters the availability of nest, cover
and food for birds. Change in structural and
compositional diversity of native vegetation would alter
composition of bird community (Leito et al., 2006;
Acevedo and Aide, 2008). This could be the case in the
disturbed habitat that was prone to loss of its native
vegetation.
Lake Abijata is known to be productive in
phytoplankton. A dominant population of Spirulina
species was reported from Lake Abijata and nitrogenfixing cyanobacterium Anabaenopsis abijatae (Kebede
and Willén, 1998) as the dominant phytoplankton
species. The lake currently recognized as a diatoms lake.
Lake Chitu still maintains an abundant Spirulina which is
the main food source for huge flocks of the lesser
flamingo. Two major phytoplankton classes namely,
Bacillariophyceae (Diatoms) and Cyanophyceae (blue
green algae) were identified from Lake Abijata (Tewodros
and Afework, 2014).
Land use/land cover changes
A study by Temesgen et al. (2013) in main Ethiopian rift
valley, in which about 80% of it is within ASLNP,
indicated that there was an expansion of cultivated and
grazing land between 1973 and 2000 at the expense of
protected/dense woodland, water bodies and wetlands,
grazed woodland and shrub land, barren land and broadleaved forest (Table 1). Similarly, a study conducted by
Molla (2014) in Arsi Negele district, which is part of the
park, showed that the increased of cultivated land and
grassland from 1973 to 2010 at the expense of acacia
woodland, shrub/bush land and bare/open land. These
were mainly caused by the current population pressure in
the district. Hence, the expansion of cultivated land and
grassland into marginal land lead to more sever land
degradation. Similarly, a study by Hurni and Ludi (2000)
revealed that human land use around the Simen
Mountains National Park has accelerated the degradation
of vegetation and soils, and land use has also intensified
basically through shortening of fallow periods and
through expansion of cultivated land. Due to the human
use in the highlands and lowlands puts pressure through
crop cultivation and livestock rearing for subsistence
agriculture, those natural forests and grasslands which
still occur in all altitudinal belts are thus increasingly
coming under pressure.
Type and extent of environmental degradation
Diminishing of lake size
Since the mid 1980s, Lake Abijata water levels have
been in almost constant decline, which is not explainable
through the rainfall record, indicating that water
abstractions are the main cause of the decline. Lake
Abijata is sensitive to any reduction of flow in the Bulbula
River, either through lake levels in Lake Ziway dropping
or through direct pumping of water along the course of
the Bulbula River to supply Ziway and Bulbula town water
supplies, or diverted for small irrigation plots. The direct
pumping of water from Lake Abijata for commercial
exploitation of soda ash by evaporation of brine also
impacts on lake levels. In addition, over-exploitation of
wood for fuel-wood and building materials in the park led
to a decline in woody vegetation which could induce
changes in the local climate, a more erratic rainfall and
severe soil erosion caused siltation that resulted in
decline in the size of the lake (Fekadu and Fekadu,
Getaneh et al.
006
Figure 2. Area of Lake Abijata (Temesgen et al., 2013).
2014). Research finding indicated that Lake Abijata’s
area decreased by 5.2% between 1973 and 2000. It is
also known that the lake lost 46% of its area between
2000 and 2006 (Figure 2) (Temesgen et al., 2013). In
addition, the water level of the lake is dropping because
of increased irrigation for agriculture in/around Lake
Ziway (Flower, 2011). If current trends in natural and
socio economic conditions continue, Lake Abijata is likely
to disappear by 2021 (Figure 3) (Meshesha et al., 2010).
There are contrasting ideas about Lake Shalla.
According to Flower (2011), Lake Shalla is not currently
decreasing. This is due to the alkaline nature of the lake
which makes water abstraction for irrigation not possible
(HGL and GRID, 2009). But, water extraction for soda
ash production is a future threat (Flower, 2011).
However, Meshesha et al. (2010) indicates that the area
of the lake deceased over 1973–2006, and projected to
decrease over the coming years (Figure 3). Thus, further
study is required on Lake Shalla.
Deterioration of vegetation
According to WWF eco-regions division, ASLNP
vegetation is Acacia-Commiphora woodland ecosystem
type within Somali Masai biome. It has dominant acacia
trees with bush land and shrubs. The dominant acacia
trees are: Acacia tortilis, Acacia Senegal, Acacia seyal,
and Balanties aegipticus (Tafese Kefyalew, 2008).
However, charcoal making and farming has depleted the
vegetation cover (Fekadu and Fekadu, 2014). Grazing of
Acacia woodland inside the Park is additional cause of
vegetation degradation (Tafese, 2008). As a result, the
park is one of the country’s most fragile area as a result
of habitat loss, mainly that of Acacia (BirdLife
International, 2012).
Grazing land degradation
Grazing land in the area was heavily degraded as a result
of local communities over dependence on diminishing
natural resources. The drivers were overgrazing and poor
rangeland management systems (BirdLife International,
2012). Because the Park area supports thousands of
population and their huge number of livestock which
increases overtime (Table 2), the area is deforested and
overgrazed leaving the area bare. Over grazing as a
result of overstocking of the wetlands and the savannah
grass of the acacia woodland leads to soil erosion and
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Point J. Agric. Biotechnol. Res.
Figure 3. Areas of Central rift valley lakes 1973-2006 and projected areas in 2016 and 2021 (Meshesha et al.,
2010).
Table 2. Livestock population in the park in different years.
Types of livestock
Cattle
Shoat
Equinesa
Total
1971
21,485
6476
2449
30,410
Livestock population
1978
1996
27,670
48,890
11,000
19,100
5380
6716
44,050
74,706
2007
132,629
40,490
10,153
183,272
2010
134,260
54,574
11,200
202,644
Note: a Horse, mule, and donkey.
Source: Debele (2007); Districts’ Agricultural Office (2010) in Fekadu Teferra and Fekadu Beyene (2014)
degradation (Tafese, 2008).
Causes of environmental degradation
Contested land tenure and overlapping claims
Ethiopia has implemented several changes in its land
ownership system since 1975, and these changes are a
source of uncertainty among farmers and rural
communities (Meshesha et al., 2010). In the study area,
local people have legitimate claims from a historical and
socio cultural perspectives with regard to property rights
to the park resources. As a result, conflicts related to the
park lasted over nearly 40 years (Table 3). The
recurrence of the conflict and unstable property rights
structure has weakened park management, which was
partly attributed to the grievance inherent in the loss of
the rights to benefit from resources inside the park
(Fekadu and Fekadu, 2014). This resulted lack of sense
of ownership and aggravated degradation of resources.
There are a variety of factors that contribute to tenure
insecurity. Gizachew (1994) stated that factors that cause
land tenure insecurity are: growing population pressure
which in turn causes scarcity and fragmentation of farm
lands; lack of a proper and accessible juridical body
responsible for land disputes; lack of knowledge on the
part of rights holders of their rights and their inability to
defend their rights; and increasing rural poverty and the
fact that farm life is becoming unviable. This implies
tenure insecurity is one factor for degradation of
resources in the park. Tenure security is considered to be
ensured through rural land registration and certification
program. This in turn enables farmers to conserve their
lands (Ayele and Tahir, 2015).
Demographic pressures
There has been a rapid growth of human population
experienced recently between 2000 and 2010 from
24,785 to 43,673 with a rate of 6% owing to high birth
rate, declining mortality rate and migration from the
surrounding highlands for cultivation. This has resulted in
the decline of average holdings and further competition
among farmers to expand land for cultivation which has
caused encroaching on land available for grazing and
wildlife conservation (Fekadu and Fekadu, 2014).
Similarly, a study by Tesfahun and Temesgen (2014) in
Bantneka watershed, Southern Ethiopia verified that due
to high population growth, average landholding size per
households has decreased from 0.68ha in 1994 to
0.48ha in 2007. As a result, agricultural practices have
expanded into upland and marginal areas, and clearing of
Getaneh et al.
008
Table 3. Historical overview of property rights and conflict in ASLNP.
No.
1
Time line
Pre-Italian Period (before 1939)
Chronological events
Land was used for communal grazing
2
1942–74 (resource depletion)
Land distributed to individuals where state granted use rights;
Small scale modern farms introduced;
Environmental damage incurred by the introduction of tractors;
ASLNP established without the consent of local community
3
1974–91 (Revolution and
post revolution)
Communities entered the race of resource exploitation, exploiting the
abandoned acacia trees(1974–78);
Soda Ash plant established in the northern shore of Lake Abijata ;
Strict government control of the forest and the park in place
4
Park condition since 1991
(transition to nearly open–access
condition)
ASLNP fell victim of despairing communities;
There was extensive damage to the property of ASLNP and wildlife;
Illegal harvesting of trees, farm land expansion, and charcoal making was no longer a
risky venture;
ASLNP was divided into 11kebeles
5
1996–2009 (contested
decentralization)
ASLNP management relegated under Oromia Agriculture Bureau;
There was lack of coordination and overlapping claims between different Bureaus of
Oromia Regional Government regarding ASLNP;
The park was divided into 18 kebeles resulting in boundary disputes;
The park fell victim to land grabbing in the name of investment promotion
6
From 2009 (recentralization)
ASLNP recentralized under Ethiopian Wildlife Conservation Authority
Source: Fekadu and Fekadu (2014)
indigenous trees has become prevalent.
Impacts of environmental degradation
ASLNP is endowed with mosaic array of micro habitats
and niches which serves for various resident wetland and
terrestrial bird species. Since the park is geographically
located along the Great Rift Valley, the entire ecosystem
serves as wintering and feeding for several migratory bird
species from Europe, Asia and other African country
(EWCA, 2012). Establishment of this park is to endorse
environmental and socio- economic services of this area.
The international effort of its establishment is to protect
wetlands of international importance for resident and
migratory bird species. The other purpose of ASLNP
establishment is to maximize the tourism potential of the
area that enables to meet the socio- economic and
environmental benefit that can sustain the park
ecosystem.
The economic, ecological and cultural significance of
wildlife resource continuation depend on the health and
integrity of its ecosystem. ASLNP has immense natural
resources including wetland, aquatic and terrestrial birds.
However, due to different socio-economic activities the
biodiversity of this park has under gone dramatic
environmental changes (Tewodros Kumssa and Afework
Bekele, 2014a).
Impact on aquatic biodiversity resources
Unsustainable resources used for several years of this
fragile park ecosystem have lead to its present degraded
state. The main activities adversely affecting the park
ecosystem and its biodiversity includes: settlement,
overgrazing, deforestation, sand mining, overfishing and
soda ash mining. As result of these economic based
activities the park area is overpopulated and the trend of
ecosystem change growing. The productivity of the water
habitat can no longer support the once rich bird and fish
life as major ecological systems has been broken. The
area is located in water deficit spot of the country which is
the result of the natural environmental problems. On the
other hand up stream water abstraction especially from
Bulbula River, increased human settlements on the
periphery of the park and deforestation of water
catchments on all sides of the basin are among external
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Point J. Agric. Biotechnol. Res.
Figure 4. Drying Lake Abijata (UNEP, 2009).
problems (Tafesse, 2008).
According to Legesse et al. (2005) the surrounding
lakes including Lake Ziway and Lake Langano through
Bulbula River and Hora Qelo River respectively are main
feeders of Lake Abijata. The main inflow of water from
these two lakes is from highland on either sides of the rift.
Lake Abijata may receive, during exceptionally prolonged
high rainfall periods an overflow from Jido River. This
indicates the threats to the lake habitat were not confined
only into the park boundary; in addition the degradation of
the rift watershed is the significant external problem.
Among one of the economic impact of degradation on
the aquatic habitat is Abijata Soda ash enterprise
expansion for which its first phase of production operated
by 1987 following the feasibility conducted during
1985/86. The production capacity of the enterprise was
also intended to eventually expand up to 200,000 and
1000,000 tons of soda ash per year in the second and
the final phase of production operation, respectively ;
where lake Shalla will be used as a main source of water
and lake Abijata as evaporation ponds (Tigist, 2009).
These economic activities, drought and high evaporation
rate retreated the water capacity of Lake Abijata affecting
the bird abundance and diversity since it is the feeding
habitat for many birds due to its algal growth. As it was
showed (Figure 4) the retreated water capacity along the
edge of Lake Abijata is declining the size of significant
feeding area for birds.
Abijata–Shalla aquatic habitat is primarily created to
serve its aquatic birds life, particularly those feed and
bread on lake in large number. There are about 400 bird
species recorded in ASLNP, almost proximate half the
number recorded for the whole county. The islands in
Lake Shalla are real bird’s paradise however, birds fly to
Lake Abijata to feed. Although, it has high alkaline nature
Lake Abijata is preferred habitat by these birds for its
shallow depth along its edge where algal food source
concentrate (Tafesse, 2008). Due to these biological
characteristics the lake is the major feeding site for
aquatic and terrestrial bird birds including both migratory
and resident ones. Flamingos and White Pelicans are
among the water birds that depend on the Lake. In the
past, the lake was fished by the local population but now
it is rarely reported.
The study result of Tewodros and Afework (2014b)
reported that Flamingos typically are the most prominent
and important consumers in the lakes. The largest
concentration of flamingo was 24,417 in Lake Abijata.
However, drastic and sudden fluctuations in number can
occur and there is a very marked exchange between the
lakes. There were more flamingos during the dry season
than the wet season in Lake Abijata and contrary to
Lakes Shalla and Chitu during the wet season. Despite
the observed fluctuations, the total flamingo population of
the area remained relatively stable, suggesting that the
flamingos responded to the effect of seasonal variation
by moving between lakes. This aspect of behavior makes
flamingos nonresident in any saline lake, moving and
exploiting various nearby lakes as their home range.
Impact on terrestrial biodiversity resources
An increase in complexity of vegetation structure, floristic
composition and heterogeneity can increase niche
diversity of bird species and vice versa. The study of
Girma et al. (2011) detailed that, both natural and human
induced disturbances to habitat including flood, drought,
deforestation change in land use, natural resource and
seasonal climatic changes affected vegetation and birds
Getaneh et al.
community structure. The change in vegetation
community structure alters the availability of nest, cover
and food for birds. Additionally, the change in vegetation
community could affect the quantity and quality of food,
water and cover which in turn alters the diversity,
abundance and distribution of birds.
The study focused on comparative analysis of the bird
community structure in the disturbed and undisturbed
habitat of ASLNP the undisturbed habitat comprises
different life forms such as woody, Shrubs, herbaceous
and grasses. These different life forms will contribute to
the species abundance, richness and diversity in the
undisturbed habitat. While in the disturbed habitat
different life form is not observed except open woody is
the only dominant stratum. The result of this comparative
analysis also describes the significant effect of
environmental degradation on ASLNP terrestrial
biodiversity (Girma et al., 2011).
Girma et al. (2011) data was gathered in dry and wet
seasons since season affects the abundance and
richness of bird due to its migratory behavior. The result
from this comparative analysis shows that, bird species
richness was high in the disturbed habitat but species
diversity was high in the undisturbed habitat of the
ASLNP. This confirms that environmental degradation
which is natural or anthropogenic in it origin will adversely
affect the biodiversity of terrestrial habitat in ASLNP. The
analysis of mean cover abundance of vegetation
communities was computed with mean abundance of
birds, the correlation coefficient is negatively correlated
with undisturbed habitat but it is positive for disturbed
habitat.
According to the study of Mesele and Afework (2012)
the average number of Giant’s gazelle population
decreased from dry season to wet season in Abijata Shalla Lake National Park. This is related to the increase
in number of cattle population in the park during the wet
season. The mammalian herbivores are important
components of terrestrial ecosystem in maintaining the
diversity and abundance of mammalian carnivore
populations. However, insensitive domestic animal
grazing is causing major changes in composition diversity
and abundance of herbivore wildlife assemblages.
Tewodros and Afework (2013) studied on Warthogs
population in this park and described that the Warthogs
population shows tendency of decline in ASLNP of
terrestrial habitat due to decrease in the quality and
quantity of their habitat range. The consequence is
migration of this population to other locality in search of
food and cover.
Conclusion
ASLNP has diverse species in terms of birds, mammal
and plant species. The park is also home to endemic
mammals and bird species that show to climatic
010
response restricted to certain area. Comparatively in
vertebrate species, the park is home to diverse bird
species. Thus, the park is still recognized and has
potentials for conservation sites of bird species. However,
reptiles, fish, amphibians and invertebrate species did not
well documented in the area. The park is also
characterized
by
Acacia-Commiphora
woodland
ecosystem type which favors savanna vegetation zone.
The most oblivious species interaction is seen in bird
species, mammals and plants. The mammalian
herbivores are important components of terrestrial
ecosystem that stabilize ecosystem of savanna grass
lands. However, the park has adversely affected by
environmental degradation, which has resulted from
expansion of settlement and cultivated land, overgrazing,
deforestation, increased irrigation, overfishing and soda
ash mining. In the aquatic habitat the disturbance to
diversity of phytoplankton along the edge of lakes is
affecting the abundance of birds during dry season. In
addition the terrestrial vegetation is under serious threat
which in reverse affecting the richness and diversity of
birds and mammalian wildlife.
Recommendations
i. Further investigation and justification is mandatory in
the taxonomic groups of fish, reptiles, amphibians and
other invertebrates in the park since these groups of
species in the ASLNP has not been documented.
ii. Reduce disturbance, habitat loss and competition with
domestic animals for forage to maintain the unique
features of the park.
iii. Land use changes towards cultivated land and grazing
land is a serious problem which has causing
environmental degradation mainly due to rapid population
growth. Therefore, creating off farm activities, family
planning measures, controlling immigration from the
surrounding highlands and maintaining soil fertility will
reduce the problem.
iv. Lake Abijata is seriously treated due to water
abstractions for Soda ash enterprise, increased irrigation
for agriculture and over-exploitation of vegetation (it could
induce severe soil erosion and causing siltation of the
lake). Thus, efficient water utilization and effective
watershed approach to water and soil management is
recommended.
v. Land tenure insecurity is causing degradation of
resources in the park. Thus, land registration and
certification might reduce the problem.
vi. The restoration and management approach of Lake
Abijata – Shalla cannot be isolated from other rift valley
lakes (Lake ziway and Lake Langano) due to their
hydrological connection. Afforestation of the ASLNP and
its surrounding areas can improve the biophysical and
socio –economic condition of this park area and enhance
ecosystem function.
011
Point J. Agric. Biotechnol. Res.
vii. It is currently the contesting issues of socio-economic
development and natural resource conservation that
degrading the biodiversity of ASLNP. Therefore it is
important to find the platform that help to meet the winwin strategy to simultaneously meet both human welfare
and conservation of natural system in ASLNP.
Ecotourism is one of the development strategy to
reconcile the economic development, socio- cultural
development and nature conservation.
REFERENCES
Acevedo, M.A. and Aide, T.M. (2008). Bird community
dynamics and habitat associations in Karst, Mangrove
and Pterocarpus forest fragment in an urban zone.
Carib. J. Sci., 44: 402-416.
Ayele, B. and Tahir, H. (2015). Land Registration vis-àvis Land Management: The Case of Gishe Rabel
District, Amhara State, Ethiopia. J. Environ. Earth Sci.,
5(5): 30-35.
BirdLife International (2012). Conserving Nature,
Improving lives: Lessons Learnt from Bird Life
International’s Improving Livelihood Projects. Bird Life
International Africa Partnership.
EWCA (2012). Ethiopian Wildlife Conservation Authority:
A checklist of the birds of the Abijata-Shalla lakes
national park (Central Rift-Valley), Addis Ababa,
Ethiopia.
EWCA (2014). Abijata Shala Lake National Park.
Ethiopian Wildlife Conservation Authority.
EWNSH (2010). Important Bird Areas of Ethiopia: A First
Inventory, Ethiopian Wildlife and Natural History
Society, Addis Ababa, Ethiopia.
Fekadu, T. and Fekadu, B. (2014). Indigenous claims and
conflicts in managing the Abijata Shalla Lakes National
Park, Ethiopia. Int. J. Biodiver. Sci. 10(3): 216-227.
Flower, R. (2011). Abijata-Shalla Lakes National Park:
Assessment of Factors Driving Environmental Change
for Management Decision-Making.
Girma, M., Yosef, M. and Afework, B. (2011). A
comparison of terrestrial bird community structure in
the undisturbed and disturbed areas of the Abijata
Shalla lakes national park, Ethiopia. Int. J. Biodiver.
Conserv. 3(9):389-404.
Gizachew, A. (1994). Rural Land Use Issues and Policy:
Overview. Dessalegn Rahmato (ed.) Land Tenure and
Land Policy in Ethiopia after Derg. Proceedings of the
Second Workshop of the Land Tenure Project. Working
Papers on Ethiopian Development No.8. The Centre for
Environment
and
Development,
University of
Trondheim, Norway. pp 1-32.
HGL and GRID (2009). Rift Valley Lakes Basin Integrated
Resources Development Master Plan Study Phase 2
Final Report, Part I Master Plan, Volume 2: Annexes AG. Report by Halcrow Group Limited (HGL) and
Generation Integrated Rural Development (GIRD)
Consultants for The Federal Democratic Republic of
Ethiopia Ministry of Water Resources. Addis Ababa,
Ethiopia. 612 pp.
Hurni, H. and Ludi, E. (2000). Reconciling Conservation
with Sustainable Development: a Participatory Study
inside and around the Simen Mountains National Park,
Ethiopia. With the assistance of an interdisciplinary
group of contributors, University of Berne, Switzerland.
Legesse, D., Woldu, Z., Mebrate, A., Mengistou, S. and
Ayenew, T. (2005). A Review of the Current Status and
an Outline of a Future Management Plan for Lakes
Abijata And Ziway. The Federal Government of
Ethiopia; Oromia Environmental Protection Office.
Leito, A., Truu, J., Roosaluste, E., Seep, K. and Podier, I.
(2006). Long term dynamics of breeding birds in broadleaved deciduous forest on Hanckasti Island in the
West-Estonian archipelago. Ornis. Fennica. 83: 124130.
Melaku, T. (2011). Wildlife in Ethiopia: Endemic Large
Mammals. IDOSI Publications, World J. Zool. 6 (2):
108-116.
Mesele, Y. and Afework, B. (2012). Population Status,
Feeding Ecology and Activity Patterns of Grant’s
Gazelle (Gazella granti) in Abijata-Shalla Lakes
National Park, Ethiopia. Asian J. Biol. Sci. 5: 20-29.
Meshesha, T., Tsunekawa, A. and Tsubo, M. (2010).
Continuing land degredation: Cause-effect in Ethiopia's
Central
Rift
Valley.
Land
Degredation
and
Devleopment.
Molla, M.B. (2014). Land Use/ land cover dynamics in the
Central Rift Valley Region of Ethiopia: The Case of Arsi
Negele District. Acad. J. Environ. Sci. 2(5): 074-088.
Rahayuninagsih, M., Mardiastuti, A., Prasetyo, L. and
Mulyani, Y. (2007). Bird community in Burung island,
Karimunjawa National Park, Central Java. Biodiversv.,
8: 183-187.
Rezenom, A. (2012). A Checklist of the Birds of the
Abijata-Shalla Lakes National Park of Ethiopia.
Ethiopian Wildlife Conservation Authority (EWCA) and
ASLNP.
Tafese, K. (2008). Integrated Assessment of ecosystem
services and stakeholder analysis of Abijata-Shalla
Lakes National Park, Ethiopia. M.Sc Theses.
Wageningen University, The Netherlands. 150pp.
Temesgen, H., Nyssen, J., Zenebe, A., Haregeweyn, N.,
Kindu, M., Lemenih, M. and Haile, M. (2013).
Ecological succession and land use changes in a lake
retreat area (Main Ethiopian Rift Valley). J. Arid
Environ. 91: 53-60.
Tesfahun, F. and Temesgen, G. (2014). Population
Growth and Land Resources Degradation in Bantneka
Watershed, Southern Ethiopia. J. Biol., Agric. Healthc.
4(15):13-16.
Tewodros Kumssa and Afework Bekele (2013).
Population status and activity pattern of desert warthog
(Phacochoerus aethiopicus) in Abijata-Shalla Lakes
National Park, Ethiopia. J. Environ. Sci. 1(1): 009-017,
Getaneh et al.
Academia Publishing.
Tewodros, K. and Afework, B. (2014a). Attitude and
Perceptions of Local Residents toward the Protected
Area of Abijata-Shalla Lakes National Park (ASLNP),
Ethiopia. J. Ecosys. Ecograph. 4: 138.
Tewodros, K. and Afework, B. (2014b). Current
Population Status and Activity Pattern of Lesser
Flamingos (Phoeniconaias minor) and Greater
Flamingo (Phoenicopterus roseus) in Abijata-Shalla
Lakes National Park (ASLNP), Ethiopia. Int. J. Biodiver.
1-8
Tigist, T. (2009). Water resource utilization and its related
effects: Lake Abijata and the surrounding. M.Sc Thesis,
Addis Ababa, Ethiopia.
UNEP (2009). National Reporting to Convention on
Biological Diversity: Least Developed Countries Face
Challenges and Obstacles. 6(6).
012
Vreugdenhil, D., Vreugdenhil, A.D., Tamirat, T., Anteneh,
S. and Zelealem, T. (2012). Gap Analysis of the
Protected Areas System of Ethiopia, with technical
contributions from Nagelkerke, L., Gedeon, K. Spawls,
S., Yalden, D., Lakew Berhanu, and Siege, L., World
Institute for Conservation and Environment, USA.
Young, J. (2012). Ethiopian Protected Areas A
‘Snapshot’. A reference guide future strategic planning
and project funding.