SUB-REGIONAL OVERVIEW

WESTERN AFRICA

The wide range of ecosystems – forests, savannahs, deserts, rivers, mountains, mangroves and seas – makes the sub-region rich in biodiversity. The Sahelian zone has several wetlands, including the Niger and Senegal rivers, Lake Chad and floodlands in Senegal and Niger which are very important for migratory birds. The inner Niger delta is a vast floodplain (more than 30 000 km²) situated in the middle of the Sahelian landscape, rich in natural resources and featuring varied ecosystems (lakes, forest floodplains, flooded grasslands and savannah) which supports the livelihoods of 1 million people. The delta is also well known as a wintering and staging area for million of migratory birds. Other important sub-regional biodiversity values include the west African manatee, a globally endangered species (Beintema and others 2001). The Guinea forest contains half the mammal species on the African continent, including the rare pygmy hippopotamus, the zebra duiker and the drill, the most threatened primate (UNEP and NESDA 2004).

Table 4: Biodiversity richness and endemism in Southern Africa
  Biodiversity opportunity Threat Response
  Area Mammals Birds Plants % of land % of land
Country km² Endemic Total Endemic Total Endemic Total transformed protected

Benin 112 620 0 188 0 307 0 2 500 9 6

Burkina Faso 274 000 0 147 0 335   1 100 48 12

Cape Verde 4 030 0 5 4 38 86 774    

Gambia 11 300 0 117 0 280 not
known
974 42 0

Ghana 238 540 1 222 0 529 43 3 725 17 5

Guinea 245 860 1 190 0 409 88 3 000 14 0

Guinea-Bissau 36 120 0 108 0 234 12 1 000 7  

Côte d’Ivoire 322 460 0 230 2 535 62 3 660 25 6

Liberia 111 370 0 193 1 372 103 2 200 30 1

Mali 1 240 190 0 137 0 397 11 1 741 15 4

Mauritania 1 025 520 1 61 0 273 not
known
1 100 3 0

Niger 1 267 000 0 131 0 299 not
known
1 460 2 8

Nigeria 923 770 4 274 2 681 205 4 715 34 4

Senegal 196 720 0 192 0 384 26 2 086 47 11

Sierra Leone 71 740 0 147 1 466 74 2 090 38 2

Togo 56 790 0 196 0 391 not
known
3 085 7 8

All countries 6 138 030 7   10   710   16 4

Source: Methodology and sources as for Table 1

CHALLENGES FACED IN REALIZING OPPORTUNITIES FOR DEVELOPMENT

Land degradation and desertification are major causes of biodiversity loss. Three factors contribute:

  • A relatively dense and growing population with strong dependence on natural resources;
  • Relatively easy access to resources; and
  • Recurrent droughts.

These processes affect grasslands, steppes, savannahs and woodlands:

  • They fragment forests and alter their structure and composition, especially when they are followed by recurrent forest and bush fires;
  • They reduce surface water points and their associated plants;
  • They strongly deplete animal populations and notably reduce a number of rare and vulnerable species through habitat degradation, sport hunting and especially through exploitation for bushmeat, which is exacerbated by drought-related food deficits.

Dust storms, forest fires, locust outbreaks and population displacement are all linked to the phenomenon of desertification, and have strongly negative consequences for people, in particular through the loss of livelihood and economic opportunities.

Land degradation is a persistent reduction in the capacity to support life and supply ecosystem services. It affects biological diversity directly and indirectly. It may affect the survival of species and alter processes that support their life, or it may trigger socioeconomic phenomena that impact on living species and their ecosystems. Land degradation phenomena directly affecting biodiversity include water and wind erosion. Along major river basins siltation processes accumulate debris and materials that engulf natural vegetation, such as the Acacia nilotica riparian forests. Trees may survive for years, but the diverse understorey may not. Soil erosion contributes to moving the seed capital of the ground, uprooting grassy as well as woody species, and in accumulation areas it smothers valuable species. This occurs in the sand dune areas of countries such as Mauritania, Mali, Niger, Nigeria and Senegal.

Indirect factors associated with land degradation that impact on biodiversity include the coping strategies people adopt to deal with environmental change. The movement of people south towards sub-humid to humid tropical areas has resulted in depletion of natural resources: loss of primary forests and woodlands, repeated logging of the secondary vegetation, and depletion of a number of species. The influx of refugees from war-stricken areas also triggers severe land degradation in host regions and the overuse of wildlife resources. More diffuse degradation of land resources also occurs in the arid and sub-humid parts. These include the extraction of tree resources outside forests for charcoal making (about 150 million tonnes/year from the savannahs and woodland areas), and the use of high-value woods. Most affected are the Meliacaea family (Khaya species), Pterocarpus erinaceus, and Dalbergia melanoxylon.

The degradation and fragmentation of natural landscapes is caused by agricultural expansion. Agricultural expansion affects the survival and regeneration of animal populations, destroys the structure of wildlife habitat, and strongly contributes to reduction of wildlife populations. The number of species threatened continues to grow; these include lion, elephant, most of the greater antelopes, and water-dependent species such as manatees and crocodiles, which could form the basis of a tourism industry.

STRATEGIES TO ENHANCE THE OPPORTUNITIES FOR DEVELOPMENT

A number of conservation efforts, some involving communities, have been undertaken. An example of a successful conservation initiative involving local communities is shown in Box 6.

Box 6: The Diawling National Park (DNP), Mauritania

In the delta of Senegal River, in Mauritania, two dams were constructed in the 1980s: the Manantali dam upstream (in 1989) for flood regulation, hydroelectricity, irrigation and navigation purposes and the Diama one downstream (in 1985), an anti-salt dam.

However, by 1997, only 100 000 ha had been equipped for irrigated agriculture, and only 44 000 ha were farmed in the end because of loss of soil fertility and increased salinity (OMVS and others 1998 cited in Hamerlynck and Duvail 2003). Hydropower production started in 2002. By 2003, no investments had been secured for the navigability scheme. Thus, the negative impacts of the Diama Dam were dire: loss of floodplains traditional functions (fishing, grazing, rain-fed cultivation, handicraft, etc). The dam also prevented exchanges between river freshwater and seawater, with the reduction of the estuary ecosystem’s great productivity.

IUCN – The World Conservation Union and the Directorate-General for International Cooperation (DGIS) (Netherlands) proposed then to help restore this delta by reintroducing inundation through the sluice gates of the dam. Negotiation between the various users within the park was undertaken to come out with a consensus water management plan. A consensus scenario for opening and closing the different sluice gates was adopted. This scenario takes into account all the resources (the spawning of fish, the Sporobolus spp. growth, the groundwater replenishment, etc) and their behaviour related to water level.

With the return of the floods came the return of people from the cities. Floodplains traditional functions and goods (cattle grazing, artisanal mat weaving using Sporobolus robustus and Acacia nilotica seedpods (for leather tanning), fisheries, and waterbirds) returned. Thus livelihood activities, by both men and women from this Senegal River valley, were restarted, contributing to the improvement of human well-being.

Source: Hamerlynck and Duvail 2003, IUCN 2003

Table 7 shows international protected areas in Western Africa. An example of successful cooperative is the endeavour of Benin, Burkina Faso and Niger, supported by external partners such as France, to protect the extensive transboundary complex of the Pendjari and Arly national parks. Concerted efforts have succeeded in maintaining the overall system and resources in the protected areas in the three participating countries. Biodiversity is relatively well conserved in this area: avifauna is represented by around 378 species; fish species, amphibians and reptiles are prominently present; and the greater mammals of the savannahs and woodland areas are extensively featured (10 000 buffalo, 4 500 elephants, 7 500 roan antelopes, 2 000 bubals, 1 100 warthogs and 1 000 kobs). Lions, cheetahs, panthers and hyenas are also well represented. The habitat is also well conserved, and the overall trend of biological diversity is deemed very positive and on the rise.

Table 7: International protected areas in Western Africa
  Biosphere reserves World heritage sites RAMSAR sites
Country Number Area (’000 ha) Number Area (’000 ha) Number Area (’000 ha)

Benin 1 623 0 0 2 139
Burkina Faso 1 186 0 0 3 299
Côte d’Ivoire 2 1 480 3 1 504 1 19
Gambia 0 0 0 0 1 20
Ghana 1 8 0 0 6 178
Guinea 2 133 1 13 6 225
Guinea Bissau 1 110 0 0 1 39
Liberia 0 0 0 0 0 0
Mali 1 2 349 1 400 3 162
Mauritania 0 - 1 1 200 2 1 231
Niger 2 25 128 2 7 957 4 715
Nigeria 1 <1 0 0 1 58
Senegal 3 1 094 2 929 4 100
Sierra Leone 0 - 0 0 1 295
Togo 0 0 0 0 2 194
Total 15 31 111 10 12 003 37 3 674

data for Cape Verde not available


Source: Data from Wetlands International undated, UNESCO 2006a, UNESCO 2006b