AFRICA ENVIRONMENT OUTLOOK
Past, present and future perspectives

THREATS TO BIODIVERSITY IN CENTRAL AFRICA

Over the years, wildlife habitat in the sub-region has come under increasing pressure from conversion to alternative land uses, particularly cultivation of cash crops, subsistence slash-and-burn cultivation and expansion of human settlements. Weak infrastructure and lax enforcement of protection have contributed to excessive rates of deforestation. Resettlement campaigns by the French administration, together with rural-urban migration, have also left large areas of forest unpopulated, and therefore unpatrolled. In the late 1980s, it was estimated that only 50 per cent of an estimated original 404 390 000 hectares of wildlife habitat remained (McNeely, Miller, Reid, Mittermeier & Werner 1990).

The rate of forest loss is a particular cause for concern in Central Africa, with the DRC losing more than 500 000 hectares of forest per year between 1990-2000 and Cameroon losing over 200 000 hectares (FAO 2001). Even though these are not the highest rates of deforestation in Africa-and allowing for the fact that even these large losses represent small percentages of the total forest area-the impacts on the functioning and biodiversity of the ecosystem, and the impacts on the local communities are highly detrimental. Loss of habitat has resulted in species becoming threatened or extinct-in DRC, for example, 40 species of mammals and 28 bird species are threatened (IUCN 2000a). The communities dependent on these species for food, construction, medicinal products or subsistence incomes are forced to find alternatives or go without.

Agricultural, pharmaceutical, and industrial opportunities are also lost, and economies suffer in the long term as a result. More sustainable rates of harvesting of forest products must therefore be adopted in order to ensure medium- to long-term supply.

In addition to the threat of habitat loss, numbers of threatened or endangered species in Central Africa are increasing because of pollution and overharvesting of selected species for food, medicinal, and commercial purposes. For example, gorillas, chimpanzees, mandrills, forest elephants, buffalo, and antelopes are coming under increasing pressure for sale as bushmeat, and illegal logging is destroying large areas of their habitat. The Drill (Mandrillus leucophaeu) is one of Africa's least-knowsn primates, and is one of the most endangered. Its range is limited to parts of Nigeria, Cameroon and Bioko Island in Equatorial Guinea. Drills are under severe pressure from hunting (Gadsby & Jenkins 1998). The savannas of northern Cameroon are an important wildlife habitat for the critically endangered, endemic, black rhino subspecies Diceros bicornis longipes. Fewer than 20 individuals remain, due to pressure from poaching. War and civil unrest are also contributing factors in the decline of these species because of resettlement of refugees in forest habitats, illegal poaching by soldiers and guerrillas, and clearing of habitat for military training. The DRC and Cameroon-richest in endemic mammals, birds and higher plants-also have the highest numbers of threatened species (see Table 2b.12). Gabon and Cameroon had the highest numbers of plants known to be threatened in the sub-region in 1997 (World Bank 2000).

Table 2b.12 Threatened species in Central Africa 2000
Country Mammals Birds Reptiles Amphibians Fishes Inverts Plants Total
 
Central African Republic 12 3 1 0 0 0 10 26
Chad 17 5 1 0 0 1 2 26
Congo 12 3 1 0 1 1 33 51
DRC 40 28 2 0 1 45 55 171
Equatorial Guinea 15 5 2 1 0 2 23 48
Gabon 15 5 1 0 1 1 71 94
Sao Tome & Principe 3 9 1 0 0 2 27 42
Cameroon 37 15 1 1 27
4
155 240
 
Source: IUCN 2000a a