Harvesting cocoa pods, Ghana
Ron Giling/Still Pictures
Land cover and land use in western Africa are largely determined by climate, and a dramatic gradation is seen from north to south in rainfall and vegetation cover. In the north, average annual rainfall is 350-850 mm/yr and savannas are the dominant ecosystems along the southern border of the Sahel (Mali, Mauritania, Niger and northern Senegal). Here, climate variability is greatest, and drought is common, and often severe. Cultivation is limited, and the dominant agricultural activity is pastoral livestock rearing. For example, in Mali and Niger, cultivation represents just 4 per cent of the land area and, in Mauritania, it is less than 1 per cent (FAOSTAT 2001). By contrast, permanent pasture accounts for 25 per cent of the land area in Mali, and nearly 40 per cent in Mauritania (FAOSTAT 2001). In the equatorial and coastal zone, rainfall is higher, with greater inter-annual and intraannual reliability, ranging from 1 000 mm/yr to 4 000 mm/yr, although periodic flooding occurs (FAOSTAT 2001). In 2000, forest cover totalled 72 million ha (almost 12 percent of the land area), although it is highly fragmented, and under increasing threat from charcoal production and collection of wood for fuel, commercial logging, and plantation and slash-and-burn agriculture (FAO 2001a). Nearly 11 per cent of the total area of western Africa is currently cultivated. Most of it is rain-fed agriculture, and cultivation mostly occurs in the equatorial belt. Togo and Nigeria have the largest percentage of land under cultivation (42 per cent and 33 per cent respectively), followed by Côte d'Ivoire and Ghana (23 per cent each) (FAOSTAT 2001).
Most of western Africa's population depends on the land for their subsistence, as well as for the production of cash crops. However, this dependency, rising economic pressure and population growth have resulted in increased demands on productivity of the land over the past 30 years. As a result, forest and agricultural lands have undergone rapid degradation and reductions in productivity.
Although subsistence agriculture is widespread, commercial agriculture also contributes significantly to the economy of the sub-region with, on average, 65 per cent of the workforce employed in this sector over the past three decades. Burkina Faso, Mali and Niger had the highest rates of employment in agriculture-more than 90 per cent-in 1990 whereas, in Cape Verde and Nigeria, employment in agriculture reached only 31 and 42 per cent respectively (World Bank 2001).
There is a wider variety of crops grown in western Africa than in some other sub-regions, although the most important are: cotton; coffee; cocoa; cassava; groundnuts; maize; millet; palm oil; rubber; sorghum; and yams. International price fluctuations have heavily influenced income from agricultural produce over the past 30 years, but it has remained one of the mainstays of GDP. For example, in Benin and Burkina Faso, the value of agricultural exports grew steadily between 1980 and 1997 (from US$55 million to US$198 million and from US$80 million to US$119 million respectively) (World Bank 2001). Côte D'Ivoire, Ghana and Nigeria experienced declines in export values between 1980 and the mid-1990s, but have seen gains since then, whereas Gambia, Liberia, Senegal and Sierra Leone have not recovered so well. Mali, Mauritania and Guinea have seen fairly constant export values (World Bank 2001). In Mauritania, value added in agriculture was US$306 million (compared to GDP of US$1 252 million) in 1999, up from US$160 million in 1980 (when GDP was US$753 million).