Mineral Requirements of Animals and Symptoms of Their Deficiencies
NAME :ADERIBIGBE ADEDOTUN
Figure 14-2. West Africa: natural forest and plantation areas 2000 and net area change 1990-2000
The total volume of West African forests is estimated at approximately 5 billion cubic metres over bark, which is 11 percent of the volume of all African forests. The volume and biomass estimates for most countries are based on existing forest inventories. In humid zones, volume assessment is focused on timber volume. In dry zones, volume assessment usually includes the whole ligneous biomass, including trunks and branches, for fuelwood consumption. Maximal production of natural vegetation in West Africa was estimated to vary from 0.1 to 2.75 m3 per hectare per year according to rainfall and vegetation type (Bellefontaine et al. 2000).
Wood provided by trees outside the forest is extremely important in this subregion. Indeed, the sparse forest cover of most West African countries makes this material very valuable, notably in dry zones where a large part of fuelwood is harvested outside the forest. Jensen (1995) estimated that the volume in fallows and sparse trees on agricultural lands constitutes approximately 30 percent of the wood resources in Burkina Faso and 19 percent in the Gambia.
FOREST MANAGEMENT AND USES
Only three of the 16 countries in West Africa provided national-level information on the forest area covered by a formal, nationally approved forest management plan (Table 14-1). Of these countries, Togo had the lowest percentage (2 percent) and Côte d'Ivoire the highest (19 percent). Partial figures were available from Nigeria (lowland rain forests only) indicating that at least 832 000 hectares (or 6 percent) of the total forest area of the country was covered by a management plan. Information was lacking for the remaining countries, including Ghana, which according to a recent ITTO study (ITTO 2000) appeared to have established all the conditions that make it likely that the country can manage its forest management units
Figure 14-2. West Africa: natural forest and plantation areas 2000 and net area change 1990-2000
The total volume of West African forests is estimated at approximately 5 billion cubic metres over bark, which is 11 percent of the volume of all African forests. The volume and biomass estimates for most countries are based on existing forest inventories. In humid zones, volume assessment is focused on timber volume. In dry zones, volume assessment usually includes the whole ligneous biomass, including trunks and branches, for fuelwood consumption. Maximal production of natural vegetation in West Africa was estimated to vary from 0.1 to 2.75 m3 per hectare per year according to rainfall and vegetation type (Bellefontaine et al. 2000).
Wood provided by trees outside the forest is extremely important in this subregion. Indeed, the sparse forest cover of most West African countries makes this material very valuable, notably in dry zones where a large part of fuelwood is harvested outside the forest. Jensen (1995) estimated that the volume in fallows and sparse trees on agricultural lands constitutes approximately 30 percent of the wood resources in Burkina Faso and 19 percent in the Gambia.
FOREST MANAGEMENT AND USES
Only three of the 16 countries in West Africa provided national-level information on the forest area covered by a formal, nationally approved forest management plan (Table 14-1). Of these countries, Togo had the lowest percentage (2 percent) and Côte d'Ivoire the highest (19 percent). Partial figures were available from Nigeria (lowland rain forests only) indicating that at least 832 000 hectares (or 6 percent) of the total forest area of the country was covered by a management plan. Information was lacking for the remaining countries, including Ghana, which according to a recent ITTO study (ITTO 2000) appeared to have established all the conditions that make it likely that the country can manage its forest management units