Mineral Requirements of Animals and Symptoms of Their Deficiencies

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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 sustainably. Decentralization has started in a majority of West African countries, clarifying the role and ownership of resources. Nevertheless, land tenure is sometimes very complex because of overlapping land tenure rights and uses. This is particularly notable in savannah regions and even more in Sahelian zones where forest, pastoral and agricultural domains overlap (Bellefontaine et al. 2000). Natural forest exploitation and management has a long history in the humid part of West Africa. A number of different systems of tropical silviculture have been tried in the past to maximize yield (e.g. tropical shelterwood, modified selection, etc.). These silvicultural techniques have not always been successful for both ecological and managerial reasons (FAO 2000; Dupuy et al. 1999). In all the countries of the subregion with tropical humid forests, government forestry departments control the right to exploit timber. Regulations specify the logging methods and the most appropriate logging systems. Private timber companies or individuals are awarded concessions by the government and issued contracts that spell out the regulations and procedures to be followed, including in some cases restocking and post harvest operations. However, monitoring and control by government are often lacking owing to limited resources. For forest plantations, agreements and contracts are set up to manage their exploitation and to prevent conflicts (FAO 2000). In dry zones, a number of pilot projects are currently in progress or have been completed to assess the consequences of increased public participation in forest management. During the 1980s, numerous projects were undertaken with limited participation. Since then, considerations of land tenure, user and interest groups and problems of conflicting uses have led to increased decentralized management of natural resources for the benefit of local people (Dupuy et al. 1999). In addition, local participation has slowly increased in...
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