Land degradation, defined as the deterioration in the quality and productive capacity of land (Benneh, Agyepong and Allotey 1990), has been identified as one of the major environmental challenges facing the central Africa sub-region. The main contributors to land degradation in this sub-region are erosion and soil compacting, as a result of extensive removal of vegetation, and exposure of the soils to heavy rainfall, increased evaporation and wind action. The main reasons for vegetation removal are commercial logging and tree cutting to provide domestic fuel, as well as clearance of forests for commercial or subsistence cultivation.
The rate of forest loss in central Africa is a cause for concern in terms of its impacts on biodiversity, atmospheric change and hydrological cycles, in addition to the concerns regarding soil erosion (UNU 1998). Chemical degradation also occurs, because of: intensive cultivation of marginal areas without sufficient fallowing; use of chemical rather than organic fertilizers; and salinization, through inundation with saltwater or irrigation with poor quality water. For example, the Congo basin has lost more than 1 million ha of original forest cover, contributing to soil erosion and the sedimentation of waterbodies (WRI 2001). The Lake Chad basin has also suffered severe vegetation loss, and potential for soil loss and desertification is high (WRI 2001).
Goat herd overgrazing fragile pasture, Chad
Vincent Dedet/Still Pictures
In the coming decades, the threat of desertification will increase, as a result of climatic changes, such as: increased evaporation; reduced rainfall and run-off; and increased frequency and severity of drought (IPCC 2001). In addition, civil unrest or conflict can result in vast movements of refugees, many of whom are settled in marginal or fragile areas. Such social and environmental pressures were clearly demonstrated in 1997, when Central African Republic (having to cope with internal disputes) received more than 50 000 refugees from Sudan, Chad, Democratic Republic of Congo, Congo Brazzaville and Rwanda. The arrival of these displaced persons put a visible strain on the already stressed food security situation (Njinyam 1998).
The consequences of land degradation, and of soil erosion and compaction, are manifest as a result of the declining ability to support natural or domesticated plant and animal production. Ultimately, this translates to reduced nutritional status of the population and to reduced export revenues. In addition, communities which are dependent on wild produce-such as fruits, nuts, animals and mushrooms, and wood for fuel-have to search further and further afield to meet their needs, and may experience food shortages or even famine during drought years. Extreme reductions in productivity may result in people abandoning their farms and migrating to urban centres, in search of improved security.
Political and economic development policies, as well as conflicts and civil unrest, have also played a role in declining food security in parts of the sub-region, as shown by the example of Cameroon in Box 2f.6. A comprehensive, integrated approach to improving food security and land quality is, therefore, a current environmental and developmental priority for central Africa. To this end, countries of the sub-region have ratified UNCCD. Chad and Cameroon are the only countries to have so far produced national reports, however, and Chad has also produced a National Action Plan. The CILSS, which encompasses Chad, has developed a sub-regional action plan to combat desertification (UNCCD 2001).
Cameroon and Chad have also developed NEAPs, which provide an overall framework for: improvement of land use; harmonization of land use policies; and environmental management. Implementation of these plans needs strengthening through additional resources and institutional arrangements. In Cameroon, the government has also embarked on a tree-planting programme, aimed at stopping the advancing desert.
|Box 2f.6 Agricultural development in Cameroon|
|Source: SANE 1997|