The application of a framework for assessing ecological condition and sustainability of use to three wetlands in Malawi

Abstract

In Africa, the direct use of wetlands has long contributed to livelihoods, but use may lead to the degradation of wetlands. In order to better understand how the biophysical features of a wetland influence the sustainability of its use, an investigation was undertaken of the ecological condition and use of three wetlands in the Kasungu District, Malawi, where human pressures on wetlands are high. The first wetland, at the head of the catchment, had sandy soils and a gentle longitudinal slope, the second wetland, lower in the catchment, had clay soils and a steeper longitudinal slope, and the third wetland was intermediate. A framework was applied to score five functional components of ecological condition: hydrology, geomorphology, soil organic matter (SOM) accumulation, nutrient cycling and vegetation composition in terms of human impact, based on pre-defined field indicators. The framework highlighted particular vulnerabilities of individual wetlands in the face of human pressure. Vulnerability varied greatly across the wetlands in terms of: recovery of native vegetation composition following cultivation, geomorphic change through gully erosion and depletion of SOM. The framework is recommended for wider application in Africa as a means of highlighting the specific vulnerabilities of individual wetlands and for the improved focus of organizations which promote the ecologically sustainable use of wetlands.