Assessing the Long-Term Ecological Sustainability of Dambo Cultivation in Southern Africa: Ten-Year Case Studies from Zambia and Malawi

摘要

Internationally, evidence-based assessments of the sustainability of cultivation in seasonal wetlands are lacking despite such areas, including dambos in southern Africa, providing key areas for cultivation. The Striking a Balance project, which supported multiple use, including cultivation, of dambos, was undertaken in Zambia and Malawi between 2006 and 2008. Using the baseline WET-SustainableUse assessments made in 2008 in four of these dambos, the procedures were repeated in 2019 to explore the ecological sustainability of current use based on the concept of Thresholds of Potential Concern (TPC). This concept was applied to the five components of ecological health, namely hydrology, geomorphology, soil organic matter, nutrient retention and vegetation composition. In all four dambos, despite ten years of multiple use including cultivation, the change in ecological health between 2008 and 2019 was generally small, and overall, the ecological health of the four dambos has largely been maintained. However, there are some concerns, particularly with respect to vegetation composition, which had fallen below the TPC for two of the dambos. The methods used and the findings appear to have wider application in Africa for long-term monitoring the ecological health of seasonal wetlands and determining the ecological bounds for wetland cultivation.