Reconstructing recent land degradation in the semi-arid Karoo of South Africa: a palaeoecological study at Compassberg, Eastern Cape

This paper forms part of an ongoing, multidisciplinary study of land degradation in the Eastern Cape, South Africa. A series of studies of erosion, runoff and the development of gullies, badlands and sediment delivery to small farm reservoirs in the Sneeuberg uplands have shown that the semi-arid Karoo is vulnerable to soil erosion. Cereal cultivation and increased livestock numbers are thought to have played a major role in triggering erosion over the last 200 years. To test this assumption, we analysed pollen, non-pollen palynomorphs and microscopic charcoal from sediments that have infilled one farm dam since the 1930s and which is located in the Sneeuberg uplands of the Eastern Cape. The results, supported by sediment source tracing, indicate that soil erosion was closely associated with agricultural activity. The reconstructions appear to be in agreement with historical documentary records. However, records of livestock stocking densities were found to be insufficiently detailed to enable direct matching against microfossil proxies for grazing, especially the coprophilous fungal spore, Sporormiella type. This study demonstrates the importance of combining sediment tracing techniques with palynological analyses to provide a more informed interpretation of land use changes as recorded by lake and reservoir sediments