MODERN DIATOM COMMUNITIES ON THE HUMPATA PLATEAU IN SOUTHWESTERN ANGOLA

The Humpata Plateau, located in southwestern (SW) Angola, connects the hyper-arid Namib Desert in the west with the wetter Okavango basin in the east, making it a fascinating area to study climate change and seasonality. As a tropical region, the climate in SW Angola is dominated by yearly fluctuations in precipitation rather than temperature. The warm/rainy season spans from the end of September through May, followed by a cold/dry season that lasts about four months. Because there is a large annual precipitation gradient from west to east in southern Angola, small changes in climate can have a large impact on annual weather patterns across the Humpata Plateau. Given the growing interest in reconstructing paleoclimates across Africa, understanding modern seasonality and its impact on the biosphere is increasing in importance. As part of the PaleoLeba project, this presentation provides preliminary results of modern data on seasonal variability in water chemistry and diatom communities of cold-water springs and rivers on the Humpata Plateau. Ultimately, these data will be used to explore historic climate change in the area using diatoms as proxies from sediment cores. The aim of this study is to begin to close the large paleoclimatological research gap in SW Africa, where studies of long-term climate change are rare.