Core research themes
Past climate change, human impact, and the environmental history of African ecosystems
Sediments accumulating on the bottom of African lakes represent one of the most valuable natural archives of tropical climate and environmental history, at both short (years to decades) and long (centuries to millennia) time scales. This history is written in a diverse range of sedimentological, geochemical and biological signatures contained in these sediments, each of them revealing part of the intriguing story of how the lake, its surrounding landscape, and the region’s climate have changed through time. Paleo-environmental reconstruction using Africa’s lake-sediment archives compensates for the lack of historical monitoring data by producing the long-term perspective needed to develop sound strategies for water-resource management and adaptation to climate change. In this research theme, we first aim to identify African lakes with the highest-quality sedimentary archives, and then exploit those archives to address a wide range of both fundamental and applied research questions such as long-term climate and ecosystem dynamics, the timing and magnitude of ancient human impact on Africa’s lakes and landscapes, and the assembly and regulation of aquatic biological communities in fluctuating tropical lakes. Fossils of aquatic invertebrates are among the most valuable indicators of the environmental change that lakes have experienced, be it natural (climate-driven hydrological change, ecological succession) or anthropogenic (eutrophication, fish introduction, siltation). Increasingly we also aim to calibrate and validate biological indicators of environmental change in the surrounding terrestrial ecosystem, such as fungal spores and the pollen and phytoliths of higher plants, to achieve a more comprehensive understanding of past climate-human-ecosystem interactions.
Selected publications
De Cort G, Bessems I, Keppens E, Mees F, Cumming B, Verschuren D, 2013. Late-Holocene and recent hydroclimatic variability in the central Kenya Rift Valley: the sediment record of hypersaline lakes Bogoria, Nakuru and Elementeita. Palaeogeography, Palaeoclimatology, Palaeoecology 388, 69-80.
Sinninghe Damsté, J.S., Verschuren, D. et al., 2011. A 25,000-year record of climate-induced changes in lowland vegetation of eastern equatorial Africa revealed by the stable carbon-isotopic composition of fossil plant leaf waxes. Earth Planet. Sci. Lett. 302, 236–246. Read more
Barker, P.A., Hurrell, E.R., Leng, M.J., Wolff, C, Cocquyt, C., Sloane, H.J. & Verschuren, D., 2011. Seasonality in equatorial climate over the last 25,000 years revealed by oxygen isotope records from Mount Kilimanjaro. Geology 39, 1111-1114. Read more
Mergeay, J., De Meester, L., Eggermont, H. & Verschuren, D., 2011. Priority effects and species sorting in a long paleo-ecological record of repeated community assembly through time. Ecology 92, 2267–2275. Read more
Van Bocxlaer, B., Verschuren, D., Schettler, G. & Kröpelin, S., 2011. Modern and early Holocene mollusc fauna of the Ounianga lakes (northern Chad): implications for the palaeohydrology of the central Sahara. J. Quat. Sci. 26, 433–447. Read more
Moernaut, J., Verschuren, D., Charlet, F., Kristen, I., Fagot, M. & De Batist, M., 2010. The seismic-stratigraphic record of lake-level fluctuations in Lake Challa: hydrological stability and change in equatorial East-Africa over the last 140 kyr. Earth and Planetary Science Letters 290(1-2), 214-223. Read more
Eggermont, H., Verschuren, D., Audenaert, L., Lens, L., Russell, J. M., Klaassen, G. & Heiri, O., 2010. Limnological and ecological sensitivity of Rwenzori mountain lakes to climate warming. Hydrobiologia 648, 123-142. Read more
Verschuren, D., Sinninghe Damsté, J.S., Moernaut, J., Kristen, I., Blaauw, M., Fagot, M., Haug, G.H. & CHALLACEA project members, 2009. Half-precessional dynamics of monsoon rainfall near the East African equator. Nature 462, 637-641. Read more
Verschuren, D., Johnson, T. C., Kling, H. J., Edgington, D. N., Leavitt, P. R., Brown, E. T., Talbot, M. R. and Hecky, R. E., 2002. History and timing of human impact on Lake Victoria, East Africa. Proc. Roy. Soc. Lond. B 269, 289-294. Read more