Andrew Cohen ⎮ Paleorecords of Watershed Deforestation and Recent Climate Change Impacts in African Lakes

My lab has investigated the timing and impacts of watershed erosion resulting from deforestation around the margins of Lake Tanganyika. Much of our work has focused on the conservation biology of modern littoral ecosystems impacted by increased sediment loading (Cohen et al., 1993Kaufman and Cohen, 1993;Cohen, 1994Cohen et al., 1996Alin et al., 1999Cohen, 2000McIntyre et al., 2005) Our work has shown that the complex history of forest cover and its effects on littoral ecosystems can be understood in the context of 18th-20th Century human demography in the region (Alin et al., 2002; Cohen et al., 2005aCohen et al., 2005bMcKee et al., 2005Palacios-Fest et al., 2005aPalacios-Fest et al., 2005bO’Reilly et al., 2005Dettman et al., 2005Cohen, 2017; Gravina et al., 2020).

We have also examined how 20th Century climate warming may be affecting lacustrine ecosystems and productivity in Lake Tanganyika, through enhanced lake stratification and weaker mixing of nutrients through the water column (O'Reilly et al., 2003; and O'Reilly et al., 2004; Tierney et al., 2010). and how sedimentation problems may be coupling with climate change to differentially impact different parts of the lake (Cohen, 2017). This research is also continuing through investigations of paleorecords to document how recent lake warming in Lake Tanganyika has impacted various trophic levels (Cohen et al, 2016; Kamulali et al., 2021).

A. Collecting multicores during the Lake Tanganyika Biodiversity
Project investigation of watershed deforestation.

B. The boundary between the forested watersheds of Gombe National Park,
along the shore of Lake Tanganyika and the deforested region immediately
north of the part. These areas formed part of our study of paleorecords
of deforestation history.