A 1.2 million year record of ecosystem evolution from Lake Malawi, Africa’s most biodiverse lake

Andy Cohen Lake

Long records of Quaternary ecological and climatic change are critical to understanding the range of potential responses of ecosystems to environmental forcing. In Africa, where complex and ancient tropical ecosystems are important parts of the landscape such records are still relatively rare. In this talk I will present an integrated lake and watershed paleoecological analysis from drill core records obtained by the Lake Malawi Drilling Project, documenting extraordinary fluctuations in climate, hydrology and ecosystem response for the southern tropics of Africa. High resolution lacustrine and terrestrial paleoecology and sedimentology data sets from these Early Pleistocene-Holocene drill cores provide the most complete record of this duration currently available from Africa.

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Time series analyses of these records demonstrate the important role that insolation, and especially ~400ka eccentricity modulated precessional cyles Malawi ecosystems. We observe shifts between more arid conditions (shallow alkaline and well mixed lake, with discontinuous desert vegetation) and more humid environments (deep, stratified, freshwater lake with dense forest). These broadly synchronous changes in lake paleoecology, lake sedimentology, and watershed vegetation demonstrate the major role of climate in regulating this system. Transitions between these lake/watershed state extremes is often very abrupt, suggesting that the combined lake/watershed repeatedly passed through hydroclimate thresholds, with important implications for the evolution of the lake’s endemic biodiversity and ecosystem. Lake Malawi also appears to have undergone a major state change after 800-700ka with an adjustement in base level of hundreds of meters that appears to reflect a change in outlet position driven by tectonics. All of these cyclic and non-cyclic changes provide an environmental template against which we can much better understand the adaptive radiation of cichlid fishes which has occurred in the lake, one of the most biodiverse lakes on earth.

 

Prof. Andrew Cohen (University of Arizona)

My research area is paleolimnology, the interpretation of lake history from sedimentary and paleontological records. Most of my work to date has involved studies of depositional environments, paleoecology, and climate history of the African Rift Lakes and the arid climate lakes of the western US. I use paleoecological and sedimentological records as primary tools in the interpretation of lake deposits, from both outcrops and sediment cores.

Event Information:

Date, Time:04/07/2016, 14:00 h – 15:00 h

Location: Room S12, Seminargebäude (Building 106), Universitätsstraße 37 , Cologne

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Geoarchaeology in the Desert: Unique Cave Sediments, Landscape Evolution and Palaeoenvironment at Sodmein Cave, Egypt

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 Before I started my PhD, I did my bachelor in Geography and the master study course “Quaternary Science & Geoarchaeology”, both at the University of Cologne. I already wrote my bachelor-thesis in the C1-project and during my master, I changed to the A1-project. My master-thesis was about first micromorphological investigations at Sodmein Cave in Egypt.

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Beyond out of Africa: the North African Middle Stone Age as a window into human origins

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EScerri

Dr. Eleanor Scerri British Academy Postdoctoral Fellow, University of Oxford

Hypotheses invoking fossil and archaeological data from the North African Middle Stone Age (MSA) include a gradual, multiregional origin of our species within Africa, an intricate history of within and out of Africa dispersals and the demographically induced origins of complex culture (d’Errico et al., 2009; Gunz et al., 2012; Scally and Durbin, 2012; Harvati and Hublin, 2013; Scerri et al., 2014a, 2014b). However, the North African MSA itself remains poorly understood, despite the implications of these hypotheses.

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Modelling African Quaternary Climate and Vegetation Change

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Prof. Martin Claussen
Max-Planck Institute for Meteorology, University of Hamburg, KlimaCampus Hamburg

Pronounced changes in African climate, deserts and tropical rain forest over the last glacial cycles presumably affected human’s way out of Africa. These changes were induced by large changes in ice masses, ocean circulation and monsoon dynamics which, in turn, were triggered by variations in the Earth orbit around the sun and subsequent alteration of meridional insolation gradients.

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IRTG Alumni Doerte Weig dances her PhD!

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Dance your phd

Running for the 6th consecutive year, “Dance your Ph.D.” is a Science sponsored contest that challenges scientists to present the outcome of their doctoral research by means of dancing. In other words, contestants are urged to use their bodies “to convey the essence of scientific research”.

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Schistosomiasis – a health risk for travelers

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Dr. med. Burkhard Rieke Facharzt für Innere Medizin, Tropenmedizin

Dr. med. Burkhard Rieke
Facharzt für Innere Medizin, Tropenmedizin

In the first CRC Lecture of the winter term 2013/14, Dr. med. Burkhard Rieke will speak about schistosomiasis (Bilharzia), a parasitic disease commonly found in Africa. Freshwater snails are the vectors (intermediary agents) of the parasitic trematodes (Schistosoma sp.), which can infect humans exposed to contaminated water. Several CRC projects are running in Africa and their project members are often exposed to water that might be contaminated by infected freshwater snails.

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