A Phytolith Supported Biosphere-Hydrosphere Predictive Model for Southern Ethiopia: Insights into Paleoenvironmental Changes and Human Landscape Preferences since the Last Glacial Maximum
Markus L. Fischer,
Felix Bachofer,
Chad L. Yost,
Ines J. E. Bludau,
Christian Schepers,
Verena Foerster,
Henry Lamb,
Frank Schäbitz,
Asfawossen Asrat,
Martin H. Trauth,
Annett Junginger
Affiliations
Markus L. Fischer
Department of Geosciences, Eberhard Karls University Tuebingen, Hoelderlinstr. 12, 72074 Tuebingen, Germany
Felix Bachofer
Observation Centre, German Aerospace Center (DLR), Muenchener Str. 29, 82234 Wessling, Germany
Chad L. Yost
Department of Earth and Environmental Systems, Indiana State University, Terre Haute, IN 47809, USA
Ines J. E. Bludau
Department of Geosciences, Eberhard Karls University Tuebingen, Hoelderlinstr. 12, 72074 Tuebingen, Germany
Christian Schepers
Institute of Prehistoric Archaeology, University of Cologne, 50931 Cologne, Germany
Verena Foerster
Institute of Geography Education, University of Cologne, 50931 Cologne, Germany
Henry Lamb
Department of Geography and Earth Sciences, Aberystwyth University, Aberystwyth SY23 3FL, UK
Frank Schäbitz
Institute of Geography Education, University of Cologne, 50931 Cologne, Germany
Asfawossen Asrat
Department of Mining and Geological Engineering, Botswana International University of Science and Technology, Private Bag 16, Palapye, Botswana
Martin H. Trauth
Institute of Geosciences, University of Potsdam, 14476 Potsdam, Germany
Annett Junginger
Department of Geosciences, Eberhard Karls University Tuebingen, Hoelderlinstr. 12, 72074 Tuebingen, Germany
During the past 25 ka, southern Ethiopia has undergone tremendous climatic changes, from dry and relatively cold during the Last Glacial Maximum (LGM, 25–18 ka) to the African Humid Period (AHP, 15–5 ka), and back to present-day dry conditions. As a contribution to better understand the effects of climate change on vegetation and lakes, we here present a new Predictive Vegetation Model that is linked with a Lake Balance Model and available vegetation-proxy records from southern Ethiopia including a new phytolith record from the Chew Bahir basin. We constructed a detailed paleo-landcover map of southern Ethiopia during the LGM, AHP (with and without influence of the Congo Air Boundary) and the modern-day potential natural landcover. Compared to today, we observe a 15–20% reduction in moisture availability during the LGM with widespread open landscapes and only few remaining forest refugia. We identify 25–40% increased moisture availability during the AHP with prevailing forests in the mid-altitudes and indications that modern anthropogenic landcover change has affected the water balance. In comparison with existing archaeological records, we find that human occupations tend to correspond with open landscapes during the late Pleistocene and Holocene in southern Ethiopia.
