Climate-Driven Ecosystem Succession in the Sahara: The Past 6000 Years
Abstract
Desiccation of the Sahara since the middle Holocene has eradicated all but a few natural
archives recording its transition from a “green Sahara” to the present hyperarid desert. Our
continuous 6000-year paleoenvironmental reconstruction from northern Chad shows progressive
drying of the regional terrestrial ecosystem in response to weakening insolation forcing of the
African monsoon and abrupt hydrological change in the local aquatic ecosystem controlled
by site-specific thresholds. Strong reductions in tropical trees and then Sahelian grassland
cover allowed large-scale dust mobilization from 4300 calendar years before the present
(cal yr B.P.). Today’s desert ecosystem and regional wind regime were established
around 2700 cal yr B.P. This gradual rather than abrupt termination of the African Humid
Period in the eastern Sahara suggests a relatively weak biogeophysical feedback on climate.
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Bibliography
Kröpelin S., Verschuren D., Lézine A.-M., Eggermont H., Cocquyt C., Francus P., Cazet J.-P., Fagot M., Rumes B., Russell J. M., Darius F., Conley D. J., Schuster M., Suchodoletz H. v., Engstrom D. R. (2008): Climate-Driven Ecosystem Succession in the Sahara: The Past 6000 Years. In: Science 320: 765-768
| author | Stefan Kröpelin and Dirk Verschuren and Anne-Marie Lézine and Hilde Eggermont and Christine Cocquyt and Pierre Francus and Jean-Pierre Cazet and Maureen Fagot and Bob Rumes and James M. Russell and Frank Darius and Daniel Conley and Mathieu Schuster and Hans von Suchodoletz and Daniel R. Engstrom |
|---|---|
| citation | Kröpelin S., Verschuren D., Lézine A.-M., Eggermont H., Cocquyt C., Francus P., Cazet J.-P., Fagot M., Rumes B., Russell J. M., Darius F., Conley D. J., Schuster M., Suchodoletz H. v., Engstrom D. R. (2008): Climate-Driven Ecosystem Succession in the Sahara: The Past 6000 Years. In: Science 320: 765-768 |
| doi | 10.1126/science.1154913 |
| journal | Science |
| key | 2008 |
| pages | 765-768 |
| type | article |
| volume | 320 |
| year | 2008 |