Document Detail

Climate-driven ecosystem succession in the Sahara: the past 6000 years.
MedLine Citation:
PMID:  18467583     Owner:  NLM     Status:  MEDLINE    
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.
S Kröpelin; D Verschuren; A-M Lézine; H Eggermont; C Cocquyt; P Francus; J-P Cazet; M Fagot; B Rumes; J M Russell; F Darius; D J Conley; M Schuster; H von Suchodoletz; D R Engstrom
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Publication Detail:
Type:  Historical Article; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Science (New York, N.Y.)     Volume:  320     ISSN:  1095-9203     ISO Abbreviation:  Science     Publication Date:  2008 May 
Date Detail:
Created Date:  2008-05-09     Completed Date:  2008-05-23     Revised Date:  2008-12-11    
Medline Journal Info:
Nlm Unique ID:  0404511     Medline TA:  Science     Country:  United States    
Other Details:
Languages:  eng     Pagination:  765-8     Citation Subset:  IM    
Africa Research Unit, Institute of Prehistoric Archaeology, University of Cologne, Jennerstrasse 8, D-50823 Köln, Germany.
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MeSH Terms
Desert Climate*
Fresh Water
Geologic Sediments
History, Ancient
Comment In:
Science. 2008 Nov 28;322(5906):1326; author reply 1326   [PMID:  19039121 ]
Science. 2008 May 9;320(5877):752-3   [PMID:  18467577 ]

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