Climate-driven ecosystem succession in the Sahara:: The past 6000 years

被引:445
作者
Kroepelin, S. [1 ]
Verschuren, D. [2 ]
Lezine, A. -M. [3 ]
Eggermont, H. [2 ]
Cocquyt, C. [2 ,4 ]
Francus, P. [5 ,6 ]
Cazet, J. -P. [3 ]
Fagot, M. [2 ]
Rumes, B. [2 ]
Russell, J. M. [7 ]
Darius, F. [1 ]
Conley, D. J. [8 ]
Schuster, M. [9 ]
von Suchodoletz, H. [10 ,11 ]
Engstrom, D. R. [12 ]
机构
[1] Univ Cologne, Africa Res Unit, Inst Prehist Archaeol, D-50823 Cologne, Germany
[2] Univ Ghent, Limnol Unit, Dept Biol, B-9000 Ghent, Belgium
[3] CNRS CEA UVSQ, Lab Sci Climat & Environm, UMR 1572, F-91191 Gif Sur Yvette, France
[4] Natl Bot Garden Belgium, B-1860 Meise, Belgium
[5] Ctr Eau Terre & Environm, Inst Natl Rech Sci, Quebec City, PQ G1K 9A9, Canada
[6] Univ Quebec, Geotop, Geochem & Geodynam Res Ctr, Montreal, PQ H3C 3P8, Canada
[7] Brown Univ, Providence, RI 02912 USA
[8] Lund Univ, Geobiosphere Ctr, Dept Geol, SE-22362 Lund, Sweden
[9] Univ Poitiers, Inst Int Paleoprimatol Paleontol Humaine Evolut &, CNRS, UMR 6046, F-86022 Poitiers, France
[10] Geoforschungszentrum Potsdam, D-14473 Potsdam, Germany
[11] Univ Bayreuth, Lehrstuhl Geomorphol, D-95440 Bayreuth, Germany
[12] Sci Museum Minnesota, St Croix Watershed Res Stn, Marine St Croix, MN 55047 USA
关键词
D O I
10.1126/science.1154913
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
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.
引用
收藏
页码:765 / 768
页数:4
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