African vegetation controlled by tropical sea surface temperatures in the mid-Pleistocene period.
The dominant forcing factors for past large-scale changes in vegetation are widely debated. Changes in the distribution of C4 plants--adapted to warm, dry conditions and low atmospheric CO2 concentrations--have been attributed to marked changes in environmental conditions, but the relative impacts of changes in aridity, temperature and CO2 concentration are not well understood. Here, we present a record of African C4 plant abundance between 1.2 and 0.45 million years ago, derived from compound-specific carbon isotope analyses of wind-transported terrigenous plant waxes. We find that large-scale changes in African vegetation are linked closely to sea surface temperatures in the tropical Atlantic Ocean. We conclude that, in the mid-Pleistocene, changes in atmospheric moisture content--driven by tropical sea surface temperature changes and the strength of the African monsoon--controlled aridity on the African continent, and hence large-scale vegetation changes.
Schefuss
Enno
E
Royal Netherlands Institute for Sea Research (NIOZ), PO Box 59, 1790 AB Den Burg, The Netherlands. schefuss@uni-bremen.de
Schouten
Stefan
S
Jansen
J H Fred
JH
Sinninghe Damsté
Jaap S
JS
D000349:Africa; D000473:Alkanes / Q000032:analysis; D001272:Atmosphere; D002245:Carbon Dioxide / Q000378:metabolism; D004391:Dust; D007053:Ice; D009792:Oceans and Seas; D063245:Plant Development; D010944:Plants / Q000737:chemistry* / Q000378:metabolism; D011157:Population Dynamics; D011891:Rain; D012621:Seasons; D012623:Seawater; D013696:Temperature; D013997:Time Factors; D014329:Tropical Climate; D014885:Waxes / Q000032:analysis
D000473:Alkanes; D004391:Dust; D007053:Ice; D014885:Waxes; D002245:Carbon Dioxide