Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10501269 | Quaternary Research | 2005 | 12 Pages |
Abstract
Pollen data from core KW31 recovered off the mouth of the Niger River (3°31â²1N-05°34ʺ1E; 1181 m water depth) provide an exceptional record of vegetation changes in the West African lowlands between 40,000 and 3500 cal yr B.P. The highly diverse microflora testify for the permanency of rain and secondary forests in the Niger river catchment, at least as gallery formations along rivers, during the last glacial period when dry conditions occurred in relation to enhanced trade-wind circulation. The direct consequence of the post-glacial warming and the correlative increase in monsoon fluxes over West Africa was the increase in forest diversity and the expansion of rain and secondary forests on the nearby continent. Comparison between KW31 pollen record and continental pollen data from 5°S to 25°N allows the evaluation of migration rates of tropical forest populations throughout North West Africa at the beginning of the Holocene and the vegetation response to the shift toward aridity recorded widely at the end of the African Humid Period around 4000 cal yr B.P.
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Geology
Authors
Anne-Marie Lezine, Jean-Pierre Cazet,