Pollen Records of Past Climate Changes in West Africa since the Last Glacial Maximum

摘要: Environmental reconstruction since the Last Glacial Maximum in Northwestern Tropical Africa has been severely limited by incompleteness of record, owing primarily to major discontinuities lacustrine sediments preserved a predominantly arid climate. Only two long and complete pollen sequences, each from deep crater lakes, have obtained register whole deglacial Holocene history humid equatorial forest (Maley, 1989). Other continental sites, all closely subject local hydrogeological conditions (Lezine Casanova, 1989) provide detailed ‘windows’ on short periods Holocene. However, comparison with marine sedimentary sequences that continuous, well dated records over longer time spans allows one reconstruct changes past atmospheric patterns West vegetation distribution sub-continental as scales. I present here review data nearby Eastern Atlantic undertaken understand response climatic hydrological different Interpretations diagrams are based numerous studies both modern deposition Equatorial evergreen semi-deciduous forests south (Brenac, 1988; Elenga, 1992; Reynaud-Farrera, 1995) Sudanian, Sahelian Saharan driest ecosystems north Edorh, 1991; Lezine Hooghiemstra, 1990; Maley, 1972, 1981; Ritchie, 1987) (Fig. 14.1). Land-sea correlations also made.