|Author(s)||Dalibard Mathieu1, Popescu Speranta-Maria1, Maley Jean2, Baudin Francois3, 4, Melinte-Dobrinescu Mihaela-Carmen5, Pittet Bernard6, Marsset Tania7, Dennielou Bernard7, Droz Laurence8, Suc Jean-Pierre3, 4|
|Affiliation(s)||1 : GeoBioStratData Consulting, F-69140 Rillieux La Pape, France.
2 : Univ Montpellier 2, Dept Paleoenvironm & Paleoclimatol, ISEM, CNRS, F-34095 Montpellier 05, France.
3 : Univ Paris 06, Univ Sorbonne, Inst Sci Terre Paris iSTeP, CNRS,UMR 7193, F-75005 Paris, France.
4 : CNRS, Inst Sci Terre Paris iSTeP, UMR 7193, F-75005 Paris, France.
5 : GeoEcoMar, Bucharest 024053, Romania.
6 : Univ Lyon 1, CNRS, Lab Geol Lyon Terre, UMR 5276, F-69622 Villeurbanne, France.
7 : IFREMER, Dept Geosci Marines, F-29280 Plouzane, France.
8 : IUEM, CNRS, Domaines Ocean, UMR 6538, F-29280 Plouzane, France.
|Source||Geobios (0016-6995) (Elsevier France-editions Scientifiques Medicales Elsevier), 2014-07 , Vol. 47 , N. 4 , P. 183-198|
|WOS© Times Cited||18|
|Note||This paper is a contribution to the REPREZAI Project (IFREMER/IUEM).|
|Keyword(s)||Central Africa, Climate, Environmental parameters, Late Pleistocene, Pollen, Vegetation dynamics|
|Abstract||The essential characteristics of the vegetation dynamics of tropical Africa remain only partially known. This study assesses the succession of vegetation-types over Central Africa during the last two glacial/interglacial cycles. Analysis of core KZai 02, which contains pollen from the Zaire River watershed (latitudes 9°N-13°S), allows the investigation of long-term patterns of plant ecosystem development and their climatic causes. Core KZai 02 (18.20 m long) was recovered from 6°24.20′S/9°54.10′E in the uppermost axial edifice of the Zaire deep sea fan. The chronology of this sedimentary archive was established using nannofossils and correlations of pollen and total organic carbon signals with the nearby core GeoB1008. The pollen record indicates that: (i) glacials (MIS 6, 4, 2) are marked by the development of afromontane (Podocarpus) forest at high altitudes when central basin lowlands were occupied by Cyperaceae marshes and savannah; (ii) during interglacials (MIS 1, 5) lowland forests were developed, marked by the successive expansion of pioneer, warm-temperate, rain forests, and mangrove indicating sea-level rise; (iii) glacial-interglacial transitions (MIS 6/5, 2/1) display similar vegetation dynamics. The strong evidence of afromontane forest and the opening of the vegetation during glacials suggest a reduced latitudinal distribution of rainfall by the strengthening of the trade wind system. West African monsoon systems were enhanced during interglacials, allowing the progressive development of lowland forests. The development of rain and pioneer forests during glacial Heinrich stadials suggests an enhancement of water availability in tropical Africa associated with these high latitude events. However, no augmentation of wind activity, described by previous studies, is evidenced by our pollen record. Similar vegetation successions during glacial/interglacial transitions suggest the diachronous and stepped intervention of CO2 (emphasizing the influence of temperature on plant ecosystems) and water availability.|
Dalibard Mathieu, Popescu Speranta-Maria, Maley Jean, Baudin Francois, Melinte-Dobrinescu Mihaela-Carmen, Pittet Bernard, Marsset Tania, Dennielou Bernard, Droz Laurence, Suc Jean-Pierre (2014). High-resolution vegetation history of West Africa during the last 145 ka. Geobios, 47(4), 183-198. Publisher's official version : https://doi.org/10.1016/j.geobios.2014.06.002 , Open Access version : https://archimer.ifremer.fr/doc/00199/31031/