Garcin Y., Deschamps Pierre, Ménot G., Saulieu Geoffroy de, Schefuss E., Sebag David, Dupont L.M., Oslisly Richard, Brademann B., Mbusnum K.G., Onama J.M., Ako A.A., Epp L.S., Tjallingii R., Strecker M.R., Brauer A., Sachse D. (2018). Early anthropogenic impact on western central African rainfrorests 2,600 y ago. Proceedings of the National Academy of Sciences of the United States, 115 (13), p. 3261-3266. ISSN 0027-8424.
Titre du document
Early anthropogenic impact on western central African rainfrorests 2,600 y ago
Année de publication
2018
Auteurs
Garcin Y., Deschamps Pierre, Ménot G., Saulieu Geoffroy de, Schefuss E., Sebag David, Dupont L.M., Oslisly Richard, Brademann B., Mbusnum K.G., Onama J.M., Ako A.A., Epp L.S., Tjallingii R., Strecker M.R., Brauer A., Sachse D.
Source
Proceedings of the National Academy of Sciences of the United States, 2018,
115 (13), p. 3261-3266 ISSN 0027-8424
A potential human footprint on Western Central African rainforests before the Common Era has become the focus of an ongoing controversy. Between 3,000 y ago and 2,000 y ago, regional pollen sequences indicate a replacement of mature rainforests by a forest–savannah mosaic including pioneer trees. Although some studies suggested an anthropogenic influence on this forest fragmentation, current interpretations based on pollen data attribute the "rainforest crisis" to climate change toward a drier, more seasonal climate. A rigorous test of this hypothesis, however, requires climate proxies independent of vegetation changes. Here we resolve this controversy through a continuous 10,500-y record of both vegetation and hydrological changes from Lake Barombi in Southwest Cameroon based on changes in carbon and hydrogen isotope compositions of plant waxes. δ13C-inferred vegetation changes confirm a prominent and abrupt appearance of C4 plants in the Lake Barombi catchment, at 2,600 calendar years before AD 1950 (cal y BP), followed by an equally sudden return to rainforest vegetation at 2,020 cal y BP. δD values from the same plant wax compounds, however, show no simultaneous hydrological change. Based on the combination of these data with a comprehensive regional archaeological database we provide evidence that humans triggered the rainforest fragmentation 2,600 y ago. Our findings suggest that technological developments, including agricultural practices and iron metallurgy, possibly related to the large-scale Bantu expansion, significantly impacted the ecosystems before the Common Era.
Plan de classement
Analyse, évolution des climats [021CLIMAT01]
;
Environnement, écologie générale [021ENVECO]
;
Etudes régionales [112ARCHEO02]
Descripteurs
PALEOENVIRONNEMENT ; PALEOCLIMAT ; HOLOCENE ; FORET ; MOSAIQUE FORET SAVANE ; FACTEUR ANTHROPIQUE ; HYDROLOGIE ; LAC ; HISTOIRE DU PEUPLEMENT
Description Géographique
CAMEROUN SUD OUEST ; ZONE TROPICALE
Localisation
Fonds IRD [F B010072522]
Identifiant IRD
fdi:010072522
