Garcin Y. auteur aut IRD Deschamps Pierre auteur aut IRD Ménot G. auteur aut IRD Saulieu Geoffroy de auteur aut IRD Schefuss E. auteur aut IRD Sebag David auteur aut IRD Dupont L.M. auteur aut IRD Oslisly Richard auteur aut IRD Brademann B. auteur aut IRD Mbusnum K.G. auteur aut IRD Onama J.M. auteur aut IRD Ako A.A. auteur aut IRD Epp L.S. auteur aut IRD Tjallingii R. auteur aut IRD Strecker M.R. auteur aut IRD Brauer A. auteur aut IRD Sachse D. auteur aut IRD text journalArticle eng text/pdf born digital access 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. specialized PALEOENVIRONNEMENT PALEOCLIMAT HOLOCENE FORET MOSAIQUE FORET SAVANE FACTEUR ANTHROPIQUE HYDROLOGIE LAC HISTOIRE DU PEUPLEMENT CAMEROUN SUD OUEST ZONE TROPICALE 112ARCHEO02 021ENVECO 021CLIMAT01 115 13 3261-3266 2018 0027-8424 https://www.documentation.ird.fr/hor/fdi:010072522 10.1073/pnas.1715336115 0027-8424 [F B010072522] https://www.documentation.ird.fr/hor/fdi:010072522 https://www.documentation.ird.fr/intranet/publi/depot/2018-04-16/010072522.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2018-04-13 2025-11-04 fdi:010072522 fre