Yannick Garcin, Pierre Deschamps, Guillemette Menot, Geoffroy de Saulieu, Enno Schefuss, David Sebag, Lydie M. Dupont, Richard Oslisly, Brian Brademann, Kevin G. Mbusnum, Jean-Michel Onana, Andrew A. Ako, Laura Saskia Epp, Rik Tjallingii, Manfred Strecker, Achim Brauer, Dirk Sachse
- 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. delta C-13-inferred vegetation changes confirm a prominent and abrupt appearance of C-4 plants in the Lake Barombi catchment, at 2,600 calendar years before AD 1950 (cal y BP), followed by anA 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. delta C-13-inferred vegetation changes confirm a prominent and abrupt appearance of C-4 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. delta D 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.…
MetadatenAuthor details: | Yannick GarcinORCiD, Pierre DeschampsORCiD, Guillemette MenotORCiD, Geoffroy de Saulieu, Enno Schefuss, David Sebag, Lydie M. DupontORCiD, Richard Oslisly, Brian Brademann, Kevin G. Mbusnum, Jean-Michel Onana, Andrew A. Ako, Laura Saskia EppORCiDGND, Rik TjallingiiORCiDGND, Manfred StreckerORCiDGND, Achim BrauerORCiDGND, Dirk SachseORCiDGND |
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DOI: | https://doi.org/10.1073/pnas.1715336115 |
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ISSN: | 0027-8424 |
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Pubmed ID: | https://pubmed.ncbi.nlm.nih.gov/29483260 |
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Title of parent work (English): | Proceedings of the National Academy of Sciences of the United States of America |
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Publisher: | National Acad. of Sciences |
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Place of publishing: | Washington |
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Publication type: | Article |
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Language: | English |
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Date of first publication: | 2018/02/26 |
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Publication year: | 2018 |
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Release date: | 2022/01/03 |
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Tag: | Western Central Africa; human activity; late Holocene; paleohydrology; rainforest crisis |
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Volume: | 115 |
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Issue: | 13 |
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Number of pages: | 6 |
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First page: | 3261 |
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Last Page: | 3266 |
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Funding institution: | ISIS-888 Project; French National Research Institute for Sustainable Development (IRD), its local office in Yaounde; LMI DYCOFAC; Deutsche Forschungsgemeinschaft (DFG)German Research Foundation (DFG) [GA1629/2]; Ministry of Science, Research, and Culture des Landes Brandenburg; Labex OT-Med project; EQUIPEX ASTER-CEREGE project; DFG-Research Center/Cluster of Excellence "The Ocean in the Earth System" at MARUM-Center for Marine Environmental Sciences |
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Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Geowissenschaften |
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DDC classification: | 9 Geschichte und Geografie / 91 Geografie, Reisen / 911 Historische Geografie |
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Peer review: | Referiert |
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Institution name at the time of the publication: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Erd- und Umweltwissenschaften |
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Publishing method: | Open Access / Bronze Open-Access |
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