Impact of climate change on the ecology of the Kyambangunguru crater marsh in southwestern Tanzania during the Late Holocene

QUATERNARY SCIENCE REVIEWS

卷:196

Article

Coffinet, Sarah^1,12,13  Huguet, Arnaud¹  Bergonzini, Laurent²  Pedentchouk, Nikolai^3,11  Williamson, David⁴  Anquetil, Christelle¹  Galka, Mariusz⁵  Kolaczek, Piotr⁵  Karpinska-Kolaczek, Monika^5,6,7  Majule, Amos⁸  Laggoun-Defarge, Fatima⁹  Wagner, Thomas¹⁰  Derenne, Sylvie¹ 

[1] Sorbonne Univ, CNRS, EPHE, PSL,UMR METIS, Campus Pierre & Marie Curie,4 Pl Jussieu, F-75252 Paris 05, France

[2] Univ Paris Saclay, UPS Univ Paris 11, CNRS, UMR GEOPS, Rue Belvedere,Bat 504, F-91405 Orsay, France

[3] Univ East Anglia, Sch Environm Sci, Norwich Res Pk, Norwich NR4 7TJ, Norfolk, England

[4] Sorbonne Univ, Inst Rech Dev, MNHN, CNRS,UMR LOCEAN,Ctr IRD France Nord, F-93143 Bondy, France

[5] Adam Mickiewicz Univ, Fac Geog & Geol Sci, Dept Biogeog & Paleoecol, Krygowskiego 10, PL-61680 Poznan, Poland

[6] Adam Mickiewicz Univ, Fac Geog & Geol Sci, Lab Wetland Ecol & Monitoring, Krygowskiego 10, PL-61680 Poznan, Poland

[7] Univ Bialystok, Ctr Study Demog & Econ Struct Preind Cent & Easte, Plac Uniwersytecki 1, PL-15420 Bialystok, Poland

[8] Univ Dar Es Salaam, Inst Resource Assessment, POB 35097, Dar Es Salaam, Tanzania

[9] Univ Orleans, CNRS, BRGM, UMR ISTO, 1A Rue Ferollerie, F-45071 Orleans, France

[10] Heriot Watt Univ, Lyell Ctr Earth & Marine Sci & Technol, Sch Energy Geosci Infrastruct & Soc EGIS, Edinburgh EH14 4AS, Midlothian, Scotland

[11] Russian Acad Sci, Inst Plant Physiol, Moscow 127276, Russia

[12] Univ Bremen, MARUM Ctr Marine Environm Sci, Organ Geochem Grp, Leobener St 8, Bremen, Germany

[13] Univ Bremen, Dept Geosci, Leobener St 8, Bremen, Germany

关键词: Holocene;    Paleoclimatology;    Paleolimnology;    East Africa;    Continental biomarkers;    Organic geochemistry;    Stable isotopes;    Palynology;   

DOI  :  10.1016/j.quascirev.2018.07.038

来源: Elsevier

【 摘 要 】

Instrumental records of temperature and hydrological regimes in East Africa evidence frequent droughts with dramatic effects on population and ecosystems. Sources of these climatic variations remain largely unconstrained, partly because of a paucity of Late Holocene records. Here, we present a multi-proxy analysis of a 4-m continuous sediment core collected in the Kyambangunguru crater marsh, in southwest Tanzania, covering the last 4000 yrs (cal. BP). We used microscopic (macro-remains, microfossils, palynofacies, pollen), elemental (carbon, nitrogen contents), molecular (br GDGTs, n-alkanes) and compound-specific isotopic (delta H-2 n-alkanes) investigations to reconstruct the environmental history of the marsh. The multi proxy record reveals that, 2500 years ago, the marsh underwent a major ecological transition from a lake to a peatland. Temperature and hydrological reconstructions evidence warmer and drier conditions between 2200 and 860 cal. BP, which probably triggered the establishment of a perennial peatland. This study is one of the first combined temperature and precipitation record of Late Holocene in the region and highlights changes in the spatial distribution of the East African climate regimes. Several cold periods are observed, between 3300 and 2000 cal. BP and since 630 cal. BP, the latter corresponding to the Little Ice Age. Moreover, wetter conditions are reported during the Medieval Climate Anomaly in contrast to other north-eastern African records suggesting that Tanzania is located at the transition between two hydro-climatic zones (north-eastern versus southern Africa) and has experienced variable contributions of these two zones over the last millennium. (C) 2018 Elsevier Ltd. All rights reserved.

【 授权许可】

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