The end of the Pleistocene tundra steppe - interactions between vegetation, climate and large herbivores in Beringia during the late Quaternary (TUNDRA-STEPPE)

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The proposed research project intends to reveal the ecological interactions of climate, vegetation and large herbivores in the Arctic during the late Quaternary following an uniformitarianistic approach by combining palaeobotanical results with studies of modern plant communities in Yakutia, Russian Federation, the western part of the former subcontinent Beringia. The results are expected to give insights into structure and functioning of arctic biogeocenoses during the Pleistocene and will contribute to the understanding of their restructuring and massive depauperation in the course of the transition to the Holocene. Grazing effects on vegetation will be studied in the frame of the existent Pleistocene Park grazing experiment, which is conducted by the cooperative Northeast Science Station Cherskii to reconstitute a mammoth steppe like ecosystem experimentally at the lower course of the Kolyma River. The results of the Pleistocene Park experiment will be compared on the one hand with unaffected vegetation along the main, climatically controlled gradient from boreal forests to tundra and to relict steppe vegetation more inland in Yakutia as well as on the other hand with reconstructed Late Pleistocene palaeovegetation recorded in syngenetic permafrost deposits. Macroscopic plant remains are preserved in excellent condition in the permafrost section Duvanny Yar in close proximity to the Pleistocene Park experiment and will be used to reconstruct structure, composition and dynamics of the late Quaternary vegetation in NE-Siberia. Special focus will be devoted to the transition from the late glacial to the Holocene when mammoth fauna declined and the ecosystem restructuring in Northeast Siberia culminated. Interesting findings are also expected from the comparison of palaeovegetation during the last two interglacials: the Eemian (Kazantsevo), when vegetation was affected by megaherbivore grazing and the Holocene, when grazing held off. By combining both approaches, we will identify the relative proportions of climate and grazing as potential main drivers determining the characteristics of extant and Pleistocene vegetation in western Beringia.