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Clim. Past Discuss., 8, 1409-1441, 2012
www.clim-past-discuss.net/8/1409/2012/ doi:10.5194/cpd-8-1409-2012 © Author(s) 2012. This work is distributed under the Creative Commons Attribution 3.0 License. |
Vegetation history of Central Chukotka deduced from permafrost paleoenvironmental records of the El'gygytgyn Impact Crater
1Institute of Geology and Mineralogy, University of Cologne, Zülpicher St. 49a, 50674, Cologne, Germany
2Arctic and Antarctic Research Institute, Bering St. 38, St. Petersburg, 199397 Russia
3Alfred Wegener Institute for Polar and Marine Research, Department of Periglacial Research, Telegrafenberg A43, 14473 Potsdam, Germany
4Faculty of Soil Science, Moscow State University, Vorobievy Gory, 119899 Moscow, Russia
5Senckenberg, Research Institute and Natural History Museum, Research Station for Quaternary Paleontology, am Jakobskirchhof 4, 99423 Weimar, Germany
Abstract. Frozen sediments from three cores bored in permafrost surrounding of the El'gygytgyn Impact Crater Lake have been studied for pollen, non-pollen palynomorphs, plant macrofossils, and rhizopods. The palynological study of the cores contributes to a higher resolution of time intervals presented in a poor temporal resolution in the lacustrine sediments; namely the Allerød and succeeding periods. Moreover, permafrost records better reflect local environmental changes, thus, allowing more reliable reconstruction of the local paleoenvironments. The new data confirm that shrub tundra with dwarf birch, shrub alder and willow dominated in the lake surroundings during the Allerød warming. Younger Dryas pollen assemblages reflect abrupt changes to grass-sedge-herb dominated environments reflecting significant climate deterioration. Low shrub tundra with dwarf birch and willow dominate the lake vicinity at the onset of the Holocene. The founds of larch seeds indicate its local presence around 11 000 cal. yr BP and, thus a northward shift of treeline by about 100 km during the early Holocene thermal optimum. Forest tundra with larch and shrub alder stands grew in the area during the early Holocene. After ca. 3500 cal. yr BP similar-to-modern plant communities became common in the lake vicinity.
Citation: Andreev, A. A., Morozova, E., Fedorov, G., Schirrmeister, L., Bobrov, A. A., Kienast, F., and Schwamborn, G.: Vegetation history of Central Chukotka deduced from permafrost paleoenvironmental records of the El'gygytgyn Impact Crater, Clim. Past Discuss., 8, 1409-1441, doi:10.5194/cpd-8-1409-2012, 2012.