Holocene vegetation and hydroclimate changes in the Kansk forest steppe, Yenisei River Basin, East Siberia

Our study focuses on the Holocene hydroclimate long-term trends in southern East Siberia and places them in the context of the adjacent areas of the Siberian taiga in the north and the arid central Asia in the south. We present a new record from the eutrophic mire, in the forest-steppe region, covering the last 9000 years. Our multi-proxy approach includes physiochemical (ash content, grain size, micro-charcoal, peat decomposition) and biological indicators (pollen, non-pollen palynomorphs, plant macrofossils, testate amoebae, molluscs). The record indicates increased humidity during the Holocene Thermal Maximum at 8150-7400 cal. a BP, and drier conditions with evidence for fires at 7400-5100 cal. a BP. Next, wetter conditions occurred at the coring site at 5100-1400 cal. a BP based on evidence of fluvial influence, which is consistent with other records in the wider region. A short-term dry episode occurred at 1400-1300 cal. a BP, followed by a wet Medieval Warm Period (1300-650 cal. a BP) and Little Ice Age (450-300 cal. a BP) and a moderately wet environment from 300 cal. a BP to the present day. These results are consistent with the previously published palaeoenvironmental reconstructions from the steppe and forest-steppe regions in the south of East and West Siberia and taken together reveal a common trend towards wetter conditions with a maximum wetness between 4500 and 3000 cal. a BP. This differs from the taiga region further north and from the Altai-Sayan Mountains and Kazakhstan Hills further south, which show the trend from dry to wet and then to drier conditions in the Holocene, and from the Trans-Baikal region where the Holocene trend is to drier conditions. This study supports the predominant influence of the North Atlantic on the regional palaeoclimate changes in the forest-steppe region of East Siberia during the Holocene.