High resolution palaeoenvironmental records in Far-Eastern Russia are rare, and the Kamchatka Peninsula is among the least studied areas of the region. This paper describes a record spanning the last ca. 11,000 yr, obtained from a bog in... more
High resolution palaeoenvironmental records in Far-Eastern Russia are rare, and the Kamchatka Peninsula is among the least studied areas of the region. This paper describes a record spanning the last ca. 11,000 yr, obtained from a bog in the southern part of Kamchatka. The radiocarbon dated core was analysed for pollen, testate amoebae, charcoal and loss-on-ignition (LOI). The vegetation during the early Holocene was dominated by grasses (Poaceae), birch (Betula) and heath (Ericaceae p. p.). Around 10,300 cal yr BP there was a substantial change in the vegetation cover to shrub alder (Alnus viridis s.I.) stands with sedges and ferns (Polypodiophyta) as well as herbs such as meadow rue (Thalictrum) in the understory. In the surroundings of Utka peatlands started to form. The variations in the vegetation cover were most probably caused by climatic changes. At the beginning of sediment accumulation, before 10,300 cal yr BP, the composition of the vegetation points to cooler summers and/or decreased annual precipitation. Around 10,300 cal yr BP, changes in vegetation occurred due to rising temperatures and/or changed water regimes. Increased abundancies of dry indicating testate amoebae after 9100 cal yr BP point to intermediate to dry soil conditions. Between 8600 and 7700 cal yr BP tree alder (Alnus incana) was widely spread at the site which probably indicates optimal environmental conditions. The tephra layer at 381-384.5 cm (ca. 8500 cal yr BP) produces a strong impact on the testate amoebae assemblages. At 7700 cal yr BP there was a sudden drop of A. incana in the local vegetation. From this time on, A. incana and also A. viridis decrease continuously whereas Betula gradually increases. The upper part of the sequence (after 6300 cal yr BP) shows higher abundancies of meadowsweet (Filipendula) and sweet gale (Myrica) pollen. After 6300 cal yr BP, changes in testate amoebae demonstrate variable soil moisture conditions at the site. Between 3700 and 1800 cal yr BP, wet conditions dominate as dry indicating testate amoebae decrease. After 1800 cal yr BP soil conditions become more variable again but this time with dry dominating testate amoebae. In contrast to surrounding regions, there is no evidence of trees such as spruce or larch growing in the surroundings of the site even though those trees are characteristic of many eastern Siberian sites. This difference might be because of the maritime influence of the Okhotsk Sea. Even dwarf pine (Pinus pumila), which is currently widely dispersed in northern Kamchatka, became part of the local vegetation only during the last 700 yr. Crown Copyright (C) 2015 Published by Elsevier B.V. All rights reserved. (Less)
Research Interests:
Research Interests:
Understanding the evolution of Arctic polar climate from the protracted warmth of the middle Pliocene into the earliest glacial cycles in the Northern Hemisphere has been hindered by the lack of continuous, highly resolved Arctic time... more
Understanding the evolution of Arctic polar climate from the protracted warmth of the middle Pliocene into the earliest glacial cycles in the Northern Hemisphere has been hindered by the lack of continuous, highly resolved Arctic time series. Evidence from Lake El'gygytgyn, NE Arctic Russia, shows that 3.6-3.4 million years ago, summer temperatures were ~8°C warmer than today when pCO2 was ~400 ppm. Multiproxy evidence suggests extreme warmth and polar amplification during the middle Pliocene, sudden stepped cooling events during the Pliocene-Pleistocene transition, and warmer than present Arctic summers until ~2.2 Ma, after the onset of Northern Hemispheric glaciation. Our data are consistent with sea-level records and other proxies indicating that Arctic cooling was insufficient to support large-scale ice sheets until the early Pleistocene
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests: Geology and Sediment Core
Research Interests:
Research Interests: Geology and Sediment Core
The reliability of Arctic climate predictions is currently hampered by insufficient knowledge of natural climate variability in the past. A sediment core from Lake El'gygytgyn (NE Russia) provides a continuous high-resolution record... more
The reliability of Arctic climate predictions is currently hampered by insufficient knowledge of natural climate variability in the past. A sediment core from Lake El'gygytgyn (NE Russia) provides a continuous high-resolution record from the Arctic spaning the past 2.8 Ma. The core reveals numerous "super interglacials" during the Quaternary, with maximum summer temperatures and annual precipitation during marine benthic isotope stages (MIS) 11c and 31 ~4-5 °C and ~300 mm higher than those of MIS 1 and 5e. Climate simulations show these extreme warm conditions are difficult to explain with greenhouse gas and astronomical forcing alone, implying the importance of amplifying feedbacks and far field influences. The timing of Arctic warming relative to West Antarctic Ice Sheet retreats implies strong interhemispheric climate connectivity
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests: Geology and Sediment Core
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests: Physical Geography, Geology, Pleistocene, Holocene, Pollen, and 4 moreTundra, Interglacial, Biome, and Taiga
Research Interests: Earth Sciences, Geology, Paleontology, Sedimentology, Structural Geology, and 11 moreQuaternary, Historical Geology, Permafrost, Late Pleistocene, Quaternary Science, Radiocarbon Dating, Magnetic Susceptibility, Marine Isotope Stage, Environmental Conditions, Total Organic Carbon, and Late Quaternary
Research Interests:
Research Interests: Physical Geography, Earth Sciences, Geology, Oceanography, Climate Change, and 15 morePermafrost, Seasonality, Arctic, Holocene, Quaternary Science, Stable Isotope, History and archaeology, Radiocarbon Dating, Late Holocene, Younger Dryas, Quaternary Science Reviews, Discrete Time Systems, Late Quaternary, Discrete time, and Preboreal
Research Interests: Earth Sciences, Geology, Oceanography, Electron Spin Resonance, Sea Ice, and 14 moreQuaternary, Arctic, Quaternary Science, History and archaeology, Arctic Ocean, Last Glacial Maximum, Marine Sediment, Quaternary Science Reviews, Elsevier, Ice Sheets, Water Depth, Ice Sheet, Late Quaternary, and Relative Sea Level
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Pollen data from a Levinson-Lessing Lake sediment core (74°28'N, 98°38'E) and Cape Sabler, Taymyr Lake permafrost sequences (74°33'N, 100°32'E) reveal substantial environmental changes on the northern Taymyr Peninsula... more
Pollen data from a Levinson-Lessing Lake sediment core (74°28'N, 98°38'E) and Cape Sabler, Taymyr Lake permafrost sequences (74°33'N, 100°32'E) reveal substantial environmental changes on the northern Taymyr Peninsula during the last c. 32 000 14C years. The continuous records confirm that a scarce steppe-like vegetation with Poaceae, Artemisia and Cyperaceae dominated c. 32 000-10 300 14C yr BP, while tundra-like vegetation with Oxyria, Ranunculaceae and Caryophyllaceae grew in wetter areas. The coldest interval occurred c. 18 000 yr BP. Lateglacial pollen data show several warming events followed by a climate deterioration c. 10 500 14C yr BP, which may correspond with the Younger Dryas. The Late Pleistocene/Holocene transition, c. 10 300-10 000 14C yr BP, is characterized by a change from the herb-dominated vegetation to shrubby tundra with Betula sect. Nanae and Salix. Alnus fruticosa arrived locally c. 9000-8500 14C yr BP and disappeared c. 4000-3500 14C yr BP. Communities of Betula sect. Nanae, broadly distributed at c. 10 000-3500 14C yr BP, almost disappeared when vegetation became similar to the modern herb tundra after 3500-3000 14C yr BP. Quantitative climate reconstructions show Last Glacial Maximum summer temperature about 4°C below the present and Preboreal (c. 10 000 14C yr BP) temperature 2-4°C above the present. Maximum summer temperature occurred between 10 000 and 5500 14C yr BP; later summers were similar to present or slightly warmer
Research Interests:
Research Interests:
Research Interests: Physical Geography, Geology, Geochemistry, Geophysics, Peat, and 7 moreHolocene, Sphagnum, Tundra, Polar, Boreas, Taiga, and Betula pubescens
Research Interests: Physical Geography, Earth Sciences, Geology, Oceanography, Quaternary, and 15 moreArctic, Holocene, Quaternary Science, Pollen, History and archaeology, Artemisia, Early Holocene, Quaternary Science Reviews, Environmental Conditions, Simulation Model, Late Quaternary, Shallow Water, Coastal Area, Model simulation, and Climatic condition
Research Interests: Geology, Oceanography, Climatology, China, Climate, and 15 moreEnvironmental Change, Monsoon, Climate Dynamics, Atmospheric sciences, Holocene, Pollen, Physical sciences, Last Glacial Maximum, Speleothem, Quantitative reconstructions, Tibetan Plateau, Precipitation, Intertropical Convergence Zone, Science Technology, and Northern China
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests: Geology and Sediment Core
Research Interests:
Research Interests: Geology and Sediment Core
Research Interests: Geology and Sediment Core
... by huge syngenetic ice wedges (Meyer et al., 2002b) and exposed over long distances along river banks of the Lena, Yana, Indigirka, and ... 72 Kienast, F., Wetterich, S., Kuzmina, S., Schirrmeister, L., Andreev, A., Tarasov, P.,... more
... by huge syngenetic ice wedges (Meyer et al., 2002b) and exposed over long distances along river banks of the Lena, Yana, Indigirka, and ... 72 Kienast, F., Wetterich, S., Kuzmina, S., Schirrmeister, L., Andreev, A., Tarasov, P., Nazarova, L., Kossler, A., Frolova, A., Kunitsky, VV, ...
Research Interests:
Research Interests:
Research Interests: Environmental Science, Geochemistry, Soil Chemistry, Nineteenth Century, Chemical and Biological Engineering, and 10 moreGlobal change, Land Use History, Atmospheric sciences, Forest soil nutrition, Land Use, Chemical Analysis, Global Biogeochemical Cycles, soil pH, Acid Deposition, and Interannual Variability
Research Interests:
Research Interests:
Research Interests:
Summary The ongoing spread of forest fires in the Siberian Arctic raises concerns on how far increasing temperatures and fire occurrence lead to biome shifts from tundra to summergreen or evergreen boreal forest. Here, we investigate... more
Summary The ongoing spread of forest fires in the Siberian Arctic raises concerns on how far increasing temperatures and fire occurrence lead to biome shifts from tundra to summergreen or evergreen boreal forest. Here, we investigate vegetation and fire regime shifts during late MIS 12 and MIS 11 c. 390–430 kyrs ago using sedimentary charcoal, anhydrosugars and pollen from Lake El'gygytgyn, NE Siberia. We find different types of centennial-to-millennial-scale biome shifts, partly accompanied by fire regime shifts. We assess the role of fire in driving and/or responding to biome changes, especially periods of abrupt warming, to gain understanding of what we can expect during the ongoing warming of the high-northern latitudes.