T62 Mire Ecosystems in West Siberia in the Holocene and the Global Carbon Cycle (Posters)
HOLOCENE CARBON ACCUMULATION AND HIGH-RESOLUTION DECOMPOSITION PROXY RECORDS FROM PEATLANDS OF WESTERN SIBERIA, RUSSIA
Paper number: T62-7
Program: Technical Sessions
Time: 1:30 PM – 4:30 PM
Authors
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Glen M. MacDonaldUniversity of Utah, Salt Lake City, UT
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Lawrence C. SmithUniv of California, Los Angeles, Los Angeles, CA
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Costya KrememetskiUniv of California, Los Angeles, Los Angeles, CA
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Karen E. FreyUniv of California, Los Angeles, Los Angeles, CA
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Olga BorisovaRussian Academy of Sciences, Moscow, N/A
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Andrei VelichkoInstitute of Geography, Russian Academy of Sciences, Moscow, N/A
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Yongwei ShengUCLA, Los Angeles, CA
Abstract
Peatland initiation and carbon (C) accumulation began throughout the Western Siberian Lowland (WSL) between 9 - 11k cal yr BP. Long-term apparent rates of C accumulation (LARCA) based on peat basal dates, depths, and densities from 75 cores averages 17.7
±± S.E.), but varies from 4.6 - 104.9 g C m-2 yr-1, and shows little relationship with latitude or peatland type. To investigate C accumulation over the Holocene, size-fraction records sampled at 2-cm resolution were developed for five cores that span the peatland distribution of the WSL. Core chronologies based on multiple radiocarbon dates per core show diferent LARCA patterns between cores. The fine organic debris fraction of the peat (material <100m m), mainly the product of incomplete plant litter decomposition, typically fluctuated between 5 - 50% of total peat mass. Periods of low debris generally correspond to periods of high LARCA. Millennium-scale departures from an overall trend of increasing fine debris with depth were evident. Paleoecological core analyses to determine autogenic and local disturbance effects on C accumulation are ongoing, but some temporal synchrony in fine-fraction records suggests at least partial regional climatic control over decomposition-mediated carbon accumulation.