2002 ARCSS All-Hands Workshop

Carbon Stocks in an Age-Series of Drained Thaw Lakes in Arctic Alaska

Xiaoyan Dai¹, Jim Bockheim², Wendy R. Eisner^3
1Soil Science, University of Wisconsin-Madison, 1525 Observatory Drive, Madison, WI, 53706, USA, Phone (608)262-8295, Fax (608)265-2595, xiaoyandai@facstaff.wisc.edu
²Soil Science, University of Wisconsin-Madison, 1525 Observaroty Drive, Madison, WI, 53706, USA, Phone (608)263-5903, Fax (608)265-2595, bockheim@facstaff.wisc.edu
³Department of Geography, University of Cincinnati, Department of Geography, University of Cincinnati, Cincinnati, OH 45221, Cincinnati, OH, 45221, USA, eisnerwr@ucmail.uc.edu

Replicate cores were taken to an average depth of 124 cm from 12 drained thaw-lake basins representing four age classes (young, medium, old and ancient) near Barrow, Alaska. Based on radiocarbon dating, the basins range from <100 to >4,000 yr BP. The cores were sectioned into decimeter intervals, and the bulk density and field moisture content were determined. Soil organic carbon (SOC) was measured on a Dohrmann DC-190 carbon analyzer and SOC stocks were estimated for the surface organic layer, the seasonal thaw layer (ca. 0-35 cm), the near-surface permafrost (35-100 cm), and the upper 1 m. The thickness of the surface organic layer, the degree of decomposition of SOC, and the organic C pool in the surface organic layer all increase with basin age. However, the organic C pools in the seasonal thaw layer, the near-surface permafrost, and the upper 1 m layer are unrelated to basin age because of high within-basin variability in C pools.

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