Systematic analysis of terrestrial carbon stocks in a small catchment of the Kolyma watershed

• Main Author: Heard, Kathryn E.
• Format: Text
• Language: unknown
• Published: Western Washington University 2014
• Subjects: Arctic; Kolyma; kolyma river; Siberia
• Online Access: https://dx.doi.org/10.25710/nahj-nw20; https://cedar.wwu.edu/wwuet/352

With the strongest climate warming occurring and predicted in the high-latitudes, understanding arctic carbon (C) cycling and the feedback of terrestrial C pools is increasingly important. Arctic terrestrial ecosystems comprise about one-third of the global terrestrial ecosystem C total with most of the C stored in soils, making the response of arctic systems to accelerated warming an issue of global concern. For this research, above- and belowground C stocks were quantified in a small catchment of the Kolyma River watershed in northeastern Siberia, with the primary goal of contributing to a more precise estimate of arctic C pools. Eighteen sites were chosen based on four categories of tree density. We assessed the correlation between soil C, vegetation C, and four environmental correlates -- slope, solar insolation, canopy density, and leaf area index. Carbon in the surface O horizon (2414 ± 391 g C m -2 , mean +/- SE) and underlying mineral soil layer to a depth of 10 cm or to the bottom of the active layer, whichever was less, (2231 ± 432 g C m -2 ) were, together, approximately four times that of the aboveground C pools (1128 ± 273 g C m -2 ). Of the environmental correlates considered, canopy cover had the most robust association with aboveground C pools (p < 0.001; r = 0.812), while no environmental variables correlated significantly with soil C pools (p > 0.05). Greater quantities of belowground C storage are consistent with previous studies in arctic terrestrial ecosystems, but a high degree of variability existed in both above- and belowground C pools. High variability will make it more difficult to accurately quantify C pools at larger spatial scales. Additionally, the identification of canopy cover as a robust biotic correlate presents alternatives to directly measuring C stocks, but this relationship needs to be verified elsewhere in the Arctic before using it in lieu of field data collection.