Variable respiration rates of incubated permafrost soil extracts from the Kolyma River lowlands, north-east Siberia

  • Joanne K. Heslop Aquatic Ecosystems Analysis Laboratory, Department of Natural Resources and Environmental Science, University of Nevada, Reno, NV, USA; bDepartment of Biology, College of the Holy Cross, Worcester, MA
  • Sudeep Chandra Aquatic Ecosystems Analysis Laboratory, Department of Natural Resources and Environmental Science, University of Nevada, Reno, NV, USA; bDepartment of Biology, College of the Holy Cross, Worcester, MA
  • William V. Sobzcak Department of Biology, College of the Holy Cross, Worcester, MA, USA; cNorth-East Science Station, Pacific Institute of Geography, Far East Branch of Russian Academy of Sciences, Cherskiy
  • Sergey P. Davydov North-East Science Station, Pacific Institute of Geography, Far East Branch of Russian Academy of Sciences, Cherskiy
  • Anna I. Davydova North-East Science Station, Pacific Institute of Geography, Far East Branch of Russian Academy of Sciences, Cherskiy
  • Valentin V. Spektor Melnikov Permafrost Institute Siberian Branch, Russian Academy of Sciences, Republic of Sakha (Yakutia), Yakutsk
  • Katey M. Walter Anthony Water and Environmental Research Center, University of Alaska Fairbanks, Fairbanks, AK
Keywords: Arctic; carbon export and processing; yedoma; climate change; greenhouse gas production

Abstract

Thawing permafrost supplies dissolved organic carbon (DOC) to aquatic systems; however, the magnitude, variability and fate of this DOC is not well constrained. Our objective was to examine DOC respiration from seasonally thawed and near-surface (<1.5 m) permafrost soils collected from five locations in the Kolyma River Basin, north-east Russia. We measured soil organic carbon (OC) content, water-soluble macronutrients (DOC, NH4, PO4) and the heterotrophic respiration potentials of soil extract DOC in five-day laboratory incubations. DOC concentrations ranged from 2.8 to 27.9 mg L−1 (n = 14). Carbon respiration was 0.03–0.47 mg C (n = 16) and 8.7–31.4%, total DOC (n = 14). While DOC concentration was a function of soil OC concentration, we did not find a relationship between C respiration and soil OC or DOC concentrations. Respiration was highest in the top active layer, but varied widely among sites, and lowest at the bottom of the active layer. Respiration from yedoma varied across sites (0.04–0.47 mg C respired, 8.7–31.4% total DOC). Despite the small sample size, our study indicates near-surface soils and permafrost are spatially variable in terms of both soil OC content and C respiration rates, and also that OC contents do not predict C respiration rates. While a larger sample size would be useful to confirm these results at broader geographic scales, these initial results suggest that soil OC heterogeneity should be considered in efforts to determine the fate of soil OC released from permafrost-dominated terrestrial ecosystems to aquatic ecosystems following permafrost thaw.

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Published
2017-05-16
How to Cite
Heslop, J., Chandra, S., Sobzcak, W., Davydov, S., Davydova, A., Spektor, V., & Walter Anthony, K. (2017). Variable respiration rates of incubated permafrost soil extracts from the Kolyma River lowlands, north-east Siberia. Polar Research, 36. Retrieved from https://polarresearch.net/index.php/polar/article/view/2648
Section
Research Articles