High biolability of ancient permafrost carbon upon thaw

Jorien E. Vonk*, Paul J. Mann, Sergey Davydov, Anna Davydova, Robert G. M. Spencer, John Schade, William V. Sobczak, Nikita Zimov, Sergei Zimov, Ekaterina Bulygina, Timothy I. Eglinton, Robert M. Holmes

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

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Abstract

Ongoing climate warming in the Arctic will thaw permafrost and remobilize substantial terrestrial organic carbon (OC) pools. Around a quarter of northern permafrost OC resides in Siberian Yedoma deposits, the oldest form of permafrost carbon. However, our understanding of the degradation and fate of this ancient OC in coastal and fluvial environments still remains rudimentary. Here, we show that ancient dissolved OC (DOC, >21,000 (14)Cyears), the oldest DOC ever reported, is mobilized in stream waters draining Yedoma outcrops. Furthermore, this DOC is highly biolabile: 34 +/- 0.8% was lost during a 14 day incubation under dark, oxygenated conditions at ambient river temperatures. Mixtures of Yedoma stream DOC with mainstem river and ocean waters, mimicking in situ mixing processes, also showed high DOC losses (14 days; 17 +/- 0.8% to 33 +/- 1.0%). This suggests that this exceptionally old DOC is among the most biolabile DOC in any previously reported contemporary river or stream in the Arctic.

Original languageEnglish
Pages (from-to)2689-2693
Number of pages5
JournalGeophysical research letters
Volume40
Issue number11
DOIs
Publication statusPublished - 16-Jun-2013

Keywords

  • Yedoma
  • permafrost
  • dissolved organic carbon
  • Kolyma River
  • DISSOLVED ORGANIC-MATTER
  • OXYGEN ISOTOPES
  • ICE-WEDGES
  • SIBERIA
  • COASTAL
  • RELEASE
  • SOILS

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