May 30, 2017

Increased nitrous oxide emissions from Arctic peatlands after permafrost thaw

Carolina Voigt, Maija E. Marushchak, Richard E. Lamprecht, Marcin Jackowicz-Korczyński, Amelie Lindgren, Mikhail Mastepanov, Lars Granlund, Torben R. Christensen, Teemu Tahvanainen, Pertti J. Martikainen, Christina Biasi
Proceedings of the National Academy of Sciences
  • States that gaseous carbon release from Arctic soils due to permafrost thawing is known to be substantial, but growing evidence suggests that Arctic soils may also be relevant sources of nitrous oxide (N2O)
  • Measures N2O emissions from 16 columns of thawing permafrost from Finnish Lapland over 33 weeks
  • Shows that N2O emissions from subarctic peatlands increase as the permafrost thaws
  • Results show that the highest postthaw emissions occurred from bare peat surfaces, a typical landform in permafrost peatlands, where permafrost thaw caused a fivefold increase in emissions
  • Finds that the presence of vegetation, known to limit N2O emissions in tundra, did decrease (by ∼90%) but did not prevent thaw-induced N2O release
  • Finds that waterlogged conditions, however, suppressed the emissions
  • Results imply that the Arctic N2O budget will depend strongly on moisture changes, and that a gradual deepening of the active layer will create a strong noncarbon climate change feedback