Thawing Yedoma permafrost is a neglected nitrous oxide source.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 34876586.
- Also identified by DOI 10.1038/s41467-021-27386-2 and PMC identifier 8651752.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
In contrast to the well-recognized permafrost carbon (C) feedback to climate change, the fate of permafrost nitrogen (N) after thaw is poorly understood. According to mounting evidence, part of the N liberated from permafrost may be released to the atmosphere as the strong greenhouse gas (GHG) nitrous oxide (N<sub>2</sub>O). Here, we report post-thaw N<sub>2</sub>O release from late Pleistocene permafrost deposits called Yedoma, which store a substantial part of permafrost C and N and are highly vulnerable to thaw. While freshly thawed, unvegetated Yedoma in disturbed areas emit little N<sub>2</sub>O, emissions increase within few years after stabilization, drying and revegetation with grasses to high rates (548 (133-6286) μg N m<sup>-2</sup> day<sup>-1</sup>; median with (range)), exceeding by 1-2 orders of magnitude the typical rates from permafrost-affected soils. Using targeted metagenomics of key N cycling genes, we link the increase in in situ N<sub>2</sub>O emissions with structural changes of the microbial community responsible for N cycling. Our results highlight the importance of extra N availability from thawing Yedoma permafrost, causing a positive climate feedback from the Arctic in the form of N<sub>2</sub>O emissions.