Gil, Jenie;
Marushchak, Maija E.;
Rütting, Tobias;
Baggs, Elizabeth M.;
Pérez, Tibisay;
Novakovskiy, Alexander;
Trubnikova, Tatiana;
Kaverin, Dmitry;
Martikainen, Pertti J.;
Biasi, Christina
Sources of nitrous oxide and the fate of mineral nitrogen in subarctic permafrost peat soils
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Media type:
E-Article
Title:
Sources of nitrous oxide and the fate of mineral nitrogen in subarctic permafrost peat soils
Contributor:
Gil, Jenie;
Marushchak, Maija E.;
Rütting, Tobias;
Baggs, Elizabeth M.;
Pérez, Tibisay;
Novakovskiy, Alexander;
Trubnikova, Tatiana;
Kaverin, Dmitry;
Martikainen, Pertti J.;
Biasi, Christina
Published:
Copernicus GmbH, 2022
Published in:
Biogeosciences, 19 (2022) 10, Seite 2683-2698
Language:
English
DOI:
10.5194/bg-19-2683-2022
ISSN:
1726-4189
Origination:
Footnote:
Description:
Abstract. Nitrous oxide (N2O) emissions from permafrost-affected terrestrialecosystems have received little attention, largely because they have beenthought to be negligible. Recent studies, however, have shown that there arehabitats in the subarctic tundra emitting N2O at high rates, such as barepeat (BP) surfaces on permafrost peatlands. Nevertheless, the processes behind N2Oproduction in these high-emission habitats are poorly understood.In this study, we established an in situ 15N-labeling experiment with twomain objectives: (1) to partition the microbial sources of N2O emitted from BP surfaces on permafrost peatlands and (2) to study the fate ofammonium and nitrate in these soils and in adjacent vegetated peat (VP) surfaces showing low N2O emissions. Our results confirm the hypothesis thatdenitrification is mostly responsible for the high N2O emissions fromBP. During the study period, denitrification contributed ∼ 79 % of the total N2O emissions from BP, whereas the contribution fromammonia oxidation was less (about 19 %). Both gross N mineralization andgross nitrification rates were higher in BP than in VP, with high C/Nratios and a low water content likely limiting N transformationprocesses and, consequently, N2O production in the latter soil type. Our results show thatmultiple factors contribute to high N2O production in BP surfaceson permafrost peatlands, with the most important factors being the absence of plants, anintermediate to high water content and a low C/N ratio, which all affectthe mineral-N availability for soil microbes, including those producingN2O. The process understanding produced here is important for thedevelopment of process models that can be used to evaluate futurepermafrost–N feedbacks to the climate system.