The long-term biogeochemical fate of C in Subarctic thawing peat plateaus ...

• Main Authors: Kjær, Sigrid Trier, Nedkvitne, Nora, Westermann, Sebastian, Dörsch, Peter
• Format: Text
• Language: English
• Published: ETH Zurich 2022
• Subjects: Northern Norway; Peat; permafrost; Subarctic; Thermokarst
• Online Access: https://dx.doi.org/10.3929/ethz-b-000542700; http://hdl.handle.net/20.500.11850/542700

Global warming causes permafrost to thaw at an unprecedented rate. In Northern Scandinavia, permafrost peat plateaus have been found to decline rapidly during the last decades, releasing old organic carbon to decomposition and runoff. Thawing peat plateaus can partly turn into thermokarst ponds, with consequences for the biogeochemical fate of the released carbon. We investigated carbon degradation of thawing permafrost peat by incubating permafrost peat and thermokarst sediments from three peat plateaus in Northern Norway. The samples were incubated field moist at 10oC for almost one year. Initial decomposition was dominated by CO2 production which strongly responded to oxygen availability, while methane (CH4) production was small. Methane production increased drastically after more than ten months, indicating that thawed permafrost peat has a considerable potential to produce CH4 after a time lag. The cumulative CH4 production of thawed permafrost peat after one year of incubation exceeded that of ... : EGUsphere ...