Circum-Arctic release of terrestrial carbon varies between regions and sources

• Published in: Nature Communications
• Main Authors: Martens, Jannik, Wild, Birgit, Semiletov, Igor, Dudarev, Oleg V., Gustafsson, Örjan
• Format: Text
• Language: English
• Published: Nature Publishing Group UK 2022
• Subjects: Article; Arctic; permafrost
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9532443/; http://www.ncbi.nlm.nih.gov/pubmed/36195594; https://doi.org/10.1038/s41467-022-33541-0

Arctic change is expected to destabilize terrestrial carbon (terrOC) in soils and permafrost, leading to fluvial release, greenhouse gas emission and climate feedback. However, landscape heterogeneity and location-specific observations complicate large-scale assessments of terrOC mobilization. Here we reveal differences in terrOC release, deduced from the Circum-Arctic Sediment Carbon Database (CASCADE) using source-diagnostic (δ(13)C-Δ(14)C) and carbon accumulation data. The results show five-times larger terrOC release from the Eurasian than from the American Arctic. Most of the circum-Arctic terrOC originates from near-surface soils (61%); 30% stems from Pleistocene-age permafrost. TerrOC translocation, relative to land-based terrOC stocks, varies by a factor of five between circum-Arctic regions. Shelf seas with higher relative terrOC translocation follow the spatial pattern of recent Arctic warming, while such with lower translocation reflect long-distance lateral transport with efficient remineralization of terrOC. This study provides a receptor-based perspective for how terrOC release varies across the circum-Arctic.