Evidence for non-steady-state carbon emissions from snow-scoured alpine tundra

• Published in: Nature Communications
• Main Authors: Knowles, John F., Blanken, Peter D., Lawrence, Corey R., Williams, Mark W.
• Format: Text
• Language: English
• Published: Nature Publishing Group UK 2019
• Subjects: Article; permafrost; Tundra
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6428862/; http://www.ncbi.nlm.nih.gov/pubmed/30898997; https://doi.org/10.1038/s41467-019-09149-2

High-latitude warming is capable of accelerating permafrost degradation and the decomposition of previously frozen carbon. The existence of an analogous high-altitude feedback, however, has yet to be directly evaluated. We address this knowledge gap by coupling a radiocarbon-based model to 7 years (2008–2014) of continuous eddy covariance data from a snow-scoured alpine tundra meadow in Colorado, USA, where solifluction lobes are associated with discontinuous permafrost. On average, the ecosystem was a net annual source of 232 ± 54 g C m(−2) (mean ± 1 standard deviation) to the atmosphere, and respiration of relatively radiocarbon-depleted (i.e., older) substrate contributes to carbon emissions during the winter. Given that alpine soils with permafrost occupy 3.6 × 10(6) km(2) land area and are estimated to contain 66.3 Pg of soil organic carbon (4.5% of the global pool), this scenario has global implications for the mountain carbon balance and corresponding resource allocation to lower elevations.