G.: Vulnerability of high-latitude soil organic carbon

• Main Authors: Guido Grosse, Jennifer Harden, Merritt Turetsky, A. David Mcguire, Philip Camill, Charles Tarnocai, Steve Frolking, Edward A. G. Schuur, Torre Jorgenson, Mark Waldrop, Robert G. Striegl
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Arctic; Climate change; permafrost; Subarctic; Thermokarst
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.419.4735; http://www.lter.uaf.edu/pdf/1546_Grosse_Harden_2011.pdf

[1] This synthesis addresses the vulnerability of the North American high‐latitude soil organic carbon (SOC) pool to climate change. Disturbances caused by climate warming in arctic, subarctic, and boreal environments can result in significant redistribution of C among major reservoirs with potential global impacts. We divide the current northern high‐latitude SOC pools into (1) near‐surface soils where SOC is affected by seasonal freeze‐thaw processes and changes in moisture status, and (2) deeper permafrost and peatland strata down to several tens of meters depth where SOC is usually not affected by short‐term changes. We address key factors (permafrost, vegetation, hydrology, paleoenvironmental history) and processes (C input, storage, decomposition, and output) responsible for the formation of the large high‐latitude SOC pool in North America and highlight how climate‐related disturbances could alter this pool’s character and size. Press disturbances of relatively slow but persistent nature such as top‐down thawing of permafrost, and changes in hydrology, microbiological communities, pedological processes, and vegetation types, as well as pulse disturbances of relatively rapid and local nature such as wildfires and thermokarst, could substantially impact SOC stocks. Ongoing