Importance of cryoturbation in redistributing organic carbon in permafrost-affected soils

This study examined the amount of soil organic carbon (SOC) incorporated by cryoturbation into the active layer and near-surface permafrost of Turbels from northern Alaska. An analysis of 21 pedons revealed that an average of 55% of the SOC density of the active layer and near-surface permafrost could be attributed to redistribution from cryoturbation. Cryoturbation occurs most strongly under conditions of poor drainage, where the parent materials are enriched in silt, and where frost boils are present. Based on published radiocarbon dates of buried SOC, cryoturbation was particularly important during periods of the mid-Holocene when the arctic underwent warming. These results suggest that continued warming of the arctic could accelerate cryoturbation and enable the soil to store more SOC than at present, thereby mitigating some of the loss of C[O.sub.2] to the atmosphere from increased soil respiration. Abbreviations: SOC, soil organic carbon.