The Quantity and Quality of Soil Organic Matter In a Sub-Arctic Cryosol.

Soils in the circumpolar permafrost zone are estimated to contain 50% (1672 Pg C) of global belowground organic carbon (OC) stores.  Predicted warming of up to 7-8º C in permafrost areas by the end of the 21^st century will increase rates of mineralization of soil organic matter (SOM) but the quantity and quality of SOM in the sub-Arctic is poorly known.  In this exploratory investigation, we characterize the quantity and quality of SOM in different genetic horizons in three pedons sampled near Inuvik, Northwest Territories, Canada using chemical (sequential cold- and hot-water extraction) and biological (100-d bioassay for mineralizable C and N) methods.  Our findings indicate that a significant proportion of the C and N pool is mineralizable.