Characterization of Soil Organic Matter Along a Climosequence in the Grassland-Forest Transition in West-Central Saskatchewan, Canada.

The role of soils as either a carbon source or sink as our climate changes is still uncertain due, in part, to our incomplete knowledge of the factors affecting the persistence of soil organic matter. As such, there is a need to describe differences in the molecular nature of soil organic matter that result from changes in environmental conditions. Nitrogen and carbon X-ray absorption near edge structure (XANES) spectra illustrating shifts in the molecular nature of soil organic matter will be presented from a climosequence located in the grassland-forest transition in west-central Saskatchewan, Canada, that exhibits a 1ºC range in mean annual temperature. Differences in soil organic nitrogen and soil organic carbon speciation resulting from climate-induced vegetation changes in surface soils, litter, and subsurface horizons are explored, with implications for soil organic matter dynamics in a changing climate.