The processes leading to spatial patterns in watershed soil respiration are poorly understood. While it is thought that soil moisture and soil temperature are the dominant controls on respiration, the dynamics and relative contribution of these variables in is uncertain. Recent work in a sub-alpine catchment in the northern Rocky Mountains has shown upslope accumulated area can be used to describe seasonal patterns in soil wetness which in turn influences soil respiration. Our objective here is to test the hypothesis that topographic relationships exist that can be used to describe patterns in soil respiration throughout a small high elevation forested watershed in the Appalachian Highlands of West Virginia. This watershed receives considerable year-round precipitation and has no distinct wet or dry period. We measured soil respiration, soil moisture, and soil temperature weekly throughout the 2009 growing season. Cumulative growing season CO2 fluxes were determined, and topographic variables were obtained from a 5m DEM interpolated from 1m LiDAR data.
Results/Conclusions
Our analysis shows that slope is related to soil respiration, with highest respiration values on lowest slopes, although this relationship is not strong. Other topographic variables were not correlated to soil respiration. This finding is important as it demonstrates that topographic patterns in a watershed without a seasonal moisture pattern are not nearly as strong as in a watershed with distinct wet and dry periods, such as in the northern Rocky Mountains.