Examining the Potential of Biochar in Post-Wildfire Rehabilitation.

High severity wildfires have significant, lasting impacts on soils and forest ecosystems.  Nutrient and soil organic matter losses and physical changes that influence plant water availability often hinder revegetation of dry conifer forests in western North America.  Land managers commonly employ Burned Area Emergency Response (BAER) treatments to counter immediate post-fire soil loss, though these practices may also stimulate recovery of soil productivity and speed revegetation.  We investigated the potential of lodgepole pine biochar to improve soil nitrogen availability, soil water relations and plant recovery in areas affected by high severity wildfire and subsequent erosion on skeletal soils in the Colorado Rockies.  We compared biochar rates (0, 2, and 20 t ha^-1) and wood mulch addition in a replicated field study and complementary greenhouse trial.  The high biochar rate nearly doubles gravimetric soil water content compared to the untreated and low biochar treatment, under a typical irrigation regime, but not under wetter conditions.  Biochar also increased extractable soil nitrate during a 4 month greenhouse trial.  On-going work will help us examine the value of various soil productivity indicators for predicting tree seedling growth and nutrient uptake and herbaceous plant cover, biomass and diversity in post-fire landscapes.  Our initial soil moisture and nutrient findings suggest that biochar may have potential to enhance soil productivity and stimulate revegetation in degraded, coarse-textured soils following fire and other perturbations.