Apr 20th, 1:00 PM - 4:00 PM
Soil Water Repellency and Ground Cover Effects on Runoff and Erosion in Response to Prescribed Burning of a Steeply Sloped Sagebrush Hill Slope
Dr. Jennifer Pierce
Rangeland managers and scientists are in need of predictive tools to accurately simulate postfire hydrologic responses and provide hydrologic risk assessment. Rangeland hydrologic modeling has advanced in recent years; however, model advancements have largely been associated with data from gently-sloping sites and have not included the effects of soil water repellency on runoff generation. This study seeks to enhance current understanding of post-fire hydrologic responses on steeply-sloped sagebrush rangelands, specifically addressing the influences of soil water repellency and ground cover. The Northwest Watershed Research Center conducted small plot rainfall simulations on a sagebrush-dominated mountainous site in the Reynolds Creek Experimental Watershed in Southwest Idaho. Experiments were conducted immediately prior to and one year following prescribed burning of the site (2007 and 2008 respectively). Results indicate that soil water repellency was unaffected by burning. Burning resulted in increased runoff from shrub coppice microsites and decreased runoff from interspace microsites. Erosion increased dramatically on both microsites after burning.