|Spaeth, K - NRCS|
Submitted to: Society for Range Management
Publication Type: Abstract Only
Publication Acceptance Date: January 24, 2004
Publication Date: January 24, 2004
Citation: Pierson, Jr., F.B., Moffet, C.A., and Spaeth, K.E. 2004 Spatial and temporal dynamics of rill erosion following wildfire on sagebrush rangeland. CD-ROM, In: Abstracts of the 57th Annual Meeting, Society for Range Management, Salt Lake City, UT., Jan 24-30, 2004. Abstract #290 Technical Abstract: Wildfire is a major ecological process and management issue on western rangelands. Fire can reduce infiltration and increase runoff and erosion causing reduced site productivity and impairing water quality. Little data is available to quantify fire-induced hydrologic impacts on rangelands or to determine how long such impacts persist. Infiltration, interrill and rill erosion processes were examined and compared to adjacent unburned areas immediately post-fire and for four years following the1999 34,400-ha Denio Fire in northwestern Nevada. Results show fire had the most dramatic long-lasting effect on rill erosion processes compared to infiltration and interrill erosion. Fire reduces ground cover allowing overland flow to more readily concentrate into rills. With little surface cover to slow the movement of water, rill water increases in depth and velocity as it moves across the soil surface compared to unburned conditions. This greater volume of fast moving water has increased energy to detach and transport sediment as if flows down the slope. Hydrologic recovery of this site was strongly correlated with the dynamics of litter buildup on the soil surface over four growing seasons following the fire. Once litter buildup reduced the amount of bare ground to less than 40-50%, rill erosion was reduced to near pre-fire conditions. These results suggest that burned area rehabilitation efforts should focus on controlling rill erosion and less on increasing infiltration following wildfire.