EVALUATING THE EFFICACY AND ECOLOGICAL IMPACTS OF BAER SLOPE STABILIZATION TREATMENTS ON THE POT PEAK/DEEP HARBOR WILDFIRE COMPLEX

Post-fire slope stabilization treatments are often prescribed for severely burned areas of a wildfire, through burned area emergency response (BAER), to reduce erosion, maintain soil productivity, protect water quality, and reduce risks to human life and property. Prescribed slope stabilization treatments can include seeding of cereal grains or grasses, fertilization, mulching, and installation of physical barriers across slope contours (e.g., contour-felled logs and straw wattles). Seeding and fertilization treatments have been proposed following several high severity wildfires in the Pacific Northwest. These treatments are designed to reduce erosion by supplementing native vegetation recovery with additional populations of fast-growing species (seeding) and increasing productivity (fertilizing). Despite the widespread use of post-fire slope stabilization treatments, and rapidly increasing costs of treatment with more frequent large and severe wildfires, there is little data establishing the general effectiveness of many commonly used treatments, especially in coniferous forests (Robichaud 2000, Beyers 2004). Effectiveness monitoring is often informal and the results are not widely reported. Additionally, some treatments may interfere with natural vegetation recovery or introduce exotic species (Beyers 2004, Keeley 2004, Kruse et al. 2004). Experimental and observational studies are needed for testing the effectiveness of new, innovative treatments, while science-based effectiveness monitoring plans are needed to assess the variability in treatment effectiveness across time and space. In response to Joint Fire Sciences AFP 2005-1, Task 2, we undertook a two-year study of BAER soil stabilization treatments that assessed 1) the relative efficacy of seeding and fertilizing treatments for providing protective soil cover (live plant and litter cover), and 2) the effects of soil stabilization treatments on post-fire vegetation dynamics, including native vegetation recovery and weed population dynamics