INFLUENCE OF PRESCRIBED BURNING ON UPLAND SOIL PROPERTIES IN MARK TWAIN NATIONAL FOREST, SOUTHEAST MISSOURI OZARKS

In the Mark Twain National forest there is a collaborative effort to restore parts of the forest to its original shortleaf pine-oak woodland areas by using a combination of silviculture and prescribed fire. The purpose of this project is to assess the effects of prescribed burning on upland forest and soil physical properties that influence erosion processes across a gradient of burned sites of different ages and unburned sites. A combination of geospatial, field, laboratory, statistical (one-way ANOVA) and modeling (USLE) methods were used to assess the effects of prescribed burns on forest and soil characteristics in Big Barren Creek watershed. On average, burned sites had significantly lower leaf litter depth (10-30%) and duff depth (10-40%), higher organic matter content (15-20%) and lower bulk densities (8-12%) in the first 0-5 cm of the soil than unburned sites. Prescribed burns did not significantly effect soil texture at any depth or percent organic matter and bulk density below 5 cm. Basal area, coarse woody debris and seedling/sapling densities were not significantly different among burned and unburned sites. There are no significant differences for soil and forest characteristics among unburned stand types, except litter and duff depth, which is stand dependent (pine> mixed> oak). USLE results indicate burned sites may have similar annual soil erosion rates compared to unburned sites.