Abstract - Soil response to prescribed fire in mixed pine-hardwood forests at Ft. Benning, Georgia

ABSTRACT

Short-term response of soil quality and nitrogen availability were examined in mixed pine-hardwood forests in the first season following prescribed fire to determine if changes in nitrogen availability were influenced more by nitrogen loss due to combustion or altered soil inorganic nitrogen transformations. Stands (16) were burned during winter-spring 2001-2. Soil temperature returned to pre-burn temperature within several hours and was related to the time of day of the burn. Fire minimally consumed the soil organic layer, which ranged from 2% to 36% of the pre-burn mass. Fire effects on mineral soil extractable total nitrogen were variable, ranging from a 54% decline to a 327% increase; however, all values were low (<6 µg N g-1 soil). Our data indicate the prescribed burns were low intensity and had little or variable effect on soil nitrogen. Detailed longer-term studies are needed to understand prescribed fire effect on soil nitrogen dynamics and sustainability of upland mixed pine-hardwood forests.