Spatial distribution of charcoal after a prescribed fire on Middle Mountain, VA

This study examines the spatial distribution of surface charcoal after a managed fire and its relationship to fire intensity and site characteristics. Such studies are lacking for the southern Appalachian Mountains. In April 2010, The Nature Conservancy conducted a ~150ha prescribed burn in pine- and oak-dominated forests on the eastern slope of Middle Mountain in western Virginia. Data were from three randomly located transects totaling 2751m from the base of the slope extending to the highest elevations. At 50m intervals I collected 400cm° surface samples (n=56) down to mineral soil, and recorded the nearest four trees, their diameters and bole char height, and other site and understory characteristics. Charcoal fragments >2mm were wet-sieved from 200mL subsamples of the surface material, dried, and weighed. Charcoal deposition and char heights on trees examined in this study showed high spatial variability in fire intensity. Average charcoal deposition across all samples was 103 kg/ha, with individual samples ranging from 0-884kg/ha, which was in the range of findings from other studies. Char height was weakly correlated with charcoal abundance suggesting a relationship between fire intensity and charcoal production. Slope was moderately correlated with charcoal deposition, with higher deposition on steeper slopes. Average char height for all trees and species was in the range of 1-3m, but char height on pines averaged 7.3m, where fires intensity appeared to increase. This work can inform land managers on fire behavior and carbon flux and has implications for reconstructions of long-term fire history from soil charcoal.