Successful Fall Burning in High Elevation Forests

Dean S.N.

The N. C. Wildlife Resources Commission (NCWRC) and The Nature Conservancy (TNC) were successful in 2011 with expanding their traditional mountain burning seasons from winter and spring to incorporate a fall burn window and complete burning projects in high elevation red oak forests on a 98-acre site at NCWRC’s Three Top Mountain Game Land and on a 87-acre area at TNC’s Bluff Mountain Preserve. Multiple attempts to conduct these projects during winter and spring burning seasons over the past several years have been thwarted by persistent gusty winds on these high elevation sites in Ashe County, NC, which average 4,600 to 4,800 feet in elevation. Additionally, the heavy snows during the last two winters compressed the leaf litter, making it slow to dry out and difficult to burn. Snow remained in patches in these higher elevation forests until mid-April. By mid-May, spring wildflowers and grasses appeared, trees were leafing out, and shading kept leaf litter too moist for desirable fire behavior.

The “fluffy” leaf litter of newly fallen leaves and favorable weather patterns during fall made fuel and site conditions conducive to burning. Fall weather patterns were very suitable with moderate relative humidity, periods of low to moderate wind speeds, adequate fuel conditions, and just enough drying days between rain showers, which followed the night after both burns. Leaves fell early at high elevations making those sites available for burning starting in mid-October. Loose leaves dried out fairly quickly after rains and produced favorable fire behavior, while the duff stayed moist and protected tree roots. Shorter day length in fall, however, put more pressure on crews to complete burns quickly to allow adequate smoke dispersal before inversions set in at sunset. Adding this mid-October through November burn window also relieved the pressure to complete all scheduled burning projects in winter and spring. NCWRC had conducted limited fall burns in the past for site preparation and to improve wildlife habitat. Adding fall burns this year proved to be the key to success in completing burns in high elevation forests.

Also, working with a number of partners in the Southern Blue Ridge-Fire Learning Network (SBR-FLN) made these burns a success. Staff from NCWRC, the lead agency on these burns, N. C. Forest Service, and N. C. Division of Parks and Recreation joined with TNC staff and volunteers to pull off these fall burns, which were designed to restore high elevation red oak forests. These burns were important for all agencies involved, serving as a model for successful collaboration. Both burn projects are part of the New River Headwaters SBR-FLN landscape with pre and post burn data collection by Dr. Peter Bates with Western Carolina University, to provide important monitoring data.