Prescribed Burning of Oak Shelterwoods: Which Fuel Models Apply?

by

Patrick Brose

Research Forester, USDA Forest Service, Northern Research Station, Irvine, PA 16329

Abstract – Land management agencies throughout the eastern United States are increasingly using prescribed fire in oak shelterwood stands to help regenerate them. However, some of these agencies lack expertise in selecting appropriate fuel models (FM) for prescribed fire planning purposes. To address this shortcoming, I conducted a fuels and fire behavior study in three oak shelterwoods in the Piedmont region of central Virginia. The objective was to determine which of the 13 standard fuel models (Anderson 1982) most accurately represented the typical forest fuels (litter, logging slash, and shrub) commonly encountered in oak shelterwoods. In each of these fuel types, I established six 30’ x 30’ plots to measure fuels and document fire behavior. Fuels were inventoried before and after prescribed burning using a modified planar transect method. Fire behavior was documented using heat-sensitive paints and photography. Results indicated that the Anderson fuel models commonly used in mixed-oak forests are reasonably accurate and can be used in prescribed fire planning with some modification. Oak leaf litter was most accurately portrayed by FM-09. Hardwood logging slash was well represented by FM-06 or FM-10. FM-06 also characterized the deciduous heath shrubs such as blueberry and huckleberry. However, the evergreen heath shrubs such as mountain laurel and rhododendron were not well represented by any of the 13 standard fuel models. When planning prescribed fires in these fuels, managers should use FM-10 and FM-04 to create a minimum and maximum estimation of expected fire behavior or develop a custom fuel model for their particular circumstances.