Economic Feasibility of Utilizing Precommercially Thinned Southern Pine as a Woody Biomass Energy Source

The use of woody biomass as a feedstock for wood-burning energy facilities and pellet mills has increased across the southern United States in recent years. Feedstock for these facilities comes in a variety of forms, including roundwood, logging residues, and mill residues. Precommercial thinning (PCT) of pine stands is sometimes used to mitigate southern pine beetle (Dendroctonus frontalis) risk that traditionally incurs added cost to landowners. Utilization of biomass from PCT for biomass energy production may provide an opportunity to reduce the costs of southern pine beetle risk mitigation practices. Potential use of PCT biomass has been suggested in previous studies, but little effort has focused on quantifying amounts available for utilization. Using a list of nonindustrial, private forests enrolled in the Virginia Department of Forestry Pine Bark Beetle Prevention Program, we conducted inventories of pine stands scheduled to undergo PCT to estimate potentially harvestable biomass. Inventories of stands in the 5- to 7-year-old and the 8- to 12-year-old age groups showed average volumes of 14.47 and 39.63 green tons per acre of biomass, respectively. Results suggest that PCT stands in the 8- to 12-year-old age group may contain sufficient volumes for economically feasible harvests based on removal estimations, thinning costs, and regional biomass prices. The feasibility of such harvests will largely depend on the degree to which harvesting costs are affected by utilizing the small-diameter stems typically found in PCT stands and local demand for biomass.