Uncertainty and Long-Term Supply
A long-term stable supply of biomass is critical to its industrial utilization. The future availability of logging residues will depend on continued future timber harvests and the ratio of residues to timber removals. According to the 2002 Forest and Rangeland Renewable Resources Planning Act (RPA) assessment (Haynes 2003), the projected timber harvests in the U. S. would generally increase during the next 50 years while regional shifts and small harvest reductions in the short run will be likely. The ratio of residues to timber removals may decrease in the future as technological advances enable us to procure and utilize smaller-size trees for manufacturing traditional forest products. Consequently, the total supply of logging residues in the U.S. would be relatively stable with a slight increase over the next 50 years. The total supply is projected to increase by 5% by 2020 and some 12% by 2050.
Yet, different areas of the country will be affected in different ways. While increases in logging residues are expected in the South Central, Southeast, and North Central regions, decreases are likely in the Pacific Southwest, Pacific Northwest, Great Plains, and Intermountain states. In the Northeast, the long-term supply of logging residues is projected to increase by 2020 after a dip in 2010 largely because of increased harvests of hardwoods (Gan and Smith 2006). In summary, the nations total supply of logging residues is predicted to remain sustainable over the next 50 years, in spite of some regional differences.
If trees are harvested for bioenergy, pulpwood, and sawlogs, competing or complementary uses of forest resources among these products may exist. A recent study using a dynamic multisector and multiregion model suggests that bioenergy would compete with traditional forest products in the use of forest resources in the short term (before 2030), but they would complement each other in the long term as more lands would be used for forest production that would increase the supply of both timber and feedstock. The short-term effect of bioenergy production on timber output would be moderate (<5% reduction in timber output) under current market and policy conditions associated with bioenergy and greenhouse gas emissions. Hence, given current limited demand for biomass feedstock and the potential expansion of forestland in the long term, both short- and long-term supply of forest biomass for energy production in the nation seems adequate.
Encyclopedia ID: p1179
