Harwoods for Woody Energy Crops In the Southeast United States: Two Centuries of Practitioner Experience.

This paper summarizes opinions from forest industry experts on the potential for hardwood tree species to serve as feedstock for bioenergy in the Southeast United States.  Hardwoods are of interest for bioenergy because of desirable physical qualities, genetic research advances, and growth potential. Experts observe that high productivity rates in southeastern plantations are confined to limited site conditions or require costly inputs. Eastern cottonwood and American sycamore grow quickly on rich bottomlands where they compete with higher-value crops. These species are also prone to pests and disease. Sweetgum is frost hardy, has few pest or disease problems, and grows across a broad range of sites, yet growth rates are relatively low. Eucalypts require few inputs and offer high potential productivity, but are limited by frost to the lower coastal plain and Florida. More time and investment in silviculture, selection, and breeding will be needed to develop hardwoods as competitive biofuel feedstock species. Loblolly pine has robust site requirements, growth rates rivaling hardwoods and lower costs of production. Because of existing stands and know-how, the forestry community considers loblolly pine to be a prime candidate for plantation bioenergy in the Southeast. Further research is required to study naturally regenerated hardwood biomass resources.