Other species can be used for biofuel production. Tennessee has approximately 13.9 million acres of forestland. Perhaps the best trees for many of the forest sites are those that have already proven to endure there. For instance, oak species have adapted to tolerate many of the dry and infertile sites and are by default, the best selection. On such sites, the rotation length would be considerably longer and the yield less than the examples outlined in this factsheet. Still, where the woody resource already exists, biofuel could be an alternative to traditional wood markets.
Short rotation woody crops eventually lose their vigor if repeatedly harvested and then allowed to re-sprout. Normally, after three rotations, productivity is lost and plantations need to be re-established. Depending on the intensity of management, this time frame could be three to six decades.
As the demand for traditional fuels continues to rise, support for alternative sources will likely increase. Approximately 55 percent of Tennessee is covered in forest, and strong consideration should be given toward the use of woody crops to produce biofuel.
"SP702-C-Short Rotation Woody Crops for Biofuels," The University of Tennessee Agricultural Extension Service, SP702C-1M-12/07 R12-1015-006-011-08 08-0088, http://trace.tennessee.edu/utk_agexbiof/11