Woody biomass from short rotation energy crops
Short rotation woody crops (SRWCs) are ideal for woody biomass production and management systems because they are renewable energy feedstocks for biofuels, bioenergy, and bioproducts that can be strategically placed in the landscape to conserve soil and water, recycle nutrients, and sequester carbon. This chapter is a synthesis of the regional implications of producing four genera of short rotation energy crops as feedstocks for fuels, chemicals, and fibers set in the rich history of research and development of these purpose-grown trees in the United States. The four genera include: Populus (cottonwoods, poplars, aspens), Salix (willows), Pinus (southern pines), and Eucalyptus (eucalypts). Key aspects of the production systems are discussed, including tree biology, genetics and tree improvement, and silvicultural management. The availability of short rotation woody biomass is evaluated on the basis of maintaining sustainability at multiple scales. Current efforts to maximize production are described. Overall, sustainable production of fuels, chemicals, and fibers from woody biomass depends on a combination of feedstocks from both forests and plantations; the importance of dedicated SRWC feedstock production systems is highlighted.