Woody energy crops in the southeastern United States: Two centuries of practitioner experience☆

Abstract

Hardwood plantations Productivity Southern pine plantationsCommercial production costs Bioenergy feedstocks a b s t r a c t Forest industry experts were consulted on the potential for hardwood tree species to serve as feedstock for bioenergy in the southeastern United States. Hardwoods are of interest for bioenergy because of desirable physical qualities, genetic research advances, and growth potential. Yet little data is available regarding potential productivity and costs. This paper describes required operations and provides a realistic estimate of the costs of producing bioenergy feedstock based on commercial experiences. Forestry practitioners reported that high productivity rates in southeastern hardwood plantations are confined to narrow site conditions or require costly inputs. Eastern cottonwood and American sycamore grow quickly on rich bottomlands, but 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 fewer inputs than do other species and offer high potential productivity but are limited by frost to the lower Coastal Plain and Florida. Further research is required to study naturally regenerated hardwood biomass resources. Loblolly pine has robust site requirements, growth rates rivaling hardwoods, and lower costs of production. More time and investment in silviculture, selection, and breeding will be needed to develop hardwoods as competitive biofuel feedstock species.Because of existing stands and fully developed operations, the forestry community considers loblolly pine to be a prime candidate for plantation bioenergy in the Southeast. ª 2010 Elsevier Ltd. All rights reserved. Backgroundi o m a s s a n d b i o e n e r g y x x x ( 2 0 1 0 ) 1 e1 2

Optimal nitrogen application rates for three intensively-managed hardwood tree species in the southeastern USA

“…Biomass price used in this analysis was assumed to be $50 per oven dry metric ton (odmt) (average value of $67 odmt À1 for non-conifer chips, -25% for transportation costs; Wood Resource Quarterly, 2012). Site preparation, cuttings, and planting amounted to $600 ha À1 (Kline and Coleman, 2010). Herbicides, insecticides, and acaricides were applied for the first 4 years of the rotation at the cost of $100 ha À1 yr À1 (Kline and Coleman, 2010); our cost includes supplies and labor.…”

Sweetgum: a new look

“…Adams US$ per Mg compared to rival species eastern cottonwood and pine which could cost 14-40 and 6-18 US$, respectively, in highly productive plantations (Kline & Coleman 2010). When costs of logging and transportation are factored in, only high producing plantations could expect to yield a profit given a target delivery price of 55 US$ per Mg (DOE 2007, Kline & Coleman 2010.…”

“…When costs of logging and transportation are factored in, only high producing plantations could expect to yield a profit given a target delivery price of 55 US$ per Mg (DOE 2007, Kline & Coleman 2010.…”

Initial effects of quinclorac on the survival and growth of high biomass tree species

“…In the north half of the southeastern region of the United States, the Interamerican Poplar (Populus trichocarpa x deltiodes) has been one of the most successful for implementation into hardwood plantations. The hybrid maintains many of the wood traits of eastern cottonwood with increased productivity (Kline & Coleman 2010). Taking advantage of hybrid vigor, clones of various crosses can be deployed on a wide range of sites while keeping high growth rates.…”

“…Under natural conditions alone, cottonwoods can grow 1.5 meters in height and 2.5 cen-timeters in diameter annually (Taylor 2001). Indeed, Populus is perhaps the most heavily researched SRWC taxa and is a widely used SRWC because of its geographic adaptability, fast growth, and ease of reproduction (Zamora et al 2015), though productivity decreases substantially after 4-8 years, which would be toward the end of a rotation for a SRWC (Kline & Coleman 2010). On the other hand, a species such American sycamore has many similar traits but lacks the prolific coppice potential.…”