Biomass production in the Central Great Plains USA under various coppice regimes

This paper presents the results of numerous short-rotation coppicing studies with nine fast-growing hardwood tree species grown in the central plains states of the United States. The objective was to compare biomass production of various tree species planted at different densities, coppiced at several intervals, and the longevity of succeeding harvests. Survival, growth, and yield were evaluated. Plant spacing ranged from 0.3×0.3 m to 2.6×2.6 m. Above-ground dormant-season coppice weight and survival on small research plots with one- to five-year coppice cutting cycles were determined. Annual yield of 4–17 oven-dry weight Mg ha−1 for black locust, boxelder, catalpa, cottonwood, honey locust, silver maple, and Siberian elm resulted after several cuts. Survival of cottonwood was about 12% over a 20-year period. Stump sprouting was prolific in silver maple (6.1 per tree); nearly twice as many as the other species compared. Multiple harvests are feasible for many of the broadleafed species evaluated in this study. Survival decreases dramatically at the very close (less than 1 m) spacings. Tonnage remains high for cutting cycles of one, two, or five years. At least three harvests appear feasible. Considering high establishment costs along with survival results conventional spacing distances of about 2 m is suggested for high biomass production especially if plantation longevity of 10 or more years is desired.