Assessment of forest management influences on total live aboveground tree biomass in William B. Bankhead National Forest, Alabama.
Forests contain a large amount of carbon (C) stored as tree biomass (above and below ground), detritus, and soil organic material. The aboveground tree biomass is the most rapid change component in this forest C pool. Thus, management of forest resources can influence the net C exchange with the atmosphere by changing the amount of C stored, particularly in landscapes dominated by forests, such as in the southeastern United States. Our work focuses on the influence of prescribed burning and thinning on total live aboveground tree (TLAT) biomass in the William B. Bankhead National Forest, Alabama. We implemented a large-scale study that involved a factorial arrangement of three levels of thinning (heavy thin to 11 m2 ha-1 basal area; light thin to 15 m2 ha-1 basal area; and no thin) and three prescribed fire intervals (no fire, 3-year return, 9-year return). Biomass was assessed among treatments using allometric equations related to tree species and diameter. Pre-treatment stands ranged from 117 to 137 Mg ha-1 TLAT biomass. Overall burning showed no significant influence on TLAT biomass. All but one treatment (light thin, no burn) had a higher rate of TLAT biomass gain post-treatment than the control. Control had an average yearly TLAT biomass gain of 4 percent per year, with the thinned treatments having averages ranging from 5 percent to 7 percent per year. Our results provided a first step for reliable and accurate measurement of biomass potential, which is increasingly important, particularly for sustainable forest management, monitoring global climate change, and forest productivity.