Scientific Reports (Jan. 23, 2015 v5, article number: 8002; doi:10.1038/srep08002) by John W. Coulston, David N. Wear and James M. Vose
Over the past century forest regrowth in Europe and North America expanded forest carbon (C) sinks and offset C emissions but future C accumulation is uncertain. Policy makers need insights into forest C dynamics as they anticipate emissions futures and goals. We used land use and forest inventory data to estimate how forest C dynamics have changed in the southeastern United States and attribute changes to land use, management, and disturbance causes. From 2007-2012, forests yielded a net sink of C because of net land use change (+6.48 Tg C yr−1) and net biomass accumulation (+75.4 Tg C yr−1). Forests disturbed by weather, insect/disease, and fire show dampened yet positive forest C changes (+1.56, +1.4, +5.48 Tg C yr−1, respectively). Forest cutting caused net decreases in C (−76.7 Tg C yr−1) but was offset by forest growth (+143.77 Tg C yr−1). Forest growth rates depend on age or stage of development and projected C stock changes indicate a gradual slowing of carbon accumulation with anticipated forest aging (a reduction of 9.5% over the next five years). Additionally, small shifts in land use transitions consistent with economic futures resulted in a 40.6% decrease in C accumulation.