CARBON SEQUESTRATION IN AN AGGRADING FOREST ECOSYSTEM IN THE SOUTHEASTERN USA

An analysis of C pools at the Panola Mountain Research Watershed (PMRW ) near Atlanta, GA, indicates that aggrading forests in the U.S. South east are an important regional C sink. The forests in this area were c ut in the early 1800s and the land was cultivated until the early 1900 s, when farming was abandoned and forest regeneration began. Cultivati on resulted in extensive erosion, which depleted soil C pools. The rat e of soil C sequestration during the 70-yr period of forest regenerati on was estimated to be between 0.34 (standard error [SE] = 0.12) and 0 .79 (SE = 0.19) Mg C ha(-1) yr(-1). There is a large potential for con tinued C accumulation in the soil at PMRW based on the difference betw een current measured soil C pools of 82 Mg C ha(-1) at PMRW and 122 Mg C ha(-1) at the nearby ''undisturbed'' Fernbank Forest in Atlanta, GA . The rate of C sequestration in biomass at PMRW was 1.17 Mg C ha(-1) yr(-1) for the regeneration period, bringing the ecosystem total to be tween 1.81 and 2.26 Mg C ha(-1) yr(-1). Carbon sequestration in temper ate forest ecosystems partially mitigates the effects of increased atm ospheric loading of CO2.