Land use and carbon storage in Georgia forests

Abstract

Disparate estimates of trends in carbon storage in the major forest regions of the earth have focused attention on: (1) possible roles of forests in the global carbon budget, and in potential climatic change, and (2) the need for detailed regional studies of the impact of forest growth, exploitation, land use change, reforestation and storage of forest products on their carbon budgets as a preliminary for determining their aggregate impact on the global budgets as a preliminary for determining their aggregate impact on the global carbon budget. The carbon budget of the forests of the Upper Piedmont of Georgia is reconstructed from presettlement to the present, and the impact of alternative futures on the region's carbon budget modeled for the next three decades and for the next century. Historic trends are based on US Bureau of the Census and USDA Forest Service records. Alternative futures are assessed using a compartment model (each compartment is a forest type-biomass class) whose transfer coefficients were systematically altered to account for plausible changes in forest exploitation, management and area. Carbon storage declined from a presettlement value of 386 x 10/sup 6/ tonnes to about 40 x 10/sup 6/ tonnes during the height of agriculture.more » Post World War II reforestation increased it to 112 x 10/sup 6/ tonnes by 1972. Further increases are expected in the next several decades in spite of reductions in the forest land base. However, the impact on the global carbon cycle of a region undergoing agricultural development is five times that of a region in agricultural decline. Long-term projections suggest that the managed forests of a region may continue to be modest carbon sinks (increased carbon storage) largely through the storage of forest biomass and carbon in forest products.« less