The Terrestrial Carbon Cycle: Managing Forest Ecosystems

The accumulation of CO2 in the atmosphere due to fossil fuel use, deforestation and other anthropogenic sources is changing the global climate (Harries et al. 2001; IPCC 2002). Current understanding of the global carbon cycle suggests that managing forests and agricultural lands to increase the sequestration of greenhouse gases (GHG) provide credible policy options (Dixon and Turner 1991, Winjum et al. 1993a, Brown 1996a, Brown et al. 1996). EPA/WED research efforts during the 1990’s estimated the amount of that carbon which could be sequestered by purposeful management actions, and the incidental amount of carbon that inadvertent land use is likely to release to the atmosphere in the future. The three specific objectives of this research were to: 1) develop or refine global, country-level and regional estimates of carbon pools and fluxes in forests, 2) evaluate the potential to conserve and manage forests to expand the accumulation of carbon, and, 3) project future forest carbon pools and fluxes during expected changes in climate and land-use. The annual exchange of carbon between forests and the atmosphere, and the amounts of carbon stored in forests, varies widely with the nature of forest cover. With land use and management, and with climatic constraints, our research showed that management of forests can significantly increase the long-term sequestration of atmospheric CO2. However, management efforts aimed at storing carbon in the tropics -the largest pools on Earth -are being countered by carbon emissions from forest destruction.