THE USDA-ARS CO_2 FLUX NETWORK: VARIATION IN RANGELAND CO_2 FLUX ACROSS YEARS ANDECOSYSTEMS

摘要

The public debate over climate change and CO_2 sequestration has caused increased scientific interest in CO_2 flux of terrestrial ecosystems. Much of the CO_2 flux research has focused on forested systems because of their high potential for CO_2 sequestration. However, rangelands (grasslands, savannas, and shrub steppes) occupy about 50% of the Earth's land surface, and depending on how one groups categories, 34 to 50% of U.S. land area (Box, 1990). Even if the CO_2 fluxes of these plant community types are low compared to forests, the large area occupied by rangelands requires that they be considered in developing terrestrial CO_2 flux budgets.