Abstract for talk, "Land Use, Carbon Cycle and Climate Change" by Atul K. Jain

Improved understanding of terrestrial carbon dynamics is taking on increased scientific and political importance following the UN climate conference in Kyoto, which encourages countries to actively manage the terrestrial biosphere as a complementary measure of emission reduction. Several mechanisms have been proposed to explain present trends in the terrestrial uptake of CO2. These mechanisms include physiological responses of terrestrial ecosystems to increasing ambient CO2 concentrations, anthropogenic N deposition, and variations in productivity due to climate variability. Each of these mechanisms may be playing a significant role in the global CO2 budget. In addition, the terrestrial biosphere is also influenced by non-anthropogenic disturbances such as lightning-induced forest fires in addition to anthropogenic disturbances, which include clearing of land for agriculture, conversion of forest to pasture, and harvest of forest products. This talk will present the concurrent effects of all important ecosystem processes and disturbances in addition to impact on historical net terrestrial CO2 uptake as estimated using an Integrated Science Assessment Model (ISAM), a geographically explicit advanced terrestrial ecosystem model.