Dynamic responses of terrestrial ecosystems structure and function to climate change in China

Our understanding of the structure and function of China's terrestrial ecosystems, particularly their responses to transient climate change on timescales of decades to centuries, can be further improved by dynamic vegetation models that include vegetation dynamics as well as biogeochemical processes. Here, the Lund-Potsdam-Jena dynamic global vegetation model was calibrated to reasonably capture the general patterns of vegetation distribution across China's terrestrial ecosystems. New parameter values were used for bioclimatic limits, and the model was validated against satellite, in situ, and inventory data for net primary production (NPP), leaf area index, and carbon storage simulations. Dynamic responses of China's terrestrial ecosystems to rising atmospheric CO(2) concentration ([CO(2)]) and climate change in the 20th and 21st centuries were then simulated. Simulations were driven by eight climate scenarios consisting of combinations of two general circulation models and four emission scenarios from Intergovernmental Panel on Climate Change Special Report Emission Scenarios ranging from low emission to fossil intensive emission. We derived possible temporal and spatial change patterns of vegetation distribution, carbon flux, and carbon pools across China. Simulations showed that regional changes in temperature and precipitation would cause substantial vegetation changes in northern, northeastern, and western China. Such vegetation dynamics, and associated mechanisms such as responses of NPP and heterotrophic respiration to rising [CO(2)] and regional climate change, would lead to corresponding changes in temporal and spatial patterns of carbon flux and carbon pools. As a result, some regional ecosystems could switch from carbon sinks to carbon sources or vice versa by the end of the 21st century. China's terrestrial ecosystems have an average carbon uptake of 0.12 to 0.20 Gt C yr(-1) over the period of 1981-2100; however, the rate of increase in carbon sinks is projected to decrease after about 2040, particularly under the fossil intensive emission scenario