The southeastern United States (SEUS), a rapidly growing region, has experienced dramatic alterations in climate, atmospheric composition, and landscape during the past century. These phenomena accompanying with the rapid population increasing in coastal counties of SEUS make this region a sensitive zone for the climate change and increasing CO₂; whereas, these changes are expected to be continued in this century, which may dramatically alter the structure and function of terrestrial ecosystems and then affect the regional carbon dynamics. Understanding the potential behavior of carbon cycling under the future climate and CO₂ scenarios over SEUS is essential for wisely dealing with the future climate condition, and for the sustainability of human society and terrestrial ecosystems. Based on our previous studies which investigated the changes of carbon storage and fluxes in SEUS in response to multiple factors, we will further project the potential changes in carbon storage and fluxes under the future climate and CO₂ scenarios during 2007-2099, by using a process-based ecosystem model Dynamic Land Ecosystem Model (DLEM). The projected climate data were downscaled from four different climate models: NCAR, GFDL, GISS, and UKMO.

Results/Conclusions

The results show that the projected changes in net carbon storage varied among different future climate and CO₂ scenarios. According to model projection, the scenario of A1B reduced carbon storage while A2 and B1 increased it during 2007-2099. Model results show a significant spatial variation in net carbon sequestration change across the southeastern US; the increases in carbon sequestration locate in the coastal area while future carbon sources in the northeast region of the southeastern US.