PARTNERS: USDA Forest Service Southern Research Station

SUMMARY: Ecosystems and natural resources across the United States have been increasingly stressed over the past decades, mainly due to population growth and climate change and variability. Quantifying changes in ecosystem processes and ecosystem services under a changing environment is critical for management decisionmaking. EFETAC scientists are developing an integrated model to estimate ecosystem water and carbon balances and the interactions among ecosystem evapotranspiration, productivity, carbon sequestration, and biodiversity at the continental scale by coupling the key processes of the hydrologic and carbon cycles. This integrated, water-centered modeling system is being built upon previous water supply and demand research that resulted in a Water Supply Stress Index (WaSSI) model. Scientists have used the WaSSI model to examine potential impacts of climate, land use, and population changes individually or in combination. The new model, WaSSI-Carbon and Biodiversity, or WaSSI-CB, is being developed by literature synthesis of international carbon flux network data and regional relationships among climate and ecosystem processes. The model is being developed and applied in the United States and internationally in Africa, Asia and North America. A web-based version of the model will be released in early 2012.

Above right: Estimated net ecosystem exchange (NEE) by the WaSSI model. Dark green areas in the southern US show higher capture potential than light areas in the western US. Click to enlarge.

Above left: The WaSSI model was used to evaluate forest ecosystem services such as stabilizing climate, capturing atmospheric CO2, reducing soil erosion, and providing clean water in Rwanda’s national park. Photo by Dr. Carter Ingram, Wildlife Conservation Service.

EFETAC's ROLE: EFETAC scientists are conducting research and developing the model.

STATUS: Ongoing

PROGRESS:

Sun, G., P. Caldwell, A. Noormets, S.G. McNulty, E. Cohen, J. Moore Myers, J.-C. Domec, E. Treasure, Q. Mu, J. Xiao, R. John, and J. Chen. 2011. Upscaling key ecosystem functions across the conterminous United States by a water-centric ecosystem model. Journal of Geophysical Research 116:G00J05. 16 PP. (PDF)

Sun, G., S.G. McNulty, J.A. Moore Myers, and E.C. Cohen. 2008. Impacts of Climate Change, Population Growth, Land Use Change, and Groundwater Availability on Water Supply and Demand across the Conterminous U.S. Watershed Update, May-August, Vol. 6, No. 2. (PDF)

Sun, G., S.G. McNulty, J.A. Moore Myers, and E.C. Cohen. 2008. Impacts of Multiple Stresses on Water Demand and Supply across the Southeastern United States. Journal of American Water Resources Association 44(6):1441-1457. (PDF)

McNulty, S.G., G. Sun, E.C. Cohen, and J.A. Moore Myers. 2007. Change in the Southern U.S. Water Demand and Supply over the Next Forty Years. Book Chapter 5. In: Wetland and Water Resource Modeling and Assessment: a Watershed Perspective. W. Ji (ed). P 43-56. CRC Press. 

Sun, G., S.G. McNulty, E. Cohen, J. Moore-Myers, and D. Wear. 2005. Modeling the impacts of climate change, land use change, and human population dynamics on water availability and demands in the Southeastern U.S. ASAE Paper No. 052219. St. Joseph, Mich.: ASAE. 

McNulty, S., G. Sun, and J. Moore Myers. 2004. Climate, Population, and Vegetation Cover Change Impacts on Water Yield and Demand Across the Southern US. In: Geographic Information Systems and Water Resources III: AWRA Spring Specialty Conference. Nashville, TN. May 17-19, 2004. 

LINKS:

Water Supply Stress Index

USDA Forest Service Southern Research Station 

CONTACT: Ge Sun, EFETAC Research Hydrologist, ge_sun@ncsu.edu or 919-515-9498

Updated December 2011