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United States Department of Agriculture

Agricultural Research Service

Research Project: HYDROLOGIC PROCESSES, SCALE, CLIMATE VARIABILITY, AND WATER RESOURCES FOR SEMIARID WATERSHED MANAGEMENT

Location: Southwest Watershed Research

Title: Ecosystem resilience despite large-scale altered hydro climatic conditions

Authors
item Ponce Campos, G. -
item Moran, Mary
item Huete, A. -
item Zhang, Y. -
item Bresloff, C. -
item Huxman, T.E. -
item Eamus, D. -
item Bosch, David
item Buda, Anthony
item Gunter, Stacey
item Scalley, T.H. -
item Kitchen, S.G. -
item Mcclaran, M.P. -
item Mcnab, W.H. -
item Montoya, D.S. -
item Morgan, Jack
item Peters, Debra
item Sadler, Edward
item Seyfried, Mark
item Starks, Patrick

Submitted to: Nature
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 1, 2012
Publication Date: January 15, 2013
Citation: Ponce Campos, G., Moran, M.S., Huete, A., Zhang, Y., Bresloff, C., Huxman, T., Eamus, D., Bosch, D.D., Buda, A.R., Gunter, S.A., Scalley, T., Kitchen, S., McClaran, M., McNab, W., Montoya, D., Morgan, J.A., Peters, D.C., Sadler, E.J., Seyfried, M.S., Starks, P.J. 2013. Ecosystem resilience despite large-scale altered hydro climatic conditions. Nature. 494:349-352.

Interpretive Summary: Large-scale, warm droughts have recently impacted North America, Africa, Europe, Amazonia, and Australia resulting in major impacts on terrestrial resources that have threatened life support systems. Food producers, resource managers and policy makers worldwide make important decisions on livelihood and food security with little understanding about how vegetation production will respond to the altered hydroclimatic conditions predicted with climate change. Here we describe the response of plant communities to the altered hydroclimatic conditions that are projected for large international regions in the 21st century. We found that plant communities exhibited a robust tolerance to low precipitation, but that efficiency constrained the capacity for response to high precipitation. This continental lack of ecosystem resilience during altered hydroclimatic conditions will result in significant reductions in carbon uptake and ultimately, food security as parts of the world become more arid.

Technical Abstract: Climate change is predicted to increase both drought frequency and duration, and when coupled with substantial warming, will establish a new hydroclimatological paradigm for many regions. Large-scale, warm droughts have recently impacted North America, Africa, Europe, Amazonia, and Australia resulting in major impacts on terrestrial ecosystems, carbon balance, and food security. Here we compare the response of plant production (above-ground net primary production, ANPP) to variability in precipitation for contrasting periods of normal precipitation variability (1980-1999) and drier, warmer conditions (2000-2009) in the Northern and Southern Hemispheres. Although ANPP sensitivity to precipitation was similar for both normal and altered hydroclimatic conditions, we found that rain-use efficiency (RUE: ANPP/precipitation) during the driest year at each site converged to a common maximum (RUEmax) that exceeded values previously reported. Further, under the altered hydroclimatic conditions of 2000-2009, the response of vegetation production to relatively wet years was significantly decreased for both woody and herbaceous ecosystems compared to the response observed in previous decadal records. This continental lack of ecosystem resilience during contemporary hydroclimatic conditions will result in significant reductions in carbon uptake and food security as parts of the world become more arid.

Last Modified: 10/1/2014