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Ecosystem resilience despite large-scale altered hydroclimatic conditions

Ponce-Campoa, Guillermo E., Moran, M. Susan, Huete, Alfredo, Zhang, Yongguang, Bresloff, Cynthia, Huxman, Travis E., Eamus, Derek, Bosch, David D., Buda, Anthony R., Gunter, Stacey A., Scalley, Tamara Heartsill, Kitchen, Stanley G., McClaran, Mitchel P., McNab, W. Henry, Montoya, Diane S., Morgan, Jack A., Peters, Debra P.C., Sadler, E. John, Seyfried, Mark S., Starks, Patrick J.
Nature 2013 v.494 pp. 349
aboveground biomass, carbon, climate change, drought, ecosystems, food security, herbaceous plants, plant response, primary productivity, rain, vegetation, woody plants, Africa, Amazonia, Australia, Europe, North America
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.