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ARS Home » Pacific West Area » Tucson, Arizona » SWRC » Research » Publications at this Location » Publication #323588

Research Project: Soil Mapping to Support the Soil Moisture Active Passive Validation Experiment 2015 (SMAPVEX15)

Location: Southwest Watershed Research Center

Title: Productivity of North American grasslands is increased under future climate scenarios despite rising aridity

Author
item HUFKENS, K. - Harvard University
item KEENAN, T.F. - Macquarie University
item FLANAGAN, L.B. - University Of Lethbridge
item Scott, Russell - Russ
item Bernacchi, Carl
item JOO, E. - University Of Illinois
item BRUNSELL, N. - University Of Kansas
item VERFAILLIE, J. - University Of California
item RICHARDSON, A.D. - Harvard University

Submitted to: Nature Climate Change
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/20/2016
Publication Date: 2/29/2016
Citation: Hufkens, K., Keenan, T., Flanagan, L., Scott, R.L., Bernacchi, C.J., Joo, E., Brunsell, N., Verfaillie, J., Richardson, A. 2016. Productivity of North American grasslands is increased under future climate scenarios despite rising aridity. Nature Climate Change. 6:710-716. doi:10.1038/nclimate2942.

Interpretive Summary: Grassland productivity is regulated by both temperature and the amount and timing of precipitation. Future climate change is therefore expected to influence the seasonality of grassland growth, with consequences for ecosystems and economies. However, the potential response of grasslands to climate change remains poorly understood. Here, we explore potential responses of grasslands to climate change across North America, using a grassland hydrology and plant growth model, a network of ground observations across a wide range of grassland ecosystems, and climate projections to 2100. Despite differences in predicted future precipitation projections, an increase in aridity is projected across most of our study area. Regardless of the increasing aridity, our results suggest widespread and consistent increases in foliage for the current range of grassland ecosystems throughout most of North America. Our analysis indicates a likely future shift of vegetation growth towards both earlier spring emergence and delayed growth stoppage in autumn, which together compensate for drought-induced reductions in summer foliage and productivity in most regions. The resulting increase in the overall productivity of North American grasslands over the coming century has important implications for agriculture, carbon cycling, and vegetation feedbacks to the atmosphere.

Technical Abstract: Grassland productivity is regulated by both temperature and the amount and timing of precipitation. Future climate change is therefore expected to influence grassland phenology and growth, with consequences for ecosystems and economies. However, the potential response of grasslands to climate change remains poorly understood. Here, we explore potential responses of grasslands to climate change across North America, using a data informed vegetation-hydrological model, a network of high-frequency ground observations across a wide range of grassland ecosystems, and CMIP-5 climate projections to 2100. Despite between-model variability in future precipitation projections, an increase in aridity is projected across most of our study area. Regardless of the increasing aridity, our results suggest widespread and consistent increases in foliage cover for the current range of grassland ecosystems throughout most of North America. Our analysis indicates a likely future shift of vegetation growth towards both earlier spring emergence and delayed senescence in autumn, which together compensate for drought-induced reductions in summer foliage cover and productivity in most regions. The resulting increase in the overall productivity of North American grasslands over the coming century has important implications for agriculture, carbon cycling, and vegetation feedbacks to the atmosphere.