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ARS Home » Plains Area » Las Cruces, New Mexico » Range Management Research » Research » Publications at this Location » Publication #300470
Title: Enhanced precipitation-variability effects on water losses and ecosystem functioning: Differential response of arid and mesic regions

Author
item SALA, OSVALDO - Arizona State University
item GHERARDI, LAUREANO - Arizona State University
item Peters, Debra

Submitted to: Climatic Change
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/15/2015
Publication Date: 7/1/2015
Publication URL: http://handle.nal.usda.gov/10113/61102
Citation: Sala, O.E., Gherardi, L.A., Peters, D.C. 2015. Enhanced precipitation-variability effects on water losses and ecosystem functioning: Differential response of arid and mesic regions. Climatic Change. 131:213-227.

Interpretive Summary: We used a process-based ecosystem model to simulate the effects of intra- and multi-annual variability in precipitation on soil water availability to plants. The model was used to simulate 35 grassland locations in the central U.S. under four level of precipitation variability (control, +25, +50, +75%) and six temporal scales ranging from intra- to multi-annual. Our results show that the scale of variability had a larger effect on soil water availability than the magnitude of change. Inter- and multi-annual variability had much larger effects than intra-annual variability. Arid-semiarid grasslands showed increases in water availability as variability increased whereas mesicgrasslands showed a decrease in water availability. These increases and decreases in water availability have consequences for shifts in lifeform between grasses and woody plants that lead to state changes. We used a process-based ecosystem model to simulate the effects of intra- and multi-annual variability in precipitation on soil water availability to plants. The model was used to simulate 35 grassland locations in the central U.S. under four level of precipitation variability (control, +25, +50, +75%) and six temporal scales ranging from intra- to multi-annual. Our results show that the scale of variability had a larger effect on soil water availability than the magnitude of change. Inter- and multi-annual variability had much larger effects than intra-annual variability. Arid-semiarid grasslands showed increases in water availability as variability increased whereas mesicgrasslands showed a decrease in water availability. These increases and decreases in water availability have consequences for shifts in lifeform between grasses and woody plants that lead to state changes.

Technical Abstract: Climate change will result in increased precipitation variability with more extreme events across a range of temporal scales. We used a process-based ecosystem model to simulate water losses and soil water availability to plants at 35 grassland locations in the central U.S. under four level of precipitation variability (control, +25, +50, +75%) and six temporal scales ranging from intra- to multi-annual.Our results show that the scale of variability had a larger effect on soil water availability than the magnitude of change, and that inter- and multi-annual variability had much larger effects than intra-annual variability. Arid-semiarid locations showed increases in water availability as variability increased whereas mesic locations showed a decrease in water availability. These increases and decreases in water availability have consequences for these systems that are susceptible to shifts in lifeform between grasses and woody plants.