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PubMed · 12907704

Plants reverse warming effect on ecosystem water balance.

Erika S Zavaleta·Brian D Thomas·Nona R Chiariello·Gregory P Asner·M Rebecca Shaw·Christopher B Field
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Abstract

Models predict that global warming may increase aridity in water-limited ecosystems by accelerating evapotranspiration. We show that interactions between warming and the dominant biota in a grassland ecosystem produced the reverse effect. In a 2-year field experiment, simulated warming increased spring soil moisture by 5-10% under both ambient and elevated CO2. Warming also accelerated the decline of canopy greenness (normalized difference vegetation index) each spring by 11-17% by inducing earlier plant senescence. Lower transpirational water losses resulting from this earlier senescence provide a mechanism for the unexpected rise in soil moisture. Our findings illustrate the potential for organism-environment interactions to modify the direction as well as the magnitude of global change effects on ecosystem functioning.

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Carbon DioxideEcosystemGreenhouse EffectPlantsSoilTemperatureWaterWater SupplyJournal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, Non-P.H.S.

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Erika S Zavaleta, Brian D Thomas, Nona R Chiariello, Gregory P Asner, M Rebecca Shaw, Christopher B Field. 2003-08-07. Plants reverse warming effect on ecosystem water balance.. https://doi.org/10.1073/pnas.1732012100

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