The effect of plant water storage on water fluxes within the coupled soil-plant system
DOMEC, Jean-Christophe
Interactions Sol Plante Atmosphère [UMR ISPA]
Nicholas School of the Environment
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Interactions Sol Plante Atmosphère [UMR ISPA]
Nicholas School of the Environment
DOMEC, Jean-Christophe
Interactions Sol Plante Atmosphère [UMR ISPA]
Nicholas School of the Environment
Interactions Sol Plante Atmosphère [UMR ISPA]
Nicholas School of the Environment
KATUL, Gabriel G.
Nicholas School of the Environment
Department of Civil and Environmental Engineering
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Nicholas School of the Environment
Department of Civil and Environmental Engineering
Langue
en
Article de revue
Ce document a été publié dans
New Phytologist. 2017, vol. 213, n° 3, p. 1093-1106
Wiley
Résumé en anglais
In addition to buffering plants from water stress during severe droughts, plant water storage (PWS) alters many features of the spatio-temporal dynamics of water movement in the soil-plant system. How PWS impacts water ...Lire la suite >
In addition to buffering plants from water stress during severe droughts, plant water storage (PWS) alters many features of the spatio-temporal dynamics of water movement in the soil-plant system. How PWS impacts water dynamics and drought resilience is explored using a multi-layer porous media model. The model numerically resolves soil-plant hydrodynamics by coupling them to leaf-level gas exchange and soil-root interfacial layers. Novel features of the model are the considerations of a coordinated relationship between stomatal aperture variation and whole-system hydraulics and of the effects of PWS and nocturnal transpiration (Fe,night) on hydraulic redistribution (HR) in the soil. The model results suggest that daytime PWS usage and Fe,night generate a residual water potential gradient (Δψp,night) along the plant vascular system overnight. This Δψp,night represents a non-negligible competing sink strength that diminishes the significance of HR. Considering the co-occurrence of PWS usage and HR during a single extended dry-down, a wide range of plant attributes and environmental/soil conditions selected to enhance or suppress plant drought resilience is discussed. When compared with HR, model calculations suggest that increased root water influx into plant conducting-tissues overnight maintains a more favorable water status at the leaf, thereby delaying the onset of drought stress.< Réduire
Mots clés
stress hydrique
sensibilité à la sécheresse
relation sol-plante-atmosphère
système vasculaire des plantes
Mots clés en anglais
drought resilience
hydraulic redistribution
leaf-level gas exchange
nocturnal transpiration
plant water storage
root water uptake
water stress
soil-plant-atmosphere relationship
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