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The effect of plant water storage on water fluxes within the coupled soil–plant system
Author(s) -
Huang ChengWei,
Domec JeanChristophe,
Ward Eric J.,
Duman Tomer,
Manoli Gabriele,
Parolari Anthony J.,
Katul Gabriel G.
Publication year - 2017
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.14273
Subject(s) - transpiration , environmental science , soil water , root system , water potential , sink (geography) , agronomy , soil science , hydrology (agriculture) , photosynthesis , biology , botany , geology , cartography , geotechnical engineering , geography
Summary 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 ( F e , night ) on hydraulic redistribution (HR) in the soil. The model results suggest that daytime PWS usage and F e , nightgenerate a residual water potential gradient ( Δ ψ p , night) along the plant vascular system overnight. This Δ ψ p , nightrepresents 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.