TY  - JOUR
AU  - Huber, Katrin
AU  - Vanderborght, Jan
AU  - Javaux, Mathieu
AU  - Vereecken, Harry
TI  - Simulating transpiration and leaf water relations in response to heterogeneous soil moisture and different stomatal control mechanisms
JO  - Plant and soil
VL  - 394
IS  - 1-2
SN  - 0032-079X
CY  - Dordrecht [u.a.]
PB  - Springer Science + Business Media B.V
M1  - FZJ-2015-05777
SP  - 109-126
PY  - 2015
AB  - AimsStomata can close to avoid cavitation under decreased soil water availability. This closure can be triggered by hydraulic (‘H’) and/or chemical signals (‘C’, ‘H + C’). By combining plant hydraulic relations with a model for stomatal conductance, including chemical signalling, our aim was to derive direct relations that link soil water availability, expressed as fraction of roots in dry soil (fdry), to transpiration reduction.MethodsWe used the mechanistic soil-root water flow model R-SWMS to verify this relation. Virtual split root experiments were simulated, comparing horizontal and vertical splits with varying fdry and different strengths of stomatal regulation by chemical and hydraulic signals.ResultsTranspiration reduction predicted by the direct relations was in good agreement with numerical simulations. For small enough potential transpiration and large enough root hydraulic conductivity and stomatal sensitivity to chemical signalling isohydric plant behaviour originates from H + C control whereas anisohydric behaviour emerges from C control. For C control the relation between transpiration reduction and fdry becomes independent of transpiration rate whereas H + C control results in stronger reduction for higher transpiration rates.ConclusionDirect relations that link effective soil water potential and leaf water potential can describe different stomatal control resulting in contrasting behaviour.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000360644200009
DO  - DOI:10.1007/s11104-015-2502-9
UR  - https://juser.fz-juelich.de/record/255643
ER  -