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Antecedent soil water content and vapor pressure deficit interactively control water potential in Larrea tridentata
Author(s) -
Guo Jessica S.,
Ogle Kiona
Publication year - 2019
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.15374
Subject(s) - antecedent moisture , vapour pressure deficit , antecedent (behavioral psychology) , water content , environmental science , larrea , soil water , shrub , transpiration , agronomy , atmospheric sciences , ecology , soil science , botany , surface runoff , biology , runoff curve number , geology , psychology , developmental psychology , photosynthesis , geotechnical engineering
Summary Plant water potential Ψ is regulated by stomatal responses to atmospheric moisture demand D and soil water availability W , but the timescales of influence and interactions between these drivers of plant Ψ are poorly understood. Here, we quantify the effects of antecedent D and W on plant Ψ in the desert shrub Larrea tridentata . Repeated measurements of plant baseline water potential Ψ B and diurnal water potential Ψ D were analyzed in a Bayesian framework to evaluate the influence of antecedent D and W at daily and subdaily timescales. Both Ψ B and Ψ D exhibited negative, 2‐ to 4‐d lagged responses to daily‐scale D ; conversely, plant Ψ D responded almost instantaneously to subdaily D , though the direction of this response depended on antecedent moisture conditions. Plant Ψ B and Ψ D responded positively and immediately (no lag) to shallow W , which contrasts the negative, lagged (6–7 d) response to deep W . The changing sensitivity of Ψ D to subdaily D highlights shifting modes of plant Ψ regulation: D effects on Ψ D range from negative to neutral to positive depending on past conditions and time of day. Explicit consideration of antecedent conditions across multiple timescales can reveal important complexities in plant responses.