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Desiccation time during drought is highly predictable across species of Eucalyptus from contrasting climates
Author(s) -
Blackman Chris J.,
Li Ximeng,
Choat Brendan,
Rymer Paul D.,
De Kauwe Martin G.,
Duursma Remko A.,
Tissue David T.,
Medlyn Belinda E.
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.16042
Subject(s) - desiccation , biology , eucalyptus , vapour pressure deficit , eucalyptus camaldulensis , environmental science , ecology , desiccation tolerance , botany , transpiration , photosynthesis
Summary Catastrophic failure of the water transport pathway in trees is a principal mechanism of mortality during extreme drought. To be able to predict the probability of mortality at an individual and landscape scale we need knowledge of the time for plants to reach critical levels of hydraulic failure. We grew plants of eight species of Eucalyptus originating from contrasting climates before allowing a subset to dehydrate. We tested whether a trait‐based model of time to plant desiccation t crit , from stomatal closure g s90 to a critical level of hydraulic dysfunction Ψ crit is consistent with observed dry‐down times. Plant desiccation time varied among species, ranging from 96.2 to 332 h at a vapour‐pressure deficit of 1 kPa, and was highly predictable using the t crit model in conjunction with a leaf shedding function. Plant desiccation time was longest in species with high cavitation resistance, strong vulnerability segmentation, wide stomatal‐hydraulic safety, and a high ratio of total plant water content to leaf area. Knowledge of t crit in combination with water‐use traits that influence stomatal closure could significantly increase our ability to predict the timing of drought‐induced mortality at tree and forest scales.