To be able to predict the probability of tree mortality due to drought at an individual and landscape scale we need knowledge of the time it takes for plants to reach critical levels of hydraulic failure (an inability to transport water).

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 that predicts the time to plant desiccation, was consistent with observed dry-down times.

We found that plant desiccation time varied among species, ranging from 96.2 to 332 hrs at a vapour-pressure deficit (VPD) of 1 KPa (i.e., VPD hrs), and was highly predictable using our model, when accounting for the process of leaf shedding.

Knowledge of the time it takes a plant to desiccate in combination with measurable traits that describe plant water-use strategies, could significantly increase our ability to predict the timing of drought-induced mortality at tree and forest scales.

  • Paper: Blackman, C. J., Li, X. , Choat, B. , Rymer, P. D., De Kauwe, M. G., Duursma, R. A., Tissue, D. T. and Medlyn, B. E. (2019), Desiccation time during drought is highly predictable across species of Eucalyptus from contrasting climates. New Phytol. Accepted Author Manuscript. doi:10.1111/nph.16042