Vegetation responds to drought through a complex interplay of plant hydraulic mechanisms, posing challenges for model development and parameterization. We present a mathematical model that describes the dynamics of leaf water-potential over time while considering different strategies by which plant species regulate their water-potentials. The model has two parameters: the parameter λ describing the adjustment of the leaf water potential to changes in soil water potential, and the parameter Δψ ww describing the typical ‘well-watered’ leaf water potentials at non-stressed (near-zero) levels of soil water potential. Our model was tested and calibrated on 110 time-series datasets containing the leaf- and soil water potentials of 66 species under drought and non-drought conditions. Our model successfully reproduces the measured leaf water potentials over time based on three different regulation strategies under drought. We found that three parameter sets derived from the measurement data reproduced the dynamics of 53% of an drought dataset, and 52% of a control dataset [root mean square error (RMSE) < 0.5 MPa)]. We conclude that, instead of quantifying water-potential-regulation of different plant species by complex modeling approaches, a small set of parameters may be sufficient to describe the water potential regulation behavior for large-scale modeling. Thus, our approach paves the way for a parsimonious representation of the full spectrum of plant hydraulic responses to drought in dynamic vegetation models.
Bibliographical noteFunding Information:
PP and AR acknowledge funding from the BMBF-and Belmont Forum-funded project “CLIMAX: Climate services through knowledge co-production: A Euro-South American initiative for strengthening societal adaptation response to extreme events”, FKZ 01LP1610A. CZ acknowledges funding by the Bavarian Ministry of Science and the Arts in the context of the Bavarian Climate Research Network (BayKliF). DL and TP acknowledge support from the European Research Council under the European Union Horizon 2020 programme (Grant 758873, TreeMort).
© Copyright © 2020 Papastefanou, Zang, Pugh, Liu, Grams, Hickler and Rammig.
- climate change
- leaf water potential
- water stress
ASJC Scopus subject areas
- Plant Science