Towards a unified theory of plant photosynthesis and hydraulics
File(s)
Author(s)
Type
Working Paper
Abstract
The global carbon and water cycles are strongly governed by the simultaneous diffusion of CO2 and water vapour through the leaves of terrestrial plants. These diffusive fluxes are controlled by plants’ adaptations to balance carbon gains and hydraulic risks. We introduce a trait-based optimality theory that unifies the treatment of stomatal responses and biochemical acclimation of plants to changing environments. Tested with experimental data from eighteen species, our model successfully predicts the simultaneous decline in carbon assimilation rate, stomatal conductance, and photosynthetic capacity during progressive soil drought. It also correctly predicts the dependencies of gas exchange on atmospheric vapour pressure deficit, temperature, and CO2. Consistent with widely observed patterns, inferred trait values for the analysed species display a spectrum of stomatal strategies, a safety-efficiency trade-off, and a convergence towards low hydraulic safety margins. Our unifying theory opens new avenues for reliably modelling the interactive effects of drying soil and air and rising atmospheric CO2 on global photosynthesis and transpiration.
Date Issued
2020-12-18
Citation
2020
Publisher
Cold Spring Harbor Laboratory
Copyright Statement
© 2021 The Author(s). It is made available under a CC-BY 4.0 International license.
License URL
Sponsor
Commission of the European Communities
Identifier
https://www.biorxiv.org/content/10.1101/2020.12.17.423132v1
Grant Number
787203
Publication Status
Published