Plant Water Potential Improves Prediction of Empirical Stomatal Models

Many biomes contain a diversity of plant stomatal strategies during water stress.

The Science

A recent study found that current leaf-level empirical models overpredict stomatal conductance during drought conditions, and a recently proposed model improves predictions during drought conditions.

The Impact

Including the impairment of soil-to-leaf water transport will improve predictions of stomatal conductance during drought conditions. Many biomes contain a diversity of plant stomatal strategies during water stress.

Summary

Ecosystem models rely on empirical relationships to predict stomatal responses to changing environmental conditions, but these are not well tested during drought conditions. Scientists from the University of Utah, in conjunction with the Next-Generation Ecosystem Experiments (NGEE)–Tropics project, compiled datasets of stomatal conductance and leaf water potential for 34 woody plant species that span global forest biomes. They tested how well three major stomatal models and a recently proposed model predicted measured stomatal conductance. They found that current models consistently overpredicted stomatal conductance during dry conditions, whereas the recently proposed model, which includes loss of hydraulic transport capacity, improved predictions compared to current models, particularly during droughts. These results also show that many biomes contain a diversity of plant stomatal strategies during water stress. Such improvements in stomatal simulation will help to predict the response of ecosystems to future climate extremes.

Principal Investigator

William Anderegg
University of Utah
anderegg@utah.edu

Program Manager

Daniel Stover
U.S. Department of Energy, Biological and Environmental Research (SC-33)
Environmental System Science
daniel.stover@science.doe.gov

Funding

Funding for this research was provided by National Science Foudation (NSF) DEB EF-1340270 and the Climate Mitigation Initiative at the Princeton Environmental Institute, Princeton University. SL acknowledges financial support from the China Scholarship Council (CSC). VRD acknowledges funding from Ramón y Cajal fellowship (RYC-2012-10970). BTW was supported by the Next-Generation Ecosystem Experiments (NGEE)–Tropics project, funded by the Office of Biological and Environmental Research, within the U.S. Department of Energy Office of Science. DJC acknowledges funding from the National Science Centre, Poland (NN309 713340). WRLA was supported in part by NSF DEB 1714972.

References

Anderegg, W. R. L., A. Wolf, A. Arango-Velez, and B. Choat, et al. "Plant water potential improves prediction of empirical stomatal models". PLOS ONE 12 e0185481  (2017). https://doi.org/10.1371/journal.pone.0185481.