Stomatal response drives between-species difference in predicted leaf water-use efficiency under elevated ozone. (15th January 2021)

• Record Type: Journal Article
• Authors: Xu, Yansen; Shang, Bo; Peng, Jinlong; Feng, Zhaozhong; Tarvainen, Lasse
• Is Part Of: Environmental pollution. Volume 269(2021)
• Publication Date: 2021-01-15
• Subjects: Ozone -- Photosynthesis -- Stomatal conductance -- Water use efficiency -- Leaf photosynthetic model; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2020.116137
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Ozone-induced changes in the relationship between photosynthesis ( A n ) and stomatal conductance ( g s ) vary among species, leading to inconsistent water use efficiency (WUE) responses to elevated ozone (O3 ). Thus, few vegetation models can accurately simulate the effects of O3 on WUE. Here, we conducted an experiment exposing two differently O3 -sensitive species ( Cotinus coggygria and Magnolia denudata ) to five O3 concentrations and investigated the impact of O3 exposure on predicted WUE using a coupled A n - g s model. We found that increases in stomatal O3 uptake caused linear reductions in the maximum rates of Rubisco carboxylation ( V cmax ) and electron transport ( J max ) in both species. In addition, a negative linear correlation between O3 -induced changes in the minimal g s of the stomatal model ( g 0 ) derived from the theory of optimal stomatal behavior and light-saturated photosynthesis was found in the O3 -sensitive M. denudata . When the O3 dose-based responses of V cmax and J max were included in a coupled A n - g s model, simulated A n under elevated O3 were in good agreement with observations in both species. For M. denudata, incorporating the O3 response of g 0 into the coupled model further improved the accuracy of the simulated g s and WUE. In conclusion, the modified V cmax, J max and g 0 method presented here provides a foundation for improving the prediction for O3 -induced changes in A n, g s and WUE. Graphical abstract: Image 1 Highlights: Effect of elevated O3 on predicted WUE was investigated using a coupled A n - g s model. Increases in stomatal O3 uptake caused linear reductions in V cmax, J max and g m . O3 -induced changes in g 0 of M. denudata w were related to decreases in A sat . Including O3 dose-responses of V cmax and J max improved the accuracy of simulated A n . O3 -induced changes in g 0 of the optimal stomatal model determined predicted WUE. Abstract : Stomatal response to elevated O3 determined predicted leaf WUE.