Updating the Dual C and O Isotope—Gas-exchange Model: A Concept to Understand Plant Responses to the Environment and Its Implications for Tree Rings

Authors

Rolf T. W. Siegwolf, Swiss Federal Institute for Forest, Snow and Landscape Research WSL
Marco M. Lehmann, Swiss Federal Institute for Forest, Snow and Landscape Research WSL
Gregory R. Goldsmith, Chapman UniversityFollow
Olga V. Churakova (Sidorova), Siberian Federal University
Cathleen Mirande-Ney, Paul Scherrer Institute
Galina Timoveeva, Paul Scherrer Institute
Rosmarie B. Weigt, Paul Scherrer Institute
Matthias Saurer, Swiss Federal Institute for Forest, Snow and Landscape Research WSL

Document Type

Article

Publication Date

6-7-2023

Abstract

The combined study of carbon (C) and oxygen (O) isotopes in plant organic matter has emerged as a powerful tool for understanding plant functional responses to environmental change. The approach relies on established relationships between leaf gas exchange and isotopic fractionation to derive a series of model scenarios that can be used to infer changes in photosynthetic assimilation and stomatal conductance driven by changes in environmental parameters (CO₂, water availability, air humidity, temperature, nutrients). We review the mechanistic basis for a conceptual model, in light of recently published research, and discuss where isotopic observations do not match our current understanding of plant physiological response to the environment. We demonstrate that (1) the model was applied successfully in many, but not all studies; (2) although originally conceived for leaf isotopes, the model has been applied extensively to tree-ring isotopes in the context of tree physiology and dendrochronology. Where isotopic observations deviate from physiologically plausible conclusions, this mismatch between gas exchange and isotope response provides valuable insights into underlying physiological processes. Overall, we found that isotope responses can be grouped into situations of increasing resource limitation versus higher resource availability. The dual-isotope model helps to interpret plant responses to a multitude of environmental factors.

Comments

This article was originally published in Plant, Cell & Environment in 2023. https://doi.org/10.1111/pce.14630

Recommended Citation

Siegwolf, R. T. W., Lehmann, M. M., Goldsmith, G. R., Churakova (Sidorova), O. V., Mirande‐Ney, C., Timoveeva, G. et al. (2023) Updating the dual C and O isotope—gas‐exchange model: a concept to understand plant responses to the environment and its implications for tree rings. Plant, Cell & Environment, 1–22. https://doi.org/10.1111/pce.14630

Copyright

The authors

Creative Commons License

This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.