Vico, Giulia
- Department of Ecology, Swedish University of Agricultural Sciences
Abstract
Photosynthesis depends on stomatal, mesophyll, and biochemical limitations, which in turn respond to the environment in complex ways. However, it remains unclear how to quantitatively describe the interrelationships among these three limitations and their response to environmental changes. We introduce a nested (bilevel) optimization modeling framework in which stomatal and non-stomatal limitations are optimized for separate optimization objectives. Stomatal optimization is prioritized, with stomatal conductance maximizing photosynthesis for set hydraulic costs. In turn, for set stomatal conductance, mesophyll conductance and biochemical capacity are optimized for maximum photosynthesis at a minimal cost. Our model reproduced observed responses of stomatal conductance, mesophyll conductance, and biochemical capacity to key environmental factors (light, air CO2 concentration, vapor pressure deficit, and soil moisture), including the different but coordinated reductions in stomatal conductance, mesophyll conductance, and biochemical capacity under water stress. Crucially, the model correctly estimated changes in intrinsic water use efficiency and provided testable predictions about how variations in plant hydraulic and photosynthetic traits drive the dynamic of photosynthetic limitations. Our work provides a novel optimization framework for understanding and predicting how mesophyll and biochemical limitations are coordinated with stomatal regulation, which facilitates further theoretical and experimental studies.
Keywords
Optimization; Photosynthesis; Stomatal conductance; Non-stomatal limitation; Mesophyll conductance
Published in
Agricultural and Forest Meteorology
2025, volume: 375, article number: 110829
Publisher: ELSEVIER
SLU Authors
UKÄ Subject classification
Ecology
Meteorology and Atmospheric Sciences
Publication identifier
- DOI: https://doi.org/10.1016/j.agrformet.2025.110829
Permanent link to this page (URI)
https://res.slu.se/id/publ/143812