A Modeling Approach to Stomatal Conductance under Different Vapor Pressure Conditions.

Area of Science:

• Plant physiology
• Environmental science
• Mathematical modeling

Background:

• Stomatal conductance regulates plant gas exchange, impacting photosynthesis and adaptation to environmental changes like global warming.
• Understanding stomatal response to environmental drivers is critical for predicting plant behavior under climate change.

Purpose of the Study:

• To develop and validate a two-dimensional nonlinear model for estimating plant stomatal conductance over time.
• To investigate the influence of environmental factors, specifically air temperature and relative humidity (via vapor pressure deficit), on stomatal conductance.
• To couple stomatal conductance dynamics with leaf water content.

Main Methods:

• A two-dimensional nonlinear model using ordinary differential equations was developed.
• A modified Gompertz-type equation was employed to capture nonlinear stomatal adjustment dynamics.
• Local and global sensitivity analyses were performed to identify key model parameters.

Main Results:

• Vapor pressure deficit was identified as the most influential factor affecting equilibrium stomatal conductance.
• The model demonstrated the ability to reproduce the primary trends of stomatal conductance in preliminary evaluations.
• Sensitivity analysis highlighted the complex interplay of environmental drivers on stomatal regulation.

Conclusions:

• The proposed model offers a novel approach to simulating stomatal conductance dynamics.
• Further validation with independent datasets is required to confirm the model's broader applicability.
• The findings contribute to a better understanding of plant responses to environmental variability and climate change.