A coupled model of photosynthesis-transpiration based on the stomatal behavior for maize (Zea mays L.) grown in the field

The study presents a theoretical basis of a stomatal behavior-based coupled model for estimating photosynthesis, A, and transpiration, E. Outputs of the model were tested against data observed in a maize (Zea mays L.) field. The model was developed by introducing the internal conductance, g ic, to CO2 assimilation, and the general equation of stomatal conductance, g sw, to H2O diffusion, into models of CO2 and H2O diffusion through the stomata of plant leaves. The coupled model is easier for practical use since the model only includes environmental variables, such as ambient CO2 concentration, leaf temperature, humidity and photosynthetic photon flux received at the leaves within the canopy. Moreover, concept of g ic, and factors controlling A and E were discussed, and applicability of the model was examined with the data collected in the maize field.