Influences of stomatal response on the partitioning of the energy within the rice canopy

A multilayer energy budget model within and above a rice canopy was developed to study influences of the stomatal response on the energy exchange processes. Micrometeorological experiments were carried out within and above a rice canopy to estimate the stomatal resistance and other parameters by fitting the calculated profiles of micrometeorological factors to the measured ones and to test the model. Relationships between the vertical profiles of stomatal resistance and those of Bowen ratio resulted that the stomatal resistance could not account for Bowen ratio directly. A standardized stomatal resistance, in which a critical stomatal resistance was incorporated, was introduced to investigate influences of the stomatal response under given meteorological conditions on the partitioning of the energy within the canopy. The critical stomatal resistance is a parameter which reflects just the physical behavior of the stomata in response to meteorological conditions. The relationships between the standardized stomatal resistance and Bowen ratio suggested that the physiological action of stomata of rice responded reasonably to the meteorological conditions and to the physical principle of energy conservation.