Characteristics and quantitative simulation of stomatal conductance of Aneurolepidium chinense.

Based on field measurements of stomatal conductance and photosynthesis of Aneurolepidium chinense,the dynamic characteristics and the relationship between stomatal conductance and environmental conditions were examined to develop a leaf stomatal conductance model for A. chinense. The results showed that the variation of stomatal conductance of A. chinense was closely correlated with environmental factors, such as physiologically active radiation (PAR), vapor pressure deficit (VPD) and air temperature (Ta). The daily variation of A. chinense stomatal conductance could be described as M-type curve at fair-weather, but⌒-type curve at cloudy weather.The value of stomatal conductance increased with the increase of PAR or Ta, but decreased with the increase of VPD. The relationship between stomatal conductance(g s) and environmental factors could be expressed as: g s=PAR(2.01Ta 2+147.74Ta-2321.11)/((444.62+PAR)(-538.04+VPD)).This model would be helpful to simulate the dynamical photosynthesis of leaf and canopy and to further simulate the NPP of ecosystems and the exchange of water and heat among the soil-plant-atmosphere continum.