Stomatal conductance characteristics and simulation of Tamarix chinensis
Research on stomatal behavior characteristics,influence on water use and response to environmental factors at blade scale,and stomatal conductance of the simulation,to understand the regional mechanism of veg-etation and the ecological system to adapt to the environment and water resources management is of great signifi-cance.In this study,the photosynthetic physiological characteristics of Tamarix chinensis were observed by the LI-COR 6400 photosynthesis measurement system in the field,and the characteristics,influence,and response to environmental factors of stomatal conductance(Gs)of Tamarix chinensis leaves were analyzed.The results showed that:(1)Atmospheric relative humidity(hs),photosynthetically active radiation(PAR)and air tempera-ture(Ta)had significant effects on Gs,and the correlation between the three environmental factors and leaves Gs was ranked as hs(0.662)＞PAR(0.613)＞Ta(0.601)in descending order.(2)The diurnal variation trend of leaf Gs of Tamarix chinensis increased at first and then decreased.At 06:00,Gs increased with PAR enhancement and Ta increase,then PAR weakened and Taa decreased,then Gs decreased.Due to the high midday Ta in June and July,stomatal closure of leaves was caused,and the maximum Gs value appeared at around 10:00 in June and July,and around 14:00 in August and September.(3)At the end of the growing season,Tamarix chinensis could adapt to the arid environment by increasing WUE by regulating Gs to achieve efficient water use.(4)By using three dif-ferent models:an experience model(Jarvis),a semi-empirical model(BWB),and the mechanism of stomatal conductance model(USO)to simulate Gs,the determination coefficient(R2),the modified efficiency coeffi-cient(MEC)and the root mean square error(RMSE)of the simulation results were(0.713,0.409,0.024),(0.482,0.309,0.158)and(0.260,0.135,0.255),respectively.Among the three models,the results of the Jar-vis model simulation were obtained with the highest R2 and MEC values and the lowest RMSE value,indicating that its simulation accuracy was the highest.
Tamarix chinensisstomatal conductanceJarvis modelBWB modelUSO model
万方数据
维普
