Diurnal Photosynthetic Dynamic of Thuja sutchuenensis under Different Light Environments

This study focused on the photosynthetic characteristics of Thuja sutchuenensis seedlings and its relationship with environmental factors under three light levels(full light,50% full light,and 25% full light).The results showed that under different light environments,the maximum value of net photosynthetic rate Pn appeared at the 8:00 with the sizes were 6.48,4.59,and 2.67 μmol·m-2·s-1.There existed"midday-depression"in the diurnal photosynthesis of T.sutchuenensis,which mostly contributed by non-stomatal factors.The results of path analysis demonstrated that among the environmental factors affecting the photosynthesis of T.sutchuenensis under different light environments,the photosynthetically active radiation and air CO2 concentration were the main decision factors,while the main limiting factor was the air temperature.