Effect of Radiative Forcing on Growth and Photosynthetic Responses of Elaeocarpus glabripetalus Merr.

[Objective] This study aimed to reveal the impact of radiative forcing on the woody plants in subtropical regions of China through the study on the effect of radiative forcing on growth and photosynthetic responses of Elaecarpus glabripetalus Merr. seedlings. [Method] Three gradients of radiative forcing treatments were applied to the species namely, control group （100% natural light）, weak radiative forcing group （39% natural light） and strong radiative forcing group （16% natural light）. The relative contents of chlorophyll, photosynthetic parameters of E. glabripetalus in different periods were measured to analyze the effects of different gradients of radiative forcing on plant height, ground diameter, chlorophyll content, gas exchange parameters, light response cure parameters. [Result] The increased ground diameter of E. glabripetalus in different treatments was the control weak radiative forcing group strong radiative forcing group; the increased plant height in the early period was strong radiative forcing group weak radiative forcing group control, but there was no significant difference during the late period; the relative content of chlorophyll was strong radiative forcing group weak radiative forcing group control. The light compensation point （LCP）, light saturation point （LSP） and the maximum net photosynthetic rate （A max ） were reduced in radiative forcing treatments. The stomatal conductance （G s ）, transpiration rate （Tr） of E. glabripetalus in strong radiative forcing group were significantly smaller than that in the control group, while there was no significant change in dark respiration rate （R d ） and apparent quantum yield （AQY）. [Conclusion] In summary, the radiative forcing can change the environmental factors which have significant effect on the ground diameter, plant height, relative content of chlorophyll and photosynthetic physiological parameters, but with the processing of treatment the effects on ground diameter and plant height increase are not significant in the late period, indicating that E. glabripetalus seedlings have some resistance and adaptability to the radiative forcing environment.