Effect of Light Intensity on the Functional Traits of Two Ormosia Species

This study investigated two Ormosia species, Ormosia henryi and Ormosia hosiei, to examine their adaptive mechanisms to varying light conditions. Four light intensity treatments were applied to measure their growth parameters, photosynthetic characteristics, leaf microstructure, and chlorophyll content. The results showed that (1) both Ormosia species exhibited significant variations in functional traits under different light conditions. Growth parameters displayed high plasticity, and photosynthetic traits and leaf structural characteristics were optimal under 50% light intensity. (2) The overall phenotypic plasticity of O. henryi and O. hosiei was similar, though differences were observed in the plasticity of PT, SD, and Chl b, indicating distinct strategies in response to environmental changes. (3) Most functional traits were significantly correlated, and their coordinated changes contributed to the formation of adaptive capacity to light variation in both species. (4) During the seedling propagation of Ormosia species, approximately 50% shading should be applied. In conclusion, this study reveals the variation and adaptive mechanisms of functional traits in Ormosia seedlings under different light intensities, providing a theoretical basis for understory light environment management and shade cultivation, as well as a reference for further studies on the light ecological strategies and shade tolerance mechanisms of Ormosia species.