Effects of different light conditions to the structure and biomass of Emmenopterys henryi seedlings

Abstract

Emmenopterys henryi is a unique genus of Rubiaceae in China. It belongs to the national precious tree species announced by the Ministry of Forestry. Shading net was used to set 20%, 40%, 60%, 80% shading and natural light (full light) respectively to measure the structure and biomass changes of E. henryi seedlings under different shading conditions. The results showed that the length, dry weight, wet weight and diameter of trunk decreased linearly with the increase of shading degree, and the difference was significant under different light conditions (p < 0.05). With the increase of shading degree, the length, dry weight and wet weight of the first branch of the main trunk of E. henryi seedlings increased first and then decreased. The diameter of the first branch of the main trunk of E. henryi seedlings decreased linearly, and the difference was significant under different light conditions (p < 0.05). With the increase of shading degree, the length and diameter of the main roots of E. henryi showed a linear downward trend, while the dry weight and wet weight showed a wavy trend of first decreasing, then rising and then decreasing, with significant differences under different light environments (p < 0.05). In general, with the decrease of light intensity, the biomass increment of E. henryi seedlings decreased significantly. The result implies that light affects the morphological composition and biomass synthesis of E. henryi seedlings.