Objective Exploring the response characteristics of landscape plants to different intensities of urban nighttime lighting can assess their tolerance and adaptability to light pollution in urban environments. The study aimed to reveal the photosynthetic response and physiological and biochemical adaptability of Fraxinus velutinoides to different intensities of urban nighttime lighting. This will provide a scientific basis for the selection of urban landscape tree species and scientific regulation of streetlight duration, and promote the sustainable development of urban ecological environments.

Method Using the commonly used tree species F. velutina as the experimental material for roadside trees in Beijing, the changes and adaptation characteristics of leaf photosynthetic parameters, photosynthetic pigment content, and stress resistance physiological and biochemical indicators under different lighting intensity gradients at night in the city were studied through field monitoring and laboratory analysis.

Result (1) The net photosynthetic rate, stomatal conductance, and transpiration rate of F. velutina leaves can actively respond to urban nighttime lighting and are positively correlated with nighttime lighting intensity. (2) With the increase of nighttime lighting intensity, the total amount of chlorophyll significantly increased, while chlorophyll a/b significantly decreased. (3) With the increase of nighttime lighting intensity in urban areas, the soluble sugar content, superoxide dismutase activity, and peroxidase activity of F. velutina leaves all increased, which to some extent alleviated the stress caused by urban nighttime lighting on leaves.

Conclusion F. velutina can actively respond to nighttime lighting by adjusting the activity of superoxide dismutase, peroxidase, and soluble sugar content, ensuring normal photosynthesis. F. velutina exhibits adaptability and response to nighttime lighting, and can be used as a tree species for urban road greening.