Abstract:

【Objective】 Four common garden trees in Zhengzhou City, including Ligustrum lucidum, Magnolia grandiflora, Platanus orientalis and Styphnolobium japonicum, were selected as the study subjects. Our study provide a theoretical basis for the ecological construction of green space and the selection of tree species of Zhengzhou City from the perspective of physiological environment. 【Method】 Photosynthetic characteristics, leaf surface dust retention, and temperature and humidity of the growth environment were measured in different seasons to reveal the effects of physiological and environmental factors on net photosynthetic rate in the plants. Two-factor analysis of variance was used to compare the differences in photosynthetic characteristics of distinct species in different seasons. The interactions between different factors and their effects on plant photosynthetic rate were explored through generalized linear mixed models and structural equation models. 【Result】 There were significant differences in the net photosynthetic rate of the four garden trees in different seasons (P<0.05),and the net photosynthetic rate of Styphnolobium japonicum was significantly higher than that of other species. The net photosynthetic rate for each species was significantly higher in summer than in the other seasons. Physiological factors (stomatal conductance and transpiration rate) and environmental factors (dust retention and humidity) were significantly correlated with net photosynthetic rate (P<0.05). Humidity had the most significant direct and indirect effects on the net photosynthetic rate of plants and was the key environmental factor affecting plant photosynthesis. 【Conclusion】 The net photosynthetic rate of S. japonicum is higher than that of other tree species, and there is strong correlation between environmental and physiological factors of L. lucidum and M. grandiflora.

Key words: garden trees, photosynthetic characteristics, physiological and enviromental factors, structural modelling, Zhengzhou City