Abstract:Pavement is one of the most important factors causing environmental changes in urban areas. In this study, saplings of three common tree species (pine, Pinus tabulaeformis; ash, Fraxinus chinensis; and maple, Acer truncatum) were planted in three different treatment plots: pervious brick pavement with a permeability coefficient of more than 0.4 mm/s, impervious brick pavement with a permeability coefficient near zero, and non-pavement (control). In response to the pavement treatments, leaf photosynthetic characteristics of the pine, ash, and maple trees were determined by measuring surface temperature, soil moisture content (20 cm), and photosynthetic parameters. The results showed that surface temperature was significantly higher in the pavement treatments than in the control treatment (P < 0.01), with a higher surface temperature noted for the pervious pavement than for the impervious pavement. For all the tree species (especially ash), soil moisture content was significantly lower in the impervious pavement treatment than in the pervious pavement and control treatments (P < 0.01). Soil moisture content was significantly higher for pine and maple in the pervious pavement treatment than in the impervious pavement and control treatments (P < 0.01). For pine and maple, the total number of days with a maximum surface temperature exceeding 40℃ accounted for 53.3% (pervious pavement treatment) and 36.1% (impervious pavement treatment) of the entire growing period. For ash, the total number of days with daily mean soil moisture content less than 15% accounted for 88.5% (impervious pavement treatment) of the entire growing period. The pavement caused heat stress on pine and maple growth, and the impervious pavement caused drought stress on ash growth, leading to a decrease in net photosynthetic rate, transpiration rate, and stomatal conductance, and, subsequently, a decrease in tree height and basal diameter. For pine, significantly lower tree height (12.6% and 18.5%) and basal diameter (18.5% and 17.1%) were noted for the pervious and impervious pavement treatments, respectively, than for the control treatment. For maple, significantly lower tree height (45.1% and 26.8%) and basal diameter (40.9% and 20.3%) were noted for the pervious and impervious pavement treatments, respectively, than for the control treatment. For ash, significantly lower tree height (11.1% and 14.6%) and basal diameter (9.4% and 11.3%) were noted for the impervious pavement treatment, than for the pervious pavement and control treatments. In conclusion, it is necessary to select heat and drought tolerant tree species, and manage land with shadowing or irrigation, in order to guarantee tree growth in paved urban environments.