Abstract: Urban greening not only includes the beautification of landscaping, but also has important ecological functions, and its ecological function is realized through the physiological activities of plants. Photosynthetic capacity often varies appreciably among species and genotypes. Such variations are usually related to basic differences in metabolism and/or leaf anatomy. The experiment was conducted to study the influence of leaf anatomical structure on photosynthetic characteristics in eight tree species in Harbin. Photosynthetic rate(P_n), respiratory rate(R_d), transpiration rate(T_r), stomatal conductance(G_s) and intercellular CO₂ concentration(C_i) were measured by a portable photosynthesis system(Model Li-Cor 6400). The leaf anatomical structure, including leaf thickness, epidermal thickness, palisade tissue thickness and sponge tissue thickness were measured by micrometer microscope. The maximum photosynthetic rate, G_s, C_i, T_r and light saturation point(LSP) were significantly different(P<0.05) in the eight species. The difference of epidermal thickness, palisade tissue thickness, upper epidermal stomatal density and lower epidermal stomatal density was significant in the eight trees(P<0.05). Although there was significant difference in photosynthetic characteristics and leaf anatomical structure among the eight species, we found that there was a correlation between them. There was a significant positive correlation between light saturation point and leaf epidermal thickness in the eight species(P<0.01), and the correlation coefficient was 0.78. The intercellular CO₂ concentration was significantly negatively correlated with the upper epidermal stomata density(P<0.05), and the correlation coefficient was -0.65. The maximum photosynthetic rate, R_d, T_r and LSP were not significantly correlated with epidermal thickness, palisade tissue thickness, sponge tissue thickness, upper epidermal stomatal density and epidermis stomatal density(P>0.05). There was no significant correlation between intercellular CO₂ concentration and epidermal thickness, palisade tissue thickness, sponge tissue thickness and epidermis stomatal density(P>0.05). There was no significant correlation between light saturation point and palisade tissue thickness, sponge tissue thickness, upper epidermal stomatal density and epidermis stomatal density(P>0.05). Although there is still a great deal to learn how the leaf anatomical structure effect on physiological process, the measurements of leaf anatomical structure have great potential to provide a better understanding of physiological process.

Key words: photosynthetic rate, anatomical structures of leaf, transpiration rate, stomatal conductance