Abstract: In this study, photosynthetic physiological indices of six garden tree species in Dalian were measured with LI-6400 photosynthesis system in different seasons. The responses of photosynthesis to different light intensities were also calculated. The results showed that the capacity of carbon sequestration and oxygen release per unit of leaf area was the strongest in summer for all the six species. The capabilities of daily carbon sequestration and oxygen release per unit of leaf area were in order of Sophora japonica var. pendula > Albizia julibrissin > Zelkova serrata > Quercus dentata > Platanus acerifolia > Pterocarya stenoptera; in terms of per individual plant, such capabilities were in order of P. acerifolia > Q. dentate > A. julibrissin > Z. serrata > P. stenoptera > S. japonica var. pendula. Stomatal conductance, intercellular CO₂ concentration, transpiration rate and light irradiance were key factors affecting the net photosynthetic rate. According to the photosynthetic lightresponse curve data, P. acerifolia and A. julibrissin had better environmental adaptability. Therefore, we recommend that P. acerifolia and A. julibrissin should be as the priority tree species and Q. dentate and S. japonica be used as tree species for high carbon sequestration and oxygen release in Dalian.

Key words: redundancy analysis, geographical environment, stepwise linear regression analysis, provenance., leaf functional trait