Studies on the Characteristics of Photosynthesis and Transpiration of 49 Garden Species in Spring in Wuhan City,China

Photosynthetic capacity(Amax),transpiration rate(Tr) and photosynthetic water use efficiency(PWUE) were measured for 49 species in four green spaces in spring in Wuhan City,Hubei Province,using a portable photosynthesis system(CIRAS-2,PP systems,Amesbury,USA).There were significant differences in Amax,Tr and PWUE among green spaces,shrubs and trees and deciduous and evergreen plants.However,the variation among green spaces was mainly related to differences among species and to a minor extent to differences in microclimate.Based on these gas exchange parameters,the species studied can be divided into four groups: low photosynthesis and low transpiration species(25 species),high transpiration and low water use efficiency species(12 species),high photosynthesis and high water use efficiency species(6 species) and low transpiration and high water use efficiency species(6 species).