Relations between Stable Carbon Isotope Discrimination and Water Use Efficiency as well as Growth for Poplar Responses of Foliar δ13C Values of Woody Plants to Different Karst Rocky Desertification Degrees in Huajiang Gorge, Guizhou RESPONSES OF PHOTOSYNTHESIS ON WATER STRESS FOR SHRUBS FROM TROPICAL RAIN FOREST AND SUBTROPICAL MONSOON FOREST Ecophysiological Responses of Seedlings of Hippophae neurocarpa to Elevated Carbon Dioxide Water Physiological Characteristics of Introduced Alnus formosana The effect of groundwater depth on the δ13C value of constructive species leaf in the lower reaches of the Tarim River Transformation of Barnyardgrass (Echinochloa crusgalli) Root Type Phosphoenolpyruvate Carboxylase Gene into Rice (Oryza sativa) Plants and Their Effects on Photosynthesitic Gas Exchange Effects of CO2 Concentration on Tall Fescue Drought Resistance and Water Use Efficiency The responses and mechanisms of water use efficiency to different water stresses of three alfalfa varieties A Study on Foliar Carbon Isotope Composition(δ13C) and Water Use Efficiency of Different Populus deltoides Clones under Water Stress COMPARISON ON THE PHYSIOLOGICAL PARAMETERS OF FIVE YULANIA SPECIES Difference in δ13C and gas exchange parameters among Populus tomentosa clones