Comparative Studies on Relation of Photosynthesis to Water Status of Two Species of Haloxylon Under Controlled Environments The Characteristic of Physiological Ecology of the Main Tree Species Used for Afforestation at Limestone Regions in North Guangdong Alfalfa’s Pre-blossoming Transpiration Coefficients and Comparison of the Water Consumption Coefficients Between Alfalfa and Maize in Terms of Economic Yield Effect of Different Soil Water Conditions on Growth and Physiology of Panax ginseng Eco-physiological traits of different-age needles of Pinus sylvestris var. mongolica plantation in Horqin sandy land of China