Abstract:Fully analyzing the photosynthetic physiological characteristics of the main sand-fixing species in multiple scenarios has important scientific meanings for the maintenance and reconstruction of the ecosystem. The artificial Populus of Horqin Sandy Land was selected as the test materials to measure the light response and CO2 response curves by using Li-6400 infrared gas analyzer. The testing scenarios included comparison across different months, tender and mature leaves, morning and afternoon, as well as different CO2 concentrations and light intensity environments. Further, the net photosynthetic rate (Pn), transpiration rate (Tr) and water use efficiency (WUE) were analyzed. The results indicated that:Under the same light intensity and CO2 concentration, the Pn at vigorous growth period was larger than that at the initial and late growth periods. The Pn, Tr and WUE were significantly different by comparing tender and mature leaves, the transpiration of tender leaves was relatively stronger, while photosynthesis of mature leaves was relatively stronger. These findings provided main reference value for the study of the physiology of artificial Populus in semiarid areas.