【Objective】In order to provide a theoretical basis for clarifying the diversity of desert plant defense pathway,this project aims to explore the daily and season changes in net photosynthetic rate,transpiration rate and water use efficiency of Tamarix hispida under different water conditions in the lower reaches of the Tarim River. 【Method】An open gas exchange system,LI- 6400 Portable Photosynthesis System was used tostudy the daily changes in net photosynthetic rate( Pn),transpiration rate( E) and water us...