Plant water relations were investigated in stands dominated by either Alhagi sparsifolia, Calligonum caput-medusae, Populus euphratica and Tamarix ramosissima in the foreland of the Qira (= Cele) Oasis on the southern margin of the Taklimakan Desert. Transpiration and stomatal conductance of the assimilation organs as well as the xylem sap flow were measured during the vegetation periods of 1999 and 2000. The plants did not exhibit signs of serious water stress, such as stomatal closure during midday or very low transpiration rates, and the xylem sap flow conformed to the pattern of incident radiation. The water use of the four species was higher than expected for desert vegetation. To study the effects of the flooding which erratically occurs in the foreland due to the variable water level in the rivers, irrigation of the experimental plots was carried out in the summer of 1999. Irrigation did not penetrate deeper than 2 m into the soil and had no significant effect on plant water status of the investigated species. From plant water relations, it can be concluded that all of the perennial plants in the Qira Oasis are dependent on ground water. To clarify the effect of harvesting on plant water relations, the removal of plant biomass by the local population was simulated by thinning the stands. Thinning had no clear effect on the water use of C. caput-medusae and P. euphratica, but on the T. ramosissima plot the remaining shoots in the thinned subplot exhibited a higher water use than those on the control plot.