Characteristics of Water Status in Populus euphratica Outside the Oases in the Taklamkan Desert

In the extremely arid area of the southern Taklamakan Desert in Xinjiang, NW China, the mean annual precipitation is less than 50 mm. Outside the river oases in this region, Populus euphratica Oliv. is a dominant woody plant in indigenous vegetation. The water status of P. euphratica was studied in the southern Taklamakan Desert. The results showed that with the stable soil water content in habitat resulting from permanent ground water table, the water stress of P. euphratica was not severe and drought stress was not the main factor to threaten the long-term survive of P. euphratica. The characteristics of water status in P. euphratica indicated that the plant depended mainly on constant sufficient water supply to cope with the extremely drought environment at its growing sites. At the same time, this species developed its physiological adaptation at cell level in transpiration. Therefore, the key factor to guarantee a sustainable survival of P. euphratica in the peripheral area of the oases is to keep the groundwater table stable in different depths.