[Water sources of with different tree ages in the oasis of desert hinterland].

Understanding vegetation water utilization can provide scientific basis for vegetation protection and rational distribution of water resources in arid desert oasis area. In this study, sapling (DBH≤10 cm), mature (10 cm<DBH≤40 cm), and overmature (DBH>40 cm) were chosen as sample trees in natural oasis of Dariaboui. We measured oxygen isotopes of xylem water and potential water sources (surface water, soil water in 0-3 m soil layer and groundwater) of with different tree ages. The IsoSource model was used to study water sources of . The results showed that soil water content increased with increasing soil depth, while the δO value of soil water decreased firstly and then stabilized. When groundwater depth was 2 m, the δO value of xylem water increased with increasing tree ages. When the depths of groundwater were 4.2 and 8 m, the δO values of xylem water decreased with increasing tree ages. Water sources of varied across tree age. When the depth of underground water was 2 m, the main water source for young trees was surface water, and the contribution proportion was 64.7%. For mature and overmature trees, it was deep soil water and ground-water, with a contribution of about 30%. When the depth of groundwater was 4.2 m, the main water sources of of different tree ages were deep soil water and groundwater, and the contribution proportion was about 30%. The lowest contribution of of different tree ages was shallow soil water, accounting for about 10%.