Wan Yan-Bo, Shi Qing-Dong, Dai Yue, Li Tao, Peng Lei, Li Hao
Ministry of Education Key Laboratory of Oasis Ecology, College of Resources and Environmental Science, Xinjiang University, Urumqi 830046, China.
Ying Yong Sheng Tai Xue Bao. 2022 Feb;33(2):353-359. doi: 10.13287/j.1001-9332.202202.008.
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%.
了解植被水分利用可为干旱沙漠绿洲地区的植被保护和水资源合理配置提供科学依据。本研究选取达里亚布伊自然绿洲中胸径≤10 cm的幼树、10 cm＜胸径≤40 cm的成年树和胸径＞40 cm的过熟树作为样本树。测定了不同树龄树木木质部水的氧同位素以及潜在水源（地表水、0-3 m土层土壤水和地下水）。利用IsoSource模型研究了树木的水源。结果表明，土壤含水量随土壤深度增加而增加，而土壤水的δO值先降低后稳定。当地下水位为2 m时，木质部水的δO值随树龄增加而增加。当地下水位为4.2 m和8 m时，木质部水的δO值随树龄增加而降低。不同树龄树木的水源不同。当地下水位为2 m时，幼树的主要水源是地表水，贡献比例为64.7%。对于成年树和过熟树，主要水源是深层土壤水和地下水，贡献比例约为30%。当地下水位为4.2 m时，不同树龄树木的主要水源是深层土壤水和地下水，贡献比例约为30%。不同树龄树木对浅层土壤水的贡献最低，约占10%。
