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应用生态学报 ›› 2022, Vol. 33 ›› Issue (2): 353-359.doi: 10.13287/j.1001-9332.202202.008

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沙漠腹地天然绿洲不同林龄胡杨水分利用来源

万彦博, 师庆东*, 戴岳, 李涛, 彭磊, 李浩   

  1. 新疆大学资源与环境科学学院, 绿洲生态教育部重点实验室, 乌鲁木齐 830046
  • 收稿日期:2021-04-13 修回日期:2021-08-26 出版日期:2022-02-15 发布日期:2022-03-01
  • 通讯作者: *E-mail: shiqd@xju.edu.cn
  • 作者简介:万彦博, 男, 1995年生, 硕士研究生。主要从事干旱区生态与水文研究。E-mail: wanyb1995@163.com
  • 基金资助:
    国家自然科学基金项目(U1703237)资助。

Water sources of Populus euphratica with different tree ages in the oasis of desert hinterland.

WAN Yan-bo, SHI Qing-dong*, DAI Yue, LI Tao, PENG Lei, LI Hao   

  1. Ministry of Education Key Laboratory of Oasis Ecology, College of Resources and Environmental Science, Xinjiang University, Urumqi 830046, China
  • Received:2021-04-13 Revised:2021-08-26 Online:2022-02-15 Published:2022-03-01

摘要: 了解干旱荒漠绿洲区主要植被的水分利用来源,能为该区域植被保护和水资源的合理分配提供科学依据。本研究以达里雅布依天然绿洲胡杨幼龄木(胸径DBH≤10 cm)、成熟木(10 cm<DBH≤40 cm)和过熟木(DBH>40 cm)为对象,测定不同林龄胡杨木质部水和潜在水源(地表水、0~3 m土层土壤水、地下水)的氧同位素,运用多水源混合模型(IsoSource模型)研究胡杨的水分利用来源。结果表明: 土壤含水量随着土层深度的增加而增加,土壤水δ18O值随着土层深度的增加先减小后趋于稳定。地下水埋深为2 m时,胡杨木质部水δ18O值随着林龄的增加逐渐增大;而地下水埋深为4.2和8 m时,胡杨木质部水δ18O值随着林龄的增加而减小。不同林龄胡杨的水分来源有差异。地下水埋深为2 m时,幼龄木的主要水源为地表水,平均贡献比例为64.7%,而成熟木和过熟木的主要水源为深层土壤水和地下水,贡献比例均为30%左右。地下水埋深为4.2 m时,不同林龄胡杨的主要水源均为深层土壤水和地下水,贡献比例均为30%左右;而浅层土壤水的贡献比例较低,均为10%左右。

关键词: 沙漠腹地, 胡杨, 林龄, 地下水埋深, 水分来源

Abstract: 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) Populus euphratica 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 P. euphratica with different tree ages. The IsoSource model was used to study water sources of P. euphratica. The results showed that soil water content increased with increasing soil depth, while the δ18O value of soil water decreased firstly and then stabilized. When groundwater depth was 2 m, the δ18O value of xylem water increased with increasing tree ages. When the depths of groundwater were 4.2 and 8 m, the δ18O values of xylem water decreased with increasing tree ages. Water sources of P. euphratica 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 P. euphratica of different tree ages were deep soil water and groundwater, and the contribution proportion was about 30%. The lowest contribution of P. euphratica of different tree ages was shallow soil water, accounting for about 10%.

Key words: desert hinterland, Populus euphratica, tree age, groundwater depth, water source