地学前缘 ›› 2026, Vol. 33 ›› Issue (1): 39-49.DOI: 10.13745/j.esf.sf.2025.10.21

• 地下水-关键带相互作用与修复 • 上一篇    下一篇

毛乌素沙地地下水动态对旱柳根系吸水的影响机制

乔冈1,2(), 尹立河1,2,*(), 徐永1,2, 张俊1, 石长春3, 余堃1   

  1. 1.中国地质调查局 西安地质调查中心, 陕西 西安 710054
    2.自然资源部陕西榆林地下水与生态野外科学观测研究站, 陕西 榆林 719053
    3.陕西省林业科学院, 陕西 西安 710082
  • 收稿日期:2025-06-18 修回日期:2025-08-12 出版日期:2026-01-25 发布日期:2025-11-10
  • 通信作者: *尹立河(1977—),男,博士,研究员,主要从事旱区生态水文地质调查研究工作。E-mail:ylihe@mail.cgs.gov.cn
  • 作者简介:乔冈(1980—),男,博士,正高级工程师,主要从事旱区包气带水循环及水文生态效应研究工作。E-mail:qgcyboy@qq.com
  • 基金资助:
    国家自然科学基金项目(41877199);国家自然科学基金项目(42302301);三秦英才特殊支持计划项目“毛乌素沙地东南缘水与生态的相互作用研究”;陕西省重点研发计划项目(2021ZDLSF05-01);陕西省面上基金项目(2025JC-YBMS-252);陕西省干旱区地下水水文过程与表生生态重点科技创新团队项目(2019TD-040);中国地质调查局地质调查项目(1212011220224);中国地质调查局地质调查项目(DD20211393);中国地质调查局地质调查项目(DD20190504);中国地质调查局地质调查项目(DD20230092)

Impact mechanisms of groundwater dynamics on root water uptake of Salix matsudana in Mu Us Sandy Land, China

QIAO Gang1,2(), YIN Lihe1,2,*(), XU Yong1,2, ZHANG Jun1, SHI Changchun3, YU Kun1   

  1. 1. Xi’an Center of Geological Survey, China Geological Survey, Xi’an 710054, China
    2. Observation and Research Station of Groundwater and Ecology in Yulin Shaanxi, MNR., Yulin 719053, China
    3. Shaanxi Academy of Forestry, Xi’an 710082, China
  • Received:2025-06-18 Revised:2025-08-12 Online:2026-01-25 Published:2025-11-10

摘要: 毛乌素沙地依赖地下水的旱柳广泛分布,尽管旱柳生长水分来源研究取得显著进展,但对于场地尺度单株旱柳根系吸水对地下水位动态的响应机制研究成果则较少,阻碍了植被与地下水互馈机制的揭示。基于此本文采用旱柳根系挖掘、原位监测试验、人工注水试验等方法,通过监测气象要素、旱柳生理参数、分层包气带水分以及地下水位等指标,结合根系垂向分布特征,分析了地下水位动态过程中包气带水分以及根系吸水策略的变化规律。结果表明:试验区旱柳根系存在一个以吸取由大气降水入渗转化成的包气带水分的浅部毛根吸水区,集中分布在埋深0.2~0.8 m范围;两个以吸取由地下水转化成的包气带水分的深部根系吸水区,其中一个是细根与侧根吸水区,出现在2.0~3.8 m范围,用于汲取深层包气带水及毛管上升水;另一个是深层垂直触及潜水面根系吸水区,分布在4.3~4.8 m范围,主要吸取地下水。以地下水转化的深部包气带水分为水源,旱柳根系吸水强度增加为原来的3倍。旱柳根系吸取由地下水转化的深部包气带水分的压力水头阈值是-10.7 m。在此基础上,进一步结合国内外类似研究,解释了地下水动态对不同根区吸水区形成的生态水文机制及其适应意义,提出旱柳实现“多层吸水/动态分配”应对极端干旱事件的建议。这些认识深化了地下水动态与旱柳吸水机制的认知,不仅推动干旱区生态水文学理论发展,也为全球沙化土地的综合治理提供科技支撑。

关键词: 地下水动态, 根系吸水, 树干液流, 原位试验, 旱柳

Abstract:

Salix matsudana is widely distributed in the Mu Us Sandy Land. Although significant progress has been made in understanding the water sources for willow growth, research on the response mechanisms of single-plant root water uptake to groundwater level dynamics remains limited at the site scale. This knowledge gap impedes a comprehensive understanding of vegetation-groundwater feedback mechanisms. To address this, our study combined root excavation, in-situ monitoring, and controlled irrigation experiments. By monitoring meteorological factors, plant physiological parameters, soil moisture at different depths, and groundwater levels—complemented by an analysis of root vertical distribution—we investigated changes in vadose zone moisture and root water uptake strategies during groundwater fluctuations. Key findings reveal: (1) The root system of Salix matsudana exhibits three distinct water-absorption zones: A shallow fibrous root zone (0.2-0.8 m depth) concentrated in the upper vadose zone, primarily absorbing moisture from precipitation infiltration; A fine and lateral root zone (2.0-3.8 m depth) that absorbs deep vadose moisture and capillary water; and A deep vertical root zone (4.3-4.8 m depth) that penetrates to the water table, primarily extracting groundwater. (2) When utilizing deep vadose moisture derived from groundwater, the intensity of root water uptake tripled. (3) The critical pressure head threshold for water uptake from deep vadose moisture derived from groundwater was identified at -10.7 m. Based on these findings and a synthesis of relevant studies, we elucidate the ecohydrological mechanisms underlying the influence of groundwater dynamics on these distinct root absorption zones and discuss their adaptive significance. Finally, we propose recommendations for implementing a “multi-layered water absorption / dynamic partitioning” strategy in Salix matsudana plantations to enhance resilience to extreme drought events. These findings advance the understanding of groundwater dynamics and willow water uptake mechanisms, contributing to eco-hydrological theory in arid regions. They also provide scientific support for global desertification control efforts.

Key words: groundwater level dynamics, root water uptake, sap flow, in-situ experiments, Salix matsudana

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