干旱区植物水分生态位与物种共存机制

doi:10.7522/j.issn.1000-694X.2025.00364

摘要/Abstract

摘要：

在干旱区，水分是植被群落稳定性与生态系统功能的关键限制因子。为适应干旱胁迫，植物在长期演化中形成了多样的生存策略。植物群落的物种多样性往往依赖于水分条件的时空异质性所驱动的生态位分化，即共存物种沿水文梯度呈现出不同的生长与生存策略。本文系统阐述了水分生态位假说的核心内涵，指出水分生态位分化是植物通过根系分布、物候响应与气孔调节等性状的差异，从而实现对有限水资源的差异化利用。在空间维度上，水分生态位表现为由土壤水分异质性驱动的根系垂直分层以及对不同深度土壤水分的差异化利用；在时间维度上，则通过“储存效应”导致物种响应呈现异质性。此外，气孔性状的种间变异为水分生态位分化提供了重要的生理机制基础。综上所述，水分生态位分化减少物种间对水资源的直接竞争，是促进干旱区植物物种稳定共存、维持群落多样性与生态系统稳定性的核心机制。稳定同位素等技术的发展为量化生态位分化提供了有力工具。深化对这一机制的理解，对于干旱区植被恢复与生态系统管理具有重要的理论和实践意义。

关键词: 荒漠植被, 水分生态位分化, 物种共存, 时空异质性, 气孔调节

Abstract:

In arid regions， water availability serves as a critical limiting factor governing the stability of plant communities and the functioning of ecosystems. To cope with drought stress， plants have developed diverse survival strategies through long-term evolutionary processes. Species diversity within plant communities often relies on niche differentiation driven by spatiotemporal heterogeneity in water availability， whereby coexisting species exhibit distinct growth and survival strategies along hydrological gradients. This paper systematically elucidates the core principles of the water niche hypothesis， emphasizing that hydrological niche segregatio enables plants to utilize limited water resources differentially through variations in traits such as root distribution， phenological responses， and stomatal regulation. Spatially， water niche differentiation manifests as vertical stratification of root systems driven by soil moisture heterogeneity； temporally， it leads to asynchronous species responses via the "storage effect." Furthermore， interspecific variation in stomatal traits provides a physiological foundation for this differentiation. In summary， hydrological niche segregatio reduces direct interspecific competition for water resources， thereby functioning as a key mechanism promoting stable coexistence among plant species， maintaining community diversity， and ensuring ecosystem stability in arid regions. Advances in techniques such as stable isotope analysis offer robust tools for quantifying niche differentiation. A deeper understanding of this mechanism holds significant theoretical and practical implications for vegetation restoration and ecosystem management in arid zones.

Key words: desert vegetation, hydrological niche segregation, species coexistence, spatiotemporal heterogeneity, stomatal regulation

中图分类号:

周海, 赵文智, 何志斌, 田丽慧, 顾虎利, 范明彦. 干旱区植物水分生态位与物种共存机制[J]. 中国沙漠, 2026, 46(1): 175-183.

Hai Zhou, Wenzhi Zhao, Zhibin He, Lihui Tian, Huli Gu, Mingyan Fan. Hydrological niche segregation and species coexistence in arid zones[J]. Journal of Desert Research, 2026, 46(1): 175-183.

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