生态阈值识别是干旱矿区植被引导型修复中重要技术环节，其中干旱阈值是诸多关键生态阈值中极为重要一项。不同干旱阈值区间矿区植被结构和功能属性会发生变化，明晰不同干旱阈值下潜在生态机制对于干预合理程度及引导修复方向的判定至关重要，现有研究对于对引发这些变化的生态机制缺乏系统梳理。在文献调研的基础上构建干旱矿区植被系统对干旱程度的响应概念模型，将干旱矿区植被系统对干旱度的响应概括为植被衰退阶段、“土壤失调”阶段和“系统崩溃”阶段。植被衰退阶段，主要表现为植被应对极端缺水环境的光合生理适应方式和特性的改变；“土壤失调”阶段，主要涉及土壤和植物之间复杂互馈作用，通过土壤侵蚀途径、灌木入侵途径及生物地球化学途径进行传递；“系统崩溃”阶段，主要由于植物生理极限触发植物−植物和植物−大气的互馈作用，导致系统多样性急剧降低。未来可在典型植物选育、研究尺度扩展、干旱诱导的灌木性状发育机制、干旱诱导的生物地球化学循环突变机制、干旱胁迫解除后植物能够自行恢复其生理活动的时间节点、生物结皮产生机制等方面进行深入研究。综述结果为干旱矿区植被引导型修复干旱阈值潜在生态机制理解提供了一个基本框架，以期为科学判定干预合理程度及引导修复方向提供生态学基础。

The identification of ecological threshold is one of the important technical links in the vegetation guided restoration in arid mining areas, and the aridity threshold is a very important one among many key ecological thresholds. There will be sudden changes in the structure and functional attributes of the vegetation system in mining areas in different aridity threshold areas. It is very important to clarify the underlying ecological mechanism under different aridity thresholds for the determination of the reasonable degree of intervention and the direction of guiding the restoration. The existing research lacks a systematic review of the ecological mechanism that causes these mutations. A conceptual model of abrupt response of dryland ecosystem to drought is constructed in this paper, which summarizes the response of dryland ecosystem to drought degree as vegetation recession stage, “soil imbalance” stage and system collapse stage. In the declining stage of vegetation, it is mainly manifested in the changes of photosynthetic physiological adaptation mode and characteristics of vegetation in response to extreme water shortage environment. The “soil imbalance” stage mainly involves the complex interaction between soil and plants, which is transmitted through soil erosion, shrub invasion and biogeochemical pathways. In the stage of system collapse, the plant-plant and plant-atmosphere interaction triggered by plant physiological limits leads to a sharp reduction in system diversity. In the future, in-depth research can be conducted on the selection of typical plants, the expansion of research scale, the development mechanism of drought induced shrub traits, the mutation mechanism of biogeochemical cycle induced by drought, the time node at which plants can resume their physiological activities after drought stress is relieved, and the mechanism of biological crust production. This study provides a basic framework for understanding the potential ecological mechanism of aridity threshold for vegetation guided restoration in arid mining areas, also provides an ecological basis for scientifically determining the reasonable degree of intervention and guiding the direction of restoration in the later stage.