三峡水库消落带生境特征与植被恢复模式

[目的]三峡水库蓄水运行后消落带生境破碎斑块化加剧，极端生境胁迫严重损害植被的结构和功能。厘清三峡水库消落带生境状况，提出适宜性植被恢复对策，重建河流受损廊道综合生态功能，对构建区域生态安全格局和保障长江流域水资源安全具有重要意义。[方法]针对三峡水库消落带植被退化与生态功能受损的突出问题，系统解析了消落带生境特征及其对植被生长的影响，围绕水库河岸受损廊道生态修复重大需求，探讨面向消落带微生境构建与植被格局功能优化的三峡水库消落带植被恢复模式。[结果]三峡水库消落带生境状况受水库运行形成的独特水位节律、出露期植被生长季气候条件、土壤侵蚀与泥沙沉积过程、土壤环境等多生境因子协同影响，呈现高度空间异质性特征。水位变动形成的淹没时长、出露时令、淹水强度是影响植株繁衍、生长的首要因素；土壤侵蚀、泥沙掩埋、土壤水养条件等影响植被生长状况。[结论]三峡水库消落带植被恢复需综合考虑水位节律、立地条件与物种形态-功能性状，选育优质抗逆物种，注重土壤基质保育，突出植被格局的分区优化配置。重建消落带综合生态功能，为水库消落带生态治理提供理论支撑和科学依据。

Habitat Condition and Vegetation Restoration Patterns in the Water Level Fluctuation Zone of the Three Gorges Reservoir

[Objective] The Three Gorges Reservoir’s impoundment has speed up habitat fragmentation and patching in the water level fluctuation zone, and extreme habitat stress has seriously damaged the structure and function of vegetation. Clarifying the habitat status of the water level fluctuation zone of the Three Gorges Reservoir, proposing an adaptive vegetation restoration strategy, and reconstructing the comprehensive ecological function of damaged river corridor are of utmost importance for building regional ecological security pattern and ensuring water resources security of the Yangtze River Basin. [Methods] In response to the prominent issues of vegetation degradation and ecological function damage, we systematically analyzed multiple habitat conditions and their influence on riparian vegetation growth. Focusing on the basic requirements for ecological restoration of damaged river corridor along reservoir banks, a vegetation restoration pattern for construction of suitable microhabitats and optimization of vegetation functional pattern was explored. [Results] The habitat conditions of the water level fluctuation zone were jointly regulated by unique water level rhythm formed by reservoir, operation, climate condition during the exposed, soil erosion and sedimentation and soil environment, which presented a distinctive spatial heterogeneity pattern. Among these, inundation duration, emergence time, and inundation intensity by seasonal water fluctuation were the primary factors affecting plant reproduction and development, while soil erosion, sedimentation burial and soil substrates affected vegetation growth. [Conclusion] Accordingly, water level, site conditions and morphological-functional trait characteristics of various vegetation should be comprehensively considered when planning vegetation restoration in the water level fluctuation zone. Meanwhile, the high-quality stress-resistant species selection, site preparation measures for soil condition improvement, and the zonal optimization of vegetation patterns were beneficial for rebuilding the comprehensive ecological function of the water level fluctuation zone. This provided theoretical support and scientific basis for the ecological management of the water level fluctuation zone in the Three Gorges Reservoir.