喀斯特区土石工程堆积体坡面植被恢复评价

Assessment on Vegetation Restoration on the Slope Surface of Accumulation Body of Earth-rock Mixing Engineering in Karst area

[目的]对喀斯特区土石工程堆积体坡面植被恢复进行评价,以期为喀斯特区工程堆积体生态修复提供基础理论支撑,并为生态文明建设提供参考依据。[方法]选取喀斯特区不同恢复年限(3,5,7 a)及不同植被类型(草地及草灌混交)的公路线性土石工程堆积体为研究对象,运用主成分分析法,选取石砾含量、土壤物理参数、土壤化学指标、水力学参数及植物群落指标构建评价指标体系,分析了土石工程堆积体坡面植被恢复特征与各生态影响因子之间的互作关系。[结果](1)喀斯特区土石工程堆积体坡面植被恢复过程是一个不断对资源和空间重新分配的过程,随着恢复时间的增加,坡面植被物种丰富度逐渐降低,群落的优势种越来越明显。(2)土壤有机质、自然含水率和饱和导水率是影响土石工程堆积坡面植被恢复初期的主要因子,而植被恢复又有助于改善其坡面土壤结构状况及养分含量,其坡面植被恢复的前期重点是如何改善坡面土壤水力学特性。(3)喀斯特区土石工程堆积体坡面先锋植被群落构建阶段的植被恢复模式可采取草灌混交,后逐步考虑增加乔木,同时适当搭配一定的深根植物。[结论]改善坡面土壤水力学特性有助于喀斯特区土石工程堆积体坡面初期植被恢复,可采取先草灌混交、后逐步搭配深根乔木的植被恢复模式。

[Objective] The aims of this study are to evaluate the vegetation restoration on the slope of the accumulation body of earth-rock mixing engineering in karst area,and to provide basic theoretical support for ecological restoration of accumulation in karst area and provide reference for ecological civilization construction.[Methods] The highway linear accumulation bodies of earth-rock mixing engineering were selected as the research object with different recovery years(3,5,7 a).Different vegetation types(grassland and grass irrigation) were selected as the research objects.The gravel content,soil physical parameters,soil chemical indicators,hydraulics parameters and plant community indexes were selected.The interaction between the vegetation restoration characteristics and the ecological influence factors was analyzed by using principal component analysis.[Results](1) The process of vegetation restoration of the slope of the accumulation body of earth-rock mixing engineering was a process of continuous redistribution of resources and space.With the increase of recovery time,the species richness of the slope vegetation gradually decreased,and the dominant species of the community became more and more obvious.(2) Soil organic matter,natural moisture content and saturated water conductivity were the main factors affecting the initial stage of vegetation restoration on the slope surface of the accumulation body of earth-rock mixing engineering,but the vegetation restoration also helped to improve the slope soil structure and nutrient content.(3) The early focus of vegetation restoration on the slope surface was how to improve the hydrodynamics characteristics of slope soil.The vegetation recovery mode of the construction stage of the pioneer vegetation community of the accumulation body of earth-rock mixing engineering could be mixed,and trees should be added gradually,and some deep root plants should be matched appropriately together.[Conclusion] Improving the slope soil hydrodynamics characteristics is conducive to the initial vegetation recovery on the slope surface of the accumulation body of earth-rock mixing engineering in karst area.Meanwhile,the vegetation restoration mode can be adopted by mixing of grass and shrub,and then gradually with deep-rooted trees.The results can provide basic theoretical support for the ecological restoration of accumulation body of engineering in karst area.