丹江口水库新形成消落带内香根草群落构建机制研究

It is an important guarantee for the successful recovery and reconstruction of damaged ecosystem that the flag species have positive effect on other species of plant community and on its ecological environment. It has the potential to act as nurse plants of other species of plant community. The Danjiangkou Reservoir is core water source area of Middle Route of the South-to-North Water Transfer Project in China. There will be a new riparian zone formed in the Danjiangkou Reservoir area after dam heightening, which belong to the damaged ecosystem. Revegetation (plantation and natural recovery) is the key to ensure ecological security of the new riparian zone. As an excellent amphibious plants, Vetiveria zizanioides has been designated as the grass species of the Danjiangkou Reservoir and its upper reaches for water and soil conservation. It has the potential to be used as flag species of artificial constructed plant community in the new riparian zone of the Danjiangkou Reservoir area. In the same elevational and similar gradient new riparian zone, we shall design different density of artificial community of Vetiveria zizanioides to explore the positive effect of the flag species i.e. Vetiveria zizanioides in the treatment of mowing on other species of plant community, on the fluctuation of physical and chemical properties of soil and on the contribution of soil seed bank to overground vegetation development. It is explained to the mechanism of stably constructing artificial community of Vetiveria zizanioides in the new riparian zone, providing theoretical basis for filtrating reasonable measures of vegetation restoration and sustainable management.

建群种对群落内其它物种及其群落环境产生正效应（促进作用），它是受损生态系统成功恢复重建的重要保障，可以在群落中充当保育物种(nurse plant)角色。丹江口库区是南水北调中线工程的重要水源地，大坝加高后的库区蓄水后周围将形成新的消落带，属于受损生态系统，植被恢复与重建是保证其生态安全的关键。香根草是一种优良的水陆两栖植物，已被列为丹江口库区及上游水土保持指定草种，可以作为消落带内构建人工群落的建群种。本项目在丹江口库区相同高程相似坡度新形成消落带内，设计种植不同密度的香根草人工群落，研究刈割处理下香根草对其他乡土植物、土壤理化性质和土壤种子库作用的影响，以此来阐释消落带人工香根草群落的稳定构建机制，为丹江口库区新形成消落带内制定合理的植被恢复措施及可持续管理提供理论依据。