科尔沁沙地沙丘植被发育过程及物种组成变化

以处于流动沙地、半固定沙地、固定沙地等阶段的群落样地为对象 ,研究了沙地植被发育过程群落物种组成的变化。研究结果表明 ,从流动沙地到半固定沙地、再到固定沙地 ,每一阶段对应着典型的群落类型 ,每一群落类型优势种的作用明显。植被发育过程物种丰富度、Shannon Wiener指数、生活型结构和科属组成的变化 ,都表明了植被发育程度的提高和群落生态功能的恢复。禾本科植物在群落中的地位和作用不断上升 ,植被的草原成分增加 ,草地质量改善和提高。

Development Process of the Vegetation and the Change ofSpecies Composition in the Horqin Sandland

The Horqin Sandland is a typical region in the farming-pasture ecotone in north China, the vegetation composed of the sparse forests and grasslands developed well in historical times. Currently, however, the land desertification has become as the serious environmental problem and has seriously restricted the sustainable regional social-economic development due to the rapid population growth and the excessive reclamation and grazing. Therefore, the regeneration of the natural vegetation is an urgent matter in the region. In this paper, the development process of the vegetation and the change of species composition in the central-southern part of the Horqin Sandland are researched by selecting some plots of communities on the mobile, semi-fixed and fixed dunes. The results show that there is a typical community type in each stage of vegetation regeneration from the mobile, semi-fixed and fixed dunes, and the effects of the dominant species in each community type are obvious. The regeneration of vegetation in the study area is revealed by the species richness, Shannon-Wiener index, life form composition and family composition of the vegetation. The function of grasses becomes more and more important, and the quality of grasslands is obviously improved.