Abstract: [Objective] Through studying different degraded degrees grassland community structure characteristics in Bayanbulak alpine steppe,the project aims to provide a theoretical basis for rational utilization of grassland degradation.[Method] Using sampling method to investigate species composition,community structure and analyze ecological economic groups and the relationship between species diversity and aboveground biomass in Bayanbulak degraded grassland.[Result] With the increase of the degree of degradation,the Stipa purpurea,the dominant species of grass was gradually degenerated into a small low Koeleria cristata.The importance values of index species of alpine steppe degradation,such as Leymus tianschanicus and Potentilla sericea increased;The aboveground biomass of Gramineae and Leguminosae forage gradually decreased;Aboveground biomass of the community was significantly reduced by 50; (P ＜ 0.05).There was a significant linear positive correlation between aboveground biomass and species richness index and a significant linear negative correlation between the diversity index and evenness index.[Conclusion] Degradation grassland vegetation community structure resulted in a significant decrease in grassland quality and productivity,and the species richness of grassland communities affected grassland productivity.

摘要： [目的]研究巴音布鲁克高寒草原退化草地植物群落结构特征,为退化草地合理利用提供理论依据.[方法]采用样方法,调查研究区退化草地物种组成、群落结构并分析生态经济类群及物种多样性与地上生物量的关系.[结果]随着退化程度的增加,草地中优势种紫花针茅被小型禾草溚草取代;高寒草原退化标志植物天山赖草、绢毛委陵菜等杂类草重要值增加;禾本科、豆科等优良牧草地上生物量逐渐减少;群落内地上生物量显著降低了50; (P ＜0.05),群落地上生物量与物种丰富度指数呈显著线性正相关,与多样性指数、均匀度指数呈显著线性负相关关系.[结论]巴音布鲁克高寒草原退化草地植被群落结构简单化,导致草地质量和生产力明显下降;草地群落物种丰富度影响草地生产力.