青海湖区针茅草原植物群落特征及群落多样性研究

根据样方调查资料，采用聚类分析法，研究了青海湖区针茅草原围栏封育后植物群落特征及群落多样性变化。结果表明，草原经过长期围栏后，群落内优势种发生了不同程度的分异，由围栏外的紫花针茅(Stipa purpurea) 青海苔草(Carex ivanovae)草原演变成围栏内的冷地早熟禾(Poa crymophila) 猪毛蒿(Artemisia scoparia)草原群落，导致了群落结构特征的变化；长期的围栏活动对提高草原群落的盖度和生产能力是有益的，但却降低了群落的物种丰富度和多样性；草原开垦后，对周围草原有明显的影响，所形成土垄的群落特征和多样性变化都发生了极大的差异，成为赖草(Leymus secalinus) 大籽蒿(Artemisia sieversiana)群落类型，群落的物种丰富度和多样性均降低。

Study on community characteristics and community diversity in Stipa steppe of Qinghai Lake region

Stipa steppe is one of the important ecosystems in Qinghai Lake region.Changes of its community characteristics and community diversity under the condition of long-term exclosure were studied in this paper.The results showed:during the long-term exclosure,the community species composition had developed differently from Stipa purpurea+Carex ivanovae community to Poa crymophila+Artemisia scoparia community.Long-term exclosure can benefit for the increase of the steppe productivity and its coverage,while the community diversity is reduced.The cultivation activity in the steppe community also led to great changes about the community characteristics and its diversity.The dominant species had been changed into Leymus secalinus and Artemisia sieversiana.The above-ground biomass and its coverage are much higher than that in the inside and the outside community,although its species number are greatly reduced.