甘南高寒草甸物种多样性与生产力的关系

利用甘南高寒草甸植物群落丰富度、多样性、生产力的抽样调查资料,分析了不同空间范围内物种多样性与生产力的关系,探讨了其形成机制.结果显示:丰富度、Shannon-Wiener α多样性指数、Simpson α多样性指数与生产力之问的关系在合作分站和玛曲分站均呈显著正相关,在玛曲县欧拉乡为不相关;Pielou α均匀度指数与生产力的关系在玛曲分站呈显著正相关,在合作分站和玛曲县欧拉乡均为不相关;Whittakerβ多样性指数与生产力的关系在合作分站和玛曲分站均呈负相关,在玛曲县欧拉乡为不相关.综合三个地区的数据分析表明:随着空间范围的扩大,丰富度、三种α多样性指数与生产力趋向于正相关关系,Whittakerβ多样性指数与生产力趋向于负相关关系.如果要改善甘南高寒草甸草场质量、提高草场生产力,那么不仅要保护物种多样性,还要提高物种空间分布的均匀性、减少环境异质性.

Relationship between species diversity and productivity of alpine meadows in Gannan Prefecture

A sample survey was conducted of species richness, species diversity, productivity of plant community in alpine meadows in Gannan Prefecture. At typical sample plots, the relationship between species diversity and productivity were analyzed at different spatial scales, and their mechanisms were discussed primarily. The results indicate that the relationships between species richness and productivity, ShannonWiener α diversity index and productivity, Simpson α diversity index and productivity are all positive at Hezuo County substation and Maqu County substation, not strong enough at Oula countryside in Maqu County; the relationship between Pielou α evenness index and productivity is positive at Maqu County substation, not strong enough at Hezuo County substation and Oula countryside; the relationship between Whittaker β diversity index and productivity is negative at Hezuo County substation and Maqu County substation, not strong enough at Oula countryside. But after expanding spatial scales to the whole researching area, following the expanding scales, the relationships between species richness and productivity, α diversity index and productivity tend to positive, and the relationship between Whittaker β diversity index and productivity tends to negative. To improve grassland quality and productivity, we not only need to protect species bio-diversity, but also to increase the evenness of species spacial distribution, and decrease environmental heterogeneity.