巴音布鲁克高寒草原羊茅(Festuca ovina)群落生态位特征

Niche characteristics of Stipa purpurea community in alpine meadow of Bayanbulak

为了解高寒草原羊茅群落植物生态位特征,运用Levins生态宽度指数和Cowell生态位相似性比例,对巴音布鲁克羊茅群落植物生态位宽度及生态位相似性比例进行计算。结果表明:9种植物4个资源维上羊茅的生态位宽度最大,其次为黄花棘豆、委陵菜,说明羊茅对环境的适应能力最强。生态位宽度较大的羊茅和紫花针茅与其他物种生态位相似性比例最高,说明羊茅和紫花针茅与其他物种存在着较大的资源竞争。而生态位较小的物种与其他物种生态位相似性比例较小。放牧使得羊茅群落内物种发生变化,在放牧压力持续增大的情况下,以羊茅和紫花针茅为优势种群的草原将向以黄花棘豆和委陵菜占优的退化方向演替。

In order to ascertain the niche characteristics of the plants in alpine Stipa purpurea grassland, used Levins niche breadth index and Corwell proportional similarity Index, carried on the computation to the niche breadth and the proportional similarity of the main plants in Bayanbulak Stipa purpurea grassland. Bayingolin Mongol Autonomous Prefecture,Xinjiang, China The result shows that the Festuca ovina occupies the widest breadth of 9 plants on 4 resource dimension levels. The next is Oxytropis ochrocephala Bunge and PotentiUa chinensis Ser. It illuminated that Festuca ovina has the best adaptability to environments. To the proportional similarity, Festuca ovina and Stipa purpurea have the most similarity with other species, which indicated that Festuca ovina and Stipa purpurea competes with other species intensively in the interspecies competition. The narrow breadth species have low proportional similarity with other species. Grazing made the species changed in Festuca ovina community. If the pressure of grazing continuous increasing, the Oxytropis ochrocephala Bunge and the Potentilla chinensis Ser will substitute for Stipa purpurea to become the dominant species in the succession process.