沱沱河地区紫花针茅群落种间联结性分析

基于方差比率(VR)、χ2检验和Jaccard指数对沱沱河地区紫花针茅群落12个主要种的种间联结性进行了分析。结果表明,紫花针茅群落优势种多物种间显著正关联,存在稳定共存的种间关系。建群种与其它物种间联结性不显著,在群落中能够稳定存在并占据优势生态位,群落处于植被演替过程的一个相对稳定的阶段。伴生种或次优势种之间联结显著,在群落中表现出很强的依赖性,分布易受其它物种的影响,在群落中不能稳定存在且只占据劣势生态位。根据种间联结性的分析结果,将紫花针茅群落分为2个不同的生态种组,但这2个生态种组并不具有明显的界限,它们之间存在着直接或间接的联系。

Interspecific associations analysis of Stipa purpurea community in Tuotuo River Area

Based on variance ratio, χ2 test, and Jaccard index, the interspecific association of twelve principal species in Stipa purpurea Steppe community in Tuotuo River Area was studied. The results showed that the overall associations among dominant species in S. purpurea community had significant positive association. The dominant species had stable coexistence relation; Constructive species showed great independence and occupied prior ecological niche in the community, which distributions were not susceptible to others. This partly accounted for the persistency of constructive species in the community. Accompanying species or secondary dominant species with others were significant. They indicated great dependency. Distributions of accompanying species or secondary dominant species were susceptible to other species and only occupied in ferior ecological niche in the community, which resulted in their transition or unstability in the ecosystem development. According to the measuring results, the principal species could be divided into two species groups. But they had no distinct limit. There was direct or indirect relation between them.