油松人工林乔木层结构与林下灌木多样性耦合关系研究

Study on the Coupling Relationship Between Arbor Layer Structure and Shrub Layer Diversity of Chinese Pine Plantation Forests

人工林生态系统是森林生态系统的重要组成部分,以陕西省延安市黄龙山林区油松人工林为研究对象,对比了4种不同密度的油松人工林样地内乔木空间结构(角尺度、混交度、密集度和大小比数)和灌木多样性(Simpson指数、Shannon-Wiener指数、Pielon指数、Gleason指数和Margalef指数)的差异,建立了乔木空间结构与灌木多样性的耦合关系,探讨了乔木空间结构和灌木多样性的作用关系。结果显示:1)在不同密度的样地中,株数密度为2300~2800株/hm2的样地空间结构最佳;2)灌木多样性受林分密度影响显著,灌木多样性在不同密度中排序为低密度>较低密度>较高密度>高密度;3)不同密度的林分中,乔木空间结构对灌木多样性的影响不同,其中株数密度为2300~2800株/hm2的林分中,灌木多样性与乔木空间结构具有较强的相关关系,在该密度下可以通过调整乔木层的结构而改变灌木层的多样性。

Plantation forest ecosystem is an important part of forest ecosystem.We use the Chinese pine which belongs to Shaanxi province Huanglong mountain as the research object and compares the four different density groups of Chinese pine plantation plots which in the difference of the spatial structure(Mingling index,Dominance index,Uniform Angle index and Crowding index)and of different shrub diversity(Simpson index,Shannon-Wiener index,Pielon index,Gleason index and Margalef index).The coupling relationship between tree spatial structure and shrub diversity was established and we discuss the relationship between them.The results showed that:(a)among the all groups,the spatial structure of the plot which showed a tree density of 2300-2800/hm2 was the best;(b)shrub diversity was significantly affected by tree density,the shrub diversity which in different tree density groups shows:low-density>mid-lower density>low-density>mid-higher density>high-density;(c)in different groups,the difference of tree spatial structure has different effects on shrub diversity,in the plots which showed a tree density of 2300~2800/hm2,a higher correlation relationship between tree spatial structure and shrub diversity could be observed.This indicates that shrub diversity could be changed via an adjustment tree spatial structure in that tree density.