关键词: 亚高山森林, 华西箭竹, 森林演替, 更新, 物种多样性

Abstract:

To understand the effects of Fargesia nitida on forest cycle succession of subalpine forests in Wolong Nature Reserve, Sichuan Province, species diversity and tree regeneration with bamboo(B⁺) and without bamboo(B^-) condition of three regeneration stages were investigated. The results showed: The F. nitida could not change the trend of diversity dynamics but had negative effect on diversity in the process of forest cycle succession, especially on the diversity of shrub layers, and species in broadleaved forest(BF) influenced by F. nitida was more significant than those in dark coniferous forest(CF). In comparison with B^-, species richness of all layers were declined, evenness and diversity of shrub layers were sharply decreased in B⁺ of three stages. Seedlings in B^- were more abundant than in B⁺ conditions of three stands as low light and thick litters in B⁺ were disadvantage for seedlings germination and growth. The number of Betula utilis individuals was most in B^- of BF, and that of Abies faxoniana was most in B^- of CF, there were still some in B⁺ of CF. F. nitida also impeded height growth of B. utilis, but had little effect on A. faxoniana, therefore, regeneration fail of B. utilis was accelerated and regeneration process of A. faxoniana was hindered by F. nitida. In conclusion, species richness and diversity of different stages were declined and tree regeneration was restricted by occurrence of F. nitida in forest cycle succession of subalpine forest.

Key words: subalpine forest, Fargesia nitida, forest cycle succession, regeneration, species diversity