| 1 The different effect of community structure character has been discussed under the different scales of artificial disturbance. The results show that the proportions of phanerophyta in life form spectrum and microphyll, entire leaf, single leaf, evergreen leaf in leaf characters are most in each community. The proportions of leather-like leaf in A Class, B Class and herbaceous leaf in C Class, D Class are also most. With the enhancement of the disturbance scale, the proportions of families, genera and species of pteridophyta, dicotyledoneae, monocotyledo, megaphanerophytes in life form spectrum, entire leaf in leaf margin, leather-like leaf in leaf texture drop or go up firstly then drop; the proportions of herbaceous leaf go up; the numbers of families, genera, and species of gymnospermae , single leaf and compound leaf in leaf type ,evergreen species and defoliated species changes very little.2 Castanopsis eyrei is dominant in A Class and second dominant in B Class while Chinese Fir and Phyllostachys heterocycla cv.pubescens heterocycla cv.pubescens become dominant influenced by artificial planting in C Class and D Class . With the increasing of artificial disturbance, the number of generas in each family,species in each family,species in each genera drops.3 This paper presents the distribution pattern of Castanopsis eyrei and its associated species in the communities with different scales of artificial disturbance using frequency testing method and aggregate indices (C, X*/X). The results show that the majority distribution patterns of Castanopsis eyrei and its associated species are aggregated patterns in population in A Class and B Class.The aggregate indices decrease gradually from seedling population to overstory population. Chinese Fir and Phyllostachys heterocycla cv. pubescens heterocycla cv. pubescens are dominant species whose distribution patterns are aggregated patterns in population in C Class and D Class with intense scales of artificial disturbance, and the associated species are very scarce in the two communities.4 The log series model is used to calculate and meet the species abundance of arbor layer and shrub layer in each community with different scales of disturbance. The results show that with the increasing of scales of disturbance, A Class and B Class in tree layer and all Classes in shrub layer obey a logarithmic series distribution, which suggest the biodiversity of the communities of A Class and B Class is high. In reverse, the biodiversity of tree layer in C Class and D Class is low than that of A Class and B Class because of intense scales of artificial disturbance.5 The paper studies the effect of main tree species' niche in the communities with3different scales of disturbance from three aspects of niche breadth, proportional similarity and overlap. The results are as follows: each index of Castanopsis eyrei is highest. The index values of LU, between Castanopsis eyrei and other tree species whether it's niche breadth is high or low are all high in A Class and B Class. These indicate that Castanopsis eyrei grows well in the circumstance such as A Class and B Class. The index value of Ljh between Cunninghamia lanceolata and other tree species is high, but the index value of LHJ is quite low. These show that Cunninghamia lanceolata control the community's circumstance and the similarity of sharing resource among species is low.6 The species diversity of the communities of Castanopsis eyrei with different scales of disturbance by human being has been studied according to Simpson index (D) ,Shannon-Wiener index (H'),Pielou eveness (J),species richness and the community dominance.The results show that with the increasing of the degree of the scales of disturbance by human beings, the community dominance goes up from A Class to D Class, each index of species diversity drops from A Class to C Class then go up to D Class, each index of shrub layer is all higher than that of tree layer in their communities respectively. The index values of species diversity... |
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