| Schima parviflora Cheng et H. T. Chang belongs to Theaceae and Schima Reinw. It distributes in Hunan, Sichuan, Guizhou and Medog in Tibet. Currently, it's studied only belonging to an appearance description stage in domestic. Its systematical research still belongs to blank. This paper is first time to systematically study its community. It hopes to theoretically inquiry into some aspects, included its population dynamic state, flora, structural features, species diversity, interspecific associations and the niche features of the communities. And it provides scientific theories for its reasonable exploitation and protection on practicing, also for the Wuling Mountains. This paper mainly results as follows:1. There are 323 vascular species in plots with the area of 4000m2, belonging to 105 families 216 genera. The species composition is not concentrated, which.is belonging to families and genera in community, but the coefficient is big.The flora belong to Centre-China province in Sino-Japanese. The flora has ancient origin and intricate floristic elements. The floristic constituents are mainly included Tropical Asia plant, North Temperate plant, East Asia and North America disjuncted plant, East Asia plant. The community plants belong to tropical origin.2. The community belongs to typical evergreen and broad-leaved forest The forest outward appearance is verdant and tidy. The vertical structure of the community is obvious, which is composed of arbor layer, shrub layer, herb layer and the vines. The life form reflects that it is warmth moist of medium subtropics weather. Three aggregate indices are used to analysis spatial distribution pattern of dominant arbor populations, which conform to aggregated distribution. It matches the characteristics for distributing of natural populations.3. Schima parviflora population is analyzed by age structure, high class structure and importance value.It shows that its age structure and high class structure is integrated and reasonable. The density of the population is big. All the population features show that the community is being placed in stable development period. The important value of the Schima parviflora is high. It shows that is dominant population in the community. It has the descending trend with the increase of the height above elevation.4. Used TWINSPAN to carry on a classification to the community, it can be classified into 3 groups 4 types.5. The community is investigated using 5 species diversity indices. The mean of the total species diversity indices are respectively calculated in the community. Richness index F is 4.0411. Simpson index D is 0.7896. Shannon-Weiner index H is 2.1571.Evenness index Js is 0.3245, and evenness index Jsw is 0.7715. Layers comparison with species diversity are bush layer>herb layer>arbor layer. It shows that the community has very high species diversity. The populations have even distribution in the community. And the community is stability at that natural condition.6. Used variance ratio (VR) to measure 16 main arbor populations, the total related difference is 1.1206, which shows positive correlation among main arbor populations and reflects that the community is in a fairy stable period. The test statistics W=44.824, which shows very small connection and each population tends to appear in the independence.Based on percentage of co-occurrence (PC), association coefficient (AC) and counteractχ2-test, the interspecific associations among main arbor populations, and the interspecific associations between Schima parviflora population and 20 main shrub populations are analyzed in the community. 66 species couples among 120 species couples of 16 species have revealed the positive correlations,.50 negative correlations and 4 relatively independent correlations. Theχ2-test shows that there are almost no significant interspecific associations, except a couple which show extremely significant positive correlation. Among which 18 species couples have revealed positive correlations and two have negative correlations between Schima parviflora population and each of the other 20 main shrub populations, but none of them is very obvious. All the results show that they have arrived stability stage at present.7. Using the niche breadth and niche overlaps,16 main arbor populations are analyzed. Schima parviflora population is with the widest niche breadth,2.0601.It shows that it has high capability of adapting environment and using resources. It is very small niche overlap between populations, which shows all the populations can coexist with little competition, and the community is in a fairy stable period.
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