| Osmanthus fragrans (Thunb.) Lour. belongs to OLEACEAE and Osmanthus Reinw. Osmanthus fragrans lived in the north and the central subtropical mountainous regions, which belongs to the south of the Yangtze River, including Hubei, Hunan, Sichuan, Anhui, Jiangxi Province, and other provinces. In the present Osmanthus fragrans communities study pretty rarely, but most of studies are about the species classification and physiology. This paper is to systematically study its community. It hopes to theoretically inquiry into some aspects, included its flora, structural features, species diversity and interspecific associations of the communities. And it provides scientific theories for its reasonable exploitation and protection on practicing, also for the Wuling Mountains, especially for Jiemuxi Nature Reserve and Xiaoxi Nature Reserve. This paper mainly results as follows:(1) There are 275 species in plots with the area of 2000m2, belonging to 90 families 188 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. The community plants belong to tropical origin.(2) The community belongs to typical evergreen and broad-leaved forest (included evergreen and decidous 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 shows distribution of conglomeration and random.(3) Osmanthus fragrans 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 Osmanthus fragrans is high. It shows that is dominant population in the community. It has the increasing trend with the increase of the height above elevation. The type of community was divided on the basis of rule of the dominant species.(4) 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 12.5594. Simpson index D is 0.9754. Shannon-Weiner index H is 3.9027.Evenness index Js is 0.3876, and evenness index Jsw is 0.9081. And the community is stability at that natural condition.(5) Used variance ratio (VR) to measure 14 main arbor populations, the total related difference is 1.4211, which shows positive correlation among main arbor populations and reflects that the community is in a fairy stable period. The test statistics W=56.8429, which shows very small connection and each population tends to appear in the independence.(6) Based on percentage of co-occurrence (PC), association coefficient (AC) and counteract x2-test, the interspecific associations among main arbor populations, and the interspecific associations between Osmanthus fragrans population are analyzed in the community. 49 species couples among 91 species couples of 114 species have revealed the positive correlations,42 negative correlations.Analysis about Osmanthus fragrans and other 13 mainly arbor populations show positive correlations that has 8 species couple and negative correlationsthat has 5 species couple,2 couple which show extremely significant positive correlation.
|
PDF Full Text Request