Study On Population Ecology And Community Characteristics Of Phoebe Zhennan In Lichuan,Hubei Province

Phoebe zhennan is the key protected plants of national level II, and is also one of the rare and endangered plants. Study on the natural population ecology and community characteristics of Phoebe zhennan will be helpful to reveal its endangered mechanism, and it is greatly important in theory and applied values on conservation, plantation and restoration of the population effectively. The habitat of community, population characteristics, community characteristics, population regeneration and endangering causes of Phoebe zhennan in Lichuan, Hubei were studied, the main results are as follows.1.The Phoebe zhennan communities in Lichuan Hubei have four important characteristics:(1) the richness of the made-up species, the species diversity is higher, (2) the population of Phoebe zhennan is the absolute dominant tree species, and seedlings and young trees are rich, (3) the community belongs to the stable type, which has the ability to complete natural regeneration, (4) the community habitat is suitable, and the community resource is very rare.2.Through investigation and analysis, we found that there are 338 species of vascular plant in the sample plots, belonging to 117 families,261 genera. The prevailing is dicotyledon, and the gymnosperm is poor. The species of Rosaceae are the most in the Phoebe zhennan communities, a total of 13 generals and 28 species. The species of Rubus are the most,10 species in it. The plant species of community is variety, and the species composition is diversity. The composition of family and general are more dispersed, and the coefficient of family and general are bigger. The characteristics show that the monotypic genus and oligotypic genus are the dominant in the Phoebe zhennan communities.3.Analysis of the size-class, the static life table and height structure of main dominant population, shows that the population size-class of Phoebe zhennan, Cunninghamia lanceolata., Cyclobalanopsis glauca and Liquidambar formosana take a rising pyramid shape. The population of Choerospondias axillaris is mature population. As the absolute dominant population, the size-class of Phoebe zhennan distributes continuously. There are two old trees of Phoebe zhennan that the diameters at breast height are 151cm and 128cm, respectively. The community of Phoebe zhennan is stable, having the ability to regenerate naturally.4.The family number of tropical type distribution is larger than that in flora in community seed flora geography. The specific value between tropical type composition(108 genera) and temperate type composition(104 genera) is 1.04. Which shows that the community is located in the intersection of tropical and temperate, and the genera of Phoebe zhennan community has some transitional features in the two areas. It is consistent with the Wuling mountain’s characteristics which belongs to subtropical zone plant flora significantly.5.The Phoebe zhennan community has the typical macroscopic features of middle subtropical zone evergreen broad-leaf forest, the community macroscopic is green all the year round, and the seasonal change is not obvious. Look from the life form composition, the phanerophytes are absolute dominant, and the chamaephytes and therophytes are at least.6.The Phoebe zhennan community is single optimal community that composed with Phoebe zhennan as the dominant population. The vertical structure composition is complex, the gradation is distinct, and the advantage is obvious. The species diversity is shrub>herb>arbor. Compared the species diversities with other PhoebeNees trees population, founded that the species distribution of Phoebe zhennan community in Lichuan Hubei was uniform relatively, the community structure was complex, and the species diversity was higher. It is indicated that the Phoebe zhennan community is a typical grew well community, and the habitat is suitable for Phoebe zhennans growth.7.The studies on ability of natural regeneration and endangered causes-show that the Phoebe zhennan ecological adaptation range is narrow relatively, and the distribution area is limited. The distance of seed propagation is limited and seeds are easy to corrupt after landing, the growth resources(mainly light and space) of seedlings and young trees are limited lead them to die. In addition, over-exploitation and utilization and the habitat was damaged seriously lead to the natural community is very deficient. So, the Phoebe zhennan community resources in Lichuan Hubei is very rare. This paper also put forward some protection suggestion of Phoebe zhennan resources.