Yunnan Eucalyptus Plantation Community Structural Characteristics And Impact Studies On The Ecological Environment

Nowadays, people in our country fetch in eucalyptus greatly to develop the industry of "woods-pulp-paper" and "woods-chipboard". But scientists and public have so many controversies on eucalyptus use and development. Eucalyptus plantation and zoology protection should be considered carefully to carry out the scientific eucalyptus plantation and harmonious development. According to the importance of economy and sensitivity of ecology, study of different eucalyptus plantation community structure and ecological effect can be carry out with the special biological, geographical and climate traits.Eucalyptus plantation community structure and system of Simao, Wenshan in Yunnan was studied. Arrangement analytical method and fuzzy math estimation was also used to assess the factors and their relations. Sustainable development and protection of plant diversity was the goal of reasonable management.(1)In the 2-year-old eucalyptus plantation community, the vertical structure of community can be obviously divided into 4 layers, including arbor layer, shrub layer, herbage layer and interbedded plant level. There is only one species of eucalyptus to form single plant canopy in the arbor layer. Shrub layer and herbage layer have more types of vegetation, with new invasive species seedlings shade-resistant and few interbedded plant. The horizontal structure of eucalyptus plantation community is collective distribution. Eucalyptus takes the absolute advantage in the arbor layer of eucalyptus plantations community and the distribution of individuals well-proportioned without diversity; the herb layer and shrub layer have many uneven distribution species and some species comes up to a great number with the outstanding dominant species. The changing trend of species-diversity in each layer is that shrub layer shows the highest species diversity among the four layers. Compared the preponderant communities of shrub layer and herbage layer in eucalyptus plantations with the preponderant species of contrasted sample land, the results show that some kinds of positive herbage vegetation, hardly growing up in the local vegetation, quickly penetrate eucalyptus plantation to update and reproduce, which result in the individuals of herbage layer in eucalyptus plantation are more than that in the contrasted sample land and the positive species increase.(2)Through AHP fuzzy mathematics comprehensive evaluation, the biological quality in the eucalyptus plantation community results as "bad" and the overall impact on the ecological environment evaluation results as "serious impact".The results of this study reflect the structure of the 2-year-old eucalyptus plantation community, with the growth of eucalyptus, the plant canopy shade, forest environment, forest species composition and community structure are all in the process of change and development, which are to be further research by locating and monitoring. Also the species diversity of shrub layer and herb layer in eucalyptus plantation, the laws and mechanism of quantitative feature dynamic changes in eucalyptus plantation community, and the recession rate of species diversity in eucalyptus plantation forest are still need to be further research.