Ecological Factor Analyzing Of The Invasion Of Eupatorium Adenophorum In Longtan Hydropower Station Reservoir

At present, the invasion of alien organisms has become a major global environmental issues, the invasion of alien species caused a great deal of negative impact to biodiversity, while also causing serious economic losses.Eupatorium adenophorum as a vicious alien invasive species, has a strong adaptability and resistance, in the process of competition with other local species, E. adenophorum with a strong competitive advantage could occupy a favorable ecological niche. In addition, it can inhibit the growth of other associated species, thus forming a single advantage community. In the1940s and1950s of last century, E. adenophorum invaded into Yunnan province from the China-Burma border. And now, E. adenophorum has been widely distributed in southwest of China, such as Yunnan, Sichuan, Guizhou and Guangxi. E. adenophorum has caused serious damages to the local ecological environment, and brought serious damages to local agriculture production too. Due to its vigorous growth, the ability to propagate, fast diffusion, the control is very difficult, and commonly used method of mechanical, chemical and biological as well as an alternative method is often heavy workload but with little success. Although the development and utilization of E. adenophorum have some research base, the costs are so high that have not been widely promoted. The distribution of E. adenophorumin in China is still expanding year by year, therefore, to clarify the invasion mechanism is necessary.This study is set within the Longtan hydropower station reservoir area, The invasive pattern was studied by randomly sampling. Such16variables as "Elevation" were be quantified to decide the different invasion of this dangerous alien species. And then made the principal component analysis, the results show that:(1) The plant height of E. adenophorum in Longtan hydropower station reservoir area is discrepancy between the degree of (0.25m-1.50m, n=71), average height is0.8775m, the standard deviation is0.3969; The distribution of density is uneven (2to509/quadrat, n=71), an average is68.7059/quadrat, the standard deviation is100.12997.(2)The information of E. adenophorum habitat could be characterized by the three main factor (including the amount of information85.826%), ecological factors (the first principal component), light wet factor (principal components), and vegetation factors (third component).(3)The occurrence of E. adenophorum is inversely proportional to "type of plot "," slope "," plant species ","the total number of trees"," height of tree "," tree layer cover "," height of shrub"," shrub layer cover ","the height of herb ","herb layer cover"; is proportional to "slope","soil moisture"," distance to farmland ".(4) Due to the impact caused by the impoundment.the occurrence of E. adenophorum is inversely proportional to "distance to water".