Investigation And Risk Assessment On Alien Invasive Plants In Dalian

The invasion of the alien invasive plants will affect gravely on stability and biodiversity in Dalian.However,so far there aren't risk assessment reaserch of Dalian.By investigations,we classified the alien invasive plants in Dalian.We researched the status quo of alien invasive plants and established the risk assessment system in Dalian by the field survey.Based on investigation and analys of the species,approuch,origin,flora,distribution,life form,habitat and harm.The main conclusions are :(1)There are 53 species in 19 families and 42 genus of alien invasive plants in Dalian.The invasive species belonging to Compositae are the most(10 species).Intentional and unintentional propagation are the main kinds of pathway.The largest number of alien invasive plants is come from North America.Herbage of annuals and biennials has most species.Flora includes widespread,pantropic,East Asia(tropics and subtropical)and tropics Sourth American disjuncted.The main distributions of the alien invasive plants in Dalian are Ganjingzi and Shahekou,The number of the two areas are 24 and 23.(2)Based on the completed invasion process and the understanding of the characteristic of each stage.By using the method of risk assessment index system and considering the characteristic of the alien invasive plants in Dalian,a integrated risk assessment system was established.By using the principle of analytic hierarchy process,the weight of the index system of one index,two index and three index has been determined.The three indicators are given different points based on the total score of 100 points.(3)According to the score of risk assessment,the risk grade can be divided into four levels: very high,high,average and low.The number of the four levels are 6,14,22 and 11.(4)Countermeasures and suggestions for management and control of alien invasive plants in Dalian are proposed out according to its distribution status and ecological influences in Dalian.