植物外来种的生态风险评估和管理

The invasion of exotic plants is a severe problem due to its tremendous damage and impact. The management and assessments of exotic plants are very important. The effective assessments include:①the properties related to establishment of exotic plant.② the factors which influence the spread of exotic plants;③ the impacts of exotic species. When evaluating exotic species, the three aspects should be integrated to assess exotic plants. Every guideline of assessment plays different role in assessment of different exotic species. At the same time, it is becoming increasingly important to predict which species will invade an area alien to them and to estimate what harm they can do. Three ways of predicting invasions of exotic species,should be conducted. Models may help us to evaluate the influence of exotic species. Managing exotic plants, especially the exthose with large distribution area, requires a coordinated strategy based on cooperation among all departments, which include forestry, agriculture, fishery, all land managers and so on. This strategy emphasizes on cooperation, education, and science, and is based on integrated management techniques. The management is divided into three steps. The first step is to effectively prevent new invasion, the second step is to control and eliminate exotic plants, in which mechanical methods, chemical means, and biocontrol technologies are used. Sometimes, the three ways are integrated in order to obtain better results. The third step is to effectively restore native vegetation and prevent reinvasion.