Damage and Pest Risk Assessment of Invasive Ageratina adenophora at Forest Land in Shuicheng County

Investigations were implemented during June and September of 2018 on distribution of invasive Ageratina adenophora at forest land in Shuicheng county, Guizhou province.Damage and risk of the invasive plant was assessed.The results showed that distribution area of A.adenophora in Shuicheng was 7 351.76 ha, accounting for 4.07% of the total surveyed forest land.The comprehensive risk assessment value was 2.63, meaning special risk.The distribution range of A.adenophora in Shuicheng was South > East > middle > North.Forest land with shrub coverage of more than 70% and Pinus yunnanensis forest had no or distribution of A.adenophora, but that with shrub coverage of less than 50% and pure Cunninghamia lanceolata forest was easy to be invaded.Recommendation was put forwarded to control and prevention in Shuicheng.