Abstract:To protect the plant and ecosystem diversity of the coastal zone and islands along Beibu Gulf, Guangxi, the species composition, origin, life forms, invasion routes and damage status of alien invasive plants were analyzed by field investigation using quadrats and transect methods and literature data. The results showed that there were total 64 invasive plants, belonging to 28 families and 55 genera, in which, Asteraceae (15 species) were the most. Herbaceous plants were most with 48 species, accounting for 75.00%. The plants originated from America were the most with 49 species. The risk level of invasion could be divided into 5 grades, among which grade Ⅰ (serious hazards) had 8 species, accounting for 12.50%. The alien invasive plants of Beibu Gulf were similar to those from Guangxi, Guangdong, Hainan and South China in species composition, life forms and origin. There were more than 60% of invasive plants come from the Americas in Beibu Gulf and inland area of China-Vietnam border in Guangxi. So, it was speculated that there were two possible invasion routes in Guangxi: one was from Hainan, and the other was from China-Vietnam border. Although the total number of alien invasive plants in Beibu Gulf was smaller than that in Guangxi, the prevention and control of 8 alien invasive species of grade Ⅰ should be paid more attention.
