Investigation and analysis on alien invasive plants in three nature reserves of Jiangsu Province.
Taking Yuntai Mountain Forest Nature Reserve in Lianyungang, Zijin Mountain Scenic Area in Nanjing and Longchi Mountain Forest Nature Reserve in Yixing, which locate in different bioclimatic zones in Jiangsu Province, as investigation regions, the species and distribution status of alien invasive plants in three nature reserves were investigated and analyzed by means of combining methods of line investigation, quadrat investigation and interview investigation. The results show that there are 13, 19 and 23 species of alien invasive plants in Yuntai Mountain Forest Nature Reserve, Zijin Mountain Scenic Area and Longchi Mountain Forest Nature Reserve, respectively, with a total of 25 species in which common species is 11 species. The invasive species belonging to Compositae are the most (12 species) and accounting for 48% of total species number, and invasive plants belonging to Amaranthaceae and Scrophulariaceae have two species, respectively. 80% of invasive species originate from America and unintentional spread is the main invasive pathway. Frequency of Erigeron annuus (L.) Pers. is the highest with a value of 51.6%, and that of Conyza canadensis (L.) Cronq. and Crassocephalum crepidioides (Benth.) S. Moore is also higher, both above 10%. Some of invasive plants have established steady breeding populations in the three reserves and do harm to ecological environment and excert a serious threat to biological diversity of nature reserves. Furthermore, countermeasures and suggestions for management and control of alien invasive plants in nature reserves are proposed out according to its distribution status and ecological influences in three reserves.