Achyut Kumar Banerjee

The conceptual framework for biological invasion process consisting of series of stages. In each stage a species has to overcome certain barriers to pass on to the next stage. The species is referred to by different terms depending on its position in this process, and different management options are implemented at different stages of invasion. The arrows describe the movement of species along the invasion pathway: (A) not transported beyond its native range; (B1 and B2) Species transported beyond its native range, and in cultivation/captivity; (B3) Species directly released into novel environment; (C0) Species released into the wild, but cannot survive for a significant period; (C1) Species surviving in the wild, but no reproduction; (C2) In the wild, species is surviving, reproducing, but not self-sustaining; (C3) Species is surviving, reproducing, and maintains self-sustaining population in the wild; (D1) Species is capable of surviving at a significant distance from the point of introduction; (D2) Species is capable of both surviving and reproducing at a significant distance from the point of introduction; (E) Species becomes fully invasive with individuals capable of dispersing, surviving, and reproducing at multiple sites in different habitats [Adopted from (Blackburn et al. 2011)]