some real data to go with all the commentary on alien invasive species. from Biological Invasions When are eradication campaigns successful? A test of common assumptions Therese Pluess, Ray Cannon, Vojtěch Jarošík, Jan Pergl, Petr Pyšek and Sven Bacher
email to [email protected] Abstract Eradication aims at eliminating populations of alien organisms from an area. Since not all eradications are successful, several factors have been proposed in the literature (mainly by referring to case studies) to be crucial for eradication success, such as infestation size or reaction time. To our knowledge, however, no study has statistically evaluated which factors affect eradication success and attempted to determine their relative importance. We established a unique global dataset on 136 eradication campaigns against 75 species (invasive alien invertebrates, plants and plant pathogens) and statistically tested whether the following factors, proposed by others were significantly related to eradication success: (1) the reaction time between the arrival/detection of the organism and the start of the eradication campaign; (2) the spatial extent of the infestation; (3) the level of biological knowledge of the organism; and (4) insularity. Of these, only the spatial extent of the infestation was significantly related to the eradication outcome: local campaigns were more successful than regional or national campaigns. Reaction time, the level of knowledge and insularity were all unrelated to eradication success. Hence, some factors suggested as being crucial may be less important than previously thought, at least for the organisms tested here. We found no differences in success rates among taxonomic groups or geographic regions. We recommend that eradication measures should generally concentrate on the very early phase of invasions when infestations are still relatively small. David Cameron Duffy Ph.D. Professor/PCSU Unit Leader/CESU Director PCSU/CESU/Department of Botany University of Hawaii Manoa 3190 Maile Way, St John 410 Honolulu, HI 96822 USA Tel 808-956-8218, FAX 808-956-4710 http://www.botany.hawaii.edu/faculty/duffy/
