US Geological Survey


Date of this Version



Published in Biological Invasions (2006) 8:1435–1437.


The movement of organisms among continents by humans has caused profound changes in the ecology of relocated species and of communities to which they have been introduced. Perhaps less than 1% of all species that arrive at foreign shores become invaders (Williamson and Fitter 1996), but the few that explode in abundance wreak tremendous environmental and economic damage (Mack et al. 2000; Pimentel et al. 2000; Xu et al. 2006). During the last decade research on invasive species has dramatically increased. For example, from 1988 to 1990 the journal Ecology published three papers with the words ‘invasive’ or ‘invader’ in their title or abstract that related to exotics. From 1998 to 2000 this number increased to 14. However, the focus of the increasing volume of research on exotic invaders has been primarily on the exchange of species between North America and Europe. Of the 14 papers on exotic invasions published in Ecology from 1998 to 2000, seven involved Europe– North America invasions and all primary empirical research focused on at least one species from Europe or North America. Two focused on a species moving to or from Asia and North America. The focus on North America and Europe may be driven by the unusually high numbers of organisms moved between these regions in the last few centuries (or to the unusually high numbers of ecologists), but regardless of why the historic focus has been on North America and Europe, future research on invasive species may shift to include those coming from and going to eastern Asia (Normile 2004).