Forest insect and pathogen species are expanding their geographical ranges through international trade at a rate that most pest specialists and ecologists find alarming. While many invaders are relatively innocuous, several species have damaging impacts on agricultural and natural resources. Furthermore, some of these non-native pests have had catastrophic impacts on ecosystem functions when they invade native communities in which they have no prior evolutionary history. Examples include the demise of chestnut trees in North America, major losses of elms in Europe and North America, Jarrah dieback in Australia, and the devastating effects of pine wood nematode in Asia. Predicting which insects or pathogens will become most problematic and devising mitigation measures to reduce the risk of their arrival and establishment has become the ‘holy grail’ for many entomologists and plant pathologists worldwide. Analysis of historical data is an essential tool for identifying important invasion pathways and weak links in the chain of biosecurity measures that must be strengthened to protect local economies and ecosystem stability. In this issue of New Phytologist, Santini et al. (pp. 238–250), provide a comprehensive and insightful analysis of historical forest pathogen establishment and spread records from Europe. A product of a collaborative (20 nations) European Union-funded project, the paper identifies dominant plant pathogen invasion pathways and key factors predicting pathogen species invasiveness, as well as habitat characteristics that render certain regions more vulnerable to pathogen invasion. All of these associations have implications for preventing future invasions.
Kerry O. Britton, Andrew M. Liebhold
See also the article by Santini et al. (previously scooped here):