Predicting which invertebrates are most likely to invade natural ecosystems: The roles of biogeography and climate

Background/Question/Methods

Biological invasions have a number of well-recognised negative ecological and economic impacts. A key part of minimising such impacts of exotic species is to be able to assess the risk of their establishment and spread in new ecosystems before they arrive. However, invasion success is the result of a combination of several factors and mechanisms, which make accurate predictions difficult. For herbivorous insects, previous studies have indicated that factors such as biogeography, climatic similarity, host phylogenetic affinities and host specificity are important, but no robust analyses of all these factors and their interactions are available. Here we report on the roles of biogeography and climate with respect to invasive beetles within the super families Curculionoidea and Chrysomeloidea that have had impacts either in North American or New Zealand natural ecosystems. Biogeographic matching between each region and the rest of the world was analysed using the Global Biodiversity Information Facility (http://www.gbif.org/), Phylocom (http://phylodiversity.net/phylocom/) and ArcGIS to estimate phylogenetic distances between plant species in different regions. Climatic similarities were tested using the climate matching function of CLIMEX.

Results/Conclusions

Biogeography and climate both have a role in determining the impacts of the species studied on natural ecosystems. Areas with analogous climates and floras with close plant phylogenetic relationships with the target region are more likely to be sources of invasive invertebrates that impact natural ecosystems. In the future, a more comprehensive analysis combining biogeographic factors, host phylogenetic affinities and host specificity should give even more accurate predictions of which non-native herbivorous insect species are likely to invade a particular geographic range.