An Updated Environmental Resistance Model for Predicting the Spread of Invasive Species

Aim

Predictive models on invasive species spread can assist in identifying large-scale invasion risk. Environmental resistance (ER) models, which predict spread based on ecological similarity to already-invaded communities, offer one approach. However, gaps remain in understanding how different ER measurements perform across different taxa and how they can be integrated with future global change. Here, we aim to discern the primary drivers of invasion spread by comparing different ER models and then use the best models to forecast future invasion dynamics.

Location

Eastern US.

Taxa

1873 invasive plants and animals.

Methods

We developed different ER measurements, including biotic similarities among native plants in their species and phylogenetic assemblages, and functional traits, and abiotic similarities in climate, soil, and human disturbances. We obtained the best ER model for each invasive species to evaluate their potential invasion extents; and we further predicted their future range shifts under climate change.

Results

Native plant similarities provided the best proxy measure of ER for both invasive plants and animals. Invasion hotspots were identified in urban and coastal areas, and the predicted potential invasion ranges under current conditions extended from these hotspots to the neighboring areas. The invasion range for most invasives was predicted to increase under future climate change, with Arthropoda and Tracheophyta generally expanding the most among all taxa. The invasives that are predicted to expand their range in the future have already occupied larger areas than the invasives whose ranges are predicted to contract.

Main Conclusions

These results highlight the importance of maintaining diverse native communities in invasion control and raise the concern of increased invasion risk in the future. Our findings call for more efforts on invasion monitoring in areas near large cities, and increased capacity for early detection and rapid response to prevent the current invasives spreading more widely.