Will climate change promote future invasions?

Abstract

Biological invasion is increasingly recognized as one of the greatest threats to biodiversity. Using ensemble forecasts from species distribution models to project future suitable areas of the 100 of the world's worst invasive species defined by the International Union for the Conservation of Nature, we show that both climate and land use changes will likely cause drastic species range shifts. Looking at potential spatial aggregation of invasive species, we identify three future hotspots of invasion in Europe, northeastern North America, and Oceania. We also emphasize that some regions could lose a significant number of invasive alien species, creating opportunities for ecosystem restoration. From the list of 100, scenarios of potential range distributions show a consistent shrinking for invasive amphibians and birds, while for aquatic and terrestrial invertebrates distributions are projected to substantially increase in most cases. Given the harmful impacts these invasive species currently have on ecosystems, these species will likely dramatically influence the future of biodiversity.

Keywords: Climate change; invasive species; land use change; species distribution models.

Fig.1. Global distribution of invasive species under current and future scenarios

(a) Projected richness in invasive species by 2000; (b) Relative change in invasive species richness between 2000 and 2100 and (c) Projected richness in invasive species by 2100.

Fig.2. Effect of climate and land use changes on the number of invasive species per pixel in each biome

Map representing the biomes (a) and the associated boxplots representing the net potential changes of invasive species number between 2000 and 2100, under the A1B emission scenarios (b).

Fig.3. Range size change for the different taxonomic groups of the 100 invasive species

Boxplot of the effect of climate and land use changes on invasive alien species range size (estimated by counting the number of suitable pixels) under A1B scenario for each species sorted by taxonomic group.

Fig.4. Temporal range size change for the 100 invasive alien species among the different taxonomic groups

Effect of climate and land use changes on range size (estimated by counting the number of suitable pixels) under A1B scenario for each species along the different time-slices. Smoothing was performed for each species using linear regression.