Ensemble forecasting of invasion risk for four alien springtail (Collembola) species in Antarctica

Biological invasions are one of the most important threats to Antarctic biodiversity. Springtails (Collembola) make up most of the diversity in soil arthropod communities in Antarctic terrestrial ecosystems. However, the potential range expansion of already established alien springtails and their consequent impacts on Antarctic ecosystems remains largely unknown. Species Distribution Models (SDMs) are a useful tool to identify areas potentially suitable for the geographical spread of alien species that are as yet unoccupied. In Antarctica, however, the application of SDMs is relatively less developed and initially received greater attention in marine rather than terrestrial environments. Here, we implement an ensemble forecasting approach and compute eight modelling algorithms to better understand the geographic distributions and potential range dynamics of four reportedly established alien springtail species (Hypogastrura viatica, Folsomia candida, Mesaphorura macrochaeta and Proisotoma minuta) on the Antarctic Peninsula. Our models identify several ice-free areas across the South Shetland Islands which offer highly suitable environmental conditions for establishment. Thus, biosecurity provisions ought to be reinforced in those sites more vulnerable to invasions. Model predictions of our ensemble SDM approach would benefit from additional field sampling effort across the introduced range and could be complemented with mechanistic models that critically need experimental physiological data to define the fundamental climatic niche of each species.