Invasive Alien Species (IAS) constitute one of the most important threats to biodiversity, causing severe ecological and socio-economic impacts. Recognizing the need for a coordinated set of actions to prevent, control and mitigate alien species invasions, the European Parliament and the Council have adopted the IAS regulation (EU Regulation no. 1143/2014) on the prevention and management of the introduction and spread of IAS.
It is widely accepted that prevention is the best strategy when tackling IAS, since it is much more cost efficient than eradication or containment and control. The key element for an effective prevention is the early warning coupled with rapid response, before an IAS could establish and widely spread within an area. Early warning can benefit from risk modelling maps, indicating areas of high probability that an IAS could successfully establish, reproduce and spread. This kind of information can be valuable to managers and stakeholders to choose and prioritize the appropriate decision making against IAS.
Elodea nuttallii is a dangerous invasive species in Europe. Environmental variables including bioclimatic data, infrastructure and nutrient levels were inserted in a Species Distribution Model in order to map areas in the European Union suitable to the species. The two main drawbacks of this method, most notably when used on invasive species, are sampling bias and model overfitting. These were compensated for by using the R package ENMeval and by extraction of occurrence data at two spatial scales. The identified areas of habitat suitability compared to Natura2000 sites. Finally, since many areas in Europe remain unaffected, the resulting areas that were 100 km removed from E. nuttallii’s known distributions were identified. These are proposed as best candidates for receiving conservation priority.
