Differential vulnerability to biological invasions: not all protected areas (and not all invaders) are the same

Abstract Protected areas (PAs) are fundamental for global biodiversity conservation but many not delivering their potential. In particular, the European Natura 2000 (N2K)–the largest coordinated network of PAs in world—has insofar proved insufficient to achieve EU’s targets. Despite adoption innovative legislation on prevention and management biological invasions, invasive alien species (IAS) remain a main threat N2K. We explored whether regulatory status N2K has been efficient prevent establishment regulated IAS (those under scope EU or national regulations) by conducting case study highly biodiverse Mediterranean region Spain. We: (1) analyzed number both unregulated differ across adjacent unprotected (belt zones), sites with additional protection as park nature reserve (APAs); (2) compared spread pathways present different status. While APAs hosted fewer IAS, did perform better than belt zones. Specifically, there were that through natural dispersal intentional human assistance zones, those dispersing unintentional similarly distributed Further, level reduce IAS. Thus, observed patterns indicate obligations bound designation an area site sufficient slow down invasions.