A gap analysis comparing the effectiveness of Natura 2000 and national protected area networks in representing European amphibians and reptiles

Protected area networks represent one of the mainstays of worldwide conservation policies and play a key role in the protection of biodiversity. While numerous studies have evaluated the extent to which reserves fulfil their role of protecting biodiversity (so called 'gap analysis') in Europe at national and subnational scales, their performance across the whole of Europe has seldom been assessed. Here we assess the effectiveness of nationally designated protected areas and the pan-European Natura 2000 network in representing and maintaining over time European amphibian and reptile biodiversity using a comprehensive and newly available species occurrence dataset. Overall, our results show that often national protected areas and Natura 2000 sites perform poorly in representing amphibians and reptiles, but highlight differences in the effectiveness of both protected area networks when the goal is to promote the persistence of the species. While nationally designated areas did not usually cover more species than a random selection of areas for both vertebrate groups across different conservation targets, Natura 2000 network usually covered significantly more species than random when the goal was to include multiple representations of each species. In any case, these covered species were mostly widespread taxa, while narrow-range species remained under-represented. Additionally, our findings provide important evidence of the need to assess sensitivity of reserve effectiveness assessments to data and decision-rules, as the effectiveness of both reserve networks varied greatly across the different thresholds used for assigning reserves to grid cells and the criteria used to consider species as covered.