Prioritisation mismatch using dispersal-based connectivity assessment

Context Prioritising connectivity conservation areas has become a main concern in landscape ecology and related ecological sciences. Prioritising is likely to differ depending on the species considered for connectivity assessments, leading to a lack of consensual decisions for territorial planning. This is the case for the establishment of a conservation network when connectivity needs cannot explicitly account for every species. Objectives The objective was to assess the relevance of designing priority areas for connectivity for groups of species based on common dispersal abilities. We aimed to assess the impact of target groups choices on predicted priority areas. Henceforth, comparing results on existing protected area networks, land use types and decisions on territorial planning. Methods The study was located at the Thau Lagoon territory (Occitanie Region, France) as a demonstrator for the methodological approach. Ecological niche modelling (ENM) was used to quantify species resistance and to identify suitable habitat patches. We coupled least-cost path with circuit theory to assess species connectivity. We classified connectivity by level and averaged the results by dispersal groups. Results We found important differences in identified priority areas between groups having dissimilar dispersal abilities, with low overlap between highly connected areas. We identified a gap in between the level of protection of low dispersal species and highly connected areas. We found mismatches between existing corridors and connectivity for low dispersal species and higher impact of expected urban sprawl projects on highly connected areas for high dispersal species. Conclusion We show that diversity in dispersal capacity must be accounted for the identification of ecological corridors in programmes aiming to restore habitat connectivity. Our findings are oriented to support decisions towards planning initiatives, from local to regional management schemes.