Variants of spatial configurations of European ecological corridors

This report presents European-level terrestrial and freshwater connectivity data combining structural and functional connectivity approaches to (1) prioritise ecological connectivity for all terrestrial vertebrates, (2) assess the structural connectivity of hundreds of European Nature Information System (EUNIS) habitat types, and (3) prioritise continental corridors in river and riparian ecosystems. We designed advanced workflows for large-scale connectivity assessments in Europe and produced information that can support conservation planning at multiple levels of governance. We combined omnidirectional circuit and graph-based models to prioritise ecological corridors for 953 different terrestrial vertebrate species categorised into 30 archetype groups. These functional connectivity outputs include raster and vector spatial information covering both continuous (wall-to-wall) connectivity data and discrete ecological corridors both at 1 km resolution. Results point to the importance of connectivity within key biogeographic regions and between large protected areas in mountainous areas with nearby smaller protected areas. We produced a consistent set of maps quantifying the structural connectivity of EUNIS terrestrial habitat types across Europe. We used a probability-weighted habitat fragmentation metric that extends the classical effective mesh size to incorporate continuous-field probabilities of habitat occurrence. These data include the structural connectivity of 232 different EUNIS habitat types at 100m resolution. Overall, forest habitat types were the most structurally well connected relative to the other habitat types like heathlands and grasslands. We followed a two-step process of structural connectivity and spatial prioritization methods to design a potential freshwater ecosystem corridor network. First, we estimated riparian and river structural connectivity and created a new database of continental freshwater barriers. Second, we identified freshwater corridors that would facilitate connectivity among protected areas and suitable habitat for all species, while minimising the number of longitudinal barriers that could compromise the functionality of the corridors. The identified barriers and riparian areas in poor condition could be the focus of future restoration efforts to maximise their freshwater connectivity and functionality.