Connectedness and connectivity of the Natura 2000 network of protected areas across country borders in the European Union

Abstract We studied the spatial connectedness of Natura 2000 site boundaries and the functional connectivity of the Natura 2000 network across the 34 terrestrial borders of the European Union. Connectivity was measured by the dispersal success of 192 reptile, amphibian, invertebrate and plant species from Annex II of the European Union Habitats Directive, based on the presence of same species on both sides of the borders. Connectedness and connectivity varied greatly between state borders, with good and bad examples found in all parts of the European Union. Connectedness and connectivity were positively correlated. However, a few outlying examples showed that good connectedness is not neces…