ETC/BD Technical paper 3/2022: Connectivity needs for grassland arthropods (Annex 2)

09 Dec 2022

Gerard Arjen de Groot, Wageningen Environmental Research (WEnR)

The EU Biodiversity Strategy to 2030 addresses the continued decline of the conservation status of habitats and species in its Member States by planning to build a ‘truly coherent network of protected areas’ via the ‘Trans-European Nature Network’ (TEN-N). The TEN-N will be build based on the existing Natura 2000 network by integrating ecological corridors using Green Infrastructure landscape elements. To ensure that GI elements are integrated in a way that constitutes a functional habitat network, a knowledge basis is needed concerning the connectivity needs of species, with a priority for species listed on the Annexes of the Habitat Directive. This comprises both an indication of dispersal distances, as well as clear barriers for dispersal, will aid the construction of a functional habitat network.

This study summarizes, for arthropods related to grassland habitats (as a proof of principle), the existing knowledge on (maximum) dispersal distances in relation to different functions which connectivity may have for survival of individuals and/or populations (i.e. trans-habitat commuting and migration, genetic exchange and recolonization) as well as potential dispersal barriers (e.g. unsuitable habitat patches, waterways or roads). Results are listed per species per order in a database and further explained in a report. Furthermore, the report provides recommendations for potential measures to improve connectivity between habitat fragments per taxonomic order. Knowledge gaps are indicated to focus further study.