Robuuste en klimaatbestendige riviernetwerken : Hotspots voor natuurontwikkeling langs de grote rivieren

The aim of Dutch public authorities is to create a river system in which all habitats indicative for a robust river system as well as the characteristic species of the system are present. The focus is on four hotspots of large-scale coherent nature along the branches of the major Dutch rivers Rhine and Meuse. In addition to the ongoing de-velopment of a string of natural areas along the major rivers (corridors), the aspiration in these hotspots is to arrive at large contiguous areas with high nature qual-ity, to serve as robust core areas and source populations for the surrounding parts of the river area. For a num-ber of indicator species (animal species representative of other species with similar habitat requirements) we have modelled with the metapopulation model LARCH whether they can develop sustainable populations. Subsequently, an estimate was made for 2050 of the habitat distribution in the hotspots that would result if all agricultural land on the riverside of the flood levees were given a nature destination, with or without shared agricultural use. Finally, based on modelling outcome additional measures were defined to realize sustaina-ble populations of indicator species, increasing riparian forests and wet grasslands. From this semi-quantitative approach it appears that for most river-bound species significant habitat improve-ments can be achieved when focussing on nature reha-bilitation in a limited number of promising hotspots.