Habitat quality assessment through a multifaceted approach: The case of the habitat 2130∗ in Italy

Sand dune perennial grasslands are valuable coastal habitats, considered among those with major conservation concerns. The priority EU habitat 2130 has an almost continuous distribution area along the coasts of Northern Europe and the Black Sea. In the Mediterranean basin it is found only along the North Adriatic coast, isolated from the rest of the distribution area, thereby representing a unique aspect of the habitat variability. The first aim of this study was to evaluate the conservation status of the EU habitat 2130 by using the concept of 'diagnostic species pool' and a 'reference state' approach by comparing extant plant community attributes to the expected condition in the absence of major environmental and anthropogenic disturbances. The second aim was to investigate the effects of natural and anthropogenic factors on EU habitat 2130 conservation status. Our study allowed to evidence an overall bad conservation status of the habitat, with a generalized decrease in the average species richness and modifications of the habitat structure. The concepts of 'diagnostic species pool' and 'reference state' turned out as the most straightforward tools to assess the conservation status. While geomorphological features, in particular dune width, and human disturbance revealed significant correlation with the conservation status, sedimentological data were not useful to detect community's quality changes. To preserve the EU 2130 priority habitat, representing a peculiar element of the North Adriatic coast, the entire dune system integrity should be pursued, avoiding direct foredune destruction and other actions preventing dune development. In addition to this, the access to the dune system should be managed in order to protect the sensitive dune vegetation from trampling impacts.