Monitoring long-term changes in Italian coastal dune vegetation: insights from the resurveydunes initiative.

Coastal dunes are unique transition zones between land and sea, supporting specialized flora and fauna adapted to harsh environmental conditions. These ecosystems exhibit a distinct plant community zonation, creating a mosaic of habitats that contributes to their remarkable biodiversity. Despite their high conservation value, Mediterranean coastal dunes have undergone significant alterations, ranking among the most threatened ecosystems in Europe. Resurveying studies offer a cost-effective approach to detecting temporal vegetation changes, particularly in highly dynamic and frequently disturbed environments like coastal dunes. Here we introduce the first results from a collaborative network of Italian vegetation scientists engaged in resurveying coastal dune habitats to track long term temporal changes. Our findings highlight an overall decline in typical and diagnostic species, alongside an increase in ruderal and non-native species, demonstrating how shifts in species composition within these habitats represent a tangible threat to their conservation. Finally, we identify key knowledge gaps and propose directions for future research.