Effects of disturbance on sandy coastal ecosystems of N-Adriatic coasts (Italy)

Coastal sand dune landscapes hold habitats of high economic, social and ecological value on a global scale. At the same time, they are among the most threatened ecosystems worldwide, facing escalating anthropogenic pressures, drawing attention to their resilience as a necessary condition for both biodiversity conservation and sustainable development. This study describes the vegetation zonation of the North-Adriatic coastal landscape which suffers from a severe and complex human utilization meanwhile holding high landscape, faunal and floral values. As plant communities, because of their specific nature, are considered good indicators of overall biodiversity and of ecosystem integrity of coastal dune environments, effects of both human and natural disturbance have been analysed through a comparison between real and potential coastal vegetation, using a hierarchical landscape classification approach. To provide a comprehensive framework for sustainable coastal management and development, a multiscale method for the assessment of the conservation status of sandy coastal environment has been applied. The assessing methodology focused first on landscape level by means of structural and compositional indicators. At a more detailed scale, floristic, vegetational and structural aspects of plant communities were analyzed along the main environmental gradient, which develops moving inland from the sea edge. Conservation status of N-Adriatic coastal zonation resulted fairly good at only few sites along the coast, mostly located where urban development and tourism are limited by legislation or simply because of the difficulty in reaching them. Elsewhere, real vegetation is deeply different from the potential zonation: erosion and tourism pressures truncate the first elements of the zonation, while towns and villages, coastal roads, pines plantations and agriculture truncate the last stages and sandy systems are trapped between erosion on the sea side and human settlements inlands, with no space for natural sediment dynamics and communities development.