Temporal changes in Adriatic coastal dunes: Results from a short term vegetation monitoring

Sandy beaches surrounding the Molise coast, facing to the Adriatic sea, are relatively well preserved if compared with other Italian littorals. In this study we present the results from a short term monitoring analyses of coastal habitats (six/eight-years) using permanent transects as part of the LTER network (Long Term Ecological Research-Italy). Vegetation monitoring was carried out along 4 belt transects along the beach-inland ecological gradient, following the coastal zonation and ranging from pioneer annual communities on the beach to Mediterranean scrubs on fixed dunes. Plant communities were sampled in contiguous 1 m x 1 m plots using a 1-10 ordinal transform scale to estimates the species' cover-abundance. All transects were conducted in sites subjected to a similar touristic pressure. Through cluster analysis we identified 5 Habitats of community interest: Annual vegetation of drift lines (Habitat 1210), Embryonic shifting dunes (Habitat 2110), Shifting dunes along the shoreline with Ammophila arenaria (Habitat 2120), Malcolmietalia dune grasslands (Habitat 2230) and Coastal dunes with Juniperus spp. (Habitat 2250). Main temporal changes were probably related to different erosion/accretion processes acting in each transect: two transects were relatively stable (without evident coastal erosion nor accretion processes), one suffered a strong retreat while the last transect showed a slight accretion process. Moreover, our study evidences that, as coastal plant communities are highly dynamic systems, even relatively short time periods could offer useful insights of annual vegetation trends.