Irene Prisco

Coastal dunes are among habitats with the worst conservation status on a global, European and national scale. Monitoring and reporting are of strategic importance to determine the effectiveness of the implementation of Habitats Directive and to preserve the unique biodiversity heritage of the Italian dunes. In this study we show main results of the 4th National Report with specific reference to the macro-habitat “Coastal Sand Dunes and Inland Dunes”, highlighting its updated current conservation status at the national and Biogeographical level. A comprehensive Working Group of territorial experts collected, updated, validated and integrated the data available for 11 Annex I Habitats, distributed in the Alpine, Continental and Mediterranean Biogeographical Regions. The conservation status was evaluated through the following criteria: geographic range, surface area, structure, functions, pressures, threats, conservation measures and prospects. Results highlighted the dramatically bad conservation status of Italian dune Habitats: the overall assessment reported 88% of habitats in bad conservation status and the remaining 12% is in inadequate conditions. Results showed a generalised threat and a worrying conservation status both on herbaceous and wooded communities, in particular in some relevant habitats, such as the shifting dunes. Main pressures and threats were linked to residential, commercial and industrial activities, as well as alien species. Although some of the changes in distribution and trends are probably deriving from more accurate and updated data, the alarming conservation status of Italian sand dunes requires a better knowledge of pressures and threats for further management actions and monitoring plans, inside and outside protected areas.

Summary: Plant communities of coastal dunes are highly biodiverse and greatly valued for the services they provide, yet they are also threatened by global change and are often neglected in conservation planning. To determine the long‐term effectiveness of conservation actions on Mediterranean coastal dunes, here we focus on Italy's coastline and (i) assess how the vegetation cover of the major psammophilous habitats and species has changed since the 1960s, (ii) identify which ecological strategies have been most successful in the face of global change and (iii) evaluate the efficacy of the protected areas network for safeguarding plant communities of coastal dunes. We compiled 2583 geo‐located vegetation relevés spanning over half a century and covering the entire length of Italy's sandy coastline. Using this data base, we developed statistical models to test whether the vegetation cover of both individual species and habitats has changed over time. We then tested whether species‐level changes in vegetation cover through time could be explained by species’ functional traits and ecological strategy. Finally, we assessed the efficacy of current conservation measures by exploring how vegetation cover responded following the expansion of the protected areas network. Our results indicate that, where protected, plant communities have generally increased in vegetation cover in recent years. The strongest increase in cover occurred in the wooded dune habitats, where late‐successional, tall‐growing and large‐seeded species show the clearest signs of recovery. However, this has come in part at the expense of dune grasslands, which thrive under natural disturbance and have declined since the 1960s. The Natura 2000 network seems to have played a central role in this recovery process, as the cumulative coastal land area under protection has tripled since the network was first established. Synthesis and applications. Our results suggest that protected areas can play an important role in safeguarding coastal dune plant communities against land‐use transformations. In this context, functional traits can be a powerful tool in guiding conservation planning, helping to identify groups of species most at risk of population declines. Nonetheless, future conservation interventions need to be mindful to ensure that the natural disturbance regime of dune ecosystems is not disrupted.

Coastal sandy ecosystems are increasingly being threatened by human pressure, causing loss of biodiversity, habitat degradation and landscape modifications. However, there are still very few detailed studies focussing on compositional changes in coastal dune plant communities over time. In this work, we investigated how coastal dune European Union (EU) habitats (from pioneer annual beach communities to Mediterranean scrubs on the landward fixed dunes) have changed during the last 20 years. Using phytosociological relevés conducted in 1989–90 and in 2010–12, we investigated changes in floristic composition over time. We then compared plant cover and the proportion of ruderal, alien and habitat diagnostic species (‘focal species’) in the two periods. Finally, we used Ellenberg indicator values to define the ‘preferences’ of the plant species for temperature and moisture. We found that only fore dune habitats showed significant differences in species cover between the two time periods, with higher plant cover in the more recent relevés and a significant increase in thermophilic species. Although previous studies have demonstrated consistent habitat loss in this area, we observed that all coastal dune plant communities remain well represented, after a 20-year period. However, fore dunes have been experiencing significant compositional changes. Although we cannot confirm whether the observed changes are strictly related to climatic changes, to human pressure or to both, we hypothesize that a moderate increment in average yearly temperature may have promoted the increase in plant cover and the spread of thermophilic species. Thus, even though human activities are major driving forces of change in coastal dune vegetation, at the community scale climatic factors may also play important roles. Our study draws on re-visitation studies which appear to constitute a powerful tool for the assessment of the conservation status of EU habitats.