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Several regulatory and management tools are commonly used to prevent negative effects of human trampling on sand dune habitats, but few studies have attempted to evaluate the effects of boardwalks on dune vegetation. We aimed to evaluate changes of species richness and cover, floristic composition and ecological functional guilds among different dune habitats 2 years after the boardwalks had been established, highlighting those habitats mainly affected by these changes. In a Special Protection Area of Molise region (Italy), we sampled 53 square plots before the installation of five wooden boardwalks (control plots) and 57 plots after the boardwalks had been set up (testing plot), across the whole dune system ranging from the upper beach to the pine forest. We compared species richness through rarefaction curves, considering two plant functional groups: focal species (characteristic and diagnostic) and ruderal/exotic species. We finally compared florist composition and cover changes between time intervals, dune habitats and functional groups. In all habitats the total plant richness of testing plots was higher than in the control plots. In beach and mobile dunes habitat focal species drive the increase in both species’ richness and cover. Dune grasslands proved to be the most affected by the presence of ruderal and exotic species, while the more stable fixed dunes habitat was less affected by species changes. Only 2 years after the boardwalks having been set up, we have found a rapid recovery since human trampling was limited. The use of boardwalks could be an effective tool for reducing negative impact of bathing tourism on coastal dunes and requires little and inexpensive maintenance.

Invasive alien plants are a major threat to biodiversity and they contribute to the unfavourable conservation status of habitats of interest to the European Community. In order to favour implementation of European Union Regulation no. 1143/2014 on invasive alien species, the Italian Society of Vegetation Science carried out a large survey led by a task force of 49 contributors with expertise in vegetation across all the Italian administrative regions. The survey summed up the knowledge on impact mechanisms of invasive alien plants in Italy and their outcomes on plant communities and the EU habitats of Community Interest, in accordance with Directive no. 92/43/EEC. The survey covered 241 alien plant species reported as having deleterious ecological impacts. The data collected illustrate the current state of the art, highlight the main gaps in knowledge, and suggest topics to be further investigated. In particular, the survey underlined competition as being the main mechanism of ecological impact on plant communities and Natura 2000 habitats. Of the 241 species, only Ailanthus altissima was found to exert an ecological impact on plant communities and Natura 2000 habitats in all Italian regions; while a further 20 species impact up to ten out of the 20 Italian administrative regions. Our data indicate that 84 out of 132 Natura 2000 Habitats (64%) are subjected to some degree of impact by invasive alien plants. Freshwater habitats and natural and semi-natural grassland formations were impacted by the highest number of alien species, followed by coastal sand dunes and inland dunes, and forests. Although not exhaustive, this research is the first example of nationwide evaluation of the ecological impacts of invasive alien plants on plant communities and Natura 2000 Habitats.

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.

Multi-year temporal studies are invaluable tools for monitoring changes in biodiversity through time. However, their applications in coastal ecosystems are still scarce. We investigated temporal trends in coastal dunes analyzing a set of 858 randomly-sampled georeferenced relevés performed between 2002 and 2015 along Central Italy’s sandy coastlines. Specifically, we explored changes in species richness and cover of targeted sandy habitats, we investigated trends in the cover of selected psammophilous native species and we assessed patterns of invasion by means of regression techniques. We observed a significant decrease in species richness and cover of the dune grasslands habitat. The species-level analysis confirmed a negative trend for two characteristic species of dune grasslands, Cutandia maritima and Medicago littoralis, while revealing a similar decline for Crucianella maritima and for Ammophila arenaria subsp. australis, key species of mobile dunes. The most striking trends emerged analyzing patterns in the cover of an invasive alien species, Carpobrotus sp., which showed a concerning increase in shifting dunes. In conclusion, our analyses reveal concerning changes involving dune grasslands, and at the same time hint at “early warnings” of degradation processes traceable in shifting dunes.

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.

The importance of taking into account ecosystems, plant communities and habitats for the development of biodiversity conservation strategies is increasingly acknowledged. Recently, the first ever European Red List of Habitats was produced, which provided an evaluation of the extinction risk of EUNIS-based natural and semi-natural habitats in Europe. As assessment unit, it used the habitat intended as a plant community, thus representing a landmark for the role of vegetation science in nature conservation. In the present paper, the results of the European Red List of Habitats are analyzed at the national scale with specific reference to the terrestrial and freshwater habitat types occurring in Italy. More than three-quarters of the assessed European habitat types were recognized for the Italian territory. The distribution of the threat categories reflects approximately the situation at the EU28 level. About 35% of the assessed habitat types are referred to a threat category; no critically endangered habitat is present in Italy. The most frequently used criteria are those related to a reduction in quantity. Some critical issues arising from the analyses are discussed. In particular, the presence of knowledge gaps is pointed out, with remarkable reference to the poor availability of spatial and quantitative data, severely affecting the application of the criteria adopted for the assessment. Descriptions of habitat types from Italy are reported, some of which are representative, emblematic or even exclusive to the Italian territory. The outcomes of the analysis represent the starting point for the future development of a national-scale Red List of Habitats. Results also emphasized how habitat types with a too broad definition pose a limit to a proper evaluation of the regional biogeographic variability, often very high in Italy, with local floristic and phytocoenotic peculiarities which do not find room in the adopted European typology. This is the reason why the development of national subtypes stands as a necessary step for the development of a realistic and effective assessment at the national scale.

Detailed monitoring studies on permanent sites are a promising tool for an accurate evaluation of short, medium or long term vegetation dynamics. This work aims to evaluate short-term changes in coastal dune herbaceous plant species and EU Habitats through a multi-temporal analysis using permanent vegetation transects. In particular, (I) we analyze changes in species richness of coastal habitats; (II) we identify changes in plant cover of selected focal plants; and (III) we relate the changes to selected climatic variables and erosion/accretion processes. We selected one of the Italian's peninsula best preserved coastal dune areas (ca. 50 km along the Adriatic sea) with a relatively homogeneous coastal zonation and low anthropic pressure but with different erosion/accretion processes. We explored changes in richness over time using generalized linear models (GLMs). We identified different ecological guilds: focal, ruderal and alien plant species and investigated temporal trends in these guilds' species richness. We also applied GLMs to determine how plant cover of the most important focal species have changed over time. Overall, in this study we observed that the influence of climatic variables was relatively small. However, we found remarkable different trends in response to erosion/accretion processes both at community and at species level. Thus, our results highlight the importance of coastal dynamics in preserving not only coastal vegetation zonation, but also species richness and focal species cover. Moreover, we identified the dune grasslands as the most sensitive habitat for detecting the influence of climatic variables throughout a short term monitoring survey. Information from this study provides useful insights for detecting changes in vegetation, for establishing habitat protection priorities and for improving conservation efforts for these fragile ecosystems.

We introduce RanVegDunes (GIVD ID EU-IT-020), the first Italian database gathering standardized, randomly- sampled vegetation data in coastal dune environments. RanVegDunes currently consists of 979 original georeferenced relevés randomly collected over about 160 km of Holocenic dune systems of central Italy between 2002 and 2015. Plots were located in five Italian administrative regions (Lazio, Campania, Abruzzo, Molise and Puglia), where sandy vegetation was randomly recorded in standardized 4-m2plots across the whole coastal zonation, thus including upper beach, embryo dunes, shifting dunes, dune grasslands, wooded dunes and Mediterranean forests. Each plot was georeferenced with a high level of accuracy using a GPS unit. For each plot, a list of vascular plant species based on updated nomenclature was compiled, and an estimate of abundance was calculated for each species using a percentage cover scale ranging from 1 to 10 (1 = 1-10%; 2 = 10-20%; ...; 10 = 90-100%). Two habitat classification systems were used for the description of collected plots: specifically, each vegetation plot was classified according to the Interpretation Manual of the 92/43/EEC Habitats Directive and also to the hierarchical structure of the EUNIS habitat classification. Currently, RanVegDunes includes vegetation plots belonging to nine EU Habitats (1210, 2110, 2120, 2210, 2230, 2250, 2260, 2270, 9340), which in turn correspond to five EUNIS Habitats (B1.1, B1.3, B1.4, B1.6, B1.7). RanVegDunes is a powerful tool for a variety of studies addressing topics such as temporal trends in coastal vegetation, ecological modeling, re-visitation studies, spatio-temporal patterns of invasion and will therefore greatly benefit from further collection of data.