Irene Prisco

The fate of threatened coastal dune habitats in Italy under climate change scenarios.

Coastal dunes worldwide harbor threatened habitats characterized by high diversity in terms of plant communities. In Italy, recent assessments have highlighted the insufficient state of conservation of these habitats as defined by the EU Habitats Directive. The effects of predicted climate change could have dramatic consequences for coastal environments in the near future. An assessment of the efficacy of protection measures under climate change is thus a priority. Here, we have developed environmental envelope models for the most widespread dune habitats in Italy, following two complementary approaches: an “indirect” plant-species-based one and a simple “direct” one. We analyzed how habitats distribution will be altered under the effects of two climate change scenarios and evaluated if the current Italian network of protected areas will be effective in the future after distribution shifts. While modeling dune habitats with the “direct” approach was unsatisfactory, “indirect” models had a good predictive performance, highlighting the importance of using species’ responses to climate change for modeling these habitats. The results showed that habitats closer to the sea may even increase their geographical distribution in the near future. The transition dune habitat is projected to remain stable, although mobile and fixed dune habitats are projected to lose most of their actual geographical distribution, the latter being more sensitive to climate change effects. Gap analysis highlighted that the habitats’ distribution is currently adequately covered by protected areas, achieving the conservation target. However, according to predictions, protection level for mobile and fixed dune habitats is predicted to drop drastically under the climate change scenarios which we examined. Our results provide useful insights for setting management priorities and better addressing conservation efforts to preserve these threatened habitats in future.

Passive Recovery of Mediterranean Coastal Dunes Following Limitations to Human Trampling

Because of the important functional role that plants play in dune ecosystems, assessing their ability to recover following human disturbance is an important task for the restoration and conservation of coastal dune ecosystems. In this study we assess the effects of limitations to human trampling on dune vegetation in a protected coastal area of central Italy. Using a diachronic approach (studying community changes over time), we compared species cover and richness in two fenced sectors with that of an open sector that has been subjected to trampling over the course of a 4-year experiment. Random vegetation sampling was performed in the three dune sectors using geo-referenced points located with a GPS (10 points in each sector). At each randomly assigned point, all vascular plant species were sampled in a 4-m2 plot. Our results indicated a significant increase in species cover and richness in the fenced sectors, while both parameters remained relatively constant in the control. It appeared that by reducing the effect of trampling, the dune system started to recover some of the spatial structure along the sea-inland gradient that typifies coastal dune vegetation communities, and which was absent in the open sector. These findings highlight the great potential of fencing as a passive recovery method for improving the conservation status of degraded and trampled Mediterranean foredune habitats, as well as helping to gain a clearer picture of how the recovery process takes place. The results of this study are encouraging for managers and stakeholders as they show how a cost-effective and passive practice such as fencing can help restore ecosystem functioning within a relatively short time-frame.

Habitat conservation in Italy: the state of the art in the light of the first European Red List of Terrestrial and Freshwater Habitats

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.

Biogeographic variability of coastal perennial grasslands at the European scale

Question: Coastal environments have often been described as azonal. While this characteristic is clear for the foredune system, it seems less evident for more inland fixed dunes, which host habitats of major conservation concern, whose features seem to be more related to local climatic conditions. We hypothesized that, unlike other coastal habitats, dune perennial grasslands differ floristically and structurally across their European range and that patterns of variation are linked to the corresponding climate. Location: European coasts (Atlantic Ocean, Baltic, Mediterranean, Black Sea). Methods: We used a large data set of phytosociological releves, representative of coastal grasslands throughout their European range. The role of climatic variables (temperature, precipitation and continentality) in determining the variability in species composition and vegetation structure (by means of life forms) was investigated through CCA, DCA and GLM. The degree of concentration of species occurrences within groups was calculated through the Phi coefficient. Results: Through multivariate analyses we identified seven major types of coastal grassland, corresponding to different geographic areas. The groups significantly differed in their climatic envelope, as well as in their species composition and community structure. Conclusion: Our results confirm the hypothesis that coastal dune perennial grasslands are subjected to local climate, which exerts significant effects on both floristic composition and community structure. As a consequence, coastal grasslands are particularly prone to the effect of possible climate change, which may alter species composition and distribution, and lead to shifts in the distribution of native plant communities.

Hard times for Italian coastal dunes: insights from a diachronic analysis based on random plots

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.