Exploring vascular flora diversity of two protected sandy coastal areas in southern Italy

Coastal ecosystems are among the world's most threatened environments, as they undergo diverse anthropogenic pressures, which trigger habitat alteration along with rarefaction and/or local extinction of native species. In this study, we performed a floristic investigation aimed at assessing the environmental status of two protected sandy areas located on the Tyrrhenian coast of southern Italy, the southern Garigliano estuary area and Castel Volturno Nature Reserve. These localities show similar geomorphological and climatic conditions, but different land uses and management practices. The sampling of the vascular plants was carried out through geo-location of species, to allow their availability to national and international floristic mapping projects. At whole territory and habitat types level, major trends for shared and exclusive species composition were identified through the analysis of life form, chorology percentage spectrum and similarity index. We detected that the total vascular flora is composed by 429 species, and found out that Garigliano is slightly richer in species (317) than Castel Volturno (311). It is important to note that Garigliano and Castel Volturno's richness in plants was considerably significant in comparison with other coastal areas of central and southern Italy. Furthermore, although we pointed out that the studied areas showed a low degree of floristic similarity, the shrubland habitat encompassed the highest number of total species and plants of floristic interest (i.e., Italian endemic, rare in Campania, plants included in CITES convention, Habitat Directive, Regional Law of Campania 40/94, National and Regional Red List) in both areas. Finally, despite a severe alteration due to direct anthropogenic disturbance and large-scale alterations that occurred in the last 60years, we showed that several species of phytogeographical interest are still found in the studied coastal sandy areas, confirming the great importance of this territory for plant diversity and conservation.