Assessing vegetation changes in coastal dunes: historical plot resurveys in a Mediterranean archipelago

Agnese Denaro 1, Caria Maria Carmela 1, Sperandii Marta Gaia 2, Malavasi Marco 1, Pisanu Stefania 3, Rivieccio Giovanni 1, Bagella Simonetta 1

Department of Chemical, Physical, Mathematical and Natural Sciences, University of Sassari, Sassari, Italy 1, Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno, Czech Republic 2, 3

Mediterranean islands, which are over 10,000, are very important from a biodiversity point of view in term of plant species and vegetation types. They are among the most vulnerable systems particularly along the costal perimeter due to anthropogenic disturbances and global changes. The objective of this study was to monitor dune vegetation dynamics through historical plot resurveys to detect temporal changes in plant communities in the La Maddalena National Park, an archipelago located in the central area of the Mediterranean basin (Sardinia, Italy). In 2023 we conducted a resurvey of six coastal dune sites to monitor vegetation changes and to assess shifts in conservation status. A total of 207 plots, distributed across 40 georeferenced transects encompassing the entire coastal dune systems, were revisited and re-sampled, replicating the methods originally used in 2011. To evaluate the conservation trends, we focused on the dynamics of both characteristic dune species and ruderal (disturbance-adapted) plants, and examined shifts in habitat types. We also analyzed alterations in plant community composition and structure, using dissimilarity indices based on presence/absence and rank-abundance curves. Our findings indicate that over the past 12 years, the coastal dune ecosystems in La Maddalena National Park have undergone significant changes, likely driven by a combination of natural and anthropogenic stressors. This research not only enhances our understanding of vegetation dynamics but also underscores the importance of continuous, long-term monitoring, particularly in vulnerable ecosystems like coastal dunes.

Main author career stage: PhD student

Contribution type: Talk

First choice session: 3. Biodiversity and global change

Second choice session: 2. Ecology