Format: ORAL

Silvano Lodetti 1, Alessandro Petraglia 2, Andrea Mondoni 1, Angela Stanisci 3, Brigitta Erschbamer 4, Elena Barni 5, Ludovica Oddi 5, Fiona Jane White 1, Graziano Rossi 1, Lena Nicklas 4, Luciano di Martino 6, Marcello Tomaselli 2, Margherita Tognela 1, Michele Carbognani 2, Pau Carnicero 4, Pietro Fanchini 1, Simone Orsenigo 1, Valter di Cecco 6, Francesco Porro 1

1 University of Pavia, Pavia, Italy 2 University of Parma, Parma, Italy 3 University of Molise, Termoli, Italy 4 University of Innsbruck, Innsbruck, Austria 5 University of Torino, Torino, Italy 6 Majella National Park, Sulmona, Italy

Since 2001, the vegetation of 28 mountains has been monitored in the Italian Alps and Apennines across seven different GLORIA Target Regions (TR). The Italian Gloria Network aims to provide insights into how Italian alpine vegetation is responding to global warming. Here we present our preliminary findings regarding changes in species richness, species abundance and diversity. Species richness increased significantly in all TRs, with an average of +4.3 species per Summit Area Sections (SASs) recorded since the first survey. The highest numbers of new species were recorded in the Alps sites, with an average of +21.5 species (+13% of the total species richness), in contrast to what has been observed for Apennine TRs (on average +7 specie; +7.4%). Local species loss was also observed but was not as pronounced and did not show clear patterns, ranging from 7 species lost in the Dolomites (S-Alps) to none in the Mont Avic (W-Alps). Species’ abundance changed significantly, with “winning” and “losing” species becoming more dominant or rarer, respectively, highlighting an ongoing process of community change. The disproportionate increment of “winning species” led to an overall decrease in species evenness, especially in the Apennines, which communities are becoming more dominated by fewer species. These findings highlight an alarming biodiversity loss associated with a warmer climate. Overall, although local site diversity (alpha-diversity) increased in most TRs due to new colonizing species, diversity among sites (beta-diversity) decreased consistently across sites, due to site-specific species loss and turnover, revealing a trend of floristic homogenization in Italian mountains. Finally, we observed a generalized increment of species belonging to similar growth forms (e.g., graminoids). However, further multidisciplinary studies (e.g., SENTINEL project, started in 2023) are needed to fully disentangle the role of functional traits in driving vegetation dynamics.