Pollinators play an important role in natural and man-made systems through interactions with many organisms, the most significant of which are those with the plants they pollinate. The observation and quantification of the interactions between plants and pollinators allow us to construct pollination networks, which are key tools to characterise the plants and pollinators communities of habitats. The “Semi-natural dry grasslands and scrublands facies on calcareous substrates” habitats, designated as 6210 according to the Natura 2000 and Habitat Directives, have been investigated for this study. Four different sites along the Apennine mountains, situated between 750 and 1450 meters a.s.l., were selected: Monte Prato Fiorito (province of Lucca, Tuscany), Monte Subasio (province of Perugia, Umbria), Parco Naturale del Gran Sasso (province of L’Aquila, in Abruzzo ), and Monte Calvo and Piana di Montenero in the Gargano Promontory (province of Foggia, in Apulia). The pollination networks and the Apoidea communities were assessed and described for each study site. 

Overall, 438 interactions between 83 plant taxa and 166 pollinator morpho-species were observed within the four sites. The highest number of plant species on which at least a single interaction was observed was identified in Prato Fiorito site (37), followed by Subasio (30), Gran Sasso (24), and Gargano (19) sites. The dominant plant families were Apiaceae and Asteraceae in Prato Fiorito, Fabaceae in Subasio, Asteraceae in Gran Sasso, and Lamiaceae in Gargano. A similar trend occurred for the pollinator morpho-species, with the highest number observed in Prato Fiorito (68), followed by Subasio (50), Gran Sasso (39), and Gargano (24) sites. Apidae family was the most represented for the number of species in both Prato Fiorito and Subasio, with the similar highest abundance of three species: Bombus lapidarius, Apis mellifera, and B. terrestris. In Gran Sasso, a dominance of Halictidae morpho-species was observed, with the highest abundance of pollinators belonging to the Lasioglossum genus. In the Gargano site, equal numbers of Apidae, Andrenidae, and Halictidae morpho-species were observed, with Lasioglossum and Andrena genera as the most abundant. Given the protected status of the four study sites, conservation parameters were also assessed. The conservation indices that could be calculated for the Prato Fiorito and Subasio sites highlighted a high degree of specialisation of the networks of these areas along with a potential vulnerability to habitat-damaging phenomena, such as habitat fragmentation and isolation.

Given the trend of loss of diversity and abundance observed for most pollinator groups in Europe, the study of the pollination networks of habitats in protected areas represents an important tool for safeguarding the biodiversity of these environments.