Biodiversity loss and habitat degradation pose critical challenges in the Mediterranean Basin, a recognized hotspot hosting unique species and ecosystems. Small islands, due to their physical isolation and fragile ecosystems, are particularly vulnerable to anthropogenic pressures, and many remain still underexplored in terms of biodiversity and ecosystem function. 

To fill the knowledge gap regarding the conservation of island terrestrial biota, in this study we investigated pollinator communities, key providers of ecosystem services, across five small Italian islands differing in size, land use and degree of isolation, by integrating morphological and molecular approaches. We analyzed the effects of land use, management as indicated by floral diversity, island area, and distance from the mainland on pollinator abundance and diversity. 

While pollinator richness was negatively influenced by island isolation, it was not significantly affected by island size, consistent with the small-island effect. In contrast, flowering plant diversity emerged as the most crucial variable driving pollinator presence and diversity, underlying the importance of how land is actually managed. Our findings highlight how sustainable land use and conservation of natural resources on islands can help maintain pollinator diversity even in anthropized and vulnerable areas. Furthermore, the genetic analyses revealed localized haplotypes and cases of population structuring, emphasizing the role of isolation in shaping unique evolutionary lineages relevant to conservation.

This study offers valuable baseline data for conservation planning and landscape restoration. It highlights the need for tailored, targeted actions to mitigate biodiversity loss and integrate ecological priorities into land management and urban planning.