Exploring the lichen biota of Italy: New records from the Italian Alps and Northern Apennines.

The onset of rapid climate change makes it urgent to intensify exploration of potentially threatened lichen biota, especially in mountain areas. In recent years we intensified field sampling in both the Alps and the Northern Apennines, and critically re-examined herbarium specimens from earlier campaigns to improve taxonomic resolution and occurrence records. This paper synthesizes those efforts, providing a robust empirical basis for assessing lichen dynamics in these mountain systems and for informing conservation priorities. Overall, we report 518 occurrences corresponding to 288 infrageneric taxa. Of these, 33 taxa are new to Italy and 255 are newly recorded for at least one Italian administrative region. For several taxa we supply integrated occurrence, ecological and molecular data that clarify aspects of their global distribution, and taxonomic circumscription. The high incidence of species with boreal-montane to arctic-alpine distributions in the Northern Apennines supports the hypothesis that these mountains act as southern outposts for elements of the arctic-boreal biota. Our results also highlight the enduring value of herbaria as repositories of primary biodiversity data and underscore the necessity of continued field exploration to keep species lists and distributional knowledge up to date in the face of accelerating environmental change.