Revealing hidden biodiversity before losing it: the lichens of the Dolomites and the challenge of global change

Mountain ecosystems are critically affected by climate change and anthropogenic pressures. Poikilohydric organisms like lichens, whose physiology is directly coupled to environmental conditions, may face severe extinction risk and habitat reduction. Despite their ecological importance and widespread use as bioindicators, lichens are often underrepresented in conservation policies due to fragmented and insufficient data. The Dolomites, with their unique topography, represent one of the most lichenologically best-known areas in Italy, but the data are scattered in various sources, hampering their accessibility. The Dolichens project addressed this gap by aggregating over 77,000 occurrences spanning 1820 to 2024 for 2071 infrageneric taxa, into an open-access database (https://italic.units.it/dolichens), setting a basis for forthcoming taxonomic, biogeographical, and ecological studies. Thanks to the data aggregation and collection promoted by the project, we compiled the checklists of the lichenized fungi of the Paneveggio-Pale di San Martino Natural Park and the Adamello-Brenta Natural Park. These recent targeted surveys led to the discovery of species new to the region, Italy, and even the science including a soon-to-be-described Lecanora species. Exploiting the Dolichens database, species distribution models were performed to investigate the range shifts of 272 lichens under different climate change scenarios. We predicted a huge habitat suitability loss in the future, particularly for fruticose and cold-adapted species. Contrary to expectations of upward range shifts, species showed complex redistribution patterns, emphasizing the urgent need for targeted conservation actions. Finally, we developed innovative methods to assess lichen diversity in forest ecosystems: simplified approaches targeting functional groups and the indicator species Lobaria pulmonaria (LIFE MODERn), and an AI-driven system for large-scale epiphytic lichen monitoring (Smart Forest Monitoring). This thesis underscores the critical role of data repositories like Dolichens in tracking biodiversity, assessing ecological changes, and directing efforts to mitigate global change impacts on vulnerable organisms like lichens.