Predicting the Future Distribution of Alpine Lichens under Climate Change Scenarios

Sara Ribotta ¹, Elisa Beninato ¹, Carolina Stringa Basile ², Luca Di Nuzzo ³, T'Ai Gladys Whittingham Forte ¹, Andrea Vannini ¹, Alessandro Petraglia ¹, Paolo Giordani ², Renato Benesperi ³, Daniele Viciani; Michele Carbognani ⁴

Università di Parma ¹, Università di Genova ², Università di Firenze ³, Università di Firenze; Università di Parma ⁴

Understanding the impact of climate change on biodiversity is crucial, particularly in alpine ecosystems where lichens serve as key bioindicators. This study focuses on three terricolous lichen species: Cetraria islandica, Nephromopsis nivalis, and Solorina crocea, chosen for their representation of a wide elevational gradient in alpine habitats and their distinct ecological niches. C. islandica thrives in alpine and subalpine zones on nutrient-poor soils. N. nivalis, a characteristic high-elevation species, is predominantly found in extreme alpine environments above the treeline, where it is adapted to dry, snow-covered habitats. S. crocea typically occupies mid-to-high altitudes, favouring moist, shaded areas near snowbeds. Using occurrence data (1980–2024) and bioclimatic variables (1 km resolution), including snow-related metrics (Snow Cover Days, Snow Water Equivalent), we developed species distribution models (SDMs) to project their potential distributions under future climate scenarios (MPI-ESM; SSP126, SSP370, SSP585) for 2011–2040, 2041–2070, and 2071–2100 time periods. Spatial cross-validation and ensemble modelling (GLM, RF, BRT, MDA, FDA) ensured robust predictions, with evaluation metrics including AUC, TSS, and the Boyce Index. Results reveal significant shifts in suitable habitats and species-specific trends in range changes. Notably, C. islandica may exhibit a geographical shift in its climatically suitable areas, N. nivalis could experience habitat fragmentation, and S. crocea might face minor changes in its distribution. Furthermore, N. nivalis appears to be the only species that, under some scenarios, could experience habitat expansion, whereas C. islandica and S. crocea are projected to suffer habitat loss. These findings underscore the urgency of monitoring alpine habitats and implementing targeted conservation strategies. For instance, higher altitude protected areas may become critical for the survival of fragmented N. nivalis populations, while C. islandica may require active interventions, such as assisted migration, to cope with the shifts of suitable areas. Additionally, community-level conservation strategies, considering both vascular plants and cryptogams, will be essential for maintaining existing vegetation diversity in alpine regions. The broader ecological implications of these shifts stress the need for adaptive management strategies that take into account not only species distribution but also the ecosystem services provided by lichens, such as nutrient cycling and soil stabilization. Future work aims to incorporate dispersal dynamics and community-level data to take into account biotic interactions between vascular plants and cryptogams for a comprehensive understanding of vegetation responses to climate change. These insights underline the urgency of conservation strategies tailored to mitigate biodiversity loss in alpine regions.

Main author career stage: PhD student

Contribution type: Talk

First choice session: 3. Biodiversity and global change

Second choice session: 2. Ecology