Diversity and ecology of nivicolous Peziza from the glacial basin of the Gran Sasso massif in the Central Apennines

Some species in the genus Peziza develop in extreme cold environments, at the margins of melting snow. In this work, we characterized the genetic structure of nivicolous Peziza populations in Campo Pericoli, a glacial basin on the Gran Sasso massif, the highest peak of the Apennines (central Italy). A hundred ascomata collected in 2020–2021 were analysed using multigene sequencing (ITS, LSU, β-tubulin, RPB2). Four topographical variables (elevation, slope, aspect, topographic wetness index) were recorded for each fruiting point and correlated with genetic diversity. Two main clades, attributable to P. heimii and P. nivalis, were inferred through clustering and phylogenetic reconstruction. No significant differences in topographical variables were found between clades, but kernel density revealed distinct spatial distributions. However, considering the global distribution of these species, P. nivalis appears to exhibit broader ecological adaptability than P. heimii. Climate warming could affect competition between these species, potentially favoring P. nivalis over P. heimii.