Range Dynamics of the Moss Pohlia cruda in Italy Under Different Climate Change Scenarios

Pohlia cruda (Hedw.) Lindb. is a cryophilous moss species with a boreo-arctic montane distribution. As global temperatures continue to rise, high-mountain plant species are increasingly forced to migrate to higher elevations to remain within their ecological and physiological tolerance limits. In this study, we applied ensemble species-distribution modeling (SDM) to evaluate the future niche availability of P. cruda in Italy under two greenhouse gas-emission scenarios and two time periods (2050 and 2090). Projections under the intermediate emission scenario (SSP2-4.5) indicate a habitat loss ranging from -24.1% to -46.7%, whereas predictions under the very high emission of greenhouse gases (SSP5-8.5) suggest even greater losses, between -28.1% and -59.9%. These findings point to a substantial reduction, fragmentation, and potential disappearance of suitable habitats for P. cruda in the coming decades. This study represents a pioneering application of bryophyte-distribution modeling for the territory of Italy and provides a foundation for integrating such approaches into conservation decisions aimed at preserving biodiversity.