Effects of forest management and habitat continuity on the genetic structure and ecological corridors of target epiphytic moss species: A landscape genetic study of Dicranum viride

Habitat fragmentation in forest ecosystems poses a major threat to biodiversity, disrupting ecological corridors, limiting gene flow, and threatening persistence, especially for forest-dependent species. Among these species, woodland specialist bryophytes represent one of the most endangered groups, with Dicranum viride, an epiphytic moss of high conservation value protected under international regulations, exemplifying this conservation concern. Despite its legal status, the factors that influence its genetic connectivity and dispersal potential remain poorly understood. In this study, we integrated molecular analyses based on genome-wide single-nucleotide polymorphism (SNP) markers with spatial modelling, including least-cost path (LCP) analyses and circuit-based connectivity models, to assess the impact of forest continuity and management on the genetic structure and ecological corridors of D. viride across temperate forest ecosystems of Central Europe. Our results revealed a complex dispersal dynamic that combines short-distance clonal propagation with rare long-distance dispersal events. Genetic clustering analyses indicated that long-term forest continuity supports unique genetic lineages. LCP analyses and circuit-based connectivity models demonstrated that naturally regenerating forests (reflecting management regime) and forests with long-term continuity (reflecting habitat age and historical stability) provide dispersal corridors with the highest habitat permeability. Our findings highlight the critical role of long-term habitat stability in maintaining the genetic diversity and population dynamics of D. viride. Conservation strategies should prioritise the protection of mature forests, the maintenance of ecological corridors, and the integration of retention forestry practices to support epiphytic bryophytes. Our study improves the understanding of how landscape connectivity influences the persistence of rare epiphytic bryophytes, offering practical insights for the conservation of biodiversity and sustainable forest management.