Does forest stand age matters in Mediterranean forests? Bryophyte richness and composition in the endemic Spanish fir woodlands

Forest continuity is often assumed to increase bryophyte diversity, yet in Mediterranean Spanish fir ( Abies pinsapo ) forests we found no effect of stand age on richness, composition, or assemblage structure. Across paired old and young stands, generalized linear mixed models showed that age (a proxy for temporal continuity) was not a significant predictor of species richness, and no age-by-environment interactions altered this result. Community structure was instead explained by atmospheric water availability and microtopographic context. Distance-based redundancy analyses identified cloud probability (horizontal rain) as the main driver of epiphyte richness, whereas terrain roughness additionally influenced terricolous and saxicolous species. Turnover (β) depended on spatial proximity rather than age, and no bryophyte species or species combinations were identified as indicators of stand age. Older Spanish fir stands lack much of the bryoflora typical of old-growth forests, likely reflecting centuries of intensive management; therefore, assessments of forest continuity in Mediterranean systems should explicitly account for historical land use. From a conservation perspective, current old-growth trees host few specialists of dead wood or of microniches on old trunks and branches. Nevertheless, the similarity of assemblages between old and young stands indicates functional connectivity and rapid colonization of regenerating patches, with older stands acting as retention/source areas that seed adjacent young forests and thereby support ongoing restoration approaches. • This is the first study on spatial and temporal habitat continuity in endemic Mediterranean conifer forests. • Traditional management practices prior to 1950 blurred the structural differences between old and young Spanish Fir forests. • Old and young stands showed similar bryophyte species richness, composition and structure. • Old trees acted as retention trees, and old patches were sources of propagules for colonizing young stands.