Traditionally, calcareous beech forests were classified and differentiated according to vascular plants. Bryophytes were often omitted or not all substrates were sampled in relevés, and therefore, the role of bryophytes in plant community differentiation remained unclear. In this paper, we studied bryophyte species richness, composition and functional patterns in vegetation units differentiated by vascular plants. We analysed 45 phytosociological relevés from 400 m2 plots in Fagus sylvatica-dominated forests on dolomite bedrock in Central Slovakia. The most frequent among 59 moss and 8 liverwort species was Tortella tortuosa, followed by Hypnum cupressiforme, Brachytheciastrum velutinum and Ctenidium molluscum. Average richness of bryophytes was 8.1 compared to 38.7 species of vascular plants. Seven bryophyte species were significantly linked to a particular vegetation unit. One-way ANOVA showed no noticeable differences in bryophyte species richness between vegetation units. However, it was negatively affected by xericity and positively by cover of rocks on soil surface. CCA revealed that species composition was affected significantly by xericity, cover of bare rocks and cover of tree layer. Mat and turf life forms prevailed, and both long-lived taxa/perennials and short-lived colonists formed the bryophyte layer. Observed bryophyte species grew mostly on rock, living and dead wood, and only minority of them on soil. Therefore, available substrates greatly contributed to the species richness of bryophytes and total plant diversity of the forest community. A complete investigation of substrates is necessary to assess the drivers of bryophyte species distribution and diversity, and their role in classification of calcareous beech forests.