The relationship between saxicolous lichen communities and rock characteristics was investigated on patterned ground in the Daisetsuzan Mountain Range, Hokkaido, Japan. A total of 900 rocks were sampled across 18 sites, and 45 lichen taxa were identified. Zero-inflated Poisson models indicated that the measured rock variables explained only minimal variation in lichen presence, suggesting that initial colonization was largely stochastic. In contrast, species richness on colonized rocks was primarily associated with surface area, which is consistent with established species–area relationships. Correlations were also identified between species richness and rock thickness, shape, and density, indicating that substrate stability may further influence species accumulation. Nonmetric multidimensional scaling revealed that community composition structure was mainly influenced by size-related characteristics, while density contributed secondarily to compositional gradients. Beta-diversity was high among sites, even within the same location, suggesting that substrate characteristics interact with colonization history to shape communities on individual patterned grounds. These findings indicate that the structuring of periglacial saxicolous lichen communities is governed by a combination of substrate heterogeneity, stability, and stochastic colonization. Keywords: Saxicolous lichens, substrate stability, species–area relationship, β-diversity.