Abstract: Northern Guangdong is suffering from severe rocky desertification. As pioneer taxa on bare rock substrates, epilithic bryophytes play a crucial role in improving habitat quality and facilitating vegetation restoration. Taking the Baiwan Nature Reserve in Guangdong Province as the study area, we investigated 48 plots and employed cluster analysis alongside canonical correspondence analysis (CCA) to explore the characteristics of epilithic bryophyte communities and their relationships with environmental factors. The results showed that a total of 69 epilithic bryophyte species belonging to 38 genera and 23 families were recorded, with mosses exhibiting absolute dominance (64 species). The dominant families were Pottiaceae, Brachytheciaceae, and Bryaceae, while the life forms were dominated by wefts and turfs, accounting for 76.8% together. Cluster analysis classified the communities into seven types. The Patrick richness index peaked at the forest edge (7.36). Under the strong environmental filtering effect of extreme high-humidity, community structure tended to be simplified, facilitating the formation of a single-dominant community of Hyophila involuta. CCA and hierarchical partitioning collectively demonstrated that elevation and shrub canopy closure were the primary environmental factors affecting community distribution, with independent effects of 1.6% and 0.9%, respectively. The coupling of hydrothermal distribution along the altitude gradient and suitable canopy shading collectively constructs a “microclimate refugium” that supports the survival and diversification of bryophytes. In arid and barren exposed-rock environments, moss communities were dominated by drought-tolerant dominant taxa (e.g., Pottiaceae), coupled with a combination of weft and turf life forms, to achieve ecological adaptation across diverse microhabitats. For future ecological restoration practices, it is crucial to overcome the traditional single-afforestation mindset and prioritize a “tree-shrub-moss” three-dimensional synergistic restoration in rocky desertification areas. By rationally regulating community canopy closure to maintain a moist understory microhabitat, the stability and resilience of the overall vegetation community can be effectively enhanced.

Key words: epilithic bryophyte, composition characteristic, diversity pattern, life form, community classification, canonical correspondence analysis