Species composition and cyanobacterial colonization of epilithic moss–cyanobacteria associations in degraded karst mountains

Moss‐associated nitrogen is an important source of nitrogen input in some ecosystems. Despite the widespread nitrogen loss and deficiency in degraded karst ecosystems, there was a lack of study and data on moss–cyanobacteria associations. In this study, we identified the species of epilithic mosses and cyanobacteria at different degrees of degradation (none, potential, light, moderate and severe) and examined the cyanobacterial colonization. The results showed that moss–cyanobacteria associations were widely distributed and diverse (28 species of mosses and 100 species of cyanobacteria) in degraded karst ecosystems, with most of the species being reported for the first time in this field. Eurohypnum leptothallum , Gollania tereticaulis and Thuidium cymbifolium were the main epilithic mosses, and the main cyanobacteria were Nostoc , Gloeocapsa and Oscillatoria . As ecosystem degradation intensified, the cyanobacterial colonization was inhibited by adverse environmental conditions and tended to decrease. However, they may still maintain a close relationship through their own traits. This study will provide new insights into the field of moss–cyanobacteria associations, allowing us to better understand and comprehend the association between moss and cyanobacteria, while also offering theoretical support for the ecological restoration of degraded karst ecosystems.