Bryophyte diversity in karst sinkholes affected by different degrees of human disturbance

The diversity of bryophytes in karst sinkholes has received little attention, and these habitats probably play a crucial role as refugia. In this study, bryophyte diversity affected by different levels of human disturbance in five karst sinkholes was compared. A total of 132 species of bryophytes (17 liverworts and 115 mosses) that belong to 64 genera and 30 families were recorded. The richness of the bryophytes in the natural sinkholes was significantly higher than that of the bryophytes in the sinkholes affected by tourism and used as farmland. Canonical correspondence analysis showed that soil moisture is one of the most important factors that affect the abundance of bryophyte distribution in the five sinkholes. Human activities, including agriculture, animal husbandry, and tourism development, reduce the bryophyte coverage of sinkholes and lead to soil moisture loss. Therefore, effective protection of karst sinkholes is required to maintain their original value for biodiversity conservation.