Ancient Ecological Disaster Site Is Now a Refuge: Bryophyte Diversity in Volcanic Lava Caves of Jingpo Lake World Geopark

Volcanic lava cave habitats are extreme environments. We carried out field investigations for five years and reported the results of bryophyte diversity in eight volcanic lava caves of Jingpo Lake World Geopark, where the largest underground lava caves in China are preserved. The results are as follows: (1) A total of 230 quadrats were set up, and 2041 bryophyte specimens were collected. The specimens belong to 272 species of 107 genera in 47 families, including 26 liverworts (13 genera, 11 families) and 246 mosses (94 genera, 36 families). (2) The α diversity of bryophytes in Underground Lava Fall Cave was the highest, while that in Foggy Cave was the lowest. (3) The dominant families included Mniaceae, etc, accounting for 55.9% of the total species. The dominant genera included <i>Plagiomnium</i>, etc, accounting for 24.3% of the total species. The dominant species included <i>Sanionia uncinata</i> (Hedw.) Loeske etc. (4) There are no shared species among all eight lava caves, and each cave has a unique species composition. (5) Compared with that in other habitats in our previous studies, the similarity of bryophyte species between lava caves and underground forests of craters was high (113 species, 40.07%), while it was low between lava caves and lava platforms (9 species, 4.65%). Our study revealed that the lava caves have a high potential for bryophyte diversity, and such ancient ecological disaster sites are now rare refuges for bryophytes. Mosses are more adapted to cave habitats than liverworts. Bryophytes in this special eco-environment need to be considered and protected in order to preserve high-quality gene resources for humans, which is of great significance for the maintenance and development of biodiversity.