Diversity and distribution of ground bryophytes in broadleaved forests in Mabian Dafengding National Nature Reserve, Sichuan, China

Bryophytes, represented by mosses, liverworts, and hornworts, contribute substantially to forest ecosystems in terms of nutrient cycling, water retention, water availability, plant biomass, and plant community maintenance. Forests provide numerous types of habitat for bryophytes, especially the ground floor. To clarify the ground bryophyte diversity and distribution in broadleaved forests, we used microcoenose sampling to investigate ground bryophytes in 34 sample plots (10 × 10 m) in the Mabian Dafengding National Nature Reserve (MDNR), Sichuan Province. Species diversity and environmental factor relationships were analyzed by using α and β diversity indexes, as well as Pearson's correlation analysis. Detrended canonical correspondence analysis (DCCA) was applied to analyze the relationships between species distribution and environmental factors. A total of 230 bryophyte species were identified in MDNR. These species include 67 liverwort species belonging to 26 genera of 20 families and 163 moss species belonging to 65 genera of 28 families. Diversity of ground bryophytes was negatively correlated to shrub cover, canopy cover, and tree number, but without significant correlations to altitude, slope, aspect, vegetation type, and herb cover. The DCCA ordination of relationships between ground bryophytes and environmental factors showed that altitude, aspect, vegetation type, and shrub cover were important to the distribution of dominant ground bryophyte species. This study quantitatively related bryophytes diversity and distribution to environmental factors, which is helpful in understanding the ecological niche of various bryophytes.