Aims In order to explore the important ecological function of moss in forest ecosystems in the southeast Xizang and provide a theoretical basis for the influence of forest disturbance on forest surface vegetation, the diversity and biomass characteristics of ground moss per unit area in different habitats in the Sygera Mountain of southeast Xizang.
Methods We collected the surface moss in the Sygera Mountain of the southeast Xizang as the investigation object, and selected 7 sample plots with similar forest stand, slope direction, slope and terrain composition, with each plot size of 100 m × 100 m. We took canopy gap of each sample plot as the center, and three different habitats (canopy gap, forest edge and understory) were selected in four directions to set 50 cm × 50 cm quadrats, with 12 quadrats for each sample plot and 168 quadrats in total. Moss survey and collection were carried out in each quadrat.
Important findings (1) 24 families, 63 genera and 110 species of moss were found in the study area, in which there were 8 dominant families, which were Pottiaceae, Dicranaceae, Polytrichaceae, Mniaceae, Bryaceae, Grimmiaceae, Brachytheciaceae and Hypnaceae. There were obvious distribution rules of different moss families, such as Dicranaceae and Bryaceae were widely distributed at all elevations, and Polytrichaceae, Bryaceae and Mniaceae were distributed at altitudes from 3 700 to 4 300 m. Most of Pottiaceae were distributed over 4 300 m. (2) The habitat of canopy gap was more complex than those of forest edge and understory and it interfered with moss composition and community structure, in which the moss community had the most species and the most complex structure. However, the moss community in understory had the least species and the simplest structure. The biomass of ground moss was the highest in the gap, followed by the edge and the lowest in the understory. (3) The biomass of ground moss was not only affected by species composition, coverage, body shape and community structure, but also resulted from the interaction of many factors rather than any one single factor.