Species composition and diversity of epiphytes of several ecotones in Ailao Mountain National Nature Reserve, Yunnan

Abstract

Epiphytic bryophytes are sensitive to environmental factors and are important components of montane moist subtropical forests. The aim of this study was to investigate the biodiversity and distribution of bole epiphytic bryophytes in the ecotones among old growth forest (OGF) and three other forest types (i.e., old growth dwarf mossy forest (ODMF), 50-yr-secondary Lithocarpus forest (SLF), and secondary Populus bonatii forest (SPF) in the Xujiaba region of Ailao Mountains, Yunnan. We evaluated species composition, biodiversity, and life forms of epiphytic bryophytes on host trunks above the ground in these ecotones and adjacent communities. Species richness and Shannon-Wiener diversity were lower in the ecotone between OGF and ODMF (EOO) than the adjacent forest communities (i.e., OGF and ODMF), whereas these indices were higher in ecotones between OGF and SLF (EOSl) and between OGF and SPF (EOSp) than the adjacent secondary forests. The distribution of some species was restricted to specific ecotones. Porella nitens and Wijkia surcularis only appeared in EOSp, and Gammiella tonkinensis was restricted to EOO. Ecotones in montane moist evergreen broad-leaved forests in Ailao Mountains exhibit an important influence on the patterns of epiphyte species composition and diversity