Tree species richness and abundance in a four-ha plot in a mid-montane humid evergreen broad-leaved forest in Gaoligong Mountains of Yunnan province, China

We censused all free-standing trees with diameter at breast height (dbh) ≥ 1 cm in a four-ha plot in a mid-montane humid evergreen broad-leaved forest in Gaoligong Mountains, Southwest China. A total of 10,546 freestanding trees with dbh ≥ 1 cm were recorded, and all individuals, including 95 species from 64 genera and 35 families were identified. Nine of 95 species had more than 300 individuals, with 4,472 in total. Eleven species had only one individual in the four-ha plot. Symplocos ramosissima (Symplocaceae), the most abundant species (837 stems), and Gordonia longicarpa (Theaceae), the species with the largest basal area (13.05 m 2 ), were most dominant in the plot. Compared with other dynamic plots in China, the plot had intermediate levels of species richness, stem density, and basal area, but the proportion of rare species and the maximum importance value were lowest. The species abundance pattern models changed from a logarithmic series model (for the trees with dhb ≥ 1 cm) to a logarithmic normal model (for the trees with dbh ≥ 10 cm), and to both geometric series model and logarithmic normal model (for the trees with dbh ≥ 20 cm), reflecting the differences in community characteristics among trees with different size.