Community Composition and Structure of Badagongshan (BDGS) Forest Dynamic Plot in a Mid-subtropical Mountain Evergreen and Deciduous Broad-leaved Mixed Forest, Central China

Mountain evergreen and deciduous broadleaved mixed forests in China are mainly distributed in the mid-subtropical mid-mountain zones. Mount Badagongshan (BDGS) is located on the northern end of the Wuling Mountains at the north rim of the mid-subtropical zone, and has a typical mountain evergreen and deciduous broadleaved mixed forest. To investigate dynamics of this forest,biodiversity origin and maintenance mechanisms in East Sichuan and West Hubei in 2010-2011,the Wuhan Botanical Garden,Chinese Academy of Sciences established one 25 hm² (500 m×500 m) forest dynamic plot of subtropical mountain evergreen and deciduous broadleaved mixed forest in the Badagongshan (BDGS) National Nature Reserve according to the standards of the Center for Tropical Forest Science (CTFS). Here,we present the flora,community composition,structure,size class and spatial distribution based data collected from all woody (bamboo and liana not included) plants with DBH≥1 cm. Our results demonstrated that BDGS was a typical mountain evergreen and deciduous broadleaved mixed forest,dominated by pantropic distribution families (24.50%) and northern temperate distribution genera (24.56%). There were nine rare and endangered wood plants. We classified 186556 individuals into 53 families,114 genera and 238 species (94 evergreen and 144 deciduous). Dominant species were from the families of Fagaceae,Ericaceae,Lauraceae and Theaceae. There were 38 species with >1000 individuals (63.16% evergreen). In total,103 rare species (< 25 individuals) accounted for 43.28% of all the woody plants. The forest strata was divided into a canopy layer dominated by Cyclobalanopsis multinervis and Fagus lucida,an understory layer dominated by Rhododendron stamineum and Litsea elongata,and a shrub layer dominated by Eurya brevistyla and Symplocos anomala. Abundant (>1000 individuals) and rare species were mainly from the shrub layer. Limited by growth form,the plot had a fairly small mean DBH (5.41 cm) and was dominated by small sized individuals (68.40%). The size class of five dominant trees was reverse J.