Abstract: Exploring community composition and structure characteristics of natural evergreen deciduous broad-leaved mixed forest in the mountainous regions of southwestern Hubei can provide scientific evidence for biodiversity conservation and sustainable utilization of forest resources. Based on survey data of woody plants with a diameter at breast height (DBH) ≥ 1 cm from a 6 hm² plot in Jinzi Mountain National Forest Farm, Hubei Province, China, we analyzed species composition, structure and floristic characteristics. Results showed that a total of 39907 woody plants were recorded within the plot, belonging to 180 species, 53 families, and 96 genera. There were 116 species of deciduous species with 23454 individuals, and 64 species of evergreen species with 16453 individuals. Both the number of species and individuals of deciduous species were higher than those of evergreen species. The importance values of deciduous and evergreen species were 73.28 and 26.72, respectively. The dominant species was Castanea henryi from the Fagaceae. The DBH classes of both evergreen and deciduous trees exhibited an inverted J-shaped distribution, while the dominant species displayed an L-shaped distribution. The tree, subtree, and shrub layers were primarily dominated by deciduous species, with evergreen species being subordinate. The floristic composition exhibited a mixture of tropical and temperate components. At the family level, tropical families (47.2%) were greater than temperate families (37.7%), whereas at the genus level, temperate genera (59.4%) were more numerous than tropical genera (36.5%). Our results will contribute to a deeper understanding of species composition and structural characteristics of subtropical evergreen and deciduous mixed forests, and provide basic information for forest protection and management.

Key words: evergreen deciduous broad-leaved mixed forest, species composition, diameter class structure, floristic characteristics, species abundance