Species composition and community structure of the subtropical evergreen broad-leaved forest in Hongling Mountain, Tianquan County, Sichuan Province, China

To understand the community types and structural characteristics of the subtropical evergreen broad-leaved forest in Hongling Mountain, Tianquan County, Sichuan Province, China, we established six 20 m×30 m sample plots between an elevation of 1700 m to 2000 m. We then analyzed species composition, community structure, biomass, and regeneration ability. Results showed that:(1) There were 182 species, belonging to 117 genera and 72 families, which demonstrated the flora characteristics of a typical subtropical evergreen broad-leaved forest; (2) The forest could be classified into three association groups and five associations; (3) The density of the tree layer was 2583-5383 plants/hm², biomass was 2.42×10⁵-4.26×10⁵ kg/hm², aboveground biomass of canopy lianas was 1.01×10³ kg/hm², biomass of woody debris (WD) was 1.65×10⁵ kg/hm², and the forest was secondary forest; (4) Seedlings were abundant, and the species similarity between seedlings and tree species was 88.89%, indicating good natural forest regeneration ability and stabilized community structure. Comprehensive analysis showed that the evergreen broad-leaved forest was dominated by Castanopsis platyacantha formation. Furthermore, although it appears to be a well-preserved secondary forest, further ecological conservation is warranted.