The functional groups and succession characteristics of dominant populations in an evergreen secondary broad-leaved forest of Wuchao Mountain

To understand the community structure and succession characteristics of Wuchao Mountain secondary forest, we analyzed niche and interspecific relationships of functional groups presenting succession stages. We investigated woody plants with diameter at breast height ≥ 1 cm in 20 m×20 m forest samples in the study area. Eleven functional traits were measured including leaf nitrogen content, leaf phosphorus content, leaf kalium content, specific leaf area, woody density, leaf dry matter content, chlorophyll content, growth form, longevity, shade tolerance, and maximum potential height. The 45 species were grouped into four functional groups, such as early successional species(PFG1), mid successional species(PFG2), mid and late successional species(PFG3), and late successional species(PFG4). The results of the interspecific association showed that the ratio of positive and negative association was close to 1, and the significant positive pairs were greater than the significant negative pairs, which indicated that the community was in a relatively stable succession statue. However, the values of niches overlap and interspecific association among PFG2, PGF3, and PFG4 were high and interspecific competition was intense. Our results suggest that the forest community of Wuchao Mountain is developing towards the later stage of succession. To restore forest ecosystems and accelerate succession, thinning of the early species competing with late species could be undertaken and commercial pioneer species could be used to reduce the amount of opening area.