Species composition and structural characteristics of mountain evergreen broad-leaved forest community in Shiwandashan, Guangxi

Abstract

Shiwandashan is one of the hotspots of biodiversity in Guangxi, and its main vegetation type is mountain evergreen broad-leaved forest. In order to understand the current community status and the development status of dominant species population structure of mountain evergreen broad-leaved forests in the region, this study was conducted in a fixed monitoring sample plot of 1 hm2 established within the evergreen broad-leaved forest community in the Shiwandashan. Woody plants with diameter at breast height (DBH) ≥ 1 cm in the sample plot community were used as the research objects to analyze their species compositions, diameter class structures, tree height structures, and the spatial distribution patterns of dominant species using the g(r) function. The results were as follows: (1) There were 7 517 woody plants with DBH ≥ 1 cm in the community, belonging to 52 families, 108 genera and 153 species. The dominant species in the community were Clethra delavayi, Schima argentea, Hartia villosa, Castanopsis hystrix, Engelhardtia roxburghiana, Ardisia quinquegona, Itea chinensis, Symplocos adenophylla, Eurya subintegra, Ilex pubescens, but the dominant position of dominant species was not obvious. (2) The overall average DBH of the community was 5.51 cm, and the distribution of diameter class and tree height was approximately an inverted “J” shape. The diameter class distribution of dominant species was mostly an inverted “J” or “L” shape, and the community had a large number of small and medium-sized diameter class standing trees, indicating a strong self-renewal ability of the community. (3) Dominant species coexisted stably in the community; the dominant species exhibited aggregated distribution in the sample plot, but there were differences in the location of aggregated distribution among dominant species. Overall, the community is currently in a good state of renewal, with the existence of dominant species in the top level community. However, the community has certain secondary characteristics and has not yet reached a stable top level community state. The dominant species can coexist stably and have the potential to inherit towards a stable top level community. Therefore, it is necessary to continue to strengthen management and promote the renewal and survival of the evergreen broad-leaved forest community in the Shiwandashan areas.

Keywords

• mountain evergreen broad-leaved forest
• species composition
• diameter class structure
• spatial distribution pattern