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.

Key words: mountain evergreen broad-leaved forest, species composition, diameter class structure, spatial distribution pattern

摘要： 十万大山是广西生物多样性热区域之一,其主要植被类型是山地常绿阔叶林。为了解区域内山地常绿阔叶林的群落现状及优势种群结构的发展现状,该文以十万大山山地常绿阔叶林1 hm²固定监测样地中胸径(DBH)≥1 cm的木本植物为研究对象,分析其物种组成、径级结构、树高结构并用g(r)函数分析优势种的空间分布格局。结果表明:(1)群落中DBH≥1 cm的木本植物共计7 517株,隶属52科108属153种; 群落的优势种有云南桤叶树(Clethra delavayi)、银木荷(Schima argentea)、毛折柄茶(Hartia villosa)、红锥(Castanopsis hystrix)、黄杞(Engelhardtia roxburghiana)、罗伞树(Ardisia quinquegona)、鼠刺(Itea chinensis)、腺叶山矾(Symplocos adenophylla)、假杨桐(Eurya subintegra)、毛冬青(Ilex pubescens),但优势种的优势地位不明显。(2)群落整体平均DBH为5.51 cm,径级、树高分布呈近似倒“J”型; 优势种的径级分布多呈倒“J”型或“L”型,群落有较强的更新能力。(3)群落优势种稳定共存; 优势种在样地中呈聚集分布,但优势种间聚集分布的位置有差异。总体而言,群落目前更新状态良好,群落中已有顶极群落优势种的存在,但群落具有一定的次生性特征,还未到达稳定的顶极群落状态,优势种间能稳定共存,有向稳定顶极群落演替的潜力,应继续加强管护,促进十万大山山地常绿阔叶林群落的更新与生存。

关键词: 山地常绿阔叶林, 物种组成, 径级结构, 空间分布格局