Abstract: In order to study the structural characteristics of woody plant community in Nanshan Nature Reserve of Shixing, Guangdong, three one-hectare sample plots at different elevations were set, and their species composition, diversity, diameter class structure and biomass were analyzed. The results showed that: (1) there were 193 species of woody plants belonging to 60 families and 115 genera in the investigated area, among which 127 species belonging to 44 families and 80 genera were the most in middle altitude sample plot. There were different dominant tree species, and the dominant families were Fagaceae and Lauraceae. (2) Shannon-Wiener diversity index (H) and Simpson diversity index (D) of woody plants were different between sample plots, and both showed a decreasing trend with the increase of altitude. (3) The diameter class structure of woody plant community in high and low altitude area was mainly small diameter class (grade I), while the diameter class structure of woody plant community in middle altitude sample plot was mainly in grade I, supplemented by individual trees in grade II and III, and the diameter class structure was more reasonable. (4) The biomass of roots, trunks, branches and leaves in different areas had significant differentces, and presented an increasing trend with the increase of altitude. The results provide scientific basis for rational forest management, biodiversity conservation and productivity prediction in Nanshan Nature Reserve of Shixing.

Key words: woody plants, species composition, diversity, diameter class structure, biomass

摘要： 为了研究广东始兴南山自然保护区的木本植物群落结构特征，通过在不同海拔高度设置3个1 hm²的典型植物群落样地，并对其物种组成、多样性、径级结构、生物量等进行分析。结果表明：(1)研究区共有木本植物193种，隶属于60科115属，其中中海拔样地的物种数最多，为127种，隶属于44科80属，不同样地的优势树种存在差异，优势科主要是壳斗科、樟科。(2)木本植物Shannon-Wiener多样性指数(H)和Simpson多样性指数(D)在不同样地间有差异，均随海拔升高呈现降低趋势。(3)高、低海拔区域的群落径级结构主要为小径级(Ⅰ级)个体，而中海拔样地的木本植物群落径级结构以Ⅰ级为主，Ⅱ、Ⅲ 径级树木个体为辅，径级结构更加合理。(4)不同样地的木本植物根、主干、枝、叶生物量有明显变化，随海拔升高呈现升高趋势。该研究为始兴南山保护区的森林合理经营、生物多样性保护以及生产力预测提供了科学依据。

关键词: 木本植物, 物种组成, 多样性, 径级结构, 生物量