广东石门台亚热带典型常绿阔叶林和亚热带山顶矮林群落特征

为了研究亚热带典型常绿阔叶林和亚热带山顶矮林的物种组成和群落结构,在广东石门台国家自然保护区内分别建立了1 hm2亚热带典型常绿阔叶林样地和1 hm2亚热带山顶矮林样地,以样地内所有胸径（DBH）≥1 cm的乔木、灌木和藤本为研究对象,分析两种森林类型的物种组成、密度、径级和株高结构。结果显示：（1）两种森林的Srensen物种相似性指数为0.41,优势种不同,但优势科却较相似;其中,茶科和杜鹃花科在两种森林中所占比例较高;（2）亚热带典型常绿阔叶林的幼苗（1 cm≤DBH〈2.5 cm）和幼树（2.5 cm≤DBH〈12.5 cm）密度都显著小于亚热带山顶矮林,但两种森林的小树（12.5 cm≤DBH〈25 cm）和大树（DBH≥25 cm）密度均无显著差异;亚热带典型常绿阔叶林幼苗和大树的平均胸径都显著大于亚热带山顶矮林,而幼树的平均胸径则显著小于亚热带山顶矮林,小树的平均胸径无显著差异;亚热带典型常绿阔叶林中小树和大树的平均高度都显著大于亚热带山顶矮林,而幼苗的平均高度显著小于亚热带山顶矮林,幼树的平均高度无显著差异。综合分析表明,亚热带典型常绿阔叶林和亚热带山顶矮林的物种组成、密度、胸径和高度结构差异较大,亚热带典型常绿阔叶林群落稳定性强于亚热带山顶矮林。

Species Composition and Community Structure of Typical Subtropical Evergreen Broad-leaved Forest and Subtropical Montane Elfin Forest in Shimentai National Nature Reserve in South China

To study species composition and community structure of typical subtropical evergreen broad-leaved forest （EBLF） and subtropical montane elfin forest （MELF）, we established 1 hm2 EBLF plots and 1 hm2 MELF plots in Shimentai National Nature Reserve in Guangdong, South China. Using all woody plants with DBH ≥1 cm, including trees, shrubs and lianas in each plot, the species composition and community structure of the plots were analyzed based on species community, density, diameter at breast height （DBH） class structure and plant height structure of the area. Results showed that dominant species differed between EBLF and MELF, with a Sorensen similarity index value of 0. 41, but dominant families （Theaceae and Ericaceae） were similar. The mean densities of seedlings （1 cm ≤ DBH 〈 2. 5 cm） and saplings （2.5 cm ≤ DBH 〈 12. 5 cm） were lower in EBLF than those inMELF, while there were no differences in density of small trees （ 12.5 cm ≤ DBH 〈 25 cm） and adult trees （ DBH ≥ 25 cm） between the two forest types. EBLF had higher mean DBH of seedlings and adult trees, but lower mean DBH of saplings than those of MELF, while there were no differences in mean DBH of small trees between the two forest types. Mean height of small trees and adult trees were higher and mean height of seedlings were lower in EBLF than those in MELF, but there were no differences in mean height of saplings between the two forest types. Our results highlight the differences in community structure and species diversity between EBLF and MELF, which likely resulted from differences in structure and diversity maintenance mechanisms of these two forest types, with FBLF being more stable than MELF.