湖南八大公山25 ha常绿落叶阔叶混交林动态监测样地群落组成与空间结构 / Community composition and spatial structure in the Badagongshan 25 ha Forest Dynamics Plot in Hunan Province
湖南八大公山国家级自然保护区位于武陵山系北缘, 区内分布有大面积的常绿落叶阔叶混交林, 物种多样性丰富, 群落结构复杂。中国科学院武汉植物园按CTFS (Center for Tropical Forest Sciences)建设规范于2010-2011年在保护区内建设了一个25 ha的动态监测样地, 为亚热带山地森林群落多样性长期动态监测提供了理想的平台。本文初步分析了八大公山25 ha样地的群落组成与空间结构。结果表明: 群落内共有木本植物存活个体186,575株, 隶属于53科114属232种; 个体数超过1,000株的有38个物种(贡献87%的个体数), 个体数最多的物种为黄丹木姜子(Litsea elongata); 样地内稀有种(≤ 25株)种数占样地总物种数的44%, 而个体数仅为样地总个体数的0.4%。样地内个体平均胸径为5.41 cm, 其中68.4%的个体DBH ≤ 5 cm, DBH ≥ 20 cm的个体数(7,474株)仅约占总个体数的4%; 个体胸径直方图呈倒“J”形, 表明样地处于良好更新与正常生长状态。样地的种-面积关系图显示物种数随样地面积的增加而同步增加, 其增长速度由迅速增长逐渐趋于稳定, 取样面积10 ha时可以涵盖90%以上的物种; 1 ha小样地个体数平均为7,261.8 ± 974.8 (SD), 物种数平均为128.2 ± 8.2 (SD), Shannon-Wiener指数平均为3.56 ± 0.11 (SD), Pielou均匀度指数变异最小, 平均为1.69 ± 0.06 (SD); 个体数与各多样性指数均无显著相关, 表明在该样地中物种多样性的取样效应不明显, 物种数量增加的原因可能来自于其他因素的控制。
Mount Badagongshan (BDGS) National Nature Reserve is located in the northern margin of Wuling Mountain, which harbor large areas of evergreen and deciduous broadleaved mixed forests. These forests have high species diversity and possess a complex community structure. In 2010-2011, a 25 ha (500 m × 500 m) forest dynamic plot was established in this reserve according to the standards of the Center for Tropical Forest Science (CTFS). Within this plot, all woody plants with DBH ≥ 1 cm were mapped and identified to species level. Based on these data, we analyzed community composition and spatial structure of the vegetation community. We found 186,575 individuals in the plot, belonging to 53 families, 114 genera and 232 species. There were 38 species that had > 1,000 individuals each and these species comprised 87% of total abundance. The most abundant species was Litsea elongata. There were 103 rare species, i.e. with ≤ 25 individuals, which accounted for 44% of all woody species but only made up 0.4% of the total abundance. Across all individuals in the plot, the average DBH was 5.41 cm. Individuals with DBH ≤ 5 cm accounted for 68.4% of the overall abundance and the 7,474 individuals with DBH ≥ 20 cm accounted for only 4% of the overall abundance. The frequency distribution of DBH appeared to have a reverse “J” shape, suggesting that the community was maintaining successful regeneration and normal growth patterns. The number of species increased linearly with increasing area. When the sampling area was increased to 10 ha, we recorded 201 species, which represented more than 90% species of the entire plot. These 1-ha samples had average abundance of 7,261.8 ± 974.8 (SD), average species richness of 128.2 ± 8.2 (SD), average of 3.56 ± 0.11 (SD) for Shannon-Wiener index, and 1.69 ± 0.06 (SD) for Pielou evenness index. There was no significant relationship between abundance and the diversity indices, suggesting that instead of the sampling effect, some other mechanisms affected the species diversity pattern in BDGS plot.
Abstract in Chinese and English, article in Chinese only.