武夷山中亚热带常绿阔叶林样地的群落特征

Community characteristics of a mid-subtropical evergreen broad-leaved forest plot in the Wuyi Mountains, Fujian Province, southeastern China

武夷山保存了典型的中亚热带原生性森林生态系统。由于以往研究的空间和时间尺度较小,方法规范性不强,该地区尚缺少大型的、规范的综合性观测和研究平台。本文依托环境保护部南京环境科学研究所等单位按照CTFS调查技术规范建立的武夷山中亚热带常绿阔叶林9.6 ha动态监测样地开展植物群落调查,从物种组成、区系特征、径级结构和空间分布格局等方面分析了其群落特征。结果表明:样地内有维管植物68科135属232种,其中乔木层内胸径≥1 cm的植物有44科86属171种。热带性质的科和属分别占总科数和总属数的68.58%和58.83%,热带特征明显。珍稀濒危物种较多,有4种国家II级重点保护野生植物、2种《中国生物多样性红色名录——高等植物卷》中的"近危"物种、1种《濒危野生动植物种国际贸易公约》(CITES)附录II物种以及72种中国特有物种,具有较高的保护和研究价值。稀有种29种,占总树种数的16.96%。重要值最大的科是壳斗科和山茶科,二者的重要值之和大于40%。米槠(Castanopsis carlesii)、毛锥(C.fordii)、甜槠(C.eyrei)和少叶黄杞(Engelhardtia fenzlii)的重要值较大,但没有明显的优势种。小径木较多,所有个体的平均胸径为5.10 cm,整体径级分布呈倒J形。乔木层可分为两个亚层,米槠、毛锥、甜槠等在第I亚层中占优势。米槠和毛锥呈均匀分布,甜槠、少叶黄杞、赤楠(Syzygium buxifolium)和木荷(Schima superba)呈聚集分布。

Wuyi Mountains preserve the primary forest ecosystem characteristic of the mid-subtropics. We established a large-scale plots in this area according to standard international protocols（Center for Tropical Forest Science, CTFS）. Community characteristics such as flora composition, floristic characteristics, DBH structure and spatial distribution patterns in a 9.6 ha plot were analyzed. The results showed that the vascular plants in the plot belonged to 68 families, 135 genera, 232 species. Among these plants, trees（DBH ≥ 1 cm） belonged to 44 families, 86 genera, 171 species. For plants with tropical elements, family and genera accounted for 68.58% and 58.83% of total, respectively, which indicates a tropical feature of the ecosystem. There were many rare and endangered species, including four State Priority Protected Wild Plant Species at Level II, two threatened species（VU） of Red List of China＇s Biodiversity, one species of Convention on International Trade in Endangered Species of Wild Fauna and Flora（CITES）（Appendix II） and 72 endemic species to China. Rare species（N = 29, less than 1 individuals/ha） accounted for 16.96%. Fagaceae and Theaceae, with a total importance values of greater than 40%, were most dominant. Castanopsis carlesii, C. fordii, C. eyrei and Engelhardtia fenzlii had the largest importance values but no species significantly dominated the community. Small sized trees dominated the plot, with a mean DBH of 5.10 cm and the DBH-class distribution presented an inverse ＂J＂ shape. The emergent layer was divided into two sub-layers with C. carlesii, C. fordii, C. eyrei dominating the first sub-layer. Castanopsis carlesii and C. fordii had an even distribution, at the same time, C. eyrei, E. fenzlii, Syzygium buxifolium and Schima superba had a clustered distribution.