广东象头山吊皮锥种群及其群落结构研究

吊皮锥（Castanopsis kawakamiiHayata）为我国特有的第三纪孑遗植物，稀有种。文章应用样方调查法分析了惠州市象头山吊皮锥种群结构及其所在群落的物种多样性。在1800m。的样方内，共记录了维管植物172种，隶属73科126属；胸径≥2．5cm的乔灌木层物种丰富度指数为8．39，Shannon—Wiener多样性指数为3．06，Pielou均匀度指数为0．80。该群落以樟科、壳斗科和山茶科为优势科，樟科植物种类最丰富，具有最高的重要值。重要值最高的树种为黄果厚壳桂（Cryptocarya concinna），其次为荷木（Schimasuperba）、唐竹（Sinobambusatootsik）和硬斗稠（Lithocarpus hancei）。比较分析了黄果厚壳桂、阿丁枫（Altingia chinensis）、鼠刺（Iteachinensis）、硬斗稠、荷木、黄杞（Engelhardtiaroxburghiana）、马尾松（Pinusmassoniana）、吊皮锥的种群结构。结果表明，黄果厚壳桂和鼠刺的种群较大，但以Ⅰ～Ⅲ级苗和幼树为主，缺乏大径级林冠层大树；荷木种群也较大，但缺乏幼苗；吊皮锥和硬斗稠为稳定型种群；阿丁枫、马尾松和黄杞的种群较小，有少量林冠层大树，但缺乏幼苗，林下自然更新不良，为衰退种群。建议加强吊皮锥的种群动态监测和迁地保护研究，促进吊皮锥资源的保护和利用。

Population of Castanopsis kawakamii and its Community on Xiangtoushan, Guangdong Province

Castanopsis kawakamii is a relict species, endemic to China. It has been listed as a rare plant in China. The population structure and species diversity of the community where the population of C. kawakamii grows on Xiangtoushan, Huizhou were studied with plot survey. A total of 172 vascular plants with diameter at the breast height (DBH) > 2.5cm were recorded in a plot with 1 800 m2. They belonged to 126 genera of 73 families. The tree species richness index of the community was 8.39, Shannon-Wiener diversity index was 3.06, and Pielou evenness index was 0.80. Lauraceae is the dominant family with the highest importance value while the species with the highest importance value was Cryptocarya concinna. The population structure of C. concinna, Altingia chinensis, Itea chinensis, Lithocarpus hancei, and Castanopsis kawakamii were compared. The results showed that the population sizes of Cryptocarya concinna and Itea chinensis were larger, but they were dominated by the seedlings, saplings and young trees with DBH < 2.5 cm, no big individuals. The two species of Fagaceae, Castanopsis kawakamii and Lithocarpus hancei had small populations. They had some big trees, but had only a few seedlings and saplings. They were degraded populations. Therefore, in situ and ex situ conservations are important for the conservation of natural population of Castanopsis kawakamii.