浙江普陀山主要林型群落结构特征分析

群落结构是植物群落研究的核心内容，对于指导营林建设、植被恢复与保护、群落结构优化、专题风景林构建具有重要的理论和现实意义。以浙江普陀山主要林型枫香Liquidambar formosana林、红山茶Camellia longicaudata林、檵木Loropetalum chinensis林、罗汉松Podocarpus macrophyllus林、青冈Cyclobalanopsis glauca林、青冈幼林、台湾蚊母树Distylium gracile林、樟树Cinnamomum camphora林等为研究对象，分析群落结构特征。结果如下:①林分结构上，各林型外貌相对完整，优势种所占比例较大，林分结构相对稳定；②胸径级分布看，枫香林、红山茶林、青冈林、台湾蚊母树林、樟树林呈“L”型；檵木林、青冈幼林为单柱型；罗汉松林为“U”型；③物种多样性上，罗汉松林的物种丰富度最大，青冈幼林的物种丰富度、Pielou指数、Shannon-Wiener指数最小，平均密度最大；台湾蚊母树林的平均密度最小，樟树林的Pielou指数和Shannon-Wiener指数最大。④植物纵横向营养投资上，枫香林在纵向生长上营养投资最大，红山茶林最小；罗汉松林在横向生长上营养投资最大，青冈林最小。青冈林和青冈幼林在纵向生长上营养投资显著大于横向生长（P<0.05），台湾蚊母树林在横向生长上营养投资显著大于纵向生长（P<0.05）。树高与胸径（R2=0.71, P<0.01）和树冠面积（R2=0.51, P<0.01）的关系幂函数拟合较好。总体上，普陀山主要林型林分结构较稳定，胸径级分布较合理，物种多样性较丰富，抗风胁迫能力较强，但还需进一步优化群落结构，增加物种多样性，提高植物对海岛环境的适应性。

Community structure for main forests in Mount Putuo,Zhejiang Province

Community structure is a theoretically and practically important plant community research field in areas of forest development, vegetative restoration and protection, community structure optimization, and special scenic spot development. In this study, forest types of Liquidambar formosana, Camellia longicaudata, Podocarpus macrophyllus, Cyclobalanopsis glauca, young Cyclobalanopsis glauca, Loropetalum chinensis, Distylium gracile, and Cinnamomum camphora were selected to analyze their structural characteristics in subtropical forests of Zhoushan Island, Zhejiang Province. Analysis included Pielou and Shannon-Wiener indices and power-fitted curves for DBH and tree crown. Results showed that stand structure and forest appearance were relatively complete indicating that forest types were dominant species and stand structure was relatively stable. With respect to diameter-class distribution, “L” type forests were Liquidambar formosana, Camellia longicaudata, Cyclobalanopsis glauca, D. gracile, and Cinnamomum camphora; whereas, unimodal type forests were Loropetalum chinensis and young Cyclobalanopsis glauca, with P. macrophyllus forest as a “U” type for diameter-class distribution. With respect to biodiversity indices, the P. macrophyllus forest had the highest species richness; the young Cyclobalanopsis glauca forest had the lowest species richness, Pielou and Shannon-Wiener indices but highest average stem density; the D. gracile forest had the lowest average stem density; and the Cinnamomum camphora forest showed the lowest Shannon-Wiener and Pielou indices. Nutrition investment in the vertical direction, was highest for the Liquidambar formosana forest and lowest in the Camellia longicaudata forest(P<0.05). Horizontal nutrition investment was highest in the P. macrophyllus forest and lowest in the Cyclobalanopsis glauca forest(P<0.05). In the Cyclobalanopsis glauca and the Cyclobalanopsis glauca young forest, vertical nutrition investment was greater than horizontal nutrition investment(P<0.05); the D. gracile forest was reversed(P<0.05). In addition, power curves of tree height fit for each DBH (R2 = 0.71, P<0.01) and crown area (R2 = 0.51, P<0.01) were highly significant. Thus, stand structure in the study area was stable, diameter-class distribution was reasonable, species diversity was high, and wind resistance was strong, but some discrepancies existed meaning more efforts to optimize community structure, increase species diversity, and improve plant adaptation to island habitats were needed.