【摘要】 应用主分量分析与聚类分析技术， 测定鼎湖山黄果厚壳桂群落不同种群的养分相似性， 并探讨了植物不同器官作为相似性测度的合理性。并认为， 茎叶较适于作为相似性测试的取样部位。测定结果表明， 主分量分析与聚类分析对茎叶样本的测定结果具有一致性， 在主分量分析中， 茎第一排序轴主要反映Ｎ、Ｐ和Ｋ 元素， 叶第一排序轴主要反映Ｋ和Ｍｇ 元素。上层乔木叶子具有较大的相似性， 下层种双盖蕨、柏拉木与薄叶梧桐的叶子具有独特的养分特征， 黄果厚壳桂不同层次的个体具有相似的特征， 即种内的不同层次个体的差别不大。双盖蕨与柏拉木的茎样与其它种最不相似， 它与叶子的测定结果相一致。黄果厚壳桂不同层次个体的茎互不相似， 反映出不同木质化程度产生的营养含量上的差异。聚类分析显示， 处于上层的荷木、椎栗与华润楠的茎最为相似， 它们与一、二层的黄果厚壳桂及鼎湖钓樟则在较高水平上聚合， 亦即相似性稍小， 但与其它种（ 或个体） 相比， 这５ 个种是较为相似的。更多还原

【Abstract】 By means of principal component analysis(PCA) and cluster analysis, this paper deals with the nutrient similarity of different populations in community \%Cryptocarya concinna\% in Dinghushan National Natural Reserves in Guangdong province. Among the five types of samples, i.e. leaf, branch, stem, bark and root, the nutrient content of leaf and stem are more acceptable to be used in computing the index of similarity.The result showed that PCA and cluster analysis demonstrated the same pattern of similarity of leaf and stem. The first axe (PCA) of stem contained more information of N,P and K, while more K and Mg information was in the first axe of leaf. The leaves of tree species in upper layer illustrated higher similarity while\% Diplazium donianum,Blastus cochinensis\% and\% Calophyllum membranaceum \%had lowest similarity to other species. The leaves of different individuals are similar to one another.The stems of Diplazium donianum and Blastus cochinensis had lowest similarity to other species, showing the similar result to leaf analysis. The cluster analysis showed that\% Schima superba,Castanopsis chinensis\% and\% Machilus chinensis \%met at very low \%λ\% value. They met with\% Cryptocarya concinna\% (in layer Ⅰ and layer Ⅱ) and \%Lindera chunii\% at a higher value. Compared to other species or individuals, these five species showed higher similarity.更多还原