东北红豆杉(Taxus cuspidata)是我国数量极少的珍贵濒危树种, 了解其天然群落的组成和特征对东北红豆杉种群的保护利用和恢复有重要意义。本文对吉林省天然东北红豆杉群落进行调查, 根据物种组成进行系统聚类分析。将20块40 m × 40 m样地划分为5种群丛类型, 分别以优势种进行命名, 即: Ⅰ. 舞鹤草-五味子+狗枣猕猴桃-紫椴+臭冷杉群丛; II. 东北羊角芹-狗枣猕猴桃-臭冷杉群丛; III. 盾叶唐松草-狗枣猕猴桃-臭冷杉群丛; IV. 舞鹤草-软枣猕猴桃-红松+紫椴+臭冷杉群丛; V. 舞鹤草-软枣猕猴桃-紫椴+臭冷杉群丛。对群丛的物种组成、群落结构和群丛类型、物种多样性进行了分析。物种多样性选用Menhinick丰富度指数、Pielou均匀度指数、Simpson优势度指数以及Shannon-Wiener多样性指数, 对比分析不同群丛特征。结果显示: 东北红豆杉植物群落组成中蔷薇科的种和属数所占比例最大; 5个群丛的多样性指数顺序为群丛V > 群丛III > 群丛IV > 群丛II > 群丛Ⅰ; 群丛Ⅰ和II具有较低的多样性和较高的优势度, 群丛II和群丛III的乔木层的多样性指数差异不明显, 但其丰富度指数和优势度指数却呈现了相反的特征; 群丛II丰富度低而优势度高, 而群丛III丰富度高而优势度低; 群丛III中的草本层的多样性高于乔木层, 群落郁闭度较低; 群丛IV和群丛V均位于和龙市荒沟林场, 随着海拔上升, 其物种多样性随之下降。结果表明, 不同物种组成的东北红豆杉植物群丛的群落特征存在显著差异。

Taxus cuspidata is a rare and endangered species in China. Understanding the composition and characteristics of its natural communities is of great significance for its conservation, utilization and restoration. In this study, with hierarchical clustering based on species composition, we classified 20 plots of 40 m × 40 m in Jilin Province into five associations, which were named after dominant species, respectively, i.e., I. Maianthemum bifolium-Schisandra chinensis + Actinidia kolomikta-Tilia amurensis + Abies nephrolepis, II. Aegopodium alpestre-Actinidia kolomikta-Abies nephrolepis, III. Thalictrum ichangense-Actinidia kolomikta-Abies nephrolepis, IV. Maianthemum bifolium-Actinidia arguta-Pinus koraiensis + Tilia amurensis + Abies nephrolepis, and V. Maianthemum bifolium-Actinidia arguta-Tilia amurensis + Abies nephrolepis. The composition, community structure, association type, and species diversity were analysized. Species diversity was indicated by the Menhinick richness index, Pielou evenness index, Simpson dominance index and Shannon-Wiener diversity index. The results suggested that the Rosaceae genera comprised a large majority of T. cuspidata communities. The diversity index of the five associations ranked as Assoc. V > Assoc. III > Assoc. IV > Assoc. II > Assoc. I. Assoc. I and Assoc. II had lower diversity and higher dominance. The differences in the diversity indices of the arbor layers in associations II and association III were not significant, but the dominance index and the richness index demonstrated an opposite trend. However, the richness was higher and the dominance was lower in association III. The herb layer’s diversity index was higher than the arbor layer’s in association III so that the coverage in association III was lower in community. Both Assoc. IV and Assoc. V were located in Huanggou Forest Farm in Helong City. With the rise in altitude, the species diversity decreases. It showed that there were significant differences in the community characteristics of T. cuspidata communities with different dominant species.