香港大榄郊野公园的植物组成与植被数量分类

通过对香港大榄郊野公园森林群落的样地调查，利用组平均法和除趋势对应分析两种方法，对样方进行聚类与排序分析。把35个样地划分为11个植被类型，森林群落可划分为台湾相思（Acacia confusa Merr．）林、红胶木（Lophostemon confertus（R．Br．）PeterG．Wilson ex J．T．Waterh．）林、木荷（Schima superba Gardner ex Champ．）林、柠檬桉（Eucalyptus citriodora Hook．）林、湿地松＋鸭脚木（Pinus elliottii Engelm．＋Schefflera octophylla（Lour．）Harms．）林、土沉香（Aquilaria sinensis（Lour．）Spreng．）林、毛叶桉（Eucalyptus torelliana F．Muell．）林;灌木群落分为山油柑＋越南叶下珠（Acronychia pedunculata（L．）Miq．＋Phyllanthus cochmchinensis（Lour．）Spreng．）矮树灌丛、豺皮樟＋桃金娘（Litsea rotoundifolia（Nees）Hemsl．var．oblongifolia（Nees）C．K．Allen＋Rhodomyrtus tomentosa（Alton）Hassk．）矮树灌丛、大头茶（Gordonia axillaris（Roxb．ex Ker Gawl．）D．Dietr．）矮树灌丛、桃金娘＋芒萁（Rhodomyrtus tomentosa （Alton）Hassk．＋Dicranopteris dichotoma（Thunb．）Bernh．）灌草丛。DCA排序结果反映海拔高度与各个森林群落的分布格局和物种组成关系不大，而环境湿度是影响森林群落物种组成的主要因素。多样性分析结果显示，台湾相思林和土沉香林多样性指数最高，说明台湾相思林逐渐向次生林演变，除了红胶木林和少数郁闭度低的台湾相思林中有强阳生性树种外，大部分人工林下植物以阳生性稍耐阴的树种为主。调查结果显示，大榄郊野公园植物生长条件东部优于西部，西部的物种丰富度和多样性指数较低，主要以人工林和灌丛为主，加上山火频繁发生，导致长期处于先锋阶段。

Floristic Composition and Quantitative Classification in Tai Lam Country Park,Hong Kong

The vegetation in Tai Lam Country Park, Hong Kong, was investigated in 35 sampling plots. Unweighted pair-group method with arithmetic averages (UPGMA) and detrended correspondence analysis (DCA) were used to classify the forest communities into 7 types (Acacia confusa Merr. Comm., Lophostemon confertus (R. Br.) Peter G. Wilson ex J. T. Waterh Comm., Schima superba Gardner ex Champ. Comm., Eucalyptus citriodora Hook. Comm., Pinus elliottii Engelm. Schefflera octophylla (Lour.) Harms. Comm., Aquilaria sinensis (Lour.) Spreng. and Eucalyptus torelliana F. Muell. Comm.) and shrub communities into 4 types (Acronychia pedunculata (L.) Miq. Phyllanthus cochinchinensis (Lour.) Spreng., Litsea rotoundifolia (Nees) Hemsl. var. oblongifolia (Nees) C. K. Allen Rhodomyrtus tomentosa (Alton) Hassk. Comm., Gordonia axillaris (Roxb ex Ker Gawl.) D. Dietr., and Rhodomyrtus tomentosa (Alton) Hassk. Dicranopteris dichotoma (Thunb.) Bernh. Comm.). DCA ordination revealed a weak relation between altitude and spatial distribution of species. The first axis of the DCA ordination indicated the humidity gradient and correlated with the diversity index scores of species. The diversity index showed that the species in most plantations had some tolerance to shade. Tristania conferta R. Br. plantations and a few Acacia confuse Merr. plantations had light-demanding species. The investigation showed that the east region in the park is more suitable for plant growing. In the west part of the park, the plants are mainly composed of plantation species and shrubs, with the diversity and richness indices of the plant community in this area lower. Because of poor soil and repeated fire, most shrub communities were at their pioneer succession stage.