广州罗岗村边次生常绿阔叶林群落分析

根据广州罗岗村这次生常绿阔叶林的调查结果，分析了该群落的组成结构特征在1200m2的样地里有维管束植物引种，隶属于40科65属其区系特点具有从热带向亚热带过渡的性质该群落分为乔木层（3亚层）、灌木层及草本层等层次乔、灌层种类较多，主要以往粟（Caastanopsischinensis）、黄桐（Endospermumchinense）和黄果厚壳桂（CryptocargaconcinnaHance）等种类组成，草本展种类少．本群落以中、小高位芽植物占优势，缺乏大高位芽、隐芽和一年生植物叶型以中型叶为主群落的大部分优势种的种群分布格局是随机分布的优势种群的立木结构分析表明，本群落处于进展演替它与30a前比较有较大的变化乔木层原优势种黄桐、猴耳环（Pithecellobiumclyperia）、亮叶肉实（Sarcospermalaurinum）等被锥粟、刺栲（Castanopsishystrix）等替代．草本层原以禾本科植物为主，现已发展为原生性较强的龙船花（Ixorachinensis）、九节（Psychotriarubra）等种类

COMMUNITY ANALYSIS OF A SECONDARY EVERGREENBROADLEAVED FOREST AT LUOGANG, GUANGZHOU

The vegetation survey on a sencondary forest at Luoguang , a villege close to Guangzhuo indicatedthat there were 81 species of vascular plants in 65 genera of 40 families in plots of 1 200 m2. The floristic composition of the community showed the transitional characteristics between tropics and subtropics. The communitywas vertically divided into tree layer(3 sublayers),bush layer and grass layer, with many species in bee layerand shrub layer, and few species in grass layer. The dominant species in the tree layer were found as Castanopsis chinensis, Endospermum chinense and Cryptocarga concinna . The Mesophanerophytes and Microphanerophytes were found having high percentage, and the Megaphanerop, Geophytes and Therophytes were notfound in the species life form spectrum of the community. The Mesophyll also had high Percentage in leaf-sizeclass spectrum of the community. The distribution pattern of the dominant species was measured by means ofs2/x ratio and T-Test, The result indicated that most of the dominant species were randomly distributed. Analysis on structures of standing trees of dominant species indicated that the community was at progressing succession. The dominant populations and their structure had changed greatly since 1960's. Castanopsis chinensis,C. hystrix replaced Endospermum chinensis, Pithecellobium clyperia , Sarcosperma laurimum in the tree layer,while Ixora chinensis , psychotia rubra superseded the grass in grass layer.