星斗山自然保护区两种群落类型乔木层优势种的生态位

Niche of Tree Layer Dominant Population of Two Community Types in Xingdoushan Nature Reserve

用双向指示种分析法(TWINSPAN)将星斗山自然保护区常绿落叶阔叶混交林划分为两个群落类型,即亮叶水青冈+多脉青冈-翅柃(Fagus lucida+Cyclobalanopsis multinervis–Eurya alata)群落(群落Ⅰ)和川陕鹅耳枥+交让木+包槲柯-翅柃(Carpinus fargesiana+Daphniphyllum macropodum+Lithocarpus cleistocarpus–Eurya alata)群落(群落Ⅱ),以重要值(IV)为资源位,分析群落乔木层优势种的生态位宽度和生态位重叠.结果显示:群落Ⅰ中交让木(Daphniphyllum macropodum)与川陕鹅耳枥(Carpinus fargesiana)之间的生态位重叠值较大,为了更好的适应群落内部环境和利用种间资源,它们在垂直结构上发生了分化;齿缘吊钟花(Enkianthus serrulatus)与长蕊杜鹃(Rhododendron stamineum)之间的生态位重叠值为0.898,由于在乔木层中占据同一个层次,为了争夺群落间共有的营养和空间资源发生了激烈的竞争;群落Ⅱ中交让木与亮叶桦(Betula luminifera)之间的生态位重叠值最大,它们在垂直结构上发生了分化;交让木与多脉青冈(Cyclobalanopsis multinervis)之间的生态位重叠较大,它们在乔木层中占据同一个层次,竞争较激烈.

We used two-way indicator species analysis（ TWINSPAN） to divide evergreen and deciduous broad-leaved mixed forest in Xingdoushan Nature Reserve into two community types,namely Fagus lucida＋ Cyclobalanopsis multinervis- Eurya alata community（ communityⅠ） and Carpinus fargesiana ＋ Daphniphyllum macropodum ＋ Lithocarpus cleistocarpus- Eurya alata community（ community Ⅱ）. We analyzed the niche breadth and niche overlap of dominant species in the communities with the important value（ IV） as the resource niche. The result showed： niche overlap between Daphniphyllum macropodum and Carpinus fargesiana had a large value in community I; in order to adapt to the environment and use the resources in the community better,they had differentiation in vertical structure; the niche overlap value between Enkianthus serrulatus and Rhododendron stamineum is 0.898,as they occupy the same level in the tree layer,in order to compete for nutrition and space resources in the community,competition occured; niche overlap between Daphniphyllum macropodum and Betula luminifera had the maximum value in community II and they had differentiation in vertical structure; niche overlap between Daphniphyllum macropodum and Cyclobalanopsis multinervis was large and they occupied the same level in the tree layer,so the competition was intense.