滇中次生常绿阔叶林优势树种的空间格局

Spatial patterns of dominant species in secondary evergreen broad-leaved forest in central Yunnan, Southwest China

采用Ripley的点格局分析方法对滇中次生常绿阔叶林中优势种滇青冈(Cyclobal-anopsis glaucoides)和滇油杉(Keteleeria evelyniana)的分布格局以及不同径级分株之间的相互关系进行了分析。结果表明:(1)总体来看,两个优势物种各径级株数分布较均匀,二者的增长处于稳定期。(2)两个优势物种在总体上及不同径级阶段主要呈聚集分布。随径级的增加,滇青冈种群的聚集程度逐渐降低,而滇油杉种群的聚集程度呈现降低-增加-降低的趋势。两个优势物种的幼树、中树和大树主要呈空间正相关或无空间关联性。(3)两优势种群不同径级之间在不同尺度下基本上无关联性,这可能是二者的生存策略存在较大差异而造成的。研究表明,在滇中森林恢复过程中,应结合植物种群的密度控制及种间相互作用来构建群落的结构。

By using Ripley＇ s point pattern analysis, the spatial patterns of the dominant species Cyclobalanopsis glaucoides and Keteleeria evelyniana in the secondary evergreen broad-leaved for- est in central Yunnan of Southwest China as well as the spatial associations among the individuals of the two species with different DBH classes were analyzed. Overall, the individuals of the two species with different DBH classes were in uniform distribution, indicating that the growth of the two populations was in stable period. The two species and their individuals with different DBH classes had a clumped distribution. With the increase of DBH class, the aggregation degree of C. glaucoides had a decreasing trend, while that of K. evelyniana decreased first, increased then, and decreased at last. A positive or no significant spatial association was observed among the saplings, juvenile trees, and adult trees of the two species. At different spatial scales, the two species of different DBH classes had less association, possibly because of the greater differ- ences in the survival strategies of the two species. It was suggested that in the restoration of the forests in central Yunnan, it would be essential to control the plant population density and attend to the interspecific interaction to build an appropriate structure of the community.