缙云山自然保护区黄牛奶树种群结构与分布格局

Population Structure and Distribution Pattern of Symplocos laurinain Jinyun Mountain National Nature Reserve

在缙云山自然保护区调查了4个有代表性的样地,应用邻接格子样方法进行本地资料收集,对黄牛奶树Symplocos laurina Wall.种群进行统计,绘制大小结构图、编制种群的特定时间生命表.该研究采用扩散系数的t检验和Morisita指数的F检验来研究黄牛奶树种群的分布格局类型,通过聚集强度指数进行种群分布格局分析.结果表明:黄牛奶树种群年龄结构为增长型,幼苗和幼树较多,种群分布格局因不同立地条件,不同尺度分布格局有所差异,总体上呈集群分布;聚块规模大体介于2S和8S之间,且出现在4S尺度下的可能性较大.黄牛奶树的分布格局和种群结构受到了内外因素的影响,内因主要为黄牛奶树自身的生物学特性,如幼苗喜阴,大树喜光等;外因主要有小生境和人为干扰等.在内外因素的作用下,该种群有促进针阔混交林向常绿阔叶林演替的趋势.

In order to describe the structure, dynamics and distribution Wall. population, 4 representative sampling plots were established and pat fie tern of the Symplocos laurina ld data were obtained by tally with the method of contiguous grid quadrate, and its time-specific life table, size structure and height structure were analyzed. The spatial distribution pattern of the tree species was studied by T test of dis persal index and F test of Morisitaps index, and its assemble intensity was analyzed through the aggregate indices of K, GI, m ~ , PAl and CA. The results showed that the population age structure of the species in the study area was of the growing type, for there were quite many seedlings and saplings there. Its dis- tribution pattern showed, on the whole, the characteristics of cluster distribution; however, in different site conditions or scales, the distribution patterns varied. The pattern scale of S. laurina population was analyzed by the Greig-Smith and Kershaw methods, and the results indicated that its scale was between 2S and 8S. The above results of this study suggested that during the succession course of mixed coniferous and broadleaf stands to evergreen broadleaved forests, the S. laurina population may play an important role.