大盘山自然保护区香果树种群结构与分布格局

The population structure and distribution pattern of Emmenopterys henryi in Dapanshan Natural Reserve of Zhejiang Province

在大盘山自然保护区设置了4个有代表性的样地,应用相邻格子法进行调查获得野外资料。对香果树种群进行统计,绘制径级结构图和高度结构图、编制种群的特定时间生命表;应用理论分布模型和聚集强度指数进行种群分布格局分析。结果表明香果树种群结构呈纺锤型,幼苗严重不足,种群有衰退的趋势;其更新是以无性繁殖为主;种群格局整体上呈集群分布,但在不同发育阶段,分布格局有所差异幼树阶段一般为集群分布,中树和大树向随机分布发展,这种分布格局变化与其生物学和生态学特性密切相关;其格局规模在介于8S和32S之间。分析认为,香果树的种群结构和分布格局受到了多种因素的影响,如群落区域小生境、香果树生物学特征以及人为干扰外等,在以上各因素的综合作用下,使得该种群形成典型的小种群。

Emmenopterys henryi, an endemic species in China, is one of the Chinese national second protective wild plants. This study was carried out in Dapan Mountain, a National Natural Reserve, Eastern China. To describe the structure and dynamics of population, 4 plots were established and field data were obtained by tally with contiguous grid quadrate method. The time-specific life table, size structure and height structure of E. henryi were analyzed. Finally, the population structure and distribution pattern of E. henryi were discussed on the basis of theoretical distributing model and assembling intensity index. The results showed that the population structure of E. henryi was a spindle type. The age structure of the population of E. henryi was declining due to lack of seedlings. There are two regeneration modes of E. henryi in forest ： sexual and asexual reproduction, but the latter was the main mode. As to the distribution pattern of E. henryi, generally speaking, the E. henryi population was clump, but there are differences among various developmental stages： clump for saplings, random for adult trees and big trees. It was related to their biological and ecological characteristics. To increase accuracy, both methods of Greig-Smith and Kershaw were used to analyse the pattern scale of the population of E. henryi.It was showed in the results that the pattern scale was between 8S and 32S. At last, the analysis indicated that the spatial distribution pattern of E. henryi populations was decided mainly by the interaction among the biological, ecological property and environmental factors and so on. Determined by the combined impact of these factors, the populations of E. henryi become typical small ones.