皖北石灰岩山地青檀种群不同发育阶段的点格局分析

Point pattern analysis of Pteroceltis tatarinowii population at its different development stages in limestone mountain area of north Anhui, East China

基于皖北石灰岩山地青檀次生林的样地调查数据,采用空间代替时间和点格局O-ring统计法,研究了青檀种群的径级结构、不同发育阶段的空间分布格局及其相互关联性。结果表明:(1)不同样地青檀种群的径级结构大体呈倒"J"型,各径级均有个体分布,但主要集中在幼苗、幼树阶段,中树和大树较少,种群均属增长型。(2)幼苗、幼树和中树在个别小尺度上呈现出明显的聚集分布,且皇藏峪种群的聚集强度显著高于相山种群;随着尺度的增加,个体趋于随机分布。成树阶段的青檀个体均表现为随机分布或接近均匀分布。(3)各发育阶段间的空间关联主要表现在中、小尺度上,随着空间尺度的增加,空间关联性不显著。青檀种群结构和空间格局主要受群落生境的异质性、自身生物学特性(尤其是克隆繁殖)以及人为活动的干扰等因素影响。

Based on the investigation data from ondary forest in limestone mountain area of north the sampling plots of Pteroceltis tatarinowii sec- Anhui, and by the methods of space substituting time and O-ring statistics, this paper studied the diameter-class structure and the spatial distribu- tion pattern and association of the P. tatarinowii population at its different development stages. In the plots, the diameter-class structure of P. tatarinowii population presented an invert ＂ J＂ shape, and the individuals, mainly seedlings and saplings but fewer medium and mature trees, were distributed in each diameter-class, showing a stable-growth type of the population in differ- ent habitats. The seedlings, saplings, and medium trees exhibited an obvious clumped distribu- tion at some small spatial scales, and the aggregate intensity of Huangcangyu population was sig- nificantly higher than that of Xiangshan population. With the increase of spatial scale, the indi- viduals tended to distribute randomly. The individuals at mature stage all exhibited random or ap- proximately uniform distribution. The spatial association of the population at different develop- ment stages was mainly at medium and small scales, and, with the increase of the scale, the spa- tial association turned to be not significant. It was suggested that the diameter-class structure and spatial distribution of the P. tatarinowii population were mainly affected by the habitat heterogeneity, population＇ s itself biological properties （ especially clonal reproduction） , and human dis- turbances.