人为干扰对油松天然林空间分布格局的影响

以山西黑茶山3种不同干扰强度的油松天然林为研究对象,采用g(r)函数点格局方法,分析不同干扰强度下,油松天然林径级结构和多样性差异,以及优势种群油松不同生长阶段个体(幼树、小树、中树和大树)的空间分布点格局。结果表明:油松径级结构呈单峰型,中径级的林木个体数较多。辛普森多样性和香农-维纳多样性随干扰强度的增加而逐渐减少;0~1 m尺度上,不同生长阶段个体呈聚集分布,随着种群发育(幼树-小树-中树-大树),油松天然林的空间格局趋于随机分布,这体现了种群的一种生存策略或适应机制。

Spatial Distributions of Pinus tabulaeformis Nature Forest under Human-caused Disturbance

With the investigation data from three types of Pinus tabulaeformis nature forest with different disturbing degrees in Heicha Mountain,Shanxi Province,we studied the diameter structure and community diversity of these types forests.We discussed the spatial pattern of P.tabulaeformis at different growth stages by g(r) function.The diameter structure was presented a unimodal distribution and middle age individuals accounted more.The Simpson and Shannon-Wiener diversity index were decreased with the increasing of the disturbing degree.All trees had a clustered distribution across a range of scales (0-1 m).Varied with growth stage (saplings-small trees-middle tree-big trees),the spatial pattern tended to be random,which showed the survival strategy and suitability in certain degree.