抚育间伐对云南松纯林结构及物种多样性的影响研究

为了了解抚育间伐对云南松纯林的结构和多样性影响,在云南松纯林内设置抚育间伐和未间伐的定位观测样地和临时样地,通过对所设置的样地进行调查测定分析,并以空间代时间对同一立地条件中抚育间伐22 a后的云南松林及未间伐的云南松林物种多样性进行了对比分析。结果表明,抚育间伐2 a后云南松林相较为整齐,林内乔木幼树出现,林分结构更加合理,林木生长加快,其树高增幅达26%,胸径增幅达28%。对树高结构来说,林木株数在每个径阶上的分布趋于正态分布。间伐使云南松密度降低,林内灌草有一定的生长空间,在短期内,灌草种群数量有一定的增加,草本层增加尤其明显,其种群数量、盖度、Shannon-Wiener指数、Simpson指数、Pielou均匀度指数Jsw和Jsi增幅分别达100%、150%、40%、53%、106%,并随着云南松纯林间伐年限的增加,灌草层物种丰富度增加更明显。

Influence of Intermediate Cutting on Structure Features and Species Diversity of Pinus yunnanensis Pure Forests

Fixed position observation site and temporary site in Pinus yunnanensis pure forests were set to study the effects of intermediate cutting on structure features and biodiversity.Population diversity of 22 a P.yunnanensis stands before and after intermediate cutting was compared and analyzed.The results indicated that the stand form was even 2 years after intermediate cutting,the young tree species appeared,the stand structure became more reasonable,the growth of tree height and DBH increased by 26 % and 28 % respectively.The numbers of trees at different heights showed the tendency of normal distribution.Intermediate cutting decreased the density of forest,produced more growing space for shrub and grass.Within short period after intermediate cutting,the number of both shrub and grass increased,especially the grass population,coverage, Shannon-Wiener index,Simpson index,Pielou evenness index Jsw and Jsi attained 100%,150%,40%,53% and 106% respectively.The richness of shrub and grass increased obviously 22 years after intermediate cutting.