大兴安岭天然白桦林群落结构特征及其物种多样性

Structure Characteristics of Natural Birch Community and Species Diversity in Great Xing'an Mountains

基于2011年大兴安岭地区的样地调查数据,分别用大小比数、混交度和角尺度来衡量林分空间结构特征;用Simpson生态优势度指数、Margalef丰富度指数、Shannon多样性指数以及Pielou均匀度指数来衡量群落的物种多样性水平。研究结果表明:随着白桦优势度的提高,群落的物种多样性、丰富度和均匀度指数均显著下降;从林分的空间结构特征来看,混交林的水平分布格局呈随机分布,林分的混交程度高,林木的生长水平整体处于中庸状态;各项指标均表明,白桦混交林具有较高的物种多样性和群落的稳定性,对白桦林向松桦混交林过渡的群落演替趋势研究有重要意义。

Based on the sample plot survey data of Great Xingan mountains region in 2011, the stand spatial structure was meas- ured with the angle of scale, mixing angle and the size of the score; The species diversity at community level was calculated with Simpson ecological dominance index, Margalef richness index, Shannon diversity index and Pielou evenness index. Research resuhs show that： with the improvement of birch dominance of community species diversity, richness and evenness index were significantly decreased ; From the perspective of the spatial structure of forest stand, the horizontal distribution pattern of random distribution, high degree of mixed forest, forest growth overall is in a state of the doctrine of the mean level; All the indexes showed that the birch mixed forests has high species diversity and community stability, to the birches to loose birch mixed forest community succession tendency of transition research has important significance.