色季拉山冷杉群落结构及物种多样性分析

Analysis on the Community Structure and Tree Species Diversity of Abies in Sygera Mountains

采用实地调查的方法对西藏色季拉山冷杉(Abies Mill.)物种展开研究。结果表明,色季拉山冷杉群落乔木层有2种,灌木层有13种,草本层有28种。冷杉群落乔木层树木种类比较单一,除生长的优势种急尖长苞冷杉[A.georgei Hand.-Mazz.var.smithii(Viguié&Gaussen)C.Y.Cheng,W.C.Cheng&L.K.Fu]外(重要值为77.7%),仅有伴生种西南花楸(Sorbus rehderiana Koehne)共生(重要值为22.3%);对灌木层和草本层阴坡、阳坡2个不同坡向生长的物种多样性进行对比分析,结果阳坡的Patrick丰富度指数R、Simpson多样性指数D和Shannon-Wiener多样性指数H′都高于阴坡;同时,随海拔高度升高,物种数量呈现减少的趋势。

The Abies Mill. species in Sygera Mountains of Tibet was studied by field investigation. The results show that among the Abies communities in Sygera Mountains, there were 2 tree layer species, 13 shrub layer species and 28 herbaceous layer species. The species of Abies communities in arbor tree was single, except for the advantage species A. georgei Hand.-Mazz. var. smithii（Viguié Gaussen）C. Y. Cheng, W. C. Cheng L. K. Fu（importance value 77.7%）, there was only one companion species, Sorbus rehderiana Koehne（importance value 22.3%）. Comparing the species diversity of shrub layer and herb layer on both shady and sunny slopes, the results showed that the richness index R, Simpson index D and Shannon Wiener diversity index H＇ of the sunny slope was all higher than that of the shady slope. Moreover, the diversity of species decrease with the increase of altitude.