陕西周至典型森林群落结构和物种多样性特征

Research on structure of typical forest community and characteristics of species diversity of Zhouzhi,Shaanxi Province

【目的】对周至老县城境内杨家沟典型森林群落的结构和物种多样性进行研究,为植被恢复与重建以及生物多样性的保护和编目提供理论依据。【方法】应用双向指示种分析法（TWINSPAN）对森林群落进行分类,以物种丰富度S、Shannon-Weiner指数、Simpson指数和Pielou均匀度指数为指标,对群落多样性及其随海拔梯度的变化进行分析。【结果】研究区的28个样地可分为9个群落类型;群落多样性顺序为：华山松林〉白桦＋太白杨林〉兴山榆林〉短柄枹栎林〉锐齿槲栎林〉山杨＋糙皮桦林〉油松林〉红桦林〉刺叶高山栎林;该区域的9种森林群落共容纳植物243种,其中蕨类植物4科4属4种,裸子植物2科4属5种,被子植物58科151属234种;物种多样性随海拔梯度呈规律性变化,即在海拔1 525~1 920 m呈上升趋势,在1 920~2 340 m呈下降趋势。【结论】研究区群落受人畜干扰强烈,导致生态系统结构功能退化、生物多样性降低,应采取有效措施减少人为因素对生态系统结构功能和演替过程的干扰与破坏;对现有的中、幼龄林应加强抚育管理,促进其恢复发展。

【Objective】 This paper carries research on structure of typical forest community and characteristics of species diversity in Yangjiagou,Zhouzhi Laoxiancheng Nature Reserve,to provide theoretical basis for vegetation restoration and reconstruction,biodiversity protection and cataloging.【Method】 We classified the forest community by two-way TWINSPAN,analysed the community diversity and its changes with the elevations of the gradient on species richness S,Shannon-Weiner index,Simpson,Pielou index and evenness index.【Result】 The 28 plots in research area can be divided into 9 community types;the order of the community diversity is Pinus armandii Corylus ferox＋Populus purdomiiUlmus bergmannianaQuercus serrata var.brevipetiolataQuercus aliena var.acutiserrataPopulus davidiana＋Betula utilisPinus tabulaeformisBetula albo-sinensisQuercus spinosa;the 9 forest communities have vegetation resources in 243 species of which pteridophyte has 4 families 4 genera 4 species,gymnosperm 2 families 4 genera 5 species,angiosperm 58 families 151 genera 234 species.Species diversity changes regularly along altitudinal gradients,which shows a rising tendency between 1 525-1 920 m,then a downtrend between 1 920-2 340 m.【Conclusion】 The forest communities in research area have been disturbed intensely by people and livestock,causing the degradation in community structure and function of ecological system and bio-diversity＇s reduction,so effective measures should be taken to decrease the artificial interference and damage to community structure and function of ecological system.