西藏色季拉山林线植被群落数量特征  

Quantitative characteristics of timberline vegetation on Mt. Shergyla, Tibet

作　　者：杨小林[1] 王景升[2,3] 陈宝雄[3] 普穷[1] 

机构地区：[1]西藏农牧学院资环学院 [2]中国科学院地理科学与资源研究所 [3]中国人民大学环境学院

出　　处：《北京林业大学学报》2011年第3期45-50,共6页Journal of Beijing Forestry University

基　　金：国家自然科学基金项目(30571484);教育部重点科技项目(208136);林业公益性行业科研专项(200804001)

摘　　要：为揭示藏东南高山林线的植被空间分布及林线植被的生态适应性,应用TWINSPAN和DCA多元分析方法,以调查样地中草本、灌木和乔木层的重要值总和为指标,对色季拉山林线植被的特征进行分析,并分别以样地和物种为单位进行数量分类和排序。调查样地为色季拉山林线研究区域(林线及附近垂直高度1000m)的森林及灌木植被类型,共26个。TWINSPAN分析结果表明:1)色季拉山林线研究区域共分布着7个群落(群丛)类型,林线区域植被类型多样,垂直带谱分明,过渡带狭窄。2)DCA排序结果与TWINSPAN分类结果较为一致,各群落类型都有自己的范围和分界线。3)样地DCA第一排序轴反映了研究区海拔梯度的影响,即植被随海拔的变化存在明显的分带;DCA第二排序轴反映了研究区土壤水分状况,即土壤水分含量随海拔的增加而增加;对角线上各群落的排列顺序综合反映了植被群落的环境异质性。In order to make clear the spatial distribution of timberline vegetation and its ecological adaptability, we quantified the characteristics of the vegetation in the timberline ecotone on Mr. Shergyla in Tibet using multivariate analysis （TWINSPAN classification and DCA ordination） of the importance values of the plant species （herb, shrub and tree layer） in each of the 26 study plots. Results from TWINSPAN showed that along the timberline ecotone in an altitudinal range of 1 000 m, seven vegetation types （associations） were distinguished and the transitional belts between adjacent vegetation types were narrow. Results from DCA were similar to those from TWINSPAN, i. e. , each vegetation type had its own ranges and demarcation lines. The first DCA ordination axis stood for altitude, and vegetation types changed with the changing altitude; the second DCA ordination axis represented soil water condition, and it increased with the increasing altitude; the ordination series in the diagonal line indicated the environmental heterogeneity of the habitats on Mt. Shergyla in Tibet.

关 键 词：林线植被 西藏 TWINSPAN分类 DCA排序 

分 类 号：S718.54[农业科学—林学]