拉萨半干旱河谷地带的植被数量生态研究  

Ecological Studies on Vegetation Quantity in the Semi-Arid Valley Region of Lasa

作　　者：杨小林[1] 赵垦田[1] 马和平[1] 禄树晖[1] 罗健[1] 

机构地区：[1]西藏农牧学院,林芝860000

出　　处：《林业科学》2010年第10期15-22,共8页Scientia Silvae Sinicae

基　　金："十一五"国家科技支撑计划重点项目(2007BAC06B02)

摘　　要：应用TWINSPAN和DCA多元分析方法,以调查样地中所有植物种的生态重要值为指标,对拉萨半干旱河谷区域植被的特征进行统计分析,并分别对样方和物种进行数量分类和排序。样方调查基本包括了该研究区域内现有的植被类型,共获得35块样地。结果表明:1)在拉萨半干旱河谷区域垂直高度1350m的范围内,共划分成4个植被型组、7个植被型、14个群系、16个群丛,研究区域植被类型多样,垂直带谱分明,过渡带狭窄;2)DCA排序结果与TWINSPAN分类结果一致,各群落类型都有各自范围和分界线;3)拉萨半干旱河谷区域植被随海拔的变化存在明显的分带,样地DCA第1排序轴反映了植物群落所在环境的海拔梯度,DCA第2排序轴反映了植物群落所处生境的水分状况,从下至上,土壤中的水分含量逐渐增加;4)DCA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。With the ecologically important value of plants in plots as an index,vegetation characteristics in the semi-arid valley region of Lasa were analyzed with TWINSPAN and DCA multivariate analysiss methods,and quantity classification and sorting of the plots and species were carried on separately. The sampling surveys basically included all cover types in the region,and we obtained 35 sample plots. TWINSPAN analysis results indicated that： 1） the 1 350 m altitude scope was divided into 4 groups of vegetation types,7 vegetation types;14 formations,and 16 associations in the semi-arid valley region. In this region,several characteristics,such as diverse vegetation,distinct vertical band spectrum,and narrow intermediate belt and so on,displayed;2） The result of DCA ordination was consistent with TWINSPAN classification,and each community type had its own scope and boundary;3） The vegetation existed obvious minute belt along with change of the elevation in the semi-arid valley region. The first sorting axis of DCA reflected the altitude gradient of the plant community in the environment and the second reflected the water status. From bottom to top,the moisture content of the soil increased gradually;4） The various communities order of rank synthesis of the DCA diagonal line reflected the vegetation community  s environmental heterogeneity,which provided a theory basis for the local vegetations zonality vegetation restoration.

关 键 词：植被 重要值 TWINSPAN分类 DCA排序 拉萨半干旱河谷 

分 类 号：S718.3[农业科学—林学]