东北植被区划及其分布格局

Regionalization and distribution pattern of vegetation of Northeast China

根据多因子环境要素聚类结果,结合地貌分异、气候区划和土壤区划,对东北植被进行了重新区划,并论述了海拔高度决定的东北植被的垂直分布规律。松嫩平原、辽河平原构成的松辽平原的植被主体为草甸,针茅(Stipa)等群落分布于较高地势的二级台地或沙丘上,为草甸植被中不连续分布的沙地植被类型或海拔决定的垂直植被带的草原类型。据此,将松辽平原植被区划为温带落叶阔叶林区域,即将温带草原区南部的东侧界限划定在大兴安岭山脊线附近,北部寒温带针林南部界限和南部暖温带落叶林北部界线遵从现有研究结果。东北植被分布具有明显的受海拔决定的垂直地带性上的环状分布格局特点。

Aims Our objectives were to consider a new scheme for vegetation regionalization of Northeast China, espe-cially for vegetation in the Songliao Plain, and to illustrate the distribution pattern of vegetation as determined by altitude. Methods We clustered the sites from Inner Mongolia steppe, east forest and central Songliao Plain with tem-perature, precipitation, soil types and underground water depth using principle component analysis （PCA）. We also analyzed the physiognomy, topography of Northeastern China using GIS, vegetation types and soil types of Songnen Plain. Important findings The dominant vegetation of Songliao Plain is meadow, an unzonal vegetation type. The Stipa communities, an indicator of the zonal vegetation type, mainly distributed on the second mesa in Songnen Plain, are a sandland vegetation type that is distributed discontinuously among meadow vegetation. Therefore, the vegetation of Songliao Plain should be regionalized as an area of temperate broad-leaved deciduous forest, and the east boundary of temperate steppe region should be moved toward to the west of the Da Hinggan Mountains. The vegetation distribution of Northeast China shows a vertical zonation determined by altitude.