Regionalization and distribution pattern of vegetation of Northeast China

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 temper- ature, 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 Sti- pa 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