This image is modified from the shapefile of the Circumpolar Arctic Vegetation Map (CAVM Team, 2003, available here). This map and its associated GIS resources classify the entire circumpolar arctic based on the vegetation type. The arctic is divided into five macro-scale vegetation types: Barrens, Graminoid Tundras, Prostrate-shrub Tundras, Erect-shrub tundras and Wetlands. Each of these vegetation types are further divided into vegetation subtypes; a description of these units and the Circumpolar Vegetation Map is available here).
The Google Earth shapefile containing the Circumpolar Arctic Vegetation Map can be downloaded here.