PEM_20K contains 1:20,000 PEM polygons with key and amalgamated (concatenated) attributes derived from the Resource Inventory Standards Committee (RISC) standard attributes. PEM divides the landscape into units according to a variety of ecological features including climate, physiography, surficial material, bedrock geology, soils and vegetation. PEM uses a modeling approach to ecosystem mapping, whereby existing knowledge of ecosystem attributes and relationships are used to predict ecosystem representation in the landscape. This layer is derived from the STE_TEI_ATTRIBUTE_POLYS_SP layer by filtering on the PROJECT_TYPE and PROJECT_MAP_SCALE attributes