| B1 - Cryptogam, herb barren |
| B2a - Cryptogam/barren complex (bedrock) |
| B3 - Noncarbonate mountain complex |
| B4 - Carbonate mountain complex |
| B2b - Prostrate shrub/barren complex (bedrock) |
| G1 - Rush/grass, forb, cryptogam tundra |
| G2 - Graminoid, prostrate dwarf-shrub, forb tundra |
| G3 - Nontussock sedge, dwarf-shrub, moss tundra |
| G4 - Tussock sedge, dwarf-shrub, moss tundra |
| P1 - Prostrate dwarf-shrub, herb tundra |
| P2 - Prostrate/Hemiprostrate dwarf-shrub tundra |
| S1 - Erect dwarf-shrub tundra |
| S2 - Low shrub tundra |
| W1 - Sedge/grass, moss wetland |
| W2 - Sedge, moss, dwarf-shrub wetland |
| W3 - Sedge, moss, low-shrub wetland |
| FW - Fresh water |
| SW - Saline water |
| GL - Glacier |
| NA - Non-Arctic |