Major vegetation types (based on "climax") A function of the physical environment (precipitation and temperature):

1. Tundra (arctic and alpine)
2. Desert (cold and warm)
3. Grassland (tall grass, mixed grass and short grass prairie)
4. Forests:

Boreal
Eastern Deciduous
Rocky Mountain Forests
Sierra Nevada Forests
Pacific Northwest Conifer Forests
Broad-Sclerophyll Forests
Sub-Tropical Forests