Landforms
In North America the temperate rainforest has essentially two landform features: small mountains and river plains. The elevations of these landforms range from 0 to about 2,300 feet above sea level.
Differences
Different latitudes receive a different amount of seasonal change due to axis tilt. The tilt produces different amounts of annual sunlight and angle of incidence as the light reaches through the atmosphere. This gives each region a different climate, and climate is what usually offsets a different biome. They have different bedrocks so their original soil composition differs even before it weathers differently. All this leads to a different degree of biodiversity on each biome.