Simplify the following text for a Grade 7 native English-speaking person.
Original: Alpine tundra is distinguished from arctic tundra , because alpine soils are generally better drained than arctic soils . Alpine tundra transitions to subalpine forests below the tree line ; stunted forests occurring at the forest-tundra ecotone are known as Krummholz .
Simplified: Alpine tundra changes to subalpine forests below the tree line .