I believe they can be changes and revised
Tropical rain forest
Tropical dry forest
Tropical dry forest / savannah
Desert
Temperate grassland
Temperate woodland
Temperate deciduous forest
Northwest coniferous forest
Boreal forest
Tundra
Because the amount of rainfall isn't the same every year
This is a negative feedback. A negative feedback is where the body detects a change in the body's internal environment and crafts a mechanism to correct it