Both matter and energy are recycled.
Matter is recycled, but energy is not.
Energy is recycled, but matter is not.
Grasses - shrubs - trees
Shrubs - trees - grasses
Trees - shrubs - grasses
The sun and the moon
Lightning and bacteria
Clouds and rain
The type of climate in a given region
The carnivores that consume other animals
The amount of nitrogen gas in the air
The rate of flow of water in a river