What do living things remove materials from the environment for?
Growth and other processes
How are materials returned to the environment?
In waste materials or when living things die and decay
Why do materials decay?
Because they ate broken down (digested) by microorganisms.
Where do microorganisms digest materials best and fastest?
In WARM, MOIST, AEROBIC conditions
What does the decay process release?
Chemicals that plants need to grow
What happens in a stable community?
The processes that REMOVE the materials are BALANCED by processes that RETURN materials, which are constantly cycled