Every fall, trees drop millions of leaves. Logs fall. Plants and animals die. Why doesn't the forest fill up with dead things? Meet the clean-up crew: the decomposers.
Key idea
Decomposers, like worms, mushrooms and tiny bacteria, break down dead plants and animals and put nutrients back into the soil.
Why it works
Decomposers eat dead things bit by bit. As they do, the nutrients inside go back into the soil. New plants take those nutrients in through their roots. So nothing is wasted: it goes around and around.
Worked example: Let's think it through
A log lies in the forest for many years. What happens to it?
- Mushrooms and other fungi grow into the wood and soften it.
- Insects, worms and bacteria eat it, little by little.
- What is left becomes part of the soil.
Answer: Decomposers break it down into soil.
Common mistake
Children often think dead leaves and logs just disappear by themselves. Decomposers eat them, and that puts nutrients back into the soil for new plants.
For the grown-up. Turn over an old log in the woods (then put it back the way it was) and look for the crew: mushrooms, beetles, worms and soft, crumbly wood. A compost pile at home works the same way. This builds on Once Living.