Matter Cycling in Ecosystems
Develop a model to describe the movement of matter among plants, animals, decomposers, and the environment in an ecosystem
What a learner can do afterwards
- Describe the role of decomposers (fungi, bacteria, worms) in breaking down dead matter
- Trace the movement of matter: plant grows using soil nutrients → animal eats plant → animal dies → decomposers return nutrients to soil
- Create or interpret a simple diagram showing matter cycling through an ecosystem
1 · Read
You already know that energy flows through a food chain and leaves as heat. Matter works differently. The atoms in a leaf, a mouse, or a fox never disappear. They get passed around and used again and again.
A leaf falls onto the forest floor. Worms chew it into tiny pieces. Bacteria and fungi break those pieces down even further until the nutrients mix into the soil. Next spring, a new plant's roots soak up those same nutrients and use them to grow.
Fungi, bacteria, and worms are nature's recyclers. Without them, dead leaves and animals would just pile up, and plants would run out of nutrients to grow.
Matter cycles from soil to living things and back again through decomposers; it never disappears.
More to read
Unit 5.1: Ecosystems & Matter Cycling
Nothing in nature is wasted, it just moves around. A plant pulls water and nutrients from the soil to grow leaves. A rabbit eats the leaves, so the matter that was plant becomes rabbit. When the rabbit dies, the story does not end there.
Decomposers are the cleanup crew. Fungi, bacteria, and worms break dead bodies and fallen leaves into tiny pieces. Those pieces return to the soil as nutrients, ready for new plants to use. Draw it as a circle: soil to plant, plant to animal, animal back to soil.
24.3 Ecology of Fungi
Fungi look quiet, but they are powerful recyclers. A mushroom on a fallen log is only the tip of a huge hidden net of threads spreading through the wood. These threads release juices that dissolve dead matter into food the fungus can soak up.
Without fungi, forests would drown in dead leaves and logs. Because fungi unlock the nutrients trapped inside, living plants get fed.
46.1 Ecology of Ecosystems
An ecosystem has living members and nonliving parts that all connect. The living members are plants, animals, and decomposers. The nonliving parts are sunlight, water, air, and soil. Matter travels between them in loops that never really stop.
Scientists build simple diagrams to show these loops. Boxes stand for each member, and arrows show where matter moves next. If you can trace one atom from soil into a leaf, into a caterpillar, and back to soil, you have read the cycle correctly.
Explore more
2 · Watch
En anglaisTake it off screen
Where it sits
Optional connections
This opens up
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
24 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.