The Online Library of Knowledge


Natural cycles

Nutrients cycleNutrients cycle Planet Earth is like a giant, self-contained spaceship. It only has a limited amount of chemical substances "on board". In nature, elements such as oxygen, carbon and nitrogen are neither made nor destroyed, but recycled—moved round and round in the form of minerals and nutrients. On land, they are taken up from the soil by plants, then into animals that eat plants, sometimes into other animals that eat plant-eating animals, returning to the soil through animal waste or when the plant or animal dies and rots away.

Orange mycena, the fruiting body of a fungusOrange mycena, the fruiting body of a fungus

Nutrients cycle

Nutrients and minerals are always recycled. They are taken up by plants through their roots. The plants are then eaten by animals. Nutrients return to the soil either through an animal’s droppings, or whenever any plant or animal dies and rots away. 

Micro-organisms in the soil, such as bacteria, along with fungi and animals such as worms, play an important part in releasing the nutrients and minerals from the decaying matter into the soil, where they are taken up by plants. And so the cycle continues.

Carbon atoms in your toenail may have once been part of a dinosaur. Since the creature died and decomposed millions of years ago, its carbon atoms have been recycled. They may be floating in the air as carbon dioxide, turned into rocks at the bottom of the sea—or have become part of the body of an animal like you.

© 2020 Q-files Ltd. All rights reserved. Switch to Mobile