Feeding roles in ecosystems

Organisms obtain energy and organic nutrients in different ways. Their feeding role describes the source they use.

A producer makes its own organic nutrients from inorganic substances. Most producers, such as plants and algae, use energy from sunlight to do this by photosynthesis.

A consumer obtains energy and organic nutrients by feeding on other organisms. A herbivore is a consumer that eats plants; a carnivore is a consumer that eats other animals.

A decomposer obtains energy from dead organic material or waste. Decomposers, such as many bacteria and fungi, break down this material and absorb the resulting nutrients.

A feeding role describes what an organism obtains its energy from, but it does not by itself give the organism’s exact position in a particular food chain. For example, a carnivore may eat a herbivore or another carnivore.