An ecosystem is a group of organisms and their physical environment. All organisms within an ecosystem need energy to survive.
2. Organisms and Energy
Organisms obtain energy from different sources. Each organism plays a role in the flow of energy through the ecosystem.
Producers make their own food through the process of photosynthesis. Plants, algae and some bacteria are producers that use the sun's energy to make food.
Consumers get energy by eating other organisms. They are often classified by what they eat. Herbivores only eat plants. Carnivores eat animals, and omnivores eat both plants and animals.
5. Example of Energy Flow
Energy flows from producers to the different types of consumers. For example, plants are eaten by herbivores such as grasshoppers. A grasshopper is eaten by a mouse, which is then eaten by a rattlesnake.
Decomposers obtain energy by eating or absorbing nutrients found in animal waste and dead bodies. Bacteria, fungi and worms are decomposers that help return raw materials to an ecosystem.