Ch. 23 Ecosystems and Biomes Sect. 1 Energy Flow in Ecosystems

Each organism has a role in the movement of energy through the ecosystem. Producer- an organism that can make its own food Consumer-an organism that obtains energy by feeding on other organisms Decomposer- an organism that breaks down dead organisms and returns the raw materials back to the environment.

Producers are plants,algae, and some bacteria that can take energy from the sun and carry out photosynthesis. Some bacteria can use chemicals from the environment and produce food through chemosynthesis.

Consumers are classified by what they eat. Herbivores- eat only plants Carnivores- eat only animals Omivores-eat both Scavengers-feed on dead bodies

Herbivores

Carnivores

Omnivore

Decomposers

Food Chain

Food Web

The arrow is pointing to the direction that receives the energy

Energy Pyramid

In general, only 10% of the energy at one level of a food web is transferred to the next, higher level. The other 90% of the energy is used by the organism for living. Since 90% is not available, there is not enough energy to support many feeding levels. That is why it looks like a pyramid. The largest amount of available energy is at the producer (bottom) level.