7thSci Energy Cycle (Windowed)

(aka Food Web)

The Energy Cycle

An autotroph is an organism that can produce its own food using light, water, carbon dioxide, or other chemicals. Because autotrophs produce their own food, they are sometimes called producers.

Autotroph (Producer)

National Geographic Encyclopedia Entry

Examples

• Giant Kelp
• Algae
• Plants
• Cyanobacteria

Heterotrophs cannot produce their own energy and must consume other organisms. Every food web includes consumers—organisms that get their energy by eating other organisms. All animals are consumers.

Consumer (Heterotroph)

National Geographic Encyclopedia Entry

Examples

• Herbivore

• Carnivore

• Omnivore

• Scavenger

Decomposers also cannot make their own food and play a critical role in the flow of energy through an ecosystem. They break apart dead organisms into simpler inorganic materials, making nutrients and other abiotic chemicals available to primary producers.

Decomposers (Heterotroph)

National Geographic Encyclopedia Entry

Examples

• Fungi
• Bacteria

Abiotic factors—nonliving things in an environment, such as air, light, and water—are critical for healthy ecosystems. Decomposers create these abiotic chemicals and enrich the soil for producers to grow and develop.

Abiotic Chemicals

National Geographic Encyclopedia Entry

Examples

• Minerals (iron, zinc, magnesium, etc.)
• Nutrients (nitrogen, potassium, etc.)
• Vitamins