Energy flow & Pyramids in Ecosystems

Producers

Organisms that take in sunlight to make their own food through photosynthesis.

Autotrophs

Another term for producers, organisms that produce their own food.

Consumers

Organisms that feed on producers or other consumers.

Heterotrophs

Another term for consumers, organisms that cannot make their own food.

Herbivores

Organisms that feed on plants.

Carnivores

Organisms that feed on other animals.

Omnivores

Organisms that feed on both plants and other animals.

Decomposers

Organisms that break down dead organisms.

Detritivores

Organisms that feed on organic waste material.

Food chain

A series of steps in which organisms transfer energy by eating and being eaten.

Food web

A network that links all of the food chains in an ecosystem.

Disturbances

Events that can dramatically affect food webs.

Primary producer

The first step in a food chain, typically a producer.

Primary consumer

The second step in a food chain, feeding on producers.

Secondary consumer

The third step in a food chain, feeding on primary consumers.

Tertiary consumer

The fourth step in a food chain, feeding on secondary consumers.

Quaternary consumer

The final step in a food chain, often feeding on tertiary consumers.

Ecological Pyramids

Three types of representation in ecosystems: Pyramid of Energy, Pyramid of Biomass, and Pyramid of Numbers.

Pyramid of Energy

Illustrates the flow of energy through different trophic levels in an ecosystem.

10% Rule

Only about 10% of the energy available within one trophic level is transferred to the next trophic level.

Biomass

The total amount of living tissue within a given trophic level.

Heat

Energy that is released into the environment as organisms expend energy on life processes.

Trophic Level

The hierarchical levels in an ecosystem that represent the flow of energy from one level to the next.

Life Processes

Activities that consume energy in organisms including respiration, movement, growth, and reproduction.