Food ChainsFood ChainsFood WebsFood Webs

Energy PyramidsEnergy Pyramids

• Autotrophs: Organism that makes own food

• Heterotrophs: Organism that consumes other organisms

•Producer Also known as primary producers

•Herbivore An organism that primarily consumes producers

Also known as primary consumers

•Omnivore An organism that can consume either

primary producers or primary consumers

•Carnivore An organism that primarily consumes primary

consumers

Also known as secondary consumers

Decomposers An organism that consumes dead organisms, and, in doing so, carry

out the natural process of decomposition

Also can be scavengers (animal decomposers) or detritivores (plant decomposers)

•Generalists consumers that have a varying diet

Specialists consumers that primarily eat

one specific organism or a very small number of organisms

Food chains and food webs

Each step in a food chain or food web is called a trophic level

Energy FlowEnergy Flow

Food Chains

Food Web

Energy Pyramid

• Three types of ecological pyramids• Pyramid of Energy

• Pyramid of Biomass

• Pyramid of Numbers

Energy Pyramids

energy transferred

energylost

• Indicates the total amount of energy present in each trophic level

• Only 10% of the overall movement of potential energy is transferred to the next tropic level

Biomass Pyramids

tertiaryconsumers

secondaryconsumers

primaryconsumers

producers

75 g/m2

150g/m2

675g/m2

2000g/m2

• Indicates the total dry mass of the organisms in each trophic level

• Thus an enormous mass of grass is required to support a smaller mass of gazelle, which in turn would support a smaller mass of lions.

Ecological Pyramidstertiaryconsumers

secondaryconsumers

primaryconsumers

producers

5

5000

500,000

5,000,000

• Shows the number of organisms in each trophic level

• the higher up one goes, fewer organisms there are