Food Chains, Webs, & Pyramids How Energy Flows in an Ecosystem

Producers, Consumers, and… Food chains

Producers A group of organisms that produce their own food using sunlight to convert water & CO2 into glucose (food) Also called autotrophs Examples: plants & algae

Producers/Autotrophs

Consumers Organisms that consume other organisms in order to live Also called heterotrophs because they cannot make their own food Examples: sharks, mushrooms, seals, cows

Consumers/Heterotrophs

Primary Consumers Eat plants Examples: giraffes, rabbits

Primary Consumers

Secondary Consumers Eat primary consumers (eat plant eaters) Examples: lions, tigers, bears (oh my!)

Secondary Consumers

Tertiary Consumers Eat secondary consumers (eats meat eaters) Examples: cougars, bears, wolves Not always present in the food chain

Tertiary Consumers

Scavengers Feed on the tissue of dead organisms (both plants and animals) Examples: crows, vultures, shrimp

Scavengers

Decomposers Absorb any dead material and break it down into simple nutrients or fertilizers Examples: bacteria & mushrooms

Decomposers

Food Chain A diagram that shows how energy in food flows from one organism to another Arrow points toward whichever organism is receiving the energy

Food Chain

Links in the Chain Every organism depends on the other organisms Example: If all of the grass died, the grasshopper would starve to death causing the snake and the hawk to starve to death until eventually even the fungi do not have anything to feed on

Chains + Chains = Food webs

Food Webs A diagram that shows the feeding relationships between organisms in an ecosystem Multiple relationships composed of multiple food chains Most organisms eat more than one organism Much more complex and accurate

Food Web

How energy flows… Energy pyramids

Energy Pyramid A triangular diagram that shows an ecosystem’s loss of energy Results as energy passes through the ecosystem’s food chain/web Shows the number of organisms and amount of matter/energy available at each level Decreases at each level because most energy is lost as heat waste

The End!