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

2. Producers, Consumers, and…
Food chains

3. 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

4. Producers/Autotrophs

5. 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

6. Consumers/Heterotrophs

7. Primary Consumers
Eat plants
Examples: giraffes, rabbits

8. Primary Consumers

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

10. Secondary Consumers

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

12. Tertiary Consumers

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

14. Scavengers

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

16. Decomposers

17. 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

18. Food Chain

19. 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

20. Chains + Chains =
Food webs

21. 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

22. Food Web

23. How energy flows…
Energy pyramids

24. 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

27. The End!