1. What do the arrows indicate?
What’s going on here?
What do the arrows indicate?

2. Food Chain Simple model Shows how energy flows through an ecosystem
Energy flows form the sun, to autotrophs, and then to heterotrophs

3. Food Chains
3-4 links in a food chain

4. Trophic Levels
Each organism in a food chain represents a feeding step/trophic level
Each level represents a link in a food chain

5. 1st Trophic Level- Autotrophs/Producers
4th Trophic Level
Consumers
3rd Trophic Level
2nd Trophic Level-
“Herbivores”
1st Trophic Level- Autotrophs/Producers

7. First trophic Level Composed of Autotrophs “Producers”
Photosynthetic organisms
Ex: grasses, trees, aquatic phytoplanton

8. 2nd Trophic: First-order Heterotrophs
Composed of Herbivores
Consume autotrophs
“Primary Consumers”
EX: Mouse

9. 3rd Trophic level: Second-order Heterotrophs
Carnivores
Can be omnivores
“Secondary Consumers”
EX: Snake consumes mouse

10. 4th Level: third- Order Heterotrophs
Top Predators
“Tertiary Consumers”
Carnivores
EX: Great Horned Owl

11. FOOD WEBS More realistic A network of interconnected food chains
Expresses all of the possible feeding relationships at each trophic level
Most organisms depend on more than one species to obtain energy and nutrients

12. Food Webs
TROPHIC LEVEL 3/4
Text
Text
TROPHIC LEVEL 2
TROPHIC LEVEL 1

13. ARROWS MUST POINT WHERE THE FOOD ENERGY IS GOING!

14. Where would decomposers go on a food web?

15. Decomposers
Decomposers will recycle nutrients back into the ground