1. Interpreting Food Webs

2. Energy Diagrams
Food Chain- shows a single pathway of energy flow in an ecosystem
Food web- shows multiple pathways of energy flow in an ecosystem
Energy pyramid shows how energy is lost
as you move from one trophic level to the next.

3. Food Chain
Food Web
Energy Pyramid

4. Trophic Levels
Trophic levels refer to the position an organism occupies in a food chain.
Fourth Trophic Level
Third Trophic Level
Second Trophic Level
First trophic Level
Producers are always found in the first trophic level

5. Trophic Levels cont….
Biomass- the amount of organic matter (nutrients) comprising a group of organisms in a habitat.
As you move up a food chain, both available energy and biomass decrease.
Energy is transferred upwards but is diminished with each transfer.
Energy Pyramid - A diagram shaped like a triangle that shows the loss of energy at each level of the food chain.

8. Energy Pyramid
Only energy stored in tissues of an organism can be transferred to the next level.
The higher up in the pyramid an organism is, the more they must eat to obtain energy.

9. III. All Living Things Need Energy
Producers- use sunlight to make food (plants and some protists)
Consumers- eat other organisms for food
Herbivore – eat producers
Carnivore – eat meat
Omnivore – eat meat and producers
Scavenger – feed on dead animals
Decomposers- break down dead organisms (fungi and some bacteria - recycle nutrients)

11. Trophic Level one is always a producer
Primary Consumer
Producer
Trophic Level one is always a producer
Level two is the primary consumer
Primary Consumers are herbivores or omnivores, because they eat producers.
Secondary
Consumer
Tertiary Consumer

12. Competition Two or more organisms try to use the same limited resource
What two organisms compete for mice as an energy source?

13. Transfer of energy
Name all of the producers from the food web

14. Which of the primary consumers are herbivores?
Name all of the primary consumers
Which of the primary consumers are omnivores?

15. Secondary Consumers Secondary Consumers are in the third trophic level
First
Name the secondary consumers above

16. Food webs show relationships
Competition- when two or more organisms try to use the same limited resource.
Are their any organisms competing in the food web?

17. Importance of predator prey Relationships
How would over fishing affect this population?
Name four prey of the lobster?