1. Agenda:
Intro to Ecosystems
Food webs & energy flow
Make your own food web
Life’s Work:
Read
Objective:
SWBAT analyze the flow of energy through trophic levels of a food web.
Do Now:
List three ways that the fast food industry has affected the environment.

2. Ecology and Organisms
Ecology: a study of connections in nature (how organisms interact with one another and their environment)
Organisms: classified into different species based on certain characteristics

4. Ecosystems and their Components
Ecosystem: a community of different species interacting together with the chemical and physical factors making up the non-living environment
Ecosystems consist of nonliving (abiotic) and living (biotic) components.

5. Habitat: the place where an organism or a population lives
Niche: The total way of life or role of a species in an ecosystem

6. Predator: an organism that captures and feeds on another animal.
Prey: an organism that serves as a source of food for another animal.

7. Key Processes: Decomposition
As plant or animal matter dies, it will break down and return the chemicals back to the soil.
Key Processes: Photosynthesis
The process in which glucose is synthesized by plants

8. On the food web on your Guided Notes:
Draw in the sun.
Draw an arrow connecting the sun to the grasses.
Label the arrow with the name of the process that is taking place.
PHOTOSYNTHESIS

9. Producer: (autotroph) uses solar energy or chemical energy to manufacture food
Consumer:(heterotroph) get their food by eating or breaking down all or parts of other organisms or their remains
                                  

10. On the food web on your Guided Notes:
Draw a “P” next to the Producer.
Draw a “C” next to a consumer. c P
PHOTOSYNTHESIS

11. Omnivores: consumers that eat producers and consumers
Consumers (Heterotrophs)
Herbivores: primary consumers that eat producers
Decomposers: digest dead organisms
Omnivores: consumers that eat producers and consumers
Carnivores: consumers that eat consumers

12. On the food web on your Guided Notes:
Label the following organisms with the correct letter:
Herbivore = H
Carnivore = Ca c P
PHOTOSYNTHESIS

13. On the food web on your Guided Notes:
DECOMPOSERS
On the food web on your Guided Notes:
Draw in the decomposers. Label them, and draw arrows connecting all of the other organisms to them. c P
PHOTOSYNTHESIS

14. Arrows always follow the flow of energy.
Food webs/chains show how energy and nutrients move from one organism to another through the ecosystem
Arrows always follow the flow of energy.

15. A Food Chain A Food Web

16. (decomposers and detritus feeders)
Each consumer is placed in a specific trophic level, based on where they are in the food chain.
First Trophic
Level
Second Trophic
Level
Third Trophic
Level
Fourth Trophic
Level
Producers
(plants)
Primary consumers
(herbivores)
Secondary consumers
(carnivores)
Tertiary consumers
(top carnivores)
Heat
Heat
Heat
Solar energy
Heat
Heat
Figure 3.17
Natural capital: a food chain. The arrows show how chemical energy in food flows through various trophic levels in energy transfers; most of the energy is degraded to heat, in accordance with the second law of thermodynamics.
Heat
Heat
Detritivores
(decomposers and detritus feeders)
Heat
Fig. 3-17, p. 64

17. Because of these tropic levels, we can use an energy pyramid to organize the food web in a different way.
RABBIT
THE SUN
On your guided notes, classify the organisms from the food web into this pyramid.

18. (decomposers and detritus feeders)
First Trophic
Level
Second Trophic
Level
Third Trophic
Level
Fourth Trophic
Level
Producers
(plants)
Primary consumers
(herbivores)
Secondary consumers
(carnivores)
Tertiary consumers
(top carnivores)
Heat
Heat
Heat
Solar energy
Heat
Heat
Figure 3.17
Natural capital: a food chain. The arrows show how chemical energy in food flows through various trophic levels in energy transfers; most of the energy is degraded to heat, in accordance with the second law of thermodynamics.
Heat
Heat
Any time that energy is transferred from one organism to another, heat is lost to the environment.
Detritivores
(decomposers and detritus feeders)
Heat
Fig. 3-17, p. 64

19. So much heat, in fact, that we use the 10% Rule:
90% of the energy at each energy level is lost in the form of heat
90%
This helps explain why:
It is more efficient to eat lower on the energy pyramid, like vegetarians do. You’re getting more energy for your buck.
Top predators are so few in number. There’s only so much energy available at the top of the pyramid.

21. On your guided notes, label the amount of energy available at each level of the pyramid.
SNAKE
SNAKE
SHREW
COUGAR
MOUSE
DEER
1,000
RABBIT
INSECTS
10,000
Kilocal.
GRASSES
THE SUN

22. On the bottom of your guided notes, complete the energy pyramids with the amount of energy available.