MODELING: Energy & Ecosystems

SC.912.L.17.9 Use a food web to identify and distinguish producers, consumers, and decomposers. Explain the pathway of energy transfer through trophic levels and the reduction of available energy at successive trophic levels.

BIOMES• Freshwater Swamp Food Web• Deciduous Forest Food Web• Tropical Rainforest Food Web• Desert Food Web• Marine Food Web

Creating a Food Chain• Open your envelope and

arrange images on your table in a simple food chain.

• Using a piece of chalk on your lab table, include arrows in your food chain to indicate direction of energy flow through your food chain.

• Label each feeding categoryproducer or autotrophprimary consumersecondary consumer tertiary consumerdecomposer

From Food Chain to Food Web• Raise your hand once you

finish your food chain.

• Add the new cards given by your teacher to your existing food chain.

• Is it still a food chain?

VIDEO: Richard Kern – Odyssey Earth

Are you missing

any organisms?

Ask your teacher for extra cards if you are missing a component of your assigned ecosystem.

• Collaborate with another team.

• Examine their food web and discuss with them their placement of organisms.

• Make suggestions for changes if you feel they have arranged or labeled something incorrectly. Then allow them to do the same for your food web.

• Be prepared to defend your choice of placement but don’t be hesitant to change your web in response to their suggestions.

PART 1: Analysis 1. What would happen if the food chains or

webs had no scavengers or decomposers?2. For most habitat, which description do you

think is more accurate – a food chain or a food web? Why?

3. What is a trophic level?4. Based on the food web interactions you just

determined, why could it be a serious problem if a consumer organism that had no predators was introduced into the system? (This sometimes occurs when non-native organisms are released from captivity)

5. Trophic Pyramida. Copy and complete

the trophic pyramid for your assigned Biome.

b. Use the following terms: - 1st trophic level- 2nd trophic level- 3rd trophic level- 4th trophic level

c. Write examples of organisms from your food web in their corresponding trophic level.

6. What do you predict is the relationship between number of individuals in a species and its trophic level?

7. Which organisms should people eat if they wanted to be most energy efficient?

VIDEO: 10% Efficiency Rule

1. If there are 1000 units of energy available at the producer level of the energy pyramid, approximately how many units of energy are available to the third-level consumer?

2. What is the original source of the energy that flows through most ecosystems?

3. What was the energy that wasn’t passed on to the next trophic level used for?

4. Why must there be a continuous supply of energy into the ecosystem?

5. Why are there usually fewer organisms in the top levels of an energy pyramid?

Activity: Food Chain Game