1. Ecosystems Unit Activity 3.3 Tracing Carbon Through Ecosystems
Carbon: Transformations in Matter and Energy
Environmental Literacy Project Michigan State University
Ecosystems Unit Activity 3.3 Tracing Carbon Through Ecosystems
Image Credit: Craig Douglas, Michigan State University

2. Unit map
You are here
Use the instructional model to show students where they are in the course of the unit.
Show slide 2 of the 3.3 Tracing Carbon Through Ecosystems PPT.

3. Reviewing the Carbon Dice Game
Atmosphere CO2
Carnivores organic carbon
Herbivores organic carbon
Producers organic carbon
Soil
Organic Carbon 99 19 70 32 2
In the Carbon Dice Game, we followed individual carbon atoms into and out of carbon pools. We found that the number of carbon atom visits to different organic matter pools followed the same pattern as the organic matter pyramid.
Revisit student ideas about the Carbon Fluxes Question.
Use 3.3 Tracing Carbon Through Ecosystems PPT. Slide 3 to discuss the initial patterns students found in Activity 3.1.

4. Carbon Movement Introduce the Matter and Energy Diagram.
Show Slide 4 of the 3.3 Tracing Carbon Through Ecosystems PPT. Show students that the right side of the diagram shows carbon pools as rectangles and carbon movement as arrows. The green rectangles are organic carbon and the grey rectangles are inorganic carbon. The left side of the diagram shows how carbon cycles from inorganic to organic carbon pools. For this activity, students will be using the right side of the diagram.

5. Carbon Movement Students complete the graphic organizer.
Pass out copies of the 3.3 Tracing Carbon Through Ecosystems Graphic Organizer. Have students complete the graphic organizer by writing the process represented by each arrow on the line in each arrow. When students are finished, show slide 5 to allow students to check their graphic organizers. Talk with students about which arrows are carbon transforming processes (photosynthesis, cellular respiration) and which arrows are carbon moving (falling leaves, death, eating).

6. Carbon Movement
Use your tracking sheet to trace your path as a carbon atom in the diagram.
Students trace their path on the graphic organizer.
Have students take out their 3.2 Carbon Dice Game Tracking Sheet. Display slide 6.
Have students use a pencil to trace how they traveled during the carbon dice game on their graphic organizer. Each time they reach the bottom of the diagram they should circle back to the top (the top and bottom pool are the same).

7. Reflecting on Tracing
Talk about the following questions with your partner:
How were your paths similar?
How did your carbon atom get to be in a carnivore?
How did your carbon atom get to be in a decomposer?
How do your paths relate to the widths of the arrows?
Have students discuss patterns with a partner.
Display slide 7. Have students compare their path with their partner.

8. Class Discussion
What are some patterns in how carbon moves through an ecosystem?
What do the widths of the arrows represent?
Why is it so rare for carbon atoms to go through a carnivore?
Have a class discussion.
Display slide 8. Have a discussion about the following questions:
What are some patterns in how carbon moves through an ecosystem?
Why is it so hard to become a carnivore in the carbon dice game?

9. Reviewing Patterns So, to recap:
Producers are the only organisms that can change inorganic carbon to organic carbon.
All other organic pools are dependent organic carbon from the Producer pool to carry out their life processes, like eating, growing, defecating, and cellular respiration.
Review the patterns.
Show Slides 9 and 10 to recap some of the main points of carbon transfer through an ecosystem.

10. Reviewing Patterns
Life processes (photosynthesis, cellular respiration, eating, defecating, dying) move carbon from one pool to another.
This continual loss of carbon atoms from organic pools is one reason the organic matter pyramid looks the way it does.
Review the patterns.
Show Slides 9 and 10 to recap some of the main points of carbon transfer through an ecosystem.