1. Ecosystems Unit Activity 3.1 Carbon Pools
Carbon: Transformations in Matter and Energy
Environmental Literacy Project Michigan State University
Ecosystems Unit Activity 3.1 Carbon Pools
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 3.1 Carbon Pools PPT.

3. Introduction
In Lesson 1 you identified key features of ecosystems including:
Organic versus inorganic carbon
Groups of organisms that have similar roles (producers, herbivores, carnivores, decomposers)
Now we will put these ideas together to learn about how scientists keep track of carbon in ecosystems
Use Slide 3 of the 3.1 Carbon Pools PPT to connect this activity to the previous lesson.

4. Scientists group parts of ecosystems into “pools” of carbon
Image Credit: Craig Douglas, Michigan State University
Students are introduced to the idea of “pools” of carbon.
Use the animation on Slides 4-6 to show how scientists categorize organisms into particular “pools” of carbon.
Use Slide 6 to help clarify what we mean by a soil carbon pool.
Optional: have students think about the number of organisms they drew in each “pool” of carbon. Which pool of carbon do they think is the largest?

5. Carnivores organic carbon
Atmosphere CO2
Carnivores organic carbon
Herbivores organic carbon
Producers organic carbon
Soil
Organic Carbon
Image Credit: Craig Douglas, Michigan State University
Introduce the idea of “pools” of carbon (cont.)
ANIMATED SLIDE-- Use in ppt slide show mode

6. Organic Carbon Carnivores Organic Carbon Herbivores Atmosphere CO2
Image Credit: Craig Douglas, Michigan State University
Introduce the idea of “pools” of carbon (cont.)
The end result of the animation, but showing the pools up closer.
Organic Carbon
Soil
Organic Carbon
Producers

7. New Information Alert: What is soil organic carbon?
Image Credit: Craig Douglas, Michigan State University
Students are introduced to the idea of “pools” of carbon. (cont.)
Students are introduced to the idea of “pools” of carbon.
Show slide 7. Tell students that in the next few lessons, we will think about soil organic carbon as the location of both decomposers (bacteria and fungi) and also dead plants and animals waiting to decay.
Optional: have students think about the number of organisms they drew in each “pool” of carbon. Which pool of carbon do they think is the largest?
It is a pool of carbon that contains:
Material from dead plants and animals waiting to decay (be eaten by decomposers) AND
Living decomposers.

8. Plants use food in two ways
Materials for growth: Biosynthesis
Food
To Cells
Energy: Cellular respiration
Students review carbon transforming processes.
Use slides 8-9 to begin to address the question of how the carbon pools are connected. Briefly review that organisms use their food in two ways: materials for growth (biosynthesis) and energy (cellular respiration).
It is important that students recognize that living organisms do not create or destroy matter or energy but only transform them in biological processes.
Image Credit: Craig Douglas, Michigan State University

9. Animals use food in two ways
Materials for growth: Biosynthesis
Food
Digestion
Energy: Cellular respiration
Students review carbon transforming processes.
Use slides 8-9 to begin to address the question of how the carbon pools are connected. Briefly review that organisms use their food in two ways: materials for growth (biosynthesis) and energy (cellular respiration).
It is important that students recognize that living organisms do not create or destroy matter or energy but only transform them in biological processes.
Image Credit: Craig Douglas, Michigan State University

10. What happens to food that animals can’t digest?
Our digestive systems cannot break down some large organic molecules (such as fiber).
These molecules leave our bodies as feces.
Students review carbon transforming processes. (cont.)
Use Slide 10 to remind students that animals CANNOT digest some of the food that they eat (such as cellulose and other fiber molecules for humans). This food leaves the animals as feces.
Image Credit: Craig Douglas, Michigan State University

11. Decomposers use food in two ways
Materials for growth: Biosynthesis
Food
Digestion
Energy: Cellular respiration
Students review carbon transforming processes. (cont.)
Use Slide 11 to discuss what happens to the feces after it leaves the cow’s body.
It is important that students recognize that living organisms do not create or destroy matter or energy but only transform them in biological processes.
Image Credit: Craig Douglas, Michigan State University

12. The organic pools and inorganic pools are connected through biological processes
Photosynthesis – transforms CO2 to organic carbon
Biosynthesis & Digestion – rearrange organic carbon molecules into other organic carbon molecules
Feces & death – moves organic carbon to the soil pool
Cellular respiration – transforms organic carbon into inorganic carbon (CO2 in the air)
Students review carbon transforming processes (cont.)
Use slide 12 to summarize the biological processes that connect carbon pools. Point out to students that death moves but does not transform carbon.

13. Scale
Just like in previous Carbon TIME Units we will be tracing matter and energy in the Ecosystems Unit. Now we will focus on tracing matter and energy across much larger scales. Therefore, the Four Questions that we are trying to answer are slightly different.
Explain that the Ecosystems Unit the focus will be on tracing matter and energy at the large scale.
Slides to emphasize that the Ecosystems Unit is focusing on a larger scale than previous organismal Units. The focus is still on tracing matter and energy, but the Four Questions are slightly different. You may wish to print the Large Scale Four Questions Poster to post in the classroom and refer to throughout the Unit.
Accommodation: Print the Large Scale Four Questions Poster. Also, provide students with a copy of the Large Scale Four Questions Handout. Have a class set in your classroom for use in the classroom only.

14. Large Scale Four Questions
Rules to Follow
The Carbon Pools Question:
Where are the carbon pools in our environment?
Atoms last forever! Atoms cannot be created or destroyed, but atoms can be rearranged to make new molecules.
Carbon atoms stay in pools unless a process moves them in our out.
The Carbon Cycling Question:
How are carbon atoms cycling among pools?
Carbon cycles! Carbon atoms cycle and recycle within Earth systems.
Carbon-transforming processes move carbon atoms among pools.
If carbon atoms leave one pool, they must enter another pool. Atoms never disappear.
The Energy Flow Question:
How does energy flow through environmental systems?
Energy flows! Energy flows through environmental systems.
Carbon-transforming processes change energy from:
Sunlight to
Chemical energy to
Work or motion energy and eventually to
Heat radiated into space.
The Stability and Change Question:
How do carbon fluxes change the size of carbon pools?
Fluxes change pools! A pool size only changes when fluxes into and out of that pool are unbalanced.
The carrying capacity is an upper limit to the photosynthesis flux in every ecosystem
Explain that the Ecosystems Unit the focus will be on tracing matter and energy at the large scale.
Slides to emphasize that the Ecosystems Unit is focusing on a larger scale than previous organismal Units. The focus is still on tracing matter and energy, but the Four Questions are slightly different. You may wish to print the Large Scale Four Questions Poster to post in the classroom and refer to throughout the Unit.
Accommodation: Print the Large Scale Four Questions Poster. Also, provide students with a copy of the Large Scale Four Questions Handout. Have a class set in your classroom for use in the classroom only.

15. How are pools and the biomass pyramid related?
Atmosphere CO2
Carnivores organic carbon
Herbivores organic carbon
Producers organic carbon
Soil
Organic Carbon
Make connections between the Carbon Pools and the Biomass Pyramid.
Tell students that in previous activities they discussed the biomass pyramid. This divides the meadow ecosystem into three simple pools: Producers, Herbivores, and Carnivores.
Use Slide 15 to show how the pools and the biomass pyramid relate to each other. Ask students to identify differences between the two.
See if they notice that in the biomass pyramid the atmosphere is not represented, yet this is a key pool in our new ecosystem model!