1. Ecosystems Unit Activity 5.1 Pools in Other Ecosystems
Carbon: Transformations in Matter and Energy
Environmental Literacy Project Michigan State University
Ecosystems Unit Activity 5.1 Pools in Other Ecosystems

2. Let’s look at organic carbon pools in real ecosystems
Cornfield
Prairie
Have students predict which ecosystems have the largest organic carbon pools.
Use slide 6 to introduce four different types of ecosystems.
Image Credit: Hannah Miller
Desert
Forest

3. Which ecosystem do you think has the most organic carbon?
Have students consider two ecosystems at a time—prairie vs. desert and cornfield vs. forest—during Slides Students should write down a prediction on a piece of paper. Ask: Which ecosystem will have the most organic carbon? They could also predict which pool they think will be the largest.
Image Credit: Hannah Miller
Prairie
Desert

4. Notice the pattern of organic carbon pool sizes
Atmosphere CO2
Carnivores organic carbon
Herbivores organic carbon
Producers organic carbon
Soil
organic carbon 30
190 2
0.1
Have students consider two ecosystems at a time—prairie vs. desert and cornfield vs. forest—during Slides Students should write down a prediction on a piece of paper. Ask: Which ecosystem will have the most organic carbon? They could also predict which pool they think will be the largest.
Image Credit: Hannah Miller
Prairie

5. Notice the pattern of organic carbon pool sizes
Atmosphere CO2
Carnivores organic carbon
Herbivores organic carbon
Producers organic carbon
Soil
Organic Carbon 3 56
0.4
0.02
Have students consider two ecosystems at a time—prairie vs. desert and cornfield vs. forest—during Slides Students should write down a prediction on a piece of paper. Ask: Which ecosystem will have the most organic carbon? They could also predict which pool they think will be the largest.
Image Credit: Hannah Miller
Desert

6. Desert
Prairie
Atmosphere CO2
Carnivores organic carbon
Herbivores organic carbon
Producers organic carbon
Soil
Organic Carbon 3 56
0.4
0.02
Atmosphere CO2
Carnivores organic carbon
Herbivores organic carbon
Producers organic carbon
Soil
Organic Carbon 30
190 2
0.1
0.1 2
Have students consider two ecosystems at a time—prairie vs. desert and cornfield vs. forest—during Slides Students should write down a prediction on a piece of paper. Ask: Which ecosystem will have the most organic carbon? They could also predict which pool they think will be the largest.
190 30

7. Which ecosystem do you think has the most organic carbon?
Have students consider two ecosystems at a time—prairie vs. desert and cornfield vs. forest—during Slides Students should write down a prediction on a piece of paper. Ask: Which ecosystem will have the most organic carbon? They could also predict which pool they think will be the largest.
Image Credit: Hannah Miller
Cornfield
Forest

8. Notice the pattern of organic carbon pool sizes
Atmosphere CO2
Carnivores organic carbon
Herbivores organic carbon
Producers organic carbon
Soil
Organic Carbon 14
127 1
0.1
Have students consider two ecosystems at a time—prairie vs. desert and cornfield vs. forest—during Slides Students should write down a prediction on a piece of paper. Ask: Which ecosystem will have the most organic carbon? They could also predict which pool they think will be the largest.
Image Credit: Hannah Miller
Cornfield

9. Notice the pattern of organic carbon pool sizes
Atmosphere CO2
Carnivores organic carbon
Herbivores organic carbon
Producers organic carbon
Soil
Organic Carbon 80
118 9
0.7
Have students consider two ecosystems at a time—prairie vs. desert and cornfield vs. forest—during Slides Students should write down a prediction on a piece of paper. Ask: Which ecosystem will have the most organic carbon? They could also predict which pool they think will be the largest.
Image Credit: Hannah Miller
Forest

10. Forest
Cornfield
Atmosphere CO2
Carnivores organic carbon
Herbivores organic carbon
Producers organic carbon
Soil
Organic Carbon 80
118 9
0.7
Atmosphere CO2
Carnivores organic carbon
Herbivores organic carbon
Producers organic carbon
Soil
Organic Carbon 14
127 1
0.1
0.1 1
Have students consider two ecosystems at a time—prairie vs. desert and cornfield vs. forest—during Slides Students should write down a prediction on a piece of paper. Ask: Which ecosystem will have the most organic carbon? They could also predict which pool they think will be the largest.
127 14

11. Desert
Prairie
Forest
Cornfield
Atmosphere CO2
Carnivores organic carbon
Herbivores organic carbon
Producers organic carbon
Soil
Organic Carbon
Atmosphere CO2
Carnivores organic carbon
Herbivores organic carbon
Producers organic carbon
Soil
Organic Carbon
Atmosphere CO2
Carnivores organic carbon
Herbivores organic carbon
Producers organic carbon
Soil
Organic Carbon
Atmosphere CO2
Carnivores organic carbon
Herbivores organic carbon
Producers organic carbon
Soil
Organic Carbon
0.7
0.1
0.02
0.1 9 1 2
0.4
Compare four different ecosystems.
Use Slide 15 of the presentation to prompt students to write down as many observations as they can about the differences between the four ecosystems.
The main thing they should notice is that the relative sizes of ecosystem pools is the same across ecosystems: the largest pool is the soil organic carbon, followed by producers, then herbivores, then carnivores.
They may also notice that soil organic carbon is the largest pool in the prairie, but the forest has the most organic carbon in producers. You may use this opportunity to talk about how pool sizes are different because of the history of the site (lots of grasses growing and dying increase the soil organic carbon pool) and the size of the organisms that live there (trees versus corn).
Image Credit: Hannah Miller
118 80
127 14 30 56 3
190

12. What pattern did you notice in all of the ecosystems?
Soil contains the largest pool of organic carbon
The producers pools is bigger than the herbivores pool
The herbivores pool is bigger than the carnivores pool
Carnivores are the smallest pool of organic carbon
Total mass of
carnivores = 100 kg
herbivores = 1000 kg
plants = 10,000 kg
Use Slide 16 to discuss patterns that they noticed across the different ecosystems and how that results in the shape of the organic matter pyramid.

13. Why does this pattern exist in ecosystems?
So far we have identified an important pattern in the relative sizes of the carbon pools in different ecosystems that results in the shape of the organic matter pyramid but an important question remains:
What are the processes that cause this pattern?
Discuss unanswered questions.
Use Slide 17 to remind students that they have not yet explained what processes cause the patterns that they have observed that result in the organic matter pyramid. They will develop an explanation in Lesson 3.