Activity 1.3: Carbon Pools (20 min)

Ask students to share their ideas and questions about ecosystems. Students will likely have heard the word “ecosystem” before. You may want to tell them that the word combines two Greek root words that mean “house” (eco) and “to combine” (system).

• What ideas do they have about what defines an ecosystem?
• Show students Slide 3 from 3 Carbon Pools PPT to define an ecosystem.
• Ask if the students can name some ecosystem types (desert, forest, prairie, tundra, etc.).

Accommodation: Before having students come up with examples of ecosystems, give an example so students have a frame of reference (e.g., desert, rainforest).

Have students locate a meadow ecosystem in the aerial photo in Slide 4 and then show Slide 5 which outlines the meadow ecosystems in red. Note: the meadow image on Slides 4 and 5 is from 44°00'19.99" N 85°58'59.62" W in Manistee National Forest. Historical imagery of this meadow can be viewed in Google Earth. It is likely a man-made meadow since it didn’t exist before 2009.

• Show Slide 6. Have students look at the pictures of meadows and identify features of a meadow ecosystem.
• Have students list all of the living things that they think may live in a meadow and record them on the board or on Slide 7.

Accommodation: Before having students identify a meadow on the aerial map, go over what a meadow is and describe its natural features (e.g., long grasses, wildflowers, open spaces).

Provide as much as you think you need to without giving too much away. Allow students time to draw or list the living things that live in a meadow ecosystem before compiling a class list.

Have students list all the places where they would find carbon in an ecosystem in Slide 8 (or on the board). Examples include plant and animal tissues, soil (dead material as well as microorganisms) and air.

• Remind students that in the Systems & Scale Unit they learned that organic carbon is bonded to hydrogen or other carbon atoms, while inorganic carbon is not. Organic molecules (such as C₆H₁₂O₆) have high energy bonds and inorganic molecules (such as CO₂) do not.
• On Slide 9, have students list the types of molecules they would find the carbon atoms in, and which of the molecules are organic versus inorganic.
• Go back to Slide 8 (or the board) and put a star next to all of the places where carbon is organic. Reminder: the inorganic carbon is in carbon dioxide in the atmosphere. All of the other carbon is organic.

Accommodation: Before going into too much depth about carbon and where to find inorganic and organic carbon, prepare or copy and paste some of the slides from the Systems and Scale Unit (5.3 Organic vs. Inorganic PPT Slides 15-20) to provide concrete visuals of the different ways carbon is present in the living world.

Use the picture of a meadow in Slides 10-13 to identify producers, herbivores, carnivores and decomposers in an ecosystem. Introduce the role of each of those type of organisms.

Use the animation on Slides 14-16 to show how scientists categorize organisms into particular “pools” of carbon.

• 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.

Show Slide 17 of the 1.3 Carbon Pools PPT. Have students partner-read the 1.3 Carbon Pools reading which explains how carbon pools are identified and measured. Read using the Questions, Connections, Questions Student Reading Strategy. See the Questions, Connections, Questions Reading Strategy Educator Resource document for information about how to engage students with this strategy.

• After pairs are finished reading, have students share their ideas about the italicized questions at the end of the reading.

Show Slide 18 of the 1.3 Carbon Pools PPT to discuss where the class is moving in the Ecosystems Unit.

Show 19 of the 1.3 Carbon Pools PPT.

• Pass out a Learning Tracking Tool for Ecosystems for Ecosystems to each student.
• Have students write the activity chunk name in the first column, "Expressing Ideas and Questions" and their role as the “Questioner.”
• Have a class discussion about what students did during the activity chunk. When you come to consensus as a class, have students record the answer in the second column of the tool.
• Have a class discussion about what students figured out during the activity chunk that will help them in answering the unit driving question. When you come to consensus as a class, have students record the answer in the third column of the tool.
• Have a class discussion about what students are wondering now that will help them move towards answering the unit driving question. Have students record the questions in the fourth column of the tool.
• Have students keep their Learning Tracking Tool for future activities.
• Example Learning Tracking Tool

Have students draw an image of an ecosystem of their choice during step 3 and list the types of organisms that might live there. Then during step 5, have students identify producers, herbivores, carnivores and decomposers in the ecosystem they drew. If they don’t have an organism in each role, encourage them to draw a new organism to play that role in their ecosystem.