Activity 3.1: Large-Scale Four Questions (20 min)

Show Slides 3 and 4 of the 3.1 Large-Scale Four Questions PPT to remind students of the Organic Matter Pyramid as an important pattern in most terrestrial ecosystems.

Ask students to review their questions that they still have about the organic matter pyramid and matter and energy in ecosystems. They can review questions they asked on the 2.3 Evidence-Based Arguments Tool for the Meadow Simulation or the Driving Questions Board.

Use Slide 5 to suggest why questions about patterns in organic matter pools.

Give each student a copy of the Large-Scale Four Questions Handout with Checklist.

Use Slide 6 to introduce and discuss the Large-Scale Four Questions, discussing how they are similar to the Three Questions from previous Carbon TIME units, but at the Ecosystem scale.

Use Slide 7 to remind students that they already know an answer to the Carbon Pools Question for meadows and other terrestrial ecosystems.

Use Slides 8-12 to help students make connections between the Carbon Cycling and Energy Flow Questions and carbon transforming processes that they have studied in previous Carbon TIME units.

• Use Slide 8 to have student read the Carbon Cycling and Energy Flow Questions on their handouts and discuss how they are like the Matter Movement, Matter Change, and Energy Change Questions that they used in previous Carbon TIME Discuss the Rules to Follow and Evidence We Can Observe portions of the handout.
• Use Slides 9-13 to review how all organisms use their food in two ways: materials for growth (biosynthesis) and energy (cellular respiration).
  • Use Slide 11 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 that add to soil organic carbon.
  • Use Slides 12 and 13 to discuss what happens to soil organic carbon: some is digested by decomposers and used for growth and cell respiration; some is not digested and remains in the soil (as humus).

Note: It is important that students recognize that living organisms do not create or destroy matter or energy but only transform them in biological processes.

Use Slide 14 to summarize the biological processes that connect carbon pools. Point out to students that feces and death move but do not transform carbon.