Activity 4.4: Seasonal Changes and Ecosystem Disturbances (40 min)

Show Slide 3. Review what students concluded from the Constant and Changing Fluxes Models.

• Show Slide 4. Pass out the 4.4 Computer Model for Seasons and Disturbances Handout to each student.
• In partners or as a whole class, have students read the handout until Part A.
• Discuss what students learned from the first two models and how Model 3 is different.

Pass out 4.4 Computer Model for Seasons and Disturbances Worksheet to each student.

• Have students follow the directions on 4.4 Computer Model for Seasons and Disturbances Handout to complete Part A and B on their worksheet.
• (Optional) Use Slides 5-11 to go through Part A and B with the students. The questions can be completed together using the slides.

Have students follow the directions on 4.4 Computer Model for Seasons and Disturbances Handout to complete Part C on their worksheet.

• (Optional) Use Slide 12 to go through Part C with the students.

Show Slide 13.

• Have students read the last section of 4.4 Computer Model for Seasons and Disturbances Handout about disturbances in real ecosystems.
• Have students answer Part D of their worksheet.

Show Slide 14. Have students share and discuss their answers to questions.

Pass out the 4.4 Fire Reading.

Have student read 4.4 Fire Reading 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 with the class what they found interesting and any questions they have.

Show slide 15 of the 4.4 Seasonal Changes and Ecosystem Disturbances PPT.

• Pass out a Learning Tracking Tool for Ecosystems to each student.
• Have students write the activity chunk name in the first column, "Carbon Pools and Fluxes, Explainers"
• 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 Ecosystems for future activities.
• Example Learning Tracking Tool