Directions 1. Use the instructional model to show students where they are in the course of the unit. Display slide 2 of the 5.3a Ecosystem Review PPT. 2. Have a class discussion about the elements of an ecosystem. Show Slide 3. Have a whole class discussion about what makes an ecosystem. Focus on the question: what elements does an ecosystem need? Make sure students note the need for producers, herbivores, carnivores, soil carbon, carbon dioxide, and sun. 3. Students work in groups on their ecosystem posters. Display Slide 4. Divide students into groups of four. Pass out a 5.3a Ecosystem Posters Handout and a poster to each group. Have each group choose which ecosystem they will focus on, making sure that at least one group is doing each of the ecosystems. Have students to continue to work through the questions on 5.3a Ecosystem Posters Handout as they complete their posters. All questions will be completed on each poster. 4. Students do a gallery walk of the posters. Display Slide 5. Display each of the posters around the room. Have groups walk around the room and look at each poster. While at each poster, students should discuss the questions on Slide 5 with their group. 6. Have a whole class review discussion. Using Slide 6, have a whole class discussion about how carbon cycles and energy flows in ecosystems using the carbon cycling diagram.