Idea for Use in the Classroom

Prior to introducing the infographic, review what students already know of ecosystem food chains and trophic levels. Provide students with a copy of the infographic and have them compare and contrast each trophic level. Encourage students to focus on changes in population size at increasing trophic levels. Connect student observations to energy flow by focusing on the blue arrows within the pyramid. Ask: What do the blue arrows represent and how do they change at increasing trophic levels? How are they related to the orange arrows? Then prompt students to consider how the observed changes between trophic levels relate to these arrows.

Students can put their observations in the context of energy using this encyclopedia article about energy transfer and energy transformations. Then have students use this article to explain how the infographic exemplifies the statement: Energy cannot be created or destroyed, but it can be transferred and transformed. Students can use their understanding to label the infographic with the types of energy within the ecosystem (solar, chemical, heat, kinetic) and the various energy transfers and transformations occurring. Challenge students to use their understanding of energy flow to deduce why there are fewer top predators compared to primary consumers within the ecosystem.

Conclude by having students explain the role of solar energy within the ecosystem. Then explain that some ecosystems do not receive any sunlight, such as those existing in the deep ocean near hydrothermal vents. Challenge students to hypothesize from where these ecosystems derive energy and then use outside research to verify their predictions.