Food Webs and Energy Transfer

Active learning builds accurate mental models of food webs by letting students physically manipulate energy flows and trophic roles. Hands-on tasks turn abstract energy loss percentages into visible patterns, making the 10 percent transfer rule memorable.

• Year 6
• Science
• 4 activities
• 30 min–45 min

Learning Objectives

1. Analyze the impact of removing a specific producer or consumer on the stability of an Australian ecosystem's food web.
2. Create a detailed food web diagram for a chosen Australian habitat, accurately representing trophic levels and energy flow.
3. Explain the quantitative energy loss at each trophic level within a given food chain, using the 10% rule.
4. Classify organisms within a local ecosystem into producer, primary consumer, secondary consumer, tertiary consumer, or decomposer roles.
5. Evaluate the role of decomposers in nutrient cycling and their importance for ecosystem health.

Concept Mapping

⏱ 45 min·Small Groups

Card Sort: Build a Reef Food Web

Provide cards with Australian reef organisms, energy values, and links. In small groups, students sort into trophic levels, calculate energy at each step, and draw connections. Discuss adjustments after teacher feedback.

Prepare & details

Analyze how the removal of a top predator can affect all trophic levels in a food web.

Facilitation Tip: During Card Sort, circulate to prompt students to justify each organism’s placement using evidence from cards.

Setup: Tables with large paper, or wall space

Materials: Concept cards or sticky notes, Large paper, Markers, Example concept map

• Understand
• Analyze
• Create
• Self-Awareness
• Self-Management

Concept Mapping

⏱ 30 min·Pairs

Domino Effect: Predator Removal Simulation

Use dominoes or blocks labelled as trophic levels in a bush ecosystem. Students knock over a top predator block and observe chain reactions. Groups record predicted versus actual impacts on lower levels.

Prepare & details

Construct a detailed food web for a specific Australian ecosystem.

Facilitation Tip: In Domino Effect, allow students to test removal scenarios multiple times to observe cascading effects.

Setup: Tables with large paper, or wall space

Materials: Concept cards or sticky notes, Large paper, Markers, Example concept map

• Understand
• Analyze
• Create
• Self-Awareness
• Self-Management

Concept Mapping

⏱ 35 min·Pairs

Energy Pyramid Construction

Students layer foam or paper cutouts for trophic levels, adding decreasing energy amounts based on 10% rule. Pairs label producers to apex predators using local species, then present pyramids.

Prepare & details

Explain the concept of energy loss at each level of a food chain.

Facilitation Tip: For Energy Pyramid Construction, have students label each level with both energy percentages and organism examples from their chosen ecosystem.

Setup: Tables with large paper, or wall space

Materials: Concept cards or sticky notes, Large paper, Markers, Example concept map

• Understand
• Analyze
• Create
• Self-Awareness
• Self-Management

Concept Mapping

⏱ 40 min·Whole Class

Decomposer Role-Play

Assign roles as producers, consumers, and decomposers in a forest web. Whole class acts out energy flow and decay processes, with observers noting losses. Debrief on cycling.

Prepare & details

Analyze how the removal of a top predator can affect all trophic levels in a food web.

Facilitation Tip: During Decomposer Role-Play, provide props like gloves or magnifying lenses to emphasize the physical act of breaking down matter.

Setup: Tables with large paper, or wall space

Materials: Concept cards or sticky notes, Large paper, Markers, Example concept map

• Understand
• Analyze
• Create
• Self-Awareness
• Self-Management

Teaching This Topic

Teach this topic by starting with concrete models before abstract diagrams. Avoid premature use of terms like ‘trophic level’ until students experience energy flow through manipulatives; research shows this sequence reduces confusion. Use local examples to anchor understanding, but rotate them to prevent cultural disconnection. Emphasize energy dissipation as a unifying concept rather than isolated facts about organisms.

What to Expect

Students will correctly assemble energy pathways, quantify losses at each level, and explain why food chains shorten in complex webs. They will also articulate the roles of producers, consumers, and decomposers in Australian ecosystems.

Watch Out for These Misconceptions

Common Misconception

During Card Sort: Build a Reef Food Web, watch for students arranging organisms in single-file chains without branches.

What to Teach Instead

Circulate and ask, ‘Can this organism be eaten by more than one type of consumer? Where else does this energy go?’ to guide students to redraw overlapping pathways.

Common Misconception

During Energy Pyramid Construction, watch for students believing energy is recycled within the ecosystem.

What to Teach Instead

Point to the pyramid’s base and ask, ‘Where does the energy come from initially?’ to redirect focus to the sun and the one-way flow of energy loss.

Common Misconception

During Domino Effect: Predator Removal Simulation, watch for students assuming only predators hunt actively.

What to Teach Instead

Prompt students to sort organism cards into ‘hunts for food’ and ‘eats plants’ columns during the simulation to clarify herbivore and omnivore roles.

Assessment Ideas

Quick Check

After Card Sort: Build a Reef Food Web, collect student webs and check for correctly labeled arrows and trophic levels using a provided answer key.

Discussion Prompt

During Domino Effect: Predator Removal Simulation, listen for students to explain cascading effects on producers and decomposers using terms like ‘energy transfer’ and ‘population change’.

Exit Ticket

After Energy Pyramid Construction, collect pyramids and review for accurate labeling of energy loss percentages and Australian organism examples at each level.

Extensions & Scaffolding

• Challenge: Ask students to design an alternative food web for a different Australian ecosystem and calculate energy transfer percentages.
• Scaffolding: Provide pre-labeled organism cards with trophic level hints for students who struggle with classification.
• Deeper: Invite students to research how human activity (e.g., land clearing or invasive species) alters energy flow in their chosen ecosystem and present findings to the class.

Key Vocabulary

Trophic Level	The position an organism occupies in a food chain, indicating its source of energy. Examples include producers, primary consumers, and secondary consumers.
Producer	An organism, typically a plant or alga, that produces its own food using light energy through photosynthesis. They form the base of most food webs.
Consumer	An organism that obtains energy by feeding on other organisms. Consumers can be herbivores, carnivores, or omnivores, occupying different trophic levels.
Decomposer	An organism, such as bacteria or fungi, that breaks down dead organic material, returning essential nutrients to the ecosystem.
Energy Transfer Efficiency	The percentage of energy from one trophic level that is incorporated into the biomass of the next trophic level, typically around 10%.