Biology · Grade 12

Active learning ideas

Ecological Succession and Disturbances

Active learning helps students grasp ecological succession because the topic involves dynamic, staged changes that are best visualized through hands-on models and real-world examples. Watching a tray of soil develop over weeks or mapping disturbances on aerial photos makes abstract concepts concrete and memorable for students who learn by doing and seeing.

• Ontario Curriculum Expectations
• HS-LS2-6

• 35–50 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Case Study Analysis
• 45 min · Small Groups

Tray Simulation: Primary Succession

Provide trays with bare rocks, lichens (moss substitute), soil builders, and seeds. Small groups add layers weekly, watering and recording species establishment over 4-6 weeks. Compare growth rates and discuss pioneer roles. Accelerate with heat lamps if time is short.

Differentiate between primary and secondary succession.

Facilitation Tip

During the Tray Simulation, remind students to record observations daily to track changes in soil depth and pioneer species establishment, reinforcing the slow pace of primary succession.

What to look for

Provide students with two scenarios: Scenario A describes a lava flow, and Scenario B describes a clear-cut forest. Ask students to write one sentence identifying the type of succession each scenario will undergo and one key difference in the initial colonizing species.

• Analyze
• Evaluate
• Create
• Decision-Making
• Self-Management

Activity 02

• Jigsaw
• 50 min · Small Groups

Jigsaw: Disturbance Analysis

Assign groups one disturbance type (fire, flood, logging) with Ontario examples and data sets. Each group analyzes impacts on succession stages, then rotates to teach peers. Synthesize findings in a class chart on community changes.

Analyze how disturbances, such as fires or floods, can influence community structure.

Facilitation Tip

For the Jigsaw Case Studies, assign each group a unique disturbance type to ensure diverse examples are shared, preventing overlap and deepening understanding of varied recovery pathways.

What to look for

Pose the question: 'How can a large wildfire, while destructive, actually benefit a forest ecosystem in the long term?' Guide students to discuss concepts like seed germination, nutrient cycling, and the creation of habitat diversity.

• Understand
• Analyze
• Evaluate
• Relationship Skills
• Self-Management

Activity 03

• Case Study Analysis
• 35 min · Pairs

Prediction Cards: Post-Disturbance Timeline

Distribute species cards with traits (pioneer, intermediate, climax). Pairs sequence them after a simulated disturbance, justifying choices based on tolerances. Class votes and revises timelines using real recovery data from Parks Canada reports.

Predict the long-term ecological changes following a major environmental disturbance.

Facilitation Tip

When using Prediction Cards, have students justify their timelines in pairs before revealing the correct sequence, fostering discussion and correcting misconceptions in the moment.

What to look for

Present students with images of different stages of succession (e.g., bare rock with lichen, young trees in a field, mature forest). Ask them to label each image with the correct stage of succession (primary, secondary, climax) and briefly explain their reasoning.

• Analyze
• Evaluate
• Create
• Decision-Making
• Self-Management

Activity 04

• Case Study Analysis
• 40 min · Whole Class

Patch Dynamics Map: Whole Class Model

On a large poster, map an ecosystem grid. Students add disturbance events and track succession patches over simulated years. Discuss how spatial variation creates mosaics, using markers for species shifts.

Differentiate between primary and secondary succession.

What to look for

Provide students with two scenarios: Scenario A describes a lava flow, and Scenario B describes a clear-cut forest. Ask students to write one sentence identifying the type of succession each scenario will undergo and one key difference in the initial colonizing species.

• Analyze
• Evaluate
• Create
• Decision-Making
• Self-Management

A few notes on teaching this unit

Teach this topic by starting with local examples students recognize, like forest fires or farmland abandonment, to build relevance. Avoid presenting succession as a linear progression toward a single climax, as research shows ecosystems are dynamic and disturbance-dependent. Use peer comparisons and real data to challenge oversimplified ideas about stability and recovery.

Successful learning looks like students accurately distinguishing between primary and secondary succession, explaining how disturbances shape ecosystems, and using evidence from simulations or case studies to support their claims. They should also recognize that climax communities are not static but shift with ongoing disturbances.

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Watch Out for These Misconceptions

• During the Patch Dynamics Map activity, watch for students who assume ecological succession always ends in a single, unchanging climax community.

  Use the Patch Dynamics Map to overlay aerial photos of Ontario landscapes, asking students to identify patches at different seral stages and explain why these mosaics persist due to frequent disturbances.

• During the Tray Simulation activity, watch for students who believe primary and secondary succession follow identical processes and timelines.

  Have students time the colonization of bare rock versus disturbed soil trays, then compare pioneer species and soil depth differences to highlight the slower, harsher conditions of primary succession.

• During the Jigsaw Case Studies activity, watch for students who assume anthropogenic disturbances always harm ecosystems more than natural ones.

  Use the case studies to guide students in comparing human actions like clear-cutting to natural events like wildfires, then facilitate a debate using evidence from their research to weigh context-dependent effects.

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Methods used in this brief

• Case Study Analysis
• Jigsaw