Biology · 9th Grade

Active learning ideas

Ecological Succession and Disturbance

Ecological succession is a dynamic process that benefits from active, visual learning because students often struggle to connect abstract timelines with real-world changes. Hands-on activities like sequencing photos or running simulations make abstract concepts such as pioneer species and soil formation concrete and memorable.

• Common Core State Standards
• HS-LS2-6
• HS-LS4-5

• 25–45 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Timeline Challenge
• 40 min · Small Groups

Photo Sequencing: Succession Timeline

Small groups receive 8 to 10 photographs taken at different times after a specific disturbance (Mount St. Helens volcano sites or Yellowstone post-1988 fire areas). Students arrange the photos in chronological order, justify the sequence using ecological logic, and label each photo with the dominant functional group and its role in facilitating the next stage.

Differentiate between primary and secondary succession.

Facilitation Tip

During Photo Sequencing, circulate and ask students to justify their ordering by pointing to visual evidence of soil formation or species presence in each image.

What to look for

Present students with two scenarios: one describing colonization of a new lava flow, the other an abandoned farm field. Ask students to write one sentence identifying which is primary succession and one sentence identifying which is secondary succession, and why.

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

Activity 02

• Simulation Game
• 45 min · Small Groups

Simulation Game: Succession Dice Game

Students represent different plant species with specific colonization, growth, and displacement rules encoded on cards. Each round, dice rolls determine whether each species establishes, grows, or is displaced. The class tracks community composition over 20 rounds, graphs the proportional representation of each species, and identifies the successional trajectory that emerges.

Explain how pioneer species modify the environment for later arrivals.

Facilitation Tip

For the Succession Dice Game, model fair play and timekeeping to ensure all groups experience the probabilistic nature of species replacement.

What to look for

Pose the question: 'Is the idea of a permanent climax community still valid today?' Facilitate a class discussion where students cite examples of ongoing disturbances and ecosystem resilience to support their arguments.

• Apply
• Analyze
• Evaluate
• Create
• Social Awareness
• Decision-Making

Activity 03

• Timeline Challenge
• 40 min · Small Groups

Collaborative Debate: Is the Climax Community Concept Accurate?

Students read two short competing passages: one presenting the classical climax community model and one presenting the modern non-equilibrium disturbance perspective. Small groups create a two-column evidence chart, then participate in a structured class discussion to develop a nuanced position on whether 'climax community' is a useful scientific concept.

Critique the concept of a 'climax community' in light of ongoing environmental change.

Facilitation Tip

In the Climax Community Debate, assign roles to students before the activity to ensure balanced participation and structured argumentation.

What to look for

Provide students with images depicting different stages of plant growth on a bare rock surface. Ask them to label the images in the correct order of primary succession and identify one pioneer species that might be present in the earliest stage.

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

Activity 04

• Think-Pair-Share
• 25 min · Pairs

Think-Pair-Share: Classifying Succession Types

Students receive six disturbance scenarios (volcanic eruption, forest fire, glacier retreat, agricultural abandonment, hurricane, quarry abandonment) and classify each as primary or secondary succession. They compare predictions with a partner, resolve differences by applying the soil criterion, and then predict the first three functional groups to colonize each site.

Differentiate between primary and secondary succession.

What to look for

Present students with two scenarios: one describing colonization of a new lava flow, the other an abandoned farm field. Ask students to write one sentence identifying which is primary succession and one sentence identifying which is secondary succession, and why.

• Understand
• Apply
• Analyze
• Self-Awareness
• Relationship Skills

A few notes on teaching this unit

Teachers should emphasize that succession is directional but not rigid, and avoid reinforcing the idea of a single, permanent climax community. Research suggests students grasp succession better when they trace cause-and-effect chains, such as how lichens break down rock to form soil, which then supports mosses and grasses. Use frequent formative checks to correct misconceptions early, especially about pioneer species and soil development.

Students will articulate the differences between primary and secondary succession, explain how pioneer species alter the environment, and evaluate the concept of climax communities with supporting evidence. Success looks like students using specific terms correctly in discussions and applying their knowledge to novel scenarios.

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Watch Out for These Misconceptions

• During Photo Sequencing, watch for students assuming all succession ends in a forest.

  During Photo Sequencing, include images of climax communities from different US biomes (e.g., grassland, desert) and ask students to describe how climate shapes the endpoint of succession based on these visuals.

• During the Succession Dice Game, students may expect primary succession to happen faster because 'new' sounds easier.

  During the Succession Dice Game, explicitly compare the time scales for primary succession (e.g., 100 years per roll) and secondary succession (e.g., 10 years per roll) on the game board to highlight why secondary succession is typically faster.

• During the Think-Pair-Share activity, students might believe pioneer species destroy their habitat by making it unsuitable for themselves.

  During Think-Pair-Share, have students trace the mechanism of soil enrichment and nitrogen fixation by pioneer species, then link this to the competitive advantages of later species, using a provided case study on lichen and moss colonization.

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Methods used in this brief

• Timeline Challenge
• Simulation Game
• Think-Pair-Share