Forest disturbance regimes help Grade 6 science students explore how fire, insect outbreaks, windthrow, flooding, and human activities change forest ecosystems. This Alberta-focused worksheet connects disturbance characteristics with regeneration, succession, and habitat changes, helping students reason about why forests respond differently to different events.

How Disturbances Change Forests

A disturbance is an event that changes an ecosystem, but its effects depend on more than the type of event. Students examine three important characteristics: frequency, or how often a disturbance occurs; intensity, or how strong its effects are; and spatial extent, or how much area it affects.

The reading passage uses Alberta's boreal forests to introduce fire cycles, mountain pine beetle outbreaks, and the openings that disturbances can create. Students consider how surviving organisms, newly available space, and changing habitat conditions can influence regeneration and succession—the gradual change in an ecosystem's community over time. They also explore how climate and land use may alter disturbance patterns.

Apply the Concepts to Forest Scenarios

The worksheet moves from reading and vocabulary into application. Multiple-choice questions ask students to recognize disturbance events, interpret frequency, intensity, and spatial extent, and explain why scientists study disturbance regimes. True-or-false statements check scientific understanding, including the difference between windthrow and insect outbreaks. Short-answer prompts invite students to describe regeneration opportunities and explain why scientists compare disturbance effects across landscapes.

A labeled diagram activity and a categorization task provide additional ways to interpret and organize information about forest disturbances. A short-note section gives students space to record key ideas for later review.

Included with the Worksheet

• ✔️ A reading passage about forest disturbance and ecosystem change
• ✔️ Student practice covering multiple-choice, true-or-false, and short-answer responses
• ✔️ A labeled diagram activity and categorization task
• ✔️ Student Notes lines at the bottom of the worksheet
• ✔️ A separate Answer Key PDF for checking responses
• ✔️ A Teacher Guide within the Answer Key PDF, with learning objectives, teaching tips, discussion questions, and common mistakes

Use It in Your Trees and Forests Unit

Use this Grade 6 forest ecology worksheet after introducing ecosystem change, as independent classroom practice, or for review before a unit assessment. The passage establishes the key terms, while the questions give students opportunities to apply them to examples such as windthrow, flooding, boreal forest fires, and mountain pine beetle outbreaks.

The Teacher Guide supports preparation and follow-up discussion. Ask students to compare a small, low-intensity disturbance with a larger event, predict how each might affect regeneration, and explain why disturbance effects can vary from one landscape to another. The answer key makes it easier to review responses and identify concepts that may need further explanation.

Build Evidence-Based Ecological Thinking

Rather than treating every disturbance as having the same result, students practise connecting event characteristics with possible ecosystem outcomes. This Alberta forest science resource develops scientific vocabulary, reading comprehension, classification, diagram interpretation, and written reasoning while keeping the focus on how forests change over time.