Science · Grade 6 · Life Systems: Diversity and Survival · Term 1

Threats to Biodiversity

Students investigate major threats to biodiversity, including habitat loss, pollution, and invasive species.

• Ontario Curriculum Expectations
• MS-LS2-4

About This Topic

Threats to biodiversity encompass habitat loss, pollution, and invasive species, key factors reducing species diversity in ecosystems. Grade 6 students explore how human activities like urbanization fragment habitats, chemical runoff pollutes waterways, and non-native species outcompete locals. These investigations align with Ontario's Life Systems strand, fostering understanding of interconnected ecosystems and human impacts.

Students compare pollution effects on aquatic life, such as algal blooms from fertilizers, versus terrestrial harm like soil contamination. They assess invasive species consequences, from ecological disruptions like zebra mussels clogging pipes to economic costs in fisheries. This builds skills in evidence-based analysis and systems thinking essential for environmental science.

Active learning shines here because threats are complex and often invisible in daily life. Simulations of habitat fragmentation or role-plays of species interactions make causes and effects concrete. Collaborative projects tracking local invasives encourage ownership and reveal real-world connections, deepening retention and motivating action.

Key Questions

1. Explain how human activities contribute to habitat loss and fragmentation.
2. Compare the impacts of different types of pollution on aquatic and terrestrial ecosystems.
3. Assess the ecological and economic consequences of invasive species in a new environment.

Learning Objectives

• Explain how human activities, such as deforestation and urbanization, lead to habitat loss and fragmentation.
• Compare the effects of different types of pollution, including chemical, plastic, and noise pollution, on aquatic and terrestrial ecosystems.
• Analyze the ecological and economic consequences of invasive species, using examples like the zebra mussel or the emerald ash borer.
• Classify human actions as either contributing to or mitigating threats to biodiversity.

Before You Start

Ecosystems and Food Webs

Why: Students need to understand the interconnectedness of living things within an ecosystem to grasp how threats to one part affect the whole.

Producers, Consumers, and Decomposers

Why: Understanding the roles of different organisms in an ecosystem is foundational to recognizing how invasive species or pollution disrupt these roles.

Key Vocabulary

Habitat Fragmentation	The process by which large, continuous habitats are broken down into smaller, isolated patches, often due to human development.
Pollution	The introduction of harmful substances or products into the environment, negatively affecting ecosystems and living organisms.
Invasive Species	A non-native species that spreads aggressively into a new environment, often outcompeting native species for resources.
Biodiversity	The variety of life in a particular habitat or ecosystem, encompassing the diversity of species, genes, and ecosystems.

Watch Out for These Misconceptions

Common Misconception

Pollution only harms aquatic ecosystems.

What to Teach Instead

Many students overlook terrestrial effects like acid rain damaging forests. Demonstrations with model ecosystems show cross-impacts, while group discussions reveal connections between air and water pollution, helping revise incomplete views.

Common Misconception

Invasive species have no predators so they always dominate.

What to Teach Instead

Students may ignore factors like disease or competition. Role-play simulations let them test scenarios, fostering debate that clarifies nuanced dynamics and builds accurate mental models through peer correction.

Common Misconception

Habitat loss is mainly from logging, not everyday human actions.

What to Teach Instead

Urban sprawl and agriculture often go unnoticed. Mapping activities link personal habits to fragmentation, with collaborative analysis showing subtle cumulative effects and encouraging broader perspectives.

Active Learning Ideas

Simulation Game: Habitat Loss Model

Provide students with paper ecosystems marked into habitat patches. Have pairs remove sections to simulate deforestation or roads, then place species cards and track population changes over 'generations' by moving cards. Discuss fragmentation effects on migration.

35 min·Pairs

Stations Rotation: Pollution Impacts

Set up stations for air, water, and soil pollution: use food coloring in water for runoff, smoke in jars for air, and oil in dirt for soil. Small groups test effects on model organisms like beans or brine shrimp, record data, and rotate. Conclude with class share-out.

45 min·Small Groups

Case Study Analysis: Invasive Species Debate

Assign invasive species like Asian carp or garlic mustard to small groups. Groups research ecological and economic impacts using provided articles, prepare pros/cons arguments, then debate whole class. Vote on management strategies.

50 min·Small Groups

Field Investigation: Local Threats

Students survey schoolyard or nearby park for signs of habitat loss, pollution, or invasives using checklists. In pairs, photograph evidence, categorize threats, and propose solutions in a shared class report.

30 min·Pairs

Real-World Connections

• Conservation biologists work in national parks and protected areas to monitor wildlife populations and implement strategies to combat habitat loss and invasive species.
• Environmental engineers design wastewater treatment plants and develop methods to reduce industrial pollution, protecting rivers and lakes vital for communities and aquatic life.
• Urban planners consider the impact of new developments on local ecosystems, aiming to minimize habitat fragmentation and preserve green spaces within cities.

Assessment Ideas

Discussion Prompt

Pose the question: 'Imagine you are a city planner. How would you balance the need for new housing with the protection of local wildlife habitats?' Facilitate a class discussion where students share their proposed solutions and justify their choices.

Quick Check

Provide students with short case studies describing different environmental scenarios (e.g., a new highway cutting through a forest, a factory releasing chemicals into a river, a garden centre selling a popular non-native plant). Ask students to identify the primary threat to biodiversity in each case and briefly explain its impact.

Exit Ticket

On a slip of paper, ask students to write down one human activity that threatens biodiversity and one action they or their community could take to reduce that threat. Collect these to gauge understanding of cause and effect.

Frequently Asked Questions

How to teach threats to biodiversity in grade 6 Ontario science?

Focus on habitat loss, pollution, and invasives through Ontario curriculum expectations. Use local examples like Great Lakes zebra mussels. Integrate key questions on human contributions via investigations that build evidence analysis skills. Hands-on models and case studies ensure engagement and depth.

What are common threats to biodiversity for students?

Habitat loss from development fragments ecosystems, pollution like plastics harms food chains, and invasive species disrupt balances. Students assess impacts via comparisons: aquatic vs. terrestrial pollution, or ecological vs. economic costs. Real Canadian cases, such as emerald ash borer, make concepts relevant.

How can active learning help students understand threats to biodiversity?

Active approaches like pollution simulations or invasive species debates turn abstract threats into observable events. Students manipulate models of habitat loss, debate solutions, and survey local sites, revealing cause-effect chains. This collaboration uncovers misconceptions, boosts retention, and sparks environmental stewardship through personal connections.

What activities address habitat loss and invasive species?

Build fragmentation models with grids and species tokens to show isolation effects. For invasives, role-play competitions or analyze Canadian case studies like purple loosestrife. These pair inquiry with discussion, aligning to standards while developing systems thinking and evaluation skills.