Ecosystems and Biodiversity

Overview

This is Lesson 2 of 10 in the Manitoba Science Year Overview unit. Students investigate how organisms depend on one another and their environment by classifying local organisms and constructing a simple food web. Examples should come from the schoolyard, farm or pasture edge, wetland, or forest, with local First Nations and Métis knowledge included respectfully through community guidance and land-based learning.

Learning intentions

Students will be able to:

• Classify organisms using observable traits and ecological roles.
• Identify producers, consumers, and decomposers in a local ecosystem.
• Explain how energy moves through a food chain or food web.
• Describe one way organisms depend on one another.
• Suggest a responsible action that supports local biodiversity.

Success criteria

• I can classify an organism using observable evidence.
• I can build a food web with arrows showing the direction of energy flow.
• I can explain what may happen if one organism is removed.
• I can recommend one stewardship action and support it with observations.

Curriculum links

• Develop and use models to explain interactions among organisms and their environment.
• Plan and carry out observations, record evidence, and communicate scientific explanations.
• Explain patterns of interdependence, energy flow, biodiversity, and environmental change.
• Read informational text, use subject-specific vocabulary, write evidence-based explanations, and participate in collaborative discussions.

Lesson structure (60 minutes)

1. 0–7 minutes — Hook and prior knowledge Open with the ecosystem mystery hook. Display a local habitat image and ask: “What living things might be connected here, even if we cannot see the connections?” Students make a quick prediction with a partner, then share one organism and one possible connection. Record ideas without correcting them immediately.

2. 7–17 minutes — Build shared understanding Use the ecosystem vocabulary and energy-flow slides to introduce organism, species, habitat, population, community, producer, consumer, decomposer, predator, prey, and biodiversity. Emphasize that arrows show energy moving from the food source to the organism that eats it. Model: sunlight → grass → grasshopper → frog → hawk; decomposers return nutrients to the soil.

3. 17–30 minutes — Organism-role sort In groups of three or four, students use the Food Web Interaction Cards to identify organism roles and relationships. Ask groups to justify two choices using observable traits or known eating relationships. Circulate and prompt: “What evidence supports your classification?” and “Could this organism have more than one relationship?”

4. 30–45 minutes — Construct a food web Distribute the local ecosystem food-web investigation sheet. Groups select a familiar habitat and draw at least five organisms, including a producer and decomposer. They connect organisms with arrows, label predator-prey relationships, and write two sentences explaining energy flow and interdependence. Students may use photographs, classroom specimens, or remembered observations rather than collecting living organisms.

5. 45–53 minutes — Change and stewardship discussion Use the food-web change and stewardship slides to present a scenario such as loss of flowering plants, introduction of an invasive plant, or pesticide use near a habitat. Groups discuss: “Which organisms are affected first?” and “What evidence would we need?” They propose one practical stewardship action, such as planting native flowering species, protecting nesting areas, or avoiding disturbance.

6. 53–60 minutes — Share and assess Groups briefly display their food webs and explain one connection and one possible human impact. Complete the final reflection on the local ecosystem food-web investigation sheet: “One organism depends on ___ because ___,” and “A responsible action is ___ because ___.” Collect sheets for formative assessment.

Resources

• the ecosystem investigation slide deck
• the local ecosystem food-web investigation sheet
• the Food Web Interaction Cards
• Local habitat photographs or teacher-selected images
• Optional real specimens, such as leaves, seeds, or feathers
• Chart paper or whiteboard
• Markers, pencils, and colored pencils
• String or yarn for a large class food web
• Local community or cultural guidance, where available

Assessment

• Observe group classification and listen for accurate use of producer, consumer, decomposer, predator, prey, habitat, and biodiversity.
• Check food webs for scientifically sensible connections, correctly directed energy arrows, and explanations supported by observations.
• Use the reflection to identify students who can explain interdependence and propose a realistic stewardship action.

Differentiation

• Provide picture cards, labeled photographs, a word bank, and sentence frames such as “The ___ is a consumer because ___” and “If ___ disappeared, ___ might ___.”
• Chunk the worksheet into one organism, one connection, and one explanation at a time. Offer accessible observation locations, sensory alternatives, and the choice to draw, speak, dictate, or write.
• Pair EAL students with supportive peers, rehearse vocabulary orally, and accept home-language discussion before sharing in English. Use clear gestures and repeated visual models.
• For advanced learners, model the effect of removing one species, investigate a possible invasive plant, or compare biodiversity in two habitats using the number and variety of organisms observed.