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Session 4: Ecosystems 🌿

Overview

Grades: 3-4 | Duration: 40 minutes | Session: 4 of 17

Students explore ecosystems and food webs, understanding how all living things are connected in God's design.

Session 4: Ecosystems

Learning Objectives

By the end of this session, students will:

  • Define ecosystem, food chain, and food web

  • Identify producers, consumers, and decomposers

  • Create a food web for a local ecosystem

  • Appreciate the interconnection of all creation

Session 4: Ecosystems

Materials Needed

  • 📸 Ecosystem pictures

  • 🧶 Yarn for food web activity

  • 📋 Organism cards

  • 📓 Engineering journals

  • 🎨 Food web poster materials

Catholic Integration

Saint Connection

St. Kateri Tekakwitha — Lily of the Mohawks, lived in harmony with nature and saw God in all creation.

Scripture

"For in him all things hold together." — Colossians 1:17

Opening Prayer

Dear God, you created an amazing world where everything is connected. Help us see your wisdom in ecosystems and be good stewards of your creation. Amen.

Lesson Procedure

Opening Circle (6 minutes)

  1. Ecosystem Definition:
  2. "A community of living things interacting with their environment"
  3. All living + non-living things work together
  4. Key Vocabulary:
  5. Producer — Makes own food (plants)
  6. Consumer — Eats others for energy
  7. Decomposer — Breaks down dead things
  8. Food Chain vs Web:
  9. Chain: Single path of energy (grass → rabbit → fox)
  10. Web: Multiple connected chains (more realistic!)
  11. St. Kateri — Saw God's design in nature

Main Activity: Food Web Exploration (26 minutes)

Part 1: Food Chain Building (6 minutes)

  • Start simple: sun → producer → consumer → decomposer

  • Minnesota examples:

  • Sun → grass → deer → wolf → bacteria

  • Sun → algae → minnow → bass → eagle

  • Energy flows from sun through all living things!

Part 2: Food Web Game (10 minutes)

  • Students receive organism cards (plants, animals, decomposers)

  • Stand in circle

  • Pass yarn to show connections:

  • "I am a plant, I'm eaten by..." → pass yarn

  • Continue building web

  • Everyone holds yarn—see the connections!

  • What happens if one organism is removed? (Pull yarn—see effects!)

Part 3: Create Food Web Poster (8 minutes)

  • Choose ecosystem: forest, prairie, wetland, pond

  • Draw food web showing:

  • At least 3 producers
  • At least 4 consumers
  • At least 2 decomposers

  • Arrows showing energy flow

  • Label: Producer, Consumer, Decomposer

Part 4: Share & Discuss (2 minutes)

  • Show webs

  • "What happens if _____ disappears?"

  • Everything is connected!

Engineering Journal (5 minutes)

  1. Draw a simple food chain (4 organisms)
  2. Label: Producer, Consumer, Decomposer
  3. Write: "Everything is connected because..."
  4. Write: "We should protect ecosystems because..."

Closing Circle (3 minutes)

  1. Connection Appreciation — "What surprised you about food webs?"
  2. Stewardship — "How can we protect ecosystems?"
  3. Closing Prayer — "God, your creation is beautifully connected. Help us protect the web of life you designed. Amen."

Assessment

Observation Checklist:

  • Defined ecosystem vocabulary

  • Participated in food web game

  • Created accurate food web

  • Understood interconnection

Differentiation

For Students Who Need Support

  • Pre-made organism cards with labels

  • Simplified food web

  • Partner work

For Advanced Students

  • Research specific ecosystem

  • Include energy percentages

  • Create disruption scenario analysis

Wonder at Home 🏠

Family Activity: Create a food web for your backyard or local park! What plants grow there? What animals live there? Research what eats what. Watch nature documentaries about ecosystems!

Teacher Notes

  • Food web yarn activity is powerful visual

  • Pull yarn to show cascade effects

  • Connect to environmental stewardship

  • Consider outdoor observation if possible

Previous: Session 3 — Tower Challenge
Next: Session 5 — Scratch Games