Mission: Build a Mini Ecosystem

Materials Needed

• Clear plastic cup, jar, or recycled container
• Small stones or gravel
• Potting soil
• Small plant, moss, or grass seeds
• Water
• Spoon
• Optional: magnifying glass, ruler, craft sticks, paper, colored pencils, and a camera
• Notebook or science journal

Learning Objectives

By the end of this lesson, the learner will be able to:

• Define ecosystem, producer, consumer, and decomposer.
• Identify how living and nonliving parts of an ecosystem work together.
• Build a simple model of an ecosystem.
• Record observations and explain how changes may affect the ecosystem.

Success Criteria

I can:

• Correctly label at least four parts of an ecosystem.
• Explain one way living things depend on nonliving things.
• Build a mini ecosystem safely and carefully.
• Make a prediction and support it with evidence from my observations.

Introduction: The Tiny World Challenge

Hook: Imagine shrinking a forest until it fits inside a jar. Could plants, water, soil, sunlight, and tiny organisms work together in this small world?

Tell the learner: “Today, you are an ecosystem engineer. You will design a tiny ecosystem, observe what happens, and explain how its parts work together.”

Think-Pair-Share or Family Discussion

1. What living things might be found in a garden, pond, or forest?
2. What nonliving things do those organisms need?
3. What might happen if a plant received no sunlight?

Quick Check: Ask the learner to name one living part and one nonliving part of an ecosystem.

Body: Learn and Build

Part 1: Key Vocabulary

Ecosystem

A community of living and nonliving things interacting in one place.

Producer

A living thing, such as a plant, that makes its own food using sunlight.

Consumer

A living thing that gets energy by eating plants or other animals.

Decomposer

An organism, such as a fungus or some bacteria, that breaks down dead material and returns nutrients to the soil.

Nonliving factor

A part of an ecosystem that is not alive, such as sunlight, water, air, soil, or rocks.

Part 2: I Do—Model the Thinking

Use a garden as an example:

• Producer: A tomato plant makes food using sunlight.
• Consumer: A caterpillar eats the tomato plant.
• Decomposer: Fungi break down fallen leaves.
• Nonliving factors: Sunlight, water, air, soil, and temperature support life.

Think aloud: “The plant needs sunlight, water, air, and nutrients from the soil. The caterpillar depends on the plant for food. When organisms die, decomposers help return nutrients to the soil. Each part is connected.”

Formative Check: Ask, “If there were no sunlight, which part of this system would be affected first? What might happen next?”

Part 3: We Do—Plan the Ecosystem

Before building, create a simple plan in the science journal. Draw the container and label:

• Producer
• Soil
• Water
• Air
• Sunlight
• Any decomposers or tiny organisms that may already be in the soil

Discuss this question: Why should the container not be filled completely with soil?

Expected idea: The plant needs room for roots, air, and water.

Part 4: You Do—Build a Mini Ecosystem

1. Place a thin layer of stones or gravel in the bottom of the container. This helps excess water collect away from the roots.
2. Add enough potting soil to cover the stones and fill about one-third of the container.
3. Make a small hole in the soil with a finger or spoon.
4. Place the plant or a few seeds in the hole and gently cover the roots or seeds.
5. Add a small amount of water. The soil should be damp, not flooded.
6. Place the ecosystem in a safe location with indirect sunlight.
7. Label the container with the date and the plant’s name.

Safety Note: Do not eat the soil or plants. Wash hands after handling soil, and ask an adult for help when using glass containers.

Observation Mission

Observe the mini ecosystem once each day for at least five days. Record information in a chart:

Choose a Challenge

Select one challenge to complete:

• Artist: Draw a detailed diagram of the ecosystem and add arrows showing how its parts depend on one another.
• Scientist: Measure the plant each day and create a simple bar graph of its growth.
• Reporter: Record a one-minute explanation of how the ecosystem works.
• Problem Solver: Predict what would happen if the ecosystem received too much water, too little sunlight, or no fresh air. Explain your reasoning.

Assessment

Formative Assessment

• Listen for correct use of ecosystem vocabulary during discussion.
• Check the learner’s labeled planning diagram.
• Ask the learner to explain why the plant needs sunlight, water, air, and soil.
• Review daily observations and provide feedback such as, “You recorded what changed. Now add an explanation for why it may have changed.”

Summative Assessment: Ecosystem Engineer Presentation

The learner presents the mini ecosystem or completed journal and explains:

1. What the ecosystem contains.
2. Which part is the producer.
3. Which nonliving factors support the ecosystem.
4. How the parts interact.
5. One prediction about what might happen if a part changed.

Simple Rubric

Differentiation and Adaptations

Support

• Provide vocabulary cards with a word, definition, and example.
• Use sentence starters: “The plant needs ___ because ___.” and “If ___ changed, then ___ might happen.”
• Allow the learner to explain ideas orally instead of writing complete paragraphs.
• Complete the building steps together, one step at a time.

Extension

• Compare two containers placed in different light conditions.
• Research a local ecosystem and identify its producers, consumers, decomposers, and nonliving factors.
• Create a food chain that could exist in a garden, pond, or forest.
• Write a paragraph explaining why biodiversity, or having many different kinds of organisms, can help an ecosystem stay healthy.

Conclusion: Tell What You Learned

Ask the learner to complete these statements:

• An ecosystem is...
• A producer is...
• One nonliving factor is...
• The plant in my ecosystem depends on...
• One change that could affect my ecosystem is...

Final Recap: An ecosystem includes living and nonliving parts that interact. Plants are producers because they make their own food. Consumers get energy by eating plants or animals, and decomposers return nutrients to the soil. Every part of an ecosystem is connected.

Optional Follow-Up

Continue observing the mini ecosystem for two weeks. At the end, write a short “scientist’s report” describing what changed, what stayed the same, and what the evidence shows about how ecosystems work.