Unit Plan 15 (Grade 5 Science): Environmental Changes & Organisms

Focus: Investigate how environmental changes (natural and human-caused) affect food webs, organism populations, and ecosystem balance, using models of matter movement among plants, animals, decomposers, and the environment.

Grade Level: 5

Subject Area: Science (Life Science • Environmental Science Connections)

Total Unit Duration: 5 sessions (one week), 50–60 minutes per session

I. Introduction

In this unit, students explore what happens to ecosystems when conditions change. Building on their understanding of producers, consumers, decomposers, and matter movement, they investigate how events like drought, pollution, habitat loss, or species removal can ripple through a food web. Students use models and scenarios to predict how populations might increase, decrease, or disappear, and how these changes affect the cycling of matter and overall ecosystem balance.

Essential Questions

• How do environmental changes (natural or human-caused) affect plants, animals, decomposers, and ecosystem balance?
• How does a change in one population affect the movement of matter among other parts of the ecosystem?
• What can food web models help us predict about the effects of adding, removing, or reducing a species?
• How can understanding ecosystem changes help people make better choices about caring for environments?

II. Objectives and Standards

Learning Objectives — Students will be able to:

1. Identify and describe examples of environmental changes (e.g., drought, pollution, construction, invasive species) in different ecosystems.
2. Use food web models to show how matter moves among plants, animals, decomposers, and the environment in a balanced ecosystem.
3. Predict and explain how changing one population (increase, decrease, or removal) will affect other organisms and matter movement in the food web.
4. Interpret simple data or scenarios showing changes in populations and connect them to ecosystem impacts.
5. Create and explain an Environmental Change & Food Web Impact Model that shows an initial balanced ecosystem, a change event, and the resulting shifts in populations and matter movement.

Standards Alignment — 5th Grade (NGSS-Aligned)

• 5-LS2-1 — Develop a model to describe the movement of matter among plants, animals, decomposers, and the environment.

Success Criteria — Student Language

• I can identify how plants, animals, decomposers, and the environment are connected in a food web.
• I can model how matter moves through an ecosystem before and after an environmental change.
• I can explain how changing the size of one population affects other populations and ecosystem balance.
• I can use words like producer, consumer, decomposer, environment, matter, ecosystem, population in my explanations.
• I can create and explain a before-and-after model that shows how an environmental change affects a food web.