Ecosystem Dynamics: Exploring Environmental Changes

Grade Level: Grade 4-7

Subject: Science

Lesson Objectives

By the end of this lesson, your students will understand the components and dynamics of ecosystems. And they'll identify natural and human factors that affect ecosystems.

Materials Needed

• Projector and computer for videos

• Images and diagrams of different ecosystems

Introduction to Ecosystem Dynamics

Today, we're exploring the world of ecosystems and how they change. We'll explore what an ecosystem is, how different factors affect it, and what happens when these factors change. By the end, you'll understand the balance within our natural world and how human activities can tip that balance.

What is an Ecosystem? (15 min)

Who can define an ecosystem? (Call on a couple of students to describe an ecosystem.)

An ecosystem is a community of living organisms—plants, animals, and microbes—interacting with their physical environment, which includes air, water, and soil. Think of a forest, a desert, or even a small pond. Each of these is an ecosystem, and every component plays a role in maintaining balance. (Show images and diagrams of various ecosystems.)

Components of an Ecosystem

• Producers: Plants that produce energy through photosynthesis.

• Consumers: Animals that eat plants or other animals.

• Decomposers: Organisms like fungi and bacteria that break down dead material.

Factors Affecting Ecosystems (15 min)

Ecosystems are dynamic, meaning they constantly change. What do you think are some of the things that can change an ecosystem? (Allow students to answer.)

Various factors can influence these changes, including:

Natural Factors

• Climate: Temperature and precipitation patterns shape ecosystems.

• Natural Disasters: Events like wildfires, hurricanes, and floods drastically alter ecosystems.

• Seasonal Changes: Different seasons bring changes in temperature and availability of resources.

Human Factors

• Pollution: Chemicals and waste harm ecosystems.

• Deforestation: Cutting down trees disrupts habitats.

• Urbanization: Building cities and infrastructure fragment ecosystems.

Case Study: The Impact of Climate Change (20 min)

One factor affecting ecosystems is climate change. Rising temperatures and shifting weather patterns are impacting ecosystems globally. 

For example, coral reefs are experiencing bleaching due to warmer ocean temperatures. This affects the corals and the marine life that depends on them. (Show a video on coral bleaching.)

Activity: Predicting Ecosystem Changes (15 min)

1. Divide your students into small groups.

2. Have each group pick an ecosystem (e.g., rainforest, tundra, ocean).

3. Each group will research, discuss, and predict how climate change could impact their chosen ecosystem.

4. Once finished, each group will present their findings to the class.

Hands-On Activity: Creating a Mini Ecosystem

Each student will create a mini-ecosystem in a jar. This activity will allow them to observe and understand the interactions between different ecosystem components and the effects of environmental changes over time.

Materials Needed

• Clear glass jars with lids (one per student or group)

• Small plants (e.g., moss, small ferns)

• Soil

• Small rocks or pebbles

• Water

• Observation charts and pens

Instructions

1. Setting Up the Mini-ecosystem

1. Place a layer of small rocks or pebbles at the bottom of the jar. This will help with drainage and prevent the roots from sitting in water.

2. Add a layer of soil on top of the rocks. The soil should be deep enough to support the plants.

3. Plant small plants like moss or ferns into the soil. Make sure the plants are well-spaced and have room to grow.

4. Lightly water the soil to moisten it. Be careful not to over-water, as excess water can cause mold growth.

5. Once your mini-ecosystem is set up, seal the jar with the lid. This will create a closed system where the water cycle can take place.

2. Observing the Mini-ecosystem

• Observe: Over the next few weeks, observe the changes in your mini-ecosystem. Look for interactions between the plants and water, changes in plant growth, and the ecosystem's overall health.

• Record: Use an observation chart to record your findings. Include columns for date, temperature (if you have a thermometer), observations (e.g., plant growth), and any changes you notice.

3. Extensions and Variations

• Comparative Study: Create two mini-ecosystems: one sealed and one open. Compare the changes and health of the ecosystems over time.

• Environmental Changes: Introduce a change to the ecosystem, such as varying the amount of light or water, and observe the effects. This can simulate environmental changes in a natural ecosystem.

4. Reflection

• Discuss: Hold a class discussion to reflect on what was learned. Discuss the importance of balance in ecosystems and how even small changes can have significant impacts.

• Reflect: Have your students write a reflection on their experience creating and observing their mini-ecosystems. Ask them to include what they learned about ecosystem dynamics and any surprises they encountered.

Written by Brooke Lektorich
Education World Contributor
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