3rd Grade Science

Investigating ecosystems, matter, and energy through hands-on experiments and observations.

Basic Concepts

What is an Ecosystem?

Discovering Ecosystems

An ecosystem is a community where living things, like plants and animals, interact with each other and with their environment, such as air, water, and soil. Every ecosystem is unique and can be as small as a puddle or as big as a forest!

What Makes Up an Ecosystem?

  • Living things: Plants, animals, fungi, and tiny microbes.
  • Non-living things: Sunlight, water, air, rocks, and soil.

All these parts work together. Plants make food using sunlight, animals eat plants or other animals, and decomposers break down dead things to keep the cycle going.

Why Are Ecosystems Important?

Ecosystems give us clean air to breathe, water to drink, and places for animals to live. When ecosystems are healthy, everyone benefits!

Types of Ecosystems

  • Forests
  • Deserts
  • Oceans
  • Grasslands
  • Ponds

Explore the world around you and see how many kinds of ecosystems you can find!

Examples

  • A pond where fish, frogs, and plants live together.

  • A forest filled with trees, squirrels, birds, and insects.

In a Nutshell

An ecosystem is a community of living and non-living things working together.

Key Terms

Ecosystem
A community of living and non-living things that interact in a specific environment.
Decomposer
Organisms that break down dead plants and animals, returning nutrients to the soil.