Ecosystems

An ecosystem is a community of organisms interacting with their environment.  An ecosystem can be any size from a large forest or body of water to a small tidal pool along a rocky coast. Regardless of size, an individual ecosystem will have similar organisms and environmental factors throughout. Earth's ecosystems are grouped into seven larger areas called biomes.

Terrestrial ecosystems are land-based ecosystems. Within this broad category are a wide range of biomes and ecosystems, ranging from the snow-covered arctic tundra to the tropical rainforests. In this lesson, we will examine the six major terrestrial biomes. While these major classifications encompass most of Earth’s land, many distinct individual ecosystems exist within these biomes. 

In lesson 3, we will examine the aquatic biome which is made up of water ecosystems. Nearly three-fourths of Earth’s surface is covered with water that all living things on our planet rely on in some way for survival. In this lesson, we will look at several specific types of aquatic ecosystems and compare their biotic and abiotic factors.

Each ecosystem has a limited amount of energy that can be passed from one organism to another. The sun provides energy that plants use to produce food, and animals get energy from eating these plants or other animals. The organisms in an ecosystem that are able to make their own food from the sun’s energy are called producers. Consumers get energy either from eating producers or from eating other consumers.

The path of energy flow through an ecosystem can be shown using food chains and food webs. A food chain shows a single path of energy flow, while a food web shows the interdependence of all organisms in an ecosystem.