Healthy Ecosystems and Our Choices

By the end of this lesson, you will be able to describe what makes an ecosystem healthy and tell how people can help or hurt it.

An ecosystem is all the living things in one place, like plants and animals, plus the nonliving things they need, like water, air, soil, and sunlight. A healthy ecosystem has clean water and clean air. It has many different kinds of plants and animals, which scientists call biodiversity. In a healthy ecosystem, every living thing can find food, water, and shelter, and the numbers of plants and animals stay fairly steady over time.

Think about a pond at a Texas park. Cattails and grasses grow along the edges. Frogs sit on the mud. Turtles rest on logs. Dragonflies zip over the water, and fish swim below. Birds come to drink and hunt. Each living thing depends on the others, so the pond keeps working year after year.

People can hurt that pond without meaning to. If trash is thrown in the water, animals may eat it or get tangled in it. If a parking lot is built right up to the shore, rainwater washes oil and litter into the pond. Cutting down all the shade trees can make the water too warm for fish. Pollution, which is harmful material added to air, water, or land, can make a whole ecosystem sick.

People can also help. Neighbors can pick up litter around the pond. Cities can plant native trees and grasses that hold soil in place. Families can put out water for birds, recycle at home, and stay on trails so plants are not crushed. Scientists can protect wetlands so animals keep their homes.

Try it: If a neighborhood planted a row of native trees and bushes beside a creek, would that most likely help the creek's ecosystem or harm it, and why?