Water Cycle

ImageMaybe you recycle cans, glass, and paper. Did you know that nature recycles, too? One of the things nature recycles is water. Water goes from the ocean, lakes, and rivers into the air. Water falls from the air as rain or snow. Rain or snow eventually find their way back to the ocean. Nature’s recycling program for water is called the water cycle.


The water cycle has four stages: storage, evaporation, precipitation, and runoff. Most of the water on Earth is in the first stage, storage. Water on Earth gets stored in oceans, lakes, rivers, ice, and even underground. The oceans store the majority of this water.


ImageSuppose you have a candy bar. You could eat the whole candy bar now, or you could divide it into pieces to eat later. Saving some of the candy bar to eat later would be a kind of conservation. You would be saving, or conserving, your candy bar so that it would last longer.

Conservationists are people who want to save Earth’s natural resources so they will last longer. Conservation is the protection and wise use of natural resources.


Natural resources are all the things on Earth that support life. Plants, animals, air, and water are natural resources.


ImageBeavers build them from sticks. Landslides create them from trees, mud, and debris. Humans make them from earth and concrete. These structures are dams. Dams hamper the flow of water in a river or stream.

Landslides don’t mean to create dams. They do so by dumping a lot of earth and other stuff in a river. Scientists think beavers build dams for protection. Beaver dams capture water in front of the lodges in which beavers live. Beavers can hide from their enemies in this deeper water. A dam also protects the beaver lodge by slowing the river’s speed.

Coral Reef

ImageImagine you are snorkeling in the warm ocean water around a tropical coral reef. You put on your mask and swim fins. You float around looking at the reef below you. The coral reef looks like strangely shaped rocks sticking up from the ocean floor. Crooked coral that looks like tree limbs twists up from cracks and caves in the reef. A big piece of coral that looks like a brain lies on the bottom. Orange and pink coral shaped like fans wave in the currents. Fish of all different shades and varieties of color swim near the reef.

Coral reefs play an important role in ocean life. Many kinds of plants, fish, and other animals live on and around a coral reef. Even the reef itself is made mostly of tiny coral animals, both living and dead.

Endangered and Extinct Animals

ImageYou have never watched a dodo bird scurry along the ground. You have never been frightened by a saber-toothed cat crouched in a tree. You have never seen the huge tusks of a mastodon. These animals once lived on Earth, but they all died out. They went extinct.

You can see still see blue whales, giant pandas, and tigers. But these animals are in danger of becoming extinct. There aren’t many of them left. Blue whales, giant pandas, and tigers are some of the endangered animals on Earth. There are thousands of others.