Boreal forests grow in places that are cold much of the time. They are found closer to the North Pole in North America, Asia, and Europe. Summers here are short and winters are long. Most of the moisture that falls on this kind of forest is snow. Conifers, trees that have needle-like leaves such as pine trees, grow in boreal forests. Moose, bear, wolves, deer, and chipmunks are animals that thrive in boreal forests.

All types of forests have some similar characteristics. All forests have a canopy, the level of a forest made up of the crowns of the forest trees. There is a forest floor, which is the ground level of a forest. In forests with a dense canopy, like a tropical forest, little light is able to penetrate the forest floor. That means, fewer plants are able to grow below the canopy.

All three types of forests grow in special situations. Small changes in the conditions in an area can change the type of forest that grows there. For instance, a boreal forest might grow on top of a high, cold mountain while the base of the same mountain might be covered in a temperate forest.

Where a forest grows also changes the way that forest helps the environment and the animals that live there. Forests that grow on the slopes of mountains help to hold soil in place as heavy rains or melting snow rushes down the hillside. Forests that grow in the moist soil surrounding streams and rivers tend to grow thicker than the surrounding landscape. These riverbank forests give animals a place to live that provides more food and easier access to water. They also help to keep soil in place. Forests that are isolated, like those on islands, tend to have fewer types of plants and animals, because new plant seeds and some animals have a tougher time reaching them. (Try to picture a squirrel swimming for miles to reach an island!!) Even the trees in a city combine to make an "urban" forest. These trees provide shade, help to clean the air, give animals a home, and make our neighborhoods more beautiful.

There are also old growth forests and new growth forests. Sometimes a forest begins on a bare patch of sand or a rocky area. Sometimes a new forest develops in an area where the forest has been cleared. First, fast-growing plants and baby trees, called pioneer plants, start to grow in the area. Next, larger plants and shrubs begin to overtake the smaller plants. Eventually trees move in and a new forest is created. As the forest ages, and the mixture of plants that make up the forest becomes stable, the forest is then called an old growth forest.

Our world would not be the same without forests. They absorb carbon dioxide from the atmosphere and release enormous amounts of oxygen. Forests influence weather patterns over large areas of the Earth and provide homes for many types of animals. And forests give us many of the products we use everyday, such as food, wood, and paper. Regardless of the type of forest, all forests enrich our daily lives and help us to survive.