Whether you live on a farm, in a small town, or on a big-city street, you are part of an environment

A thin shell of air, water, and land - called the biosphere - holds all of life on earth

The material that makes up your body, and all life on earth...

You could learn a lot about an elephant by measuring its trunk...

Poisonous tree frogs, towering redwoods, and mammoth blue whales...

When natural barriers such as mountain chains or oceans isolate...

Energy and matter pass from one living thing to another...

Staying alive is no easy task. Every day, plants and animals must contend...

Not every relationship in nature is competitive.

Everywhere you look in nature, plants and animals seem...

The ecology of a region is influenced by its climate...

Climates can change over short or long periods of time.

Although it’s a good thing that the earth is now much warmer

From the freezing Siberian taiga to the hot, steamy rain forests of Africa...

Named for Boreas, the Greek god of the north wind, boreal forests rival...

Stately oaks, maples, and other broad-leaved hardwood trees dominate temperate forests

Temperate rain forests are the rarest type of woodlands on earth

Tropical rain forests are found in the hot, humid climates that lie near the earth’s equator

In South Africa, these forests are called fynbos, in California, chaparral.

Glossary of terms