Deserts are places on earth that are characterized by little vegetation and rain. They are made up of sand or rocks and gravel. Deserts cover about one-fifth of all the land in the world. Most deserts lie along the Tropic of Cancer and Tropic of Capricorn, imaginary lines that lie north and south of the equator.

Oases are parts of the desert where plants grow and water is almost always available. An oasis is formed by a pool of water trapped between layers of rock beneath the desert floor. The regular water in an oasis allows people to settle in the desert and even grow crops.

Some deserts are named and nicknamed things like Death Valley, "the empty quarter," and "the place from where there is no return" because of the lack of water there.

Climate:

The desert is the hottest biome on earth. However, the desert is also a land of extremes. It can be over 100 degrees Farenheit during the day but below 32 degrees at night. This change is because deserts are bare. There is little protection to keep them from heating up in the sun and cooling off when the sun disappears at night. The amount of rainfall also varies. Though there is little rain in a desert, when it does rain, it pours. Violent rainstorms can cause flashfloods in the desert. After a storm, the desert may not see any rain for weeks or months.

Plants

There are some plants that are able to survive in the desert. They may have to go without fresh water for over a year! They also have to adjust to very hot days and very cold nights. Some plants have very long roots which grow in to the ground to reach underground water sources. Some up as much water as they can during the rain and save it in their stems and leaves. Some store the food and water underground in thick roots.

Rain brings life to the desert. Shortly after a big storm, billions of seeds come to life in the form of flowering plants. These plants are called ephemerals. Eight weeks after a rain, the flowers are gone.

The cactus is the most well-known desert plant. This old man cactus has a layer of hair that helps it to store water.

Animals

There are hundreds of different animals that live in deserts. However, most of them can only be found at dawn or dusk because that is when they move around. For the rest of the day, animals bury themselves in the sand or hide beneath rocks to keep cool. Animals that come out at night are called nocturnal. Animals in the desert eat plants and each other to survive. Many feed on the roots, stems, leaves, and seeds of plants. These animals are then eaten by bigger animals. Some animals get enough water from their food, but others must travel to water holes.