Most of the major deserts of the world lie in areas crossed by the trade winds. The Sahara of Africa is the world's largest desert. It contains complex linear dunes that are separated by almost 6 kilometers. Skylab photograph. These deserts are in interior drainage basins far from oceans and have a wide range of annual temperatures. The Sonoran Desert of southwestern North America is a typical midlatitude desert.
A rare rain in the Tengger, a midlatitude desert of China, exposes ripples and a small blowout on the left. Winds will shortly cover or remove these features.
Rain shadow deserts are formed because tall mountain ranges prevent moisture-rich clouds from reaching areas on the lee, or protected side, of the range. As air rises over the mountain, water is precipitated and the air loses its moisture content. A desert is formed in the leeside "shadow" of the range.
A sand sea is in the lower center on the right, but desert pavement, gray in color, dominates this desert. The few oases in the desert and the vegetation in the mountains at the top are in red. A blanket of snow separates the vegetation in the Tian Shan from the rain shadow desert. Crescent-shaped dunes are common in coastal deserts such as the Namib, Africa, with prevailing onshore winds.
Low clouds cover parts of the Namib in this space shuttle photo. Another common misconception is that deserts are just vast areas of sand dunes, devoid of life.
In fact, some desert areas are composed of large areas of dunes, but many are much more geographically diverse, the landscape being comprised of scrub, rocky and gravelly areas with sparse vegetation. All deserts harbor life. Many types of insects, plants, reptiles and small mammals and birds call deserts home all over the world. These life forms have adapted to the desert's harsh conditions and have come to thrive there.
Some deserts, like the driest in the world, the Atacama, receive little or no rain. These places are extremely arid, and very little life exists there. Other deserts like the Sonoran Desert in Arizona receive close to the maximum yearly rainfall for deserts and are fairly well populated with many types of fauna and flora. The Sonoran Desert, while still arid, is lush compared to other deserts, supporting over 2, species of plants.
Rains in the spring produce incredible flushes of greenery and flowers as the plants, dormant for most of the year, take advantage of the rain. Saguaro cacti reach enormous size, collecting and storing immense amounts of water when it does rain, and surviving for months until the next rainfall. Most deserts get what little precipitation they do receive in a few, heavy rainfalls, rather than many light rains spread out over the course of the year.
This leads to seasonal lakes and rivers which may last a few months, or even only a few days. Dry river beds are a common sight in many deserts, and are called wadis in some African and Middle Eastern deserts. Some rainfalls may bring torrents of 5 to 10 cm of rain in a few hours, leading to flash flooding in ravines or canyons, a seemingly paradoxical occurrence in the driest places on Earth.
Arctic and Antarctic deserts receive their precipitation almost entirely as snow. Many factors affect precipitation in deserts. Mountains often cause an effect called "rainshadow. Millions of people had to leave their farms and seek a living in other parts of the country. Desertification is an increasing problem. Every year, about 6 million square kilometers 2. The Sahara Desert crept kilometers 39 miles south between and South Africa is losing million metric tons short tons of topsoil each year.
Many countries are working to reduce the rates of desertification. Trees and other vegetation are being planted to break the force of the wind and to hold the soil. Windbreak s made of trees have been planted throughout the Sahel , the southern border region of the Sahara Desert.
These windbreaks anchor the soil and prevent sand from invading populated areas. They anchor the drifting sand with a gridlike network of straw fences. Straw is poked partway into the sand, forming a pattern of small squares along the contours of the dunes. The resulting fences break the force of the wind at ground level, stopping dune movement by confining the sand within the squares of the grid.
New technologies are also being developed to combat desertification. Nanoclay keeps the sand moist, clumping it together and preventing it from blowing away. Deserts Get Hotter Rising temperatures can have huge effects on fragile desert ecosystems. Global warming is the most current instance of climate change. Human activities such as burning fossil fuel s contribute to global warming. In deserts, temperatures are rising even faster than the global average.
This warming has effects beyond simply making hot deserts hotter. For example, increasing temperatures lead to the loss of nitrogen , an important nutrient, from the soil. Heat prevents microbe s from converting nutrients to nitrate s, which are necessary for almost all living things. This can reduce the already limited plant life in deserts.
Climate change also affects rainfall patterns. Climate scientists predict that global warming will lead to more rainfall in some regions, but less rainfall in other places. Areas facing reduced precipitation include areas with some of the largest deserts in the world: North Africa Sahara , the American Southwest Sonoran and Chihuahuan , the southern Andes Patagonia , and western Australia Great Victoria. In literature and in legend, deserts are often described as hostile places to avoid.
Today, people value desert resources and biodiversity. Communities, government s, and organizations are working to preserve desert habitats and increase desert productivity.
Hot and Cold Deserts The largest hot desert in the world is the Sahara, which is 9 million square kilometers 3. It isn't the hottest place on Earth, though. The highest temperature on Earth was recorded there: The largest polar desert is Antarctica, at 13 million square kilometers 5 million square miles.
Antarctica boasts the lowest official temperature recorded on Earth: Rising from the Ashes The desert city of Phoenix, Arizona, is named for the mythical desert bird that burns to death only to be reborn, rising from its own ashes. The city of Phoenix was built on top of the ruins of canals built by the Hohokam people between and CE. The Hohokam used the canals to irrigate their crops. Modern-day residents also rely on an extensive canal system to provide irrigation.
Devil of a Storm Dust devils are common in hot deserts. They look like tiny tornadoes, but they start on the ground rather than in the sky. When patches of ground get very hot, the heated air above them begins to rise and spin. This whirling column of hot air picks up dust and dirt. These spinning columns of dirt can rise hundreds of feet in the air. Freak Floods Deserts are defined by their dryness. However, flash floods take more lives in deserts than thirst does.
Also called industrial agriculture. Also called Ancestral Puebloans. Carbon dioxide is also the byproduct of burning fossil fuels. Also called the Wet Sahara. Also called hydroelectric energy or hydroelectric power.
Monsoon usually refers to the winds of the Indian Ocean and South Asia, which often bring heavy rains. Native American usually does not include Eskimo or Hawaiian people.
Also called a salt flat, sink, or salt pan. Also called a playa, sink, or salt pan. Also called a midlatitude desert. Sometimes, water rights include the amount of water a consumer is allowed to use. The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit.
The Rights Holder for media is the person or group credited. Caryl-Sue, National Geographic Society. Dunn, Margery G. For information on user permissions, please read our Terms of Service. If you have questions about how to cite anything on our website in your project or classroom presentation, please contact your teacher. They will best know the preferred format. When you reach out to them, you will need the page title, URL, and the date you accessed the resource. If a media asset is downloadable, a download button appears in the corner of the media viewer.
If no button appears, you cannot download or save the media. Text on this page is printable and can be used according to our Terms of Service. Any interactives on this page can only be played while you are visiting our website. You cannot download interactives. A terrestrial ecosystem is a land-based community of organisms and the interactions of biotic and abiotic components in a given area. Examples of terrestrial ecosystems include the tundra, taigas, temperate deciduous forests, tropical rainforests, grasslands, and deserts.
The type of terrestrial ecosystem found in a particular place is dependent on the temperature range, the average amount of precipitation received, the soil type, and amount of light it receives.
Use these resources to spark student curiosity in terrestrial ecosystems and discover how different abiotic and biotic factors determine the plants and animals found in a particular place. A biome is an area classified according to the species that live in that location. Temperature range, soil type, and the amount of light and water are unique to a particular place and form the niches for specific species allowing scientists to define the biome.
However, scientists disagree on how many biomes exist. Some count six forest, grassland, freshwater, marine, desert, and tundra , others eight separating two types of forests and adding tropical savannah , and still others are more specific and count as many as 11 biomes.
Use these resources to teach middle school students about biomes around the world. Economies are often molded by the location and cultures of which they are apart. This explains why distinct regional economies develop to serve the unique needs of people. Use these resources to teach students about the regional economies found throughout the world.
Deserts may seem lifeless, but in fact many species have evolved special ways to survive in the harsh environments. Deserts are extremely dry environments that are home to well-adapted plants and animals.
The main types of deserts include hot and dry deserts, semi-arid deserts, coastal deserts, and cold deserts. Join our community of educators and receive the latest information on National Geographic's resources for you and your students. Skip to content. Twitter Facebook Pinterest Google Classroom. Encyclopedic Entry Vocabulary. I've been through the desert on a rock with no name. Photograph by Steve Zappe, MyShot.
Also called a wadi. Aswan Dam. Atacama Desert. Cambyses II. Death Valley. Dust Bowl. Fossil fuels formed from the remains of ancient plants and animals. Gobi Desert. Great Plains. Green Sahara. Indus Valley Civilization. Inland Empire. King David. Middle East. Native American. Excess nitrates can choke freshwater ecosystems. Resources can be natural or human. Sahara Desert. Tropic of Cancer.
Tropic of Capricorn. Also called an arroyo. Media Credits The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit. Last Updated Oct. Media If a media asset is downloadable, a download button appears in the corner of the media viewer. Text Text on this page is printable and can be used according to our Terms of Service.
Interactives Any interactives on this page can only be played while you are visiting our website. Related Resources. Terrestrial Ecosystem. View Collection. Regional Economies. Deserts Explained. View Article. Desert Biome. Desert Woodland. View Photograph. Educational Resources in Your Inbox. Educational Resources in Your Inbox Join our community of educators and receive the latest information on National Geographic's resources for you and your students.
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