Biomes deserts

BI0ME5 Introduction arth is home to millions of different organisms, all of which have specific survival needs These organisms rely on their environment, or the place where they live, for their survival All plants and animals have relationships with their environment They interact with the environment itself, as well as the other plants and animals within the environment This interaction creates an ecosystem Different organisms have different needs Not every animal can survive in extreme climates Not all plants require the same amount of water Earth is composed of many types of environments, each of which provides organisms with the living conditions they need to survive Organisms with similar environmental needs form communities in areas that meet these needs These areas are called biomes A biome can have several ecosystems Some desert rock formations are formed by erosion The rock cap on top of these formations protects the fragile rock underneath from further erosion r Deserts are a type of biome Most deserts are barren landscapes dotted with massive rock structures or sand dunes Some of the hottest and driest places on Earth are deserts Very little rain falls in deserts, and the temperatures are often very hot In any desert, it is difficult for plants and animals to survive Deserts are home to some of the most unique creatures in the world Many species have adapted to these harsh living conditions and lack of food and water Most desert plants grow low to the ground because of the intense heat and lack of water • • , Though the size of Earth's deserts is always ohanginy, they cover betv/een >and percent of Earth's suríace That is ahout 8.6 million square miles (22 million square kilometers) Some deserts flood, hut they still not receive enough rain to fill and sustain a river Water either seeps into underground rivers beneath the soil, or it evaporates BI0ME5 Desert Locations any of the largest deserts in the world are located north and south of the equator, near the Tropic of Cancer and the Tropic of Capricorn The closer a desert is to the equator, the hotter its temperatures The Sahara Desert is 3,499,881 square miles (9,064,650 sq km) and covers nearly onethird of northern Africa Neighboring the Sahara is the Arabian Desert This desert is located in Egypt It stretches about 999,966 square miles (2,589,900 sq km) from the Nile River Valley in the west to the Red Sea and the Gulf of Suez in the east Few people live in this desert People living in desert areas tend to live close to sources of water The Siwa oasis in Egypt has a population of 15,000 and also serves as a popular tourist destination Some continents have more than one desert Africa is home to not only the Sahara Desert, hut the Kalahari and I NamJb Deserts as well Tlie Kalahari is 220,000 square miles (569,800 sq km) in area The Namib covers 13,000 square miles (33,670 sq km) Desertification is the process hy which fertile land becomes a desert The arctic regions of the North and South Poles are home to cold deserts These deserts have freezing temperatures throughout the entire year Sand in the desert is transported by wind The Atacama Desert, in Chile, South America, is the driest place on Earth Eiich year, it receives fewer than 0.01 inches (0.004 centimetersi of rain In Australia is home to the Great Victoria Desert, which measures 249,991 square miles (647,475 sq km) It is one of four deserts in Australia's interior These four deserts are part of a region called the Outback The North American Desert, located in the southeastern United States, is 539,000 square miles (1,400,000 sq km) in area This desert includes the Great Basin, Mojave, Sonora, and Chihuahua Deserts The Gobi Desert is the largest desert in Asia It stretches about 500,000 square miles (1,300,000 sq km) through China and Mongolia some parts of the Atacama Desert, it has not rained for nearly 400 years WHERE IN THE WORLD! D eserts are found on most of the world's continents This map shows where the world's major deserts are located Find the place where you live on the map Do you live close to a desert? If not, which deserts are closest to you? Arctic Ocean Atlantic Ocean South America N Deserts A 1000 500 2000 kilometers 1000 miles m Southern Ocean 10 BI0ME5 Hot and Cold Climates eserts are areas that receive little or no precipitation Precipitation is rain, snow, or fog For an area to be considered a desert, it must receive fewer than 10 inches (25 cm) of precipitation each year Most deserts are very hot places, where daytime temperatures can reach 140° Fahrenheit (60° Celsius) Sand and hot sunshine are often associated with deserts, but not all deserts are warm In some parts of the world, including near the North and South Poles, cold deserts resemble the tundra biome Cold deserts are covered with ice or snow There is little precipitation in these deserts, but the temperature is so cold the snow does not melt Over time, tall layers of snow and ice form f Other deserts are hot during the day and freezing cold at night The Sahara Desert is one of the hottest deserts on Earth Here, temperatures are scorching hot during the day, but drop below 32° F (0° C) at night The deserts of North America and the Cobi Desert in Asia are well known for their warm climates During the winter, temperatures can become so cold that the landscape is sometimes dusted with a thin layer of snow FASCINATING PACTS Gobi means "waterless place" in Mongolian, one of the languages spoken in China Sahara is the Arahian word for "desert" or "deserted land." Winter precipitation in the desert usually falls as rain, hut when temperatures are tow enough, precipitation sometimes falls as snow 11 Erosion can completely remove all sand from an area, exposing a hard crust The world's deserts continually grow and expand Covered in sand, gravel, or rock, desert landscapes are always changing Erosion wears away the rock and sand Flash flooding can move the land Erosion Erosion is the process of land being worn away by wind, rain, or water Most deserts are covered in small pebbles or gravel that has broken away from larger stone structures With no shelter from trees, rock formations are worn away and chipped by wind and rain These larger pieces of rock break into smaller boulders Boulders become rocks Over time, rocks become sand Flooding Flash flooding takes place when bursts of water cover large parts of the desert land in just a few minutes The force of these brief and fast floods carries away loose rocks and sand There are very few plants or trees to prevent the soil from washing away Water in a desert can cause great movement in the landscape Flash flooding rarely occurs in deserts Growth Sometimes, animals eat all of the vegetation, or plant life, in fertile areas near deserts These areas are too dry to grow new plants, so they become part of the desert landscape In this way, deserts constantly grow in size Wind, rain, mining, and logging also cause deserts to form 12 BI0ME5 Types of Deserts eserts form for many reasons Ceographic location, climate, precipitation, and elements such as wind influence the creation of desert biomes There are four main types of deserts Hot Deserts Coastal Deserts Ciant masses of air swirl above Earth's surface As Earth rotates, hot air rushes toward the equator This air moves north and south through the Tropic of Cancer and the Tropic of Capricorn As the warm air moves nearer to Earth's surface, it absorbs moisture from the air and land This dries out the desert landscape Coastal deserts are located near water These deserts have hot climates with little rain Coastal deserts are often covered in mist or fog, but water evaporates too quickly for many types of plants to grow Rain Shadow Deserts Rain shadow deserts are found in areas that are sheltered by tall mountain ranges The ranges block precipitous clouds and ocean moisture from reaching the land This creates pockets of desert land Polar Deserts Polar deserts are found in areas with cool temperatures and little precipitation In parts of the North Pole and Antarctica, there are large areas of rock that are rarely covered in ice and snow FASCINATINC FACTS Sometimes hiomes are side by side The Mount Charleston Wilderness area serves as an oasis from the surrounding Nevada desert The recreational area contains 18,000 acres (7,284 hectares) of bristlecone pine Scientists studying pictures of tbe surface of Mars bave found a 1,930,510-square-mile(5,000,000-sq-km) area they believe is a desert Tbe surface of tbis desert appears to be covered in sand dunes Tbe landscape of polar deserts is often cbaracterized by harren rocks and sparsely dispersed plants FURTHER RESEARCH H ow can I find more information about ecosystems, deserts, and animals? Libraries have many interesting books about ecosystems, deserts, and animals Science centers are great places to learn about ecosystems, deserts, and animals The Internet offers some great Web sites dedicated to ecosystems, deserts, and animals BOOKS WEB fITEf Arnosky, Jim Watching Desert Wildlife Hanover, PA: National Geographic, 2002 Where can I learn about desert plants Baker, Lucy Life in the Deserts New York, NY: Two-Can Publishers, 2000 Heisey, Adriel Under the Sun: A Sonoran Desert Odyssey Tucson, AZ: Rio Nuevo Publishers, 2000 Martin, Michael and Elke Wallner Deserts of the Earth London, England: Thames and Hudson, 2004 and animals? What's It Like Where You Live? http://mbgnet.mobot.org/sets/ desert^index.htm How can I learn more about desert biomes? World Biomes—Desert www.worldbiomes.com/ biomes_desert.htm How can I learn about ecology and biomes? Kids Do Ecology www nceas.ucsb.edu/nceasweb/kids/ecology/faq.html ûLOSSARy adapted: changed to suit the environment amphibian: cold-blooded animals with moist, smooth skin basalt: rock made from volcanic lava droughts: periods of dry weather ecosystem: a community of living things sharing an environment equator: an imaginary line drawn around Earth's center hydrated: supplied with water to maintain a fluid balance invertebrates: animals that not have a backbone irrigate: to water larvae: the young of any invertebrate minerals: substances or elements that occur in nature nutrients: substances that feed plants or animals organisms: living things solar energy: power created using energy from the Sun Tropic of Cancer: an imaginary iine north of the equator Tropic of Capricorn: an imaginary line south of the equator INDEX amphibians 16, 22 Arabian Desert 6,14, 24 Atacama Desert 7, cacti 17,18,19,20,29 climate 10, 12,16,26 coastal deserts 12,29 ecology 4, 26, 27 erosion 4, 11 Gobi Desert 7,10,21 Great Victoria Desert 7, hot deserts 12,28 insects 16,20,22,29 invertebrates 16,22,29 North American Desert oases 16,23,29 plateaus 13,29 playas 13,29 polar deserts 12,29 rain shadow deserts 12 reptiles 16,22.23 rock formations 11,13,29 Sahara Desert 6,7,9, 10,22 sand dunes 5, 12, 13,29 ECO CHALLENGE I How many continents have deserts? What are the four types of deserts? Name five desert features How high can hot-desert temperatures reach? Name three desert careers What type of water is found in aquifers? / (5 What special adaptation camels have? VVhy people hunt elephants? Which animals are the desert's smallest «creatures? Where cacti store water? ' • > • Answers puBS uo 'saunp puBS JB|Od LJ;J83 UO iueut;uoo Ajane ' BUILD A fOLAR STILL P eople have found many ways to survive in the desert For example^ people use solar stills to gather water Try building a solar still in your backyard MATERIALS RESULTS • shovel • jar • clear garbage bag • to 10 medium-sized rocks • smaller rock • measuring glass Over time, moisture from the ground and heat from the Sun causes condensation to form on the underside of the bag The rock in the center of the bag directs the water to run into the jar Use a measuring glass to find out how much water you collected.^^ With the help of an adult, dig a round hole in a sandbox or garden The hole must have a flat bottom and should be no bigger than a garbage bag Put the jar in the center of the hole Lay the garbage bag over the top of the hole Put the medium-sized rocks around the bag to hold it in place Place the small rock in the center of the bag over the jar, and wait for it to fill with water FURTHER RESEARCH H ow can I find more information about ecosystems, deserts, and animals? Libraries have many interesting books about ecosystems, deserts, and animals Science centers are great places to learn about ecosystems, deserts, and animals The Internet offers some great Web sites dedicated to ecosystems, deserts, and animals BOOKS WEB fITEf Arnosky, Jim Watching Desert Wildlife Hanover, PA: National Geographic, 2002 Where can I learn about desert plants Baker, Lucy Life in the Deserts New York, NY: Two-Can Publishers, 2000 Heisey, Adriel Under the Sun: A Sonoran Desert Odyssey Tucson, AZ: Rio Nuevo Publishers, 2000 Martin, Michael and Elke Wallner Deserts of the Earth London, England: Thames and Hudson, 2004 and animals? What's It Like Where You Live? http://mbgnet.mobot.org/sets/ desert^index.htm How can I learn more about desert biomes? World Biomes—Desert www.worldbiomes.com/ biomes_desert.htm How can I learn about ecology and biomes? Kids Do Ecology www nceas.ucsb.edu/nceasweb/kids/ecology/faq.html ûLOSSARy adapted: changed to suit the environment amphibian: cold-blooded animals with moist, smooth skin basalt: rock made from volcanic lava droughts: periods of dry weather ecosystem: a community of living things sharing an environment equator: an imaginary line drawn around Earth's center hydrated: supplied with water to maintain a fluid balance invertebrates: animals that not have a backbone irrigate: to water larvae: the young of any invertebrate minerals: substances or elements that occur in nature nutrients: substances that feed plants or animals organisms: living things solar energy: power created using energy from the Sun Tropic of Cancer: an imaginary iine north of the equator Tropic of Capricorn: an imaginary line south of the equator INDEX amphibians 16, 22 Arabian Desert 6,14, 24 Atacama Desert 7, cacti 17,18,19,20,29 climate 10, 12,16,26 coastal deserts 12,29 ecology 4, 26, 27 erosion 4, 11 Gobi Desert 7,10,21 Great Victoria Desert 7, hot deserts 12,28 insects 16,20,22,29 invertebrates 16,22,29 North American Desert oases 16,23,29 plateaus 13,29 playas 13,29 polar deserts 12,29 rain shadow deserts 12 reptiles 16,22.23 rock formations 11,13,29 Sahara Desert 6,7,9, 10,22 sand dunes 5, 12, 13,29 ... precipitation, and elements such as wind influence the creation of desert biomes There are four main types of deserts Hot Deserts Coastal Deserts Ciant masses of air swirl above Earth's surface As Earth... desert^index.htm How can I learn more about desert biomes? World Biomes Desert www.worldbiomes.com/ biomes_ desert.htm How can I learn about ecology and biomes? Kids Do Ecology www nceas.ucsb.edu/nceasweb/kids/ecology/faq.html... desert^index.htm How can I learn more about desert biomes? World Biomes Desert www.worldbiomes.com/ biomes_ desert.htm How can I learn about ecology and biomes? Kids Do Ecology www nceas.ucsb.edu/nceasweb/kids/ecology/faq.html