desert and tundra biome

8/3/2019 Desert and Tundra Biome

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DESERTBIOME


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Aurene G. AlcanaKryzia May C. AbantoDennise L. Amoranto


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GENERAL DISCRIPTION :

About 1/5 of the earths land

surface is covered bydeserts. Deserts are

characterized by lack ofmoisture. There are only fewliving organisms that can


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Desert, term applied to regions ofthe earth that are characterized by

less than 254 mm (10 in) of annualrainfall, an evaporation rate thatexceeds precipitation, and, in mostcases, a high averagetemperature. Because of a lack ofmoisture in the soil and lowhumidity in the atmosphere, mostof the sunlight penetrates to the

ground.


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Daytime temperatures canreach 55 C (131 F) in theshade. At night the desertfloor radiates heat back tothe atmosphere, and thetemperature can drop tonear freezing.


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Namib Desert


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SPECIFIC DESCRIPTION:

Climate: Very dryTemperature: Hot during the dayand cold during the night. The airbecomes quickly hot during the dayand cools rapidly at night because

the air contains little or no moistureto modify the temperature. Strongwinds often occur in the desert,

carrying dust and wind.


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Soil: Sandy, dry and loose;contains mineral like calcite

Rainfall: Less than 10cm in ayear


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Vegetation: Bushes and shrubsare widely scattered; cacti andsmall flowers cover the desertusually after every occasionalrains

Animals: Lizards, snakes,eagles, owls, toads, insects andsmall birds


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Desert Tortoise

The desert tortoise, Gopherus agassizii, is found in

deserts throughout the southwest United States andnorthwest Mexico. The tortoise, its burrows, and itshabitat are vulnerable to highway traffic, off-roadvehicles, and cattle grazing. Adults can grow to 38centimeters (15 inches) and may live more than 80years.


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Kangaroo Rat

Kangaroo rats live in colonies in dry regions of North

America, emerging from their burrows at night to foragefor food. These animals have extremely efficient kidneysthat help them conserve water by producing highlyconcentrated urine. The kangaroo rat gets its name fromits extremely long hind legs, which it uses to hop.


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DingoThe dingo, whichinhabits only Australia,

probably descendsfrom Asiandomesticated dogsbrought to Australia by

prehistoric peoples.Although dingoes areprimarily carnivorous,feeding upon insects,carrion, birds,mammals andreptiles, they alsooccasionally feed onplant material.


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Bactrian CamelThe Bactrian camelhas two humps onits back. It has astockier build andslightly shorter legsthan the one-

humped Arabiancamel. Most of theworlds Bactriancamels are found in

the steppes anddeserts of Mongoliaand northwesternChina.


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Cactus

Many cacti, such

as the prickly pearcactus shownhere, carry outphotosynthesis in

enlarged stemsrather thanleaves. The stemsalso serve to storewater, essentialforphotosynthesis.


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Boojum Tree

The boojum tree, nativeto arid areas such asthe Baja CaliforniaPeninsula innorthwestern Mexico,may reach heights of

up to 20 m ( 66 ft ).Older specimens maytwist into unusualshapes.


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Most desert regions have been formed bymovements of air masses over the planet. Asthe earth turns on its axis, it produces giganticair swirls. Hot air rising over the equator flowsnorthward and southward; the currents cool inthe upper regions and descend as high-pressure areas in two subtropical zones. Northand south of these zones are two more areas ofascending air and low pressure. Still farther

north and south are the two polar regions ofdescending air. As air rises, it cools and loses itsmoisture. As it descends, it warms and picks upmoisture, drying out the land.


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WORLD DESERT REGION


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Most deserts arise due to

atmospheric wind conditions. Warmair masses created two belts ofdesert, one along the Tropic of

Cancer and the other along the Tropicof Capricorn. Other deserts resultfrom the effects of ocean currents on

landmasses, where cool air massescarry fog and mist, but little rain, alongcoastal regions.


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Other desert areas result from the influence of

ocean currents on landmasses. As cold watersmove from the Arctic and Antarctic regionstoward the equator and come into contact withthe edges of continents, they are augmentedby upwellings of cold water from the oceandepths. Air currents cool as they move acrosscold water; they carry fog and mist but little

rain. Such currents flow across the coastalregions of southern California, Baja California,southwest Africa, and Chile; although oftenshrouded in mist, these coasts are deserts.


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Sahara Northern Africa 9,100,000 3,500,000

Gobi Mongolia/Northeastern China 1,300,000 500,000

Patagonian Argentina 670,000 260,000

Rub' al KhaliSouthernArabianPeninsula

650,000 250,000

Great Sandy NorthwesternAustralia 390,500 150,000

Largest Deserts in the World

Area 1 Desert Location sq km sq mi


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GreatVictoria

SouthwesternAustralia 390,500 150,000

Chihuahuan Mexico/SouthwesternUnited States 360,000 140,000

TaklaMakan Northern China 360,000 140,000

Sonoran Mexico/SouthwesternUnited States 310,000 120,000

Kalahari Southwestern Africa 260,000 100,000



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Kyzyl Kum Uzbekistan 260,000 100,000

Thar India/Pakistan 260,000 100,000Simpson Australia 100,000 40,000

Mohave southwestern UnitedStates 52,000 20,000

1) Desert areas are very approximate, becauseclear physical boundaries may not occur.



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The Saharais the largest

desert in theworld.Temperatures range frommore than54.4C(130F)

during theday to belowfreezing atnight.Sahara Desert


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Gobi Desert

The largest desert in Asia,the Gobi straddles theborder between Mongoliaand China. It contains aseries of basins that aredivided by low, flat-toppedranges and isolated hills,

as pictured here.


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Patagonian AndesPatagonia is a vastregion of desertplateaus insouthernArgentina. TheAndes Mountainsin Patagonia arecharacterized bythese soaringgranite pillars inTorres del PaineNational Park innearby Chile.


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Rubal Khali


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Takla MakanThe Takla Makan desert, a bleak region of driftingsand dunes, lies in northwestern China. Camels are

used for transport across the region.


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GreatSandy

Acacia, tussocks, and desert oaks survive in the harsh, aridconditions of Western Australias Great Sandy Desert. Locatedin the northwest between the Pilbara and Kimberley regions, thisred sand dune desert is believed to contain untapped mineralresources. More than half of Western Australia is desert andsparsely populated.


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Sonoran DesertLocated nearTucson,

Arizona,SaguaroNational Parkpreserves theSonoran

Deserthabitat of thesaguarocactus.Several

saguaroforests arelocated withinthe 370-sqkm (141-sq

mi) park.


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Kalahari Desert


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TUNDRABIOME


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General Description

Tundras are found inarctic regions; cold and

lack water; trees do notgrow


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Tundra, Arctic plains encompassingmost of Earths terrain north of theconiferous forest belt, dominated bycotton grass, heath, lichen, moss,sedge, and willow. Similar plains,called alpine tundra, occur above thetimberline in the high mountains ofthe world. The Antarctic region has afew areas of tundra as well.


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Tundra comes from the word tunturi, meaning treeless plain. It is noted for itsfrost- molded landscapes, extremely lowtemperatures, little precipitation, poornutrients and short growing seasons.

Dead organic materials function asnutrient pool. The two major nutrientsare nitrogen phosphorus. Nitrogen iscreated by biological fixation. Andphosphorus is created by precipitation.


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SPECIFIC DESCRIPTIONClimate: Cold and limited sunlight

Temperature: Average temperatureis 23 0F or -5 0C

Rainfall: Less than 25 cm annually


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Soil: Ground covered with little snow.

Below the surface soil is permanentlyfrozen (permafrost). Decompositionis very slow because of the extreme

cold.Vegetation: Lichens, mosses,

grasses, dwarf shrubs; trees cannotgrow because of extreme cold andfrozen ground


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HeatherAssorted cultivarsof the

representativegenus of the heathfamily, Erica, areseen here, together

with Scotchheather ( Calluna vulgaris ), a speciesfound over much ofthe cool-temperatearea of theNorthernHemisphere.


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LichenLichens, which arecommonly found onrocks, bark, or poorsoil, are compositeorganisms made upof a fungus and analga. The lichen

seen here growingon a tree is one ofthe fruticose lichens.It is made up of a

layer of algal cells, amiddle layer offungal hyphae, andan outer layer offungal tissue.


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Moss

There are over 14,000species of primitiveplants called mossesbelonging to the phylumBryophyta. Mostspecies are terrestrialand, although requiringabundant moisture, arehighly adaptable, livingon rocks, tree trunks,stumps, wooden

buildings, and asphaltroofing shingles.Several species areadapted for life in bogs,swamps, and streams.


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Animals: Reindeer, oxen, rabbits, caribou,and foxes

Adaptation: The animals like reindeer surviveby moving to other places when food becomes

scarce. The oxen are protected from cold bythick coats. The smaller animals like rabbitsand foxes burrow into the snow and feed ontiny bits of plants. Tundra inhabitants havewhite coats in winter and brown coats insummer. This change in coloration enablesthem to adapt to the season, protecting them

in winter and summer.


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Reindeer

In the spring the reindeer make their long

migration north to give birth and feast on thetender shoots of the tundra. In the winter theyreturn to the interior, digging up lichens withtheir large hooves. Roughly half of the world's 5million reindeer are domesticated, tended by

herders in Scandinavia and Russia.

Rangifer tarandus The reindeercovers the farnorthern forestsand tundra ofEurope, Asia, andNorth America(where it is calleda caribou). Unlike

other members ofthe deer family,both the male andfemale reindeergrow antlers.


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European Rabbit

Rabbits eat

grasses,cultivated plants,herbs, and bark.Rabbitssometimesdamagepastures and

farms byburrowing andeating crops.


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ArcticFox

The arctic fox wears two coats. Its warm-weather coat is gray-brown.During the winter, however, its fur is a thick, white camouflage

against a landscape of snow and ice, protection both from predatorsand from the harsh temperatures of tundra latitudes. The foxs smallsnout and ears also conserve heat, as do its fur-covered feet,reminiscent of a rabbits . Temperatures drop to -70 C (-94 F) beforethe arctic fox begins to shiver. A small number have blue coloration

in colder months, alternating to a rich brown in the summer.


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Collared Lemming

The collaredlemming is a small

rodent that is widelydistributedthroughout tundraregions of the

northernhemisphere.Lemmings providethe best-known

example ofirruption a type ofmigratory cycle thatoccurs in extremeclimates.


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Dall Sheep

Dall sheep,sometimes calledthinhorn sheep,inhabit cliff regionsin Alpine and Arctictundra areas ofnorthern BritishColumbia. Relatedto the musk ox andthe moutain goat,these sheep canhave either black,gray, or whitecoats, depending

on the subspecies.


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Common PtarmiganFound in tundra areas ofthe northern hemisphere,the rock ptarmigan is welladapted to its icyenvironment. Feathereddown to the toes, thisgrouse withstands severe

blizzards by digging aburrow in a snowdrift andwarming it with its ownbody heat. During the

summer months hens digshallow burrows in openground, in which theyincubate between 8 and13 eggs.


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This skilled climber is found on wet, cold cliffs and alpinetundra in the Rocky Mountains of the United States andCanada. Among mountain goats, Oreamnos americanus, the males mark rutting territory with a scent secreted fromglands behind the horns. Competing males do not buttheads but instead try to jab each other with their spikelikehorns.

Rocky

MountainGoat

Al k T d


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The vast tundra (Arctic plains) of Alaska, Siberia, and othersubpolar regions contains a layer of frozen subsoil calledpermafrost. The area of frozen ground has decreased due torising temperatures, and scientists are concerned that as thepermafrost melts it will release large amounts of methane, apotent greenhouse gas, into the atmosphere. This would

accelerate global warming.

Alaskan TundraGlobal warming hasbeen most dramaticin the Arctic, wheretemperatures haverisen almost twice

as much as theglobal average.


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Arctic Tundra

Tundra, or low-growing

vegetationincluding shrubs,grasses, mosses,and herbs, coversthe plains andcoastal regions ofthe Arctic. Shown

here is tundra inDenali NationalPark and

Preserve, Alaska.


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NorthernRussia

In far northern Russia, the treeless, frozen tundradisplays a brief burst of color with the appearance ofmosses, lichens, and shrubs during the shortsummer. In this region the ground is permanentlyfrozen to great depths, and even in summer only ashallow surface layer thaws.


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THANKYOU!!!


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GROUP 8

desert and tundra biome

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