A HUMAN PERSPECTIVE In 1352, 48-year-old Ibn Battuta, a great traveler from Morocco, set out for the empire of Mali in West Africa.His most challenging obstacle was the Sahara, a desert nearly the samesize as the continental United States. Battuta and his caravan set out inFebruary. They traveled only in early morning and early evening toavoid the midday heat. Even so, they still battled temperatures of near-ly 100 degrees during the day and freezing temperatures at night.Reaching Mali around April, Batutta covered more than 1,000 miles, allon foot. The Sahara today remains just as hazardous—fewer than 2 million of Africa’s approximately 800 million people live in it.

A Warm ContinentYou can see from the map on page 421 that Africa lies almost entirelybetween the tropic of Cancer and the tropic of Capricorn. This locationgives most of Africa warm, tropical temperatures.

THE DESERTS The Sahara is the largest desert in the world. Saharaactually means “desert” in Arabic. It stretches about 3,000 miles acrossthe continent, from the Atlantic Ocean to the Red Sea, and also runs1,200 miles from north to south. Temperatures can rise as high as136.4°F in the summer, hot enough to fry an egg on the sand. But tem-peratures can also fall below freezing at night in winter.

Only about 20 percent of the Sahara consists of sand. Toweringmountains, rock formations, and gravelly plains make up the rest. Forinstance, the Tibesti Mountains, located mostly in northwestern Chad,rise to heights of more than 11,000 feet. Other African deserts includethe Kalahari and the Namib.

Travel in the Sahara is risky because of the extreme conditions. Manytravelers rely on the camel as desert transportation. A camel can go for

Climate and Vegetation Main Ideas• Africa contains dry and hot

deserts, warm tropics, and permanently snow-capped mountains.

• Africa’s vegetation includesthick rain forests, tallgrasslands, and desert areas.

Places & TermsSahara Serengeti Plain

aquifer canopy

oasis

Connect to the Issueseconomic developmentAfrica’s tropical rain forestsare being cut down forfarmland and valuable timber.

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PLACE Rolling sand dunes areonly a small part of the Sahara’svaried landscape. How might an expanding desertaffect the lives of the peopleliving near it?

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II

I

30°S

40°S

20°S

10°S

0°

10°N

20°N

30°N

Tropic of Cancer

Equator

50°E40°E30°E10°E 20°E0°10°W20°W30°W

Tropic of Capricorn

Mediterranean Sea

Gulf ofGuinea

Moz

ambi

que

Cha

nnel

Red Sea

INDIANOCEAN

ATLANTICOCEAN

LakeVictoria

L. Nyasa

L. Chad

L. Tanganyika

0

0 400 800 kilometers

400 800 miles

Lambert Azimuthal Equal-Area Projection

Tropical wet

Tropical wet and dry

Desert

Semiarid

Mediterranean

Humid subtropical

Marine west coast

Highland

N

S

EW

Climate and Vegetation 421

up to 17 days without water. Inaddition, wind-blown sand has lit-tle effect on a camel. It closes itsnostrils and just keeps walking.

Ironically, as much as 6,000 feetunder this hottest and driest ofplaces lie huge stores of under-ground water called aquifers. Insome places, this water has come tothe surface. Such a place is calledan oasis. It supports vegetationand wildlife and is a criticalresource for people living in thedesert.

THE TROPICS Africa has a largetropical area—the largest of anycontinent. In fact, nearly 90 percentof the continent lies within thetropics of Cancer and Capricorn, asyou can see on the map to the right.Temperatures run high most of theyear. The hottest places are in theparts of the Sahara that lie in thenation of Somalia. July tempera-tures average between 110°F and115°F almost every day. Differencesin temperature between winter andsummer in the Tropics are barelynoticeable. Differences in temperature between night and day actuallytend to be greater than any difference between seasons. A saying inAfrica says that nighttime is the “winter” of the tropics.

Sunshine and RainfallRainfall in Africa is often a matter of extremes. Some parts get toomuch rain, while other parts receive too little. The amount of rainfallcan also vary greatly from year to year as well as season to season.These variations have had a tremendous impact on East Africa, whichendured several droughts in the 1980s and 1990s.

RAINFALL PATTERNS The rain forest in Central Africa receives themost precipitation, as rain falls throughout the year. Most of the rest ofAfrica, however, has one or two rainy seasons. Africa’s tropical savannastretches through the middle of the continent. It covers nearly half thetotal surface area of Africa. Rainy seasons in this area can last up to sixmonths. The closer an area is to the equator, the longer the rainy sea-son. The closer an area is to the desert, the longer the dry season.

Africa’s west coast also receives a great deal of rain. The region aroundMonrovia, Liberia, experiences an average annual rainfall of more than120 inches. In contrast, many parts of Africa barely get 20 inches of rainover the course of a year. In the Sahara and other deserts, rain may not

AFR

ICA

Climates of Africa

SKILLBUILDER: Interpreting MapsREGION What climate zones are found only in Southern Africa?

PLACE What is Africa’s most dominant climate zone?

Using the AtlasWhich climate

regions of Africado the tropics ofCancer andCapricorn passthrough?A. Answer Cancerpasses throughdesert, andCapricorn passesmostly throughdesert and semiarid.

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PLACE These wilde-beests live in SerengetiNational Park, whichwas founded in 1951.How might the parkhelp conservationefforts in Africa?

fall for years. Children living in those areas may not see rain until theyare five or six years old!

AFRICA’S MODERATE AREAS A Mediterranean climate exists on thenorthern and southern tips of the continent. Clear, blue skies in theseplaces are normal. Rain falls usually only in the winter—December andJanuary in North Africa and June and July in Southern Africa. Summertemperatures in Johannesburg, South Africa, average around 68°F.

A Grassy ContinentAfrica’s vegetation—like its climate—is almost mirrored north andsouth of the equator. Africa’s vegetation consists of grasslands, rainforests, and a wide variety of other plant life.

TROPICAL GRASSLAND Tropical grassland covers most of the conti-nent. One example of this grassland is the Serengeti Plain in northernTanzania. Its dry climate and hard soil prevent the growth of trees andmany crops, but these conditions are perfect for growing grass.Serengeti National Park, located within the Serengeti Plain, containssome of the best grasslands in the world. Some of these grasses cangrow taller than the average person. The abundance of grass makesSerengeti National Park an ideal place for grazing animals. Huge herdsof wildebeests, gazelles, and zebras roam there. It is the place where

the largest numbers of land mam-mals still make annual migrations.

Africa’s ExtremesAn enormous tropical rain foreststretches across Central Africa.

RAIN FOREST The major rainforests of Africa sit on the equator inthe area of the Congo Basin. Onesquare acre of rain forest can containalmost 100 different kinds of trees.It may also be home to hundreds ofspecies of birds. The massive num-ber of plants, leaves, and trees blockout much of the sunlight that wouldotherwise hit the floor of the rainforest. Beneath this umbrella of veg-etation, the air is hot and filled withmoisture. As a result, plants andother vegetation quickly decompose,or decay. For example, a fallen leaf inEurope decomposes in about a year.A leaf on the jungle floor in Africadecomposes in about six weeks.

Most animals in a rain forest live inthe canopy. The canopy refers to theuppermost layer of branches, about

BackgroundSerengeti means“endless plains” in the Masailanguage.

422

Seeing PatternsHow do rain

forests maintainsuch a high levelof moisture?

B. Answer Thelarge number ofplants and treesblock out sunlightand trap moistureunderneath.

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Climate and Vegetation 423

MOVEMENTAnimals, such as thischimpanzee, moveabout the Ituri rainforest in theDemocratic Republicof the Congo.

Places & TermsExplain the meaning ofeach of the followingterms.

• Sahara

• aquifer

• oasis

• Serengeti Plain

• canopy

Taking Notes PLACE Review the notes you tookfor this section.

• What are the different climatesfound in Africa?

• How does climate affect thevegetation of Africa?

Climate and

Vegetation

Main Ideas a. What is the largest

climatic feature in Africa?

b. Why does most of Africahave high temperatures?

c. What are the differentkinds of vegetationgrowing in Africa?

Geographic ThinkingMaking Comparisons Whatare the similarities betweenthe climates of Africa northand south of the equator?Think about:

• the Sahara

• where the equator cutsacross Africa

MAKING COMPARISONS Choose a place in Africa and a place in the United States at aboutthe same latitude. Use encyclopedias or the Internet to compare the climate and vegetation ofthe two places. Create a chart comparing the two locations.

AFR

ICA

150 feet above the ground. Birds, mon-keys, and flying foxes move from tree totree and enjoy the bounty of the rainforest. A large number of snakes live inthese rain forests, too. The Gaboonviper, the largest African viper, canweigh as much as 18 pounds and havefangs more than two inches long.Another snake, the black-necked cobra,can shoot its venom more than eightfeet through the air.

However, farmers using slash-and-burn agricultural methods are endan-gering the existence of the rain forest.As you read in Chapter 9, slash-and-burn farming is a method in whichpeople clear fields by cutting andburning trees and other vegetation,the ashes of which fertilize the soil.After farmers have exhausted the soil,they burn another patch of forest.Slash-and-burn farming is responsible for the nearly complete destruc-tion of Madagascar’s rain forest. Experts estimate that over half of Africa’soriginal rain forest has been destroyed.

VARIETIES OF PLANTLIFE All of Africa’s regions contain a variety ofvegetation. North Africa contains sizable oak and pine forests in theupper reaches of the Atlas Mountains. The mangrove tree of West Africasprouts up along river banks in swamps and river deltas. Mangrove treeroots are breeding grounds for fish. They also help to build up dry landby holding silt. In the next section, you will read about different ways thatpeople in Africa have interacted with their environment.

BackgroundThe NationalCancer Instituteestimates that 70percent of theplants founduseful for cancertreatment arefound only in rainforests.

RESEARCH LINKSCLASSZONE .COM

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