Africa, the second largest continent (after Asia), covering about one-fifth of

the total land surface of Earth. The continent is bounded on the west by
the Atlantic Ocean, on the north by the Mediterranean Sea, on the east by
the Red Sea and the Indian Ocean, and on the south by the mingling waters
of the Atlantic and Indian oceans.

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education: Africa

Before the arrival of the European colonial powers, education in Africa was

designed to prepare children for responsibility…

Africa’s total land area is approximately 11,724,000 square miles (30,365,000

square km), and the continent measures about 5,000 miles (8,000 km) from
north to south and about 4,600 miles (7,400 km) from east to west. Its
northern extremity is Al-Ghīrān Point, near Al-Abyaḍ Point (Cape Blanc),
Tunisia; its southern extremity is Cape Agulhas, South Africa; its farthest point
east is Xaafuun (Hafun) Point, near Cape Gwardafuy (Guardafui), Somalia;
and its western extremity is Almadi Point (Pointe des Almadies), on Cape
Verde (Cap Vert), Senegal. In the northeast, Africa was joined to Asia by
the Sinai Peninsula until the construction of the Suez Canal. Paradoxically,
the coastline of Africa—18,950 miles (30,500 km) in length—is shorter than
that of Europe, because there are few inlets and few large bays or gulfs.
Off the coasts of Africa a number of islands are associated with the continent.
Of these Madagascar, one of the largest islands in the world, is the most
significant. Other, smaller islands include the Seychelles, Socotra, and other
islands to the east; the Comoros, Mauritius, Réunion, and other islands to the
southeast; Ascension, St. Helena, and Tristan da Cunha to the
southwest; Cape Verde, the Bijagós Islands, Bioko, and São Tomé and
Príncipe to the west; and the Azores and the Madeira and Canary islands to
the northwest.
The continent is cut almost equally in two by the Equator, so that most of
Africa lies within the tropical region, bounded on the north by the Tropic of
Cancer and on the south by the Tropic of Capricorn. Because of the bulge
formed by western Africa, the greater part of Africa’s territory lies north of the
Equator. Africa is crossed from north to south by the prime meridian(0°
longitude), which passes a short distance to the east of Accra, Ghana.
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In antiquity the Greeks are said to have called the continent Libya and the
Romans to have called it Africa, perhaps from the Latin aprica (“sunny”) or the
Greek aphrike (“without cold”). The name Africa, however, was chiefly applied
to the northern coast of the continent, which was, in effect, regarded as a
southern extension of Europe. The Romans, who for a time ruled the North
African coast, are also said to have called the area south of their settlements
Afriga, or the Land of the Afrigs—the name of a Berber community south
of Carthage.
The whole of Africa can be considered as a vast plateau rising steeply from
narrow coastal strips and consisting of ancient crystalline rocks. The plateau’s
surface is higher in the southeast and tilts downward toward the northeast. In
general the plateau may be divided into a southeastern portion and a
northwestern portion. The northwestern part, which includes
the Sahara (desert) and that part of North Africa known as the Maghrib, has
two mountainous regions—the Atlas Mountains in northwestern Africa, which
are believed to be part of a system that extends into southern Europe, and the
Ahaggar (Hoggar) Mountains in the Sahara. The southeastern part of the
plateau includes the Ethiopian Plateau, the East African Plateau, and—in
eastern South Africa, where the plateau edge falls downward in a scarp—
the Drakensberg range. One of the most remarkable features in the geologic
structure of Africa is the East African Rift System, which lies between 30° and
40° E. The rift itself begins northeast of the continent’s limits and extends
southward from the Ethiopian Red Sea coast to the Zambezi River basin.
Africa contains an enormous wealth of mineral resources, including some of
the world’s largest reserves of fossil fuels, metallic ores, and gems
and precious metals. This richness is matched by a great diversity of
biological resources that includes the intensely lush equatorial rainforests of
Central Africa and the world-famous populations of wildlife of the eastern and
southern portions of the continent. Although agriculture (primarily subsistence)
still dominates the economies of many African countries, the exploitation of
these resources became the most significant economic activity in Africa in the
20th century.
Climatic and other factors have exerted considerable influence on the patterns
of human settlement in Africa. While some areas appear to have been
inhabited more or less continuously since the dawn of humanity, enormous
regions—notably the desert areas of northern and southwestern Africa—have
been largely unoccupied for prolonged periods of time. Thus, although Africa
is the second largest continent, it contains only about 10 percent of the world’s
population and can be said to be underpopulated. The greater part of the
continent has long been inhabited by black peoples, but in historic times there
also have occurred major immigrations from both Asia and Europe. Of all
foreign settlements in Africa, that of the Arabs has made the greatest impact.
The Islamic religion, which the Arabs carried with them, spread from North
Africa into many areas south of the Sahara, so that many western African
peoples are now largely Islamized.
This article treats the physical and human geography of Africa, followed by
discussion of geographic features of special interest. For discussion of
individual countries of the continent, see such articles as Egypt, Madagascar,
and Sudan. African regions are treated under the titles Central Africa, eastern
Africa, North Africa, Southern Africa, and western Africa; these articles also
contain the principal treatment of African historical and cultural development.
For discussion of major cities of the continent, seesuch articles
as Alexandria, Cairo, Cape Town, Johannesburg, and Kinshasa. Related
topics are discussed in the articles literature, African; literature, South
African; architecture, African; art, African; dance, African; music,
African; theatre, African; art and architecture, Egyptian; Islam; arts, Islamic;
and Islamic world.
Davidson S.H.W. NicolThe Editors of Encyclopaedia Britannica

Geologic History
General considerations
The African continent essentially consists of five
ancient Precambriancratons—Kaapvaal, Zimbabwe, Tanzania, Congo, and
West African—that were formed between about 3.6 and 2 billion years ago
and that basically have been tectonically stable since that time; those cratons
are bounded by younger fold belts formed between 2 billion and 300 million
years ago. All of those rocks have been extensively folded and
metamorphosed (that is, they have been modified in composition and
structure by heat and pressure). Precambrian rock outcrops appear on some
57 percent of the continent’s surface, while the rest of the surface consists of
largely undeformed younger sediments and volcanic rocks.

Ruwenzori RangeRugged peaks of the Ruwenzori Range, east-central Africa.P. Jaccod/DeA Picture Library

The oldest rocks are of Archean age (i.e., about 4.6 to 2.5 billion years old)
and are found in the so-called granite-gneiss-greenstone terrains of the
Kaapvaal, Zimbabwe, and Congo cratons. They consist of gray, banded
gneisses, various granitoids, and rather well-preserved volcanic rocks that
show evidence of submarine extrusion (i.e., emission of rock material in
molten form) and formation under high temperatures. The rock
type komatiite is particularly diagnostic of those volcanic sequences and is
almost exclusively restricted to the Archean Eon. The cratons were
tectonically stabilized by voluminous granite intrusions toward the end of the
Archean and were then covered by clastic sediments, some of which contain
economically important gold and uranium deposits (e.g., the Witwatersrand
System in South Africa).
The Proterozoic Eon (2.5 billion to about 541 million years ago) is
characterized by the formation of several mobile belts, which are long, narrow
zones of strongly deformed and metamorphosed rocks that occur between the
cratons and probably resulted from the collision between the cratons due to
plate tectonic processes. The oldest mobile belts are found in Archean rocks,
such as the Limpopo belt separating the Kaapvaal from the Zimbabwe craton.
Younger belts were formed during a continentwide thermotectonic event
known as the Eburnian (2.2 to 1.8 billion years ago), which gave rise to the
Birimian assemblage in western Africa, the Ubendian assemblage in east-
central Africa, and large volumes of rocks in Angola. Still younger belts of the
Kibaran thermotectonic event (1.2 billion to 950 million years ago) are found in
eastern and Southern Africa.
The end of the Precambrian was marked by a major event of mobile-belt
formation known as the Pan-African episode (about 950 to 550 million years
ago), which generated long fold belts, such as the Mozambique belt along the
east coast of Africa, the Damara and Katanga belts extending
from Namibia into the Democratic Republic of the Congo and Zambia, the
West Congo belt between Angola and Gabon, the Dahomey-Ahaggar belt
between Ghana and Algeria, and the Mauritanide belt
from Senegal to Morocco.
A unique late Precambrian evolution is recorded in the so-called Arabian-
Nubian Shield of northeastern Africa and Arabia. There, large volumes of
volcanic and granitoid rocks were generated in an island-arc, marginal-basin
setting—an environment similar to that of the present southwestern Pacific
Ocean. Rocks were accreted onto the ancient African continent, the margin of
which was then near the present Nile River, by subductionprocesses identical
to those observed today. (Subduction involves the descent of the edge of one
lithospheric plate beneath that of another where two such plates collide.)
The interiors of the ancient cratons were not affected by the above tectonic
events, and intracratonic sedimentary and volcanic sequences accumulated in
large basins. The most important of those are the Transvaal basin on the
Kaapvaal craton that contains economically important iron ore deposits; the
Congo basin; and the West African basin, with its thick late Proterozoic
sediments including a prominent tillite horizon that marks a major glaciation
event at the end of the Precambrian.

After the Precambrian, Africa’s geologic history is characterized by the

following events: the formation of fold belts in the Paleozoic Era (about 541 to
252 million years ago) in South Africa (the Cape fold belt), Morocco (the Anti-
Atlas belt), and Mauritania (the Mauritanide belt) bordering the older cratons;
voluminous basaltic volcanism some 230 to 200 million years ago in South
Africa, Namibia, and East Africa, known as the Karoo System, that was
probably related to the beginning of the breakup of
the Gondwanasupercontinent; the formation of a young mountain belt in
northwestern Africa some 100 to 40 million years ago as a result of collision
between the African and European plates, together with the closure of the
ancestral Mediterranean Sea (the Tethys Sea); and the development of
the East African Rift System during the Cenozoic Era (i.e., roughly the past 66
million years), leading to the opening of the Red Sea, the northeast drift of the
Arabian Plate, and the fracturing of the ancient crust of Africa along several
long rift valleys, accompanied by extensive volcanism.

Little KarooLittle Karoo, near Oudtshoorn, Western Cape province, South Africa.© Daleen
Loest/Shutterstock.com

Rock types and structural evolution

The Precambrian
The oldest rocks consist of gneisses, granites, metasediments, and
metavolcanic rocks 3.6 to 2.5 billion years old; all are variably deformed and
metamorphosed to some degree. The best-preserved assemblages occur in
the Kaapvaal and Zimbabwe cratons and contain large deposits of gold and
sulfide minerals. The volcanic suites are dominated by basaltic and komatiitic
lavas, often interlayered with metasediments and generally referred to as
greenstone belts. Those structures are often found together with layered
gneisses, or they are intruded by granitoid plutons. Several generations of
greenstones have been recognized. The oldest formed about 3.4 billion years
ago, the second some 3 to 2.9 billion years ago, and the third some 2.7 to 2.6
billion years ago. Some of the oldest traces of life are preserved as unicellular
algae in Precambrian cherts of the Barberton greenstone belt in
the Transvaal region of South Africa. The end of the Archean is marked by
voluminous granite intrusions, after which Africa’s cratons became tectonically
stable. One of the most spectacular features marking the end of the Archean
is the intrusion of the Great Dyke in Zimbabwe, a large, layered body of mafic-
ultramafic rocks with substantial deposits of chromium, asbestos, and nickel. It
is still not clear whether Archean evolution was characterized by the same
plate tectonic processes that are seen today, and there are suggestions that
the greenstone belts are remnants of ancient oceanic crust. Cratonic
(essentially undeformed) sediments appear in the stratigraphic record for the
first time in the late Archean and are best developed in the Kaapvaal craton of
Southern Africa.
The early Proterozoic (about 2.5 to 1.6 billion years ago) is characterized by
cratonic clastic sediments on the stable cratons—the best examples are the
Witwatersrand-Ventersdorp-Transvaal basin of Southern Africa and the
Francevillian basin in Gabon—and by metavolcanic-metasedimentary rocks
and granitoids in noncratonic areas such as the extensive Birimian terrain of
western Africa extending from Senegal to Ghana. Of particular interest are
extensive stromatolite-bearing limestones and economically important iron
formations in the Transvaal sequence of South Africa that provide evidence
for an oxygen-rich atmosphere by about 2.2 billion years ago. About 2 billion
years ago the Bushveld Complex—which is one of the
largest differentiated igneous bodies on Earth, containing major deposits
of platinum, chromium, and vanadium—was emplaced in the northern
Kaapvaal craton. The middle part of the early Proterozoic was dominated by
powerful orogenic (mountain-building) processes that gave rise to fold belts in
which sedimentary and volcanic rocks originally deposited in deep basins
along the continental margins were severely deformed, metamorphosed,
intruded by granitoid plutons, and finally uplifted into mountain ranges,
probably as a result of continental collision. That Eburnian event was
particularly active in western Africa, where it deformed the Birimian
assemblages; but it was also active in eastern Africa, where it generated the
Ubendian belt in southern Tanzania, and in southwestern Africa, where it
formed major rock units in Angola and northern Namibia. By the end of the
early Proterozoic, the Archean crustal blocks had grown into cratons of
considerable size.
The record of the middle Proterozoic (about 1.6 to 1 billion years ago)
shows deposition of continental sediments and volcanic rocks on the cratons
and adjacent to the earlier fold belts (molasse deposits). Undeformed or only
mildly folded successions are found in Southern Africa (Waterberg and
Matsap sequences), in northern Zambia, and in the Democratic Republic of
the Congo. Elsewhere, sedimentary and volcanic sequences were deposited
in elongate basins that were later subjected to intense deformation and
metamorphism during the Kibaran event. That important thermotectonic
episode gave rise to the Kibaran-Burundian fold belt in east-central Africa, the
Ruwenzori belt in Uganda, and the Namaqua-Natal belt in South Africa and
Namibia.
The late Proterozoic (about 1 billion to 541 million years ago) is again
characterized by platform deposits in stable areas, such as the West African
craton (Taoudeni and Tindouf basins), the Congo craton, the Kalahari craton
(Nama basin of Namibia), and the Tanzania craton (Bukoban beds). Tectonic
and magmatic activity was concentrated in mobile belts surrounding the stable
areas and took place throughout the late Proterozoic, during the so-called
Pan-African thermotectonic event. Long, linear belts—such as the Damara-
Katanga of central and southwestern Africa, the Mozambique belt of eastern
Africa, and the Dahomey-Ahaggar belt of western Africa—formed during that
time, and some of those belts contain diagnostic rock assemblages that
indicate that they resulted from continental collisions. Many late Precambrian
sequences of Africa contain one or two beds of tillites (sedimentary rocks that
are composed of lithified clay and rock sediments produced by the action of
ice), which are thought to have resulted from an extensive glaciation that
covered much of Africa at that time. In the Arabian (Eastern) Desert
of Egypt and in the Red Sea Hills of Sudan, a predominance of volcanic rocks
and granitoids, together with frequent remnants of ancient oceanic crust,
document an evolution similar to what is now occurring in the island-arc
systems of the southwestern Pacific. Those rocks clearly demonstrate that
plate tectonic processes operated in the late Precambrian.
The Paleozoic Era
The Paleozoic Era consists of
the Cambrian, Ordovician, Silurian, Devonian, Carboniferous,
and Permian periods and includes two major mountain-building episodes. The
continent of Africa may be said to have taken shape during the Paleozoic. A
glacial period during the Ordovician is evidenced by widespread
deposition tillites, which may be seen in southern Morocco, throughout
western Africa, and in subequatorial Africa as far south as Namibia. That tillite
sequence marks the transition from the end of the Precambrian to the
beginning of the Cambrian Period.

Table MountainTable Mountain overlooking Cape Town and Table Bay, Western Cape province, South
Africa.Glowimages/Getty Images

Marine fossils of the Cambrian Period (about 541 to 485 million years ago) are
found in southern Morocco, the Western and Mauritanian Sahara, and
Namibia. In Egypt and in the Arabian Peninsula their presence has been
revealed by drilling. Elsewhere they remain unknown.
During the Ordovician Period (about 485 to 444 million years ago),
fossiliferous marine sandstone completely covered northern and western
Africa, including the Sahara. The Table Mountain sandstone of South
Africa constitutes its only other trace. That period is, in addition, remarkable
for broad, large-scale deformation of the African crust, which raised the
continental table of the central and western Sahara by approximately 5,000
feet (1,500 metres). Each emergence resulted in the creation of valleys that
became flooded when the continent subsided. Toward the end of the period,
the Sahara became glaciated, and tillites and sandstones filled the valleys. A
complete change of sedimentation characterized the Silurian Period (about
444 to 419 million years ago), which is indicated by the deposits of graptolitic
shales (those containing small fossil colonies of extinct marine animals of
uncertain zoological affinity) in the Arabian Peninsula and in northwestern
Africa.
Marine fossils of the Devonian Period (about 419 to 359 million years ago) are
found in North Africa and in the Sahara. Traces also have been discovered in
parts of Guinea, Ghana, and Arabia, as well as in Gabon; they also occur in
the Bokkeveld Series of South Africa. Fossilized plants that
include Archaeosigillaria (ancient club mosses) may be traced in formations of
the earlier Devonian Period in the Sahara and in South Africa (Witteberg
Series).
The Carboniferous Period (about 359 to 299 million years ago) was marked
by the onset of several major tectonic events. Evidence of marine life that
existed in the earlier part of the period comes from fossils found in North
Africa, the central and western Sahara, and Egypt. During the middle and later
parts of the Carboniferous, the Hercynian mountain-building episodes
occurred as a result of collision between the North American and African
plates. The Mauritanide mountain chain was compressed and folded at that
time along the western margin of the West African craton from Morocco to
Senegal. Elsewhere, major uplift or subsidence occurred, continuing until the
end of the Triassic Period (i.e., about 201 million years ago). Those structures
were synformal (folded with the strata dipping inward toward a central axis) in
the Tindouf and Taoudeni basins of western Algeria, Mauritania, and Mali and
antiformal (forming a mountainous spine or dome) at Reguibat in
eastern Western Sahara.
The late Carboniferous Period is represented throughout the Sahara by layers
of fossilized plants and sometimes—as in Morocco and Algeria—by seams of
coal. Different phenomena may be observed, however, in the region of
subequatorial Africa, including the Dwyka tillite, which covers part of South
Africa, Namibia, Madagascar, an extensive portion of the Congo Basin, and
Gabon. At several places in South Africa, the Dwyka strata are covered by
thin marine layers that serve to demarcate the transition from the
Carboniferous to the Permian Period and that form the beginning of the great
Karoo System.
Marine fossils of the Permian Period (about 299 to 252 million years ago) are
visible in southern Tunisia, in Egypt, in the Arabian Peninsula, on the coasts
of Tanzania, and in the Mozambique Channel. Elsewhere, traces of the
Permian are of continental rather than marine origin and are included in the
Karoo System in South Africa. There, the lower Permian strata are known as
the Ecca Series and are divided into three groups: the Lower Ecca (containing
almost 1,000 feet [300 metres] of shales), the Middle Ecca (some 1,650 feet
[500 metres] of sandstone, seams of coal, and fossilized plants), and
the Upper Ecca (about 650 feet [200 metres] of shales again).
The upper Permian is represented by the lower part of the Beaufort Series,
which continued forming into the early Triassic Period. The Beaufort Series is
almost 10,000 feet (3,000 metres) thick and is famous for its amphibianand
reptile fossils; a similar series is also found in southern Russia. Other Permian
formations, not as rich in coal, occur in the Democratic Republic of the Congo,
Tanzania, Kenya, Uganda, Zambia, Zimbabwe, Mozambique, and
Madagascar.
The absence of primary marine formations throughout Southern Africa should
be emphasized. It is not yet known whether that absence is due to a hiatus in
deposition or to erosion.
The Mesozoic Era
The Mesozoic Era (about 252 to 66 million years ago) is divided into three
periods—the Triassic, Jurassic, and Cretaceous—and is remarkable for the
transgression of ancient seas and for the emergence of massive land
formations containing interesting fossil remains.
Marine formations

During the Triassic Period (about 252 to 201 million years ago), ancient seas
left deposits of marine formations in North Africa, the southern Sahara, Egypt,
Arabia, and parts of Tanzania and northern Madagascar. Deposits from
the Jurassic Period (about 201 to 145 million years ago) extend to the Atlantic
basins of the Río de Oro region of Western Sahara and Senegal along the
northwest coast of the continent. In the middle of the Jurassic a great
transgression of the Indian Ocean extended over Somalia and much
of Ethiopia. That event was followed by a series of marine transgressions in
the Cretaceous Period (about 145 to 66 million years ago), including those
along the coasts of equatorial Africa when Gondwana broke up and the
present Atlantic and Indian oceans took shape; during one transgression a
shallow sea covered much of the northern and central Sahara and Egypt as
far south as Sudan; and a later one again covered the same areas, as well as
western Arabia and the west coast of Madagascar.
Continental formations

In Africa north of the Equator and in Arabia, Mesozoic continental formations

covered large areas. During the Triassic the Saharan Zarzaitine Series,
containing dinosaur and other reptilian fossil remains, was deposited.
The Saharan Taouratine Series, containing fossils of vegetation and of great
reptiles, was laid down during the Jurassic. In the upper Karoo System of
subequatorial Africa, formed during the early Triassic Period, the Beaufort
Series contains fossils of fish, amphibians, and reptiles. The final stages of the
Triassic and the early Jurassic periods were characterized by the terminal
folding of the Cape mountain chain, by subsidence in the Karoo basin, by
fracturing, and by widespread upwelling of Karoo basaltic lavas
through fissures, creating formations some 4,000 feet (1,200 metres) thick,
such as the Drakensberg range along the eastern border of Lesothoand in
South Africa.
During the Jurassic and the Cretaceous periods, widespread sediments were
deposited that contain fossilized plants, dinosaurs, and smaller reptiles.
Certain unique eruptions occurred during the Cretaceous that led to the
creation of kimberlite pipes (near-cylindrical rock bodies, usually
approximately vertical and derived from melting at great depth in the upper
mantle) in Southern and Central Africa; some of those, particularly in South
Africa, Botswana, Namibia, Angola, and the Democratic Republic of the
Congo, contain large quantities of diamonds and are the main source of that
precious mineral.
The Cenozoic Era
The Cenozoic, the most recent major interval of geologic time (i.e., the past 66
million years), is commonly divided into the Paleogene, Neogene,
and Quaternary periods. The Paleogene and Neogene (about 66 to 2.6 million
years ago) are remarkable for their great tectonic movements, which resulted
in the Alpine orogeny. During that mountain-building episode, the Atlas
Mountains of northwestern Africa were folded and uplifted. Notable too are the
formation of the Red Sea rift valley and the volcanism and rifting that took
place during the later stages of the period.

Atlas MountainsToubkal peak (top right) in the High Atlas Mountains, Morocco.Tom McHugh/Photo
Researchers
Marine formations

The initial epoch of the Cenozoic, the Paleocene (about 66 to 56 million years
ago), is important for its marine formations with animal fossils, including
nummulites (a large kind of foraminifera, which are unicellular animals of
macroscopic size), nautiloids (shelled cephalopods, which are mollusks with
tentacles attached to their heads), and echinoids (sea urchins); all of those
are found in North and West Africa and in the Sahara. With the exception of
the Sahara, nummulites of the Eocene Epoch (about 56 to 34 million years
ago) are found in the same places, as well as on the African coasts of the
Indian Ocean. There also are lepidocyclines (foraminifera) of the Oligocene
Epoch (about 34 to 23 million years ago) and of the Miocene Epoch (about 23
to 5.3 million years ago).
Continental formations

Several levels may sometimes be distinguished in the continental formations

of the Cenozoic Era. They include lower Eocene levels
containing Pseudoceratodes (a genus of gastropod) and Dyrosaurus (a type
of reptile), as well as upper Eocene and Oligocene levels containing silicified
wood and fossilized fish, turtles, crocodiles, snakes, and mammals. In Egypt
the Oligocene deposits found in the Al-Fayyūm area contain mammals, birds,
turtles, and crocodiles. Sediments of the lower Miocene, which are found on
the banks of Lakes Rudolf and Victoria in East Africa, contain mastodon (a
large elephant-like mammal) and Proconsul africanus(a large ape). Central
Asian hipparions (three-toed ancestors of the horse), which simultaneously
entered Africa and Europe during the late Miocene Epoch (about 11 to 5.3
million years ago), also left their fossilized remains in the region, as did
genera of hominoid (humanlike) apes—e.g., Kenyapithecus of Kenya—at
about the same time.
 Rudolf, LakeLake Rudolf, northern Kenya.Doron

Tectonic movements
The first major folding of the Tell Atlas Mountains of North Africa took place in
the Oligocene Epoch. In the Miocene, North African flysch (thick and
extensive deposits composed largely of sandstone) formed layers that, from
the Rif mountain range of Morocco to northern Tunisia, were pushed from the
north toward the south. The High Plains area, farther south, which as a whole
was only mildly deformed, was bounded on the south by the northern Atlas
Mountains, which intervened between it and the Saharan Atlas. Continental
movements lifted the Aurès mountains to a height of about 3,300 feet (1,000
metres) during the middle of the Miocene; the Aurès are bounded on the
south by the northern Sahara structural line, which extends from Agadir in
Morocco in the west to the Gulf of Gabes in Tunisia in the east, dividing the
African Shield from the folded Mediterranean, or Alpine, zone.
Formation of the Red Sea
Tectonic movements in the region of the Arabian-Nubian Shield that took
place at the end of the Oligocene and the beginning of the Miocene Epoch
almost separated Arabia from Africa. A trough (fault-bounded depression)
developed because of divergence in the crust between northeastern Africa
and western Arabia, and the Mediterranean Sea swept into the resulting rift
valley, forming a gulf that extended to Yemen. The gulf was prevented from
joining the Indian Ocean only by an isthmus that stretched from Djibouti in the
west to Aden (Yemen) in the east.
At the end of the Miocene the Isthmus of Suez was formed, and the gulf
became a saline lake at the bottom of which thick evaporites (sediments
formed as a result of evaporation) were laid down. The isthmus permitted
Asian animal life to pass into Africa during part of the Pliocene Epoch (from
about 5.3 to 2.6 million years ago). Subsidence of the Djibouti-Aden isthmus,
also during the Pliocene, permitted the Indian Ocean to flow into the Red Sea
as far as the Isthmus of Suez.
Volcanism and rifting

Tectonic movements during the Miocene and Pliocene scored the African
continent with a network of faults that generally trended northeast to
southwest and northwest to southeast. Volcanic eruptions and basaltic
upwellings accompanied fracturing in the Ahaggar area of southern Algeria, in
the Tibesti area of Libya and Chad, in Ethiopia, throughout East Africa, and
in Cameroon, as well as in the islands of Bioko (formerly Fernando Po)
and São Tomé and Príncipe in the Gulf of Guinea.

AhaggarAhaggar, North Africa.Bertrand Devouard

Pleistocene and Holocene developments

The Quaternary Period (i.e., about the past 2,600,000 years) is divided into
the Pleistocene Epoch (about 2,600,000 to 11,700 years ago) and
the Holocene, or Recent, Epoch (the past 11,700 years). It represents a
phase of continuing volcanic activity that caused the basement rocks of the
Ahaggar and Tibesti mountains of the central Sahara to rise. The
activity manifested itself in eruptions, in the deepening of the Saharan valleys,
and in the extrusion of flood basalt.
During the cold humid periods called pluvials, which correspond to the glacial
phases of the Northern Hemisphere, the glaciers that covered the high
mountains of East Africa were 3,000 to 5,000 feet thicker than those
remaining in the summit zones today. Elsewhere the desert zones of
the Sahara and the Kalahari were alternately subjected first to humid and then
to dry and arid phases that expanded the desert surface at the expense of
adjacent forested zones.
The oldest levels at which hominin remains have been found are known as
the Villafranchian-Kaguerian Series and are recognized in Ethiopia and Kenya.
Those levels date to approximately three to four million years ago and contain
fossils of the genus Australopithecus. The Kaguerian-Kamasian Interpluvial
levels, which date to about 500,000 years ago, contain the remains of Homo
erectus at Olduvai Gorge (Tanzania) and in Morocco, Algeria, and Chad.

AustralopithecusLearn about the Australopithecus genus.Contunico © ZDF Enterprises GmbH, Mainz

The Kamasian, or Second, Pluvial of the middle Pleistocene Epoch

corresponds to the Mindel in Europe. A dry but not a desert climate is implied
by the Kamasian-Kanjeran Interpluvial levels at Olduvai Gorge. The Kanjeran,
or Third, Pluvial occurred during the middle Pleistocene and corresponds to
the Riss Pluvial in Europe.
An arid phase, which greatly reduced forest land, is revealed in the Kanjeran-
Gamblian Interpluvial levels, lasting from about 60,000 to 55,000 years ago.
That period corresponds to an important tectonic phase marked by uplift and
subsidence in North Africa and activity along all the faults, in particular those
in eastern Africa. It was at that time that eastern Africa assumed its present
topographic character.
During the Gamblian, or Fourth, Pluvial, which occurred from approximately
30,000 to 15,000 years ago, three distinct humid phases are separated by
drier intervals. During those phases the dimensions of Lake Chad and those
of the glaciers of Mount Kenya and of Kilimanjarodiminished rapidly. The
postpluvial phase that followed the period, equivalent to the postglacial phase
of the Northern Hemisphere, was marked by a succession of alternating dry
and humid stages and by the desertification of both the Sahara and the
Kalahari, a process that began about 3,000 BCE.

Mount Kenya, central Kenya.© Jiri Kasal/Fotolia

Alfred Kröner

Land
Relief
The physiography of Africa is essentially a reflection of the geologic history
and geology that is described in the previous section. The continent,
composed largely of a vast rigid block of ancient rocks, has geologically young
mountains at its extremities in the highlands of the Atlas Mountainsin the
northwest and the Cape ranges in the south. Between these mountainous
areas is a series of plateau surfaces, with huge areas that are level or slightly
undulating, above which stand occasional harder and more
resistant rock masses. Surrounding these surfaces is a zone of
plateau slopes below which are narrow coastal belts widening along the
Mediterranean coast, the coastlands of Tanzania and Mozambique, a narrow
belt between the Niger and Cunene (Kunene) rivers, and an area northward
of the Gambia and Sénégal rivers.

Physical regions of AfricaEncyclopædia Britannica, Inc.

 BRITANNICA QUIZ

African Leaders: Part One

Ellen Johnson Sirleaf

Kilimanjaro (19,340 feet [5,895 metres]) is the highest point on the continent;
the lowest is Lake Assal (515 feet [157 metres] below sea level) in Djibouti. In
proportion to its size, Africa has fewer high mountains and fewer lowland
plains than any other continent. The limited areas above 8,000 feet are either
volcanic peaks or resistant massifs. All the land below 500 feet occurs within
500 miles of the coast, except for two small basins in the Sahara.
 Summit of Kilimanjaro, northeastern Tanzania.© Shawn McCullars

The higher areas of the south and east are in marked contrast to the
considerably lower elevation of the western and northern parts of the
continent. South of a line drawn from near the mouth of the Congo River to
the Gulf of Aden, most of the land lies 1,000 feet or more above sea level, and
much of it exceeds 3,000 and even 4,000 feet. North of the line there is
relatively little land above 3,000 feet, most of the area being between 500 and
1,000 feet above sea level; there are also broad coastal lowlands, except in
the region of the Atlas Mountains and, in the east, beyond the Nile.
 MoroccoThe rugged Atlas Mountains surround a valley in Morocco.Victor Englebert/Photo Researchers

The highest extensive areas are to be found in Ethiopia, parts of which

exceed 15,000 feet. Southward the East African Plateau is highest in Kenya,
where it is often 8,000 feet or more above sea level; there are occasional
volcanic peaks that are much higher, such as Kilimanjaro, Mount
Kenya(17,058 feet), Meru (14,978 feet), and Elgon (14,178 feet).
The Ruwenzori (Rwenzori) Range—sometimes called the Mountains of the
Moon—which reaches its highest elevation at Margherita Peak (16,795 feet)
on the borders of the Democratic Republic of the Congo and Uganda, is not
volcanic in origin. From East Africa the plateau extends southward, often with
a well-defined though not continuous escarpment particularly noticeable in
the Drakensberg of Southern Africa, where Ntlenyana, or Ntshonyana, is
11,424 feet and Mont-aux-Sources 10,823 feet high. There the plateau edges
are especially marked, because the rock formations are hard and horizontal,
whereas in Ethiopia they are conspicuous because of faulting. Where the
rocks are softer and less resistant, the escarpment is not so pronounced and
so forms less of a barrier to climatic influences and to humanmovement.

 

Afromontane moorland of tussocky grasses, giant groundsel, and lobelias on the slopes of Mount
Kenya.Caroline Weaver/Ardea London

Margherita Peak in the Ruwenzori Mountains, Uganda© Lauré Communications/Paul Joynson-Hicks

To the north and west of the plateau area of the southern parts of the
continent there is a general descent to the lower areas of the basins of the
Congo, Niger, and Nile rivers. The only large areas that extend above 3,000
feet are in the folded ranges of the Atlas Mountains and in the central Sahara,
where resistant granites form the massifs of Ahaggar and Tibesti. The interior
uplands of western Africa and of Cameroon consist of ancient crystalline rocks,
reaching considerable heights only in the Fouta Djallonplateau in Guinea, in
the Guinea Highlands, which also extend over the borders of Sierra
Leone and Liberia, in the Jos Plateau in Nigeria, in the Adamawa region of
Nigeria and Cameroon, and in the Cameroon Highlands. There are extensive
low-lying areas near the coast and in the basins of the Sénégal, Gambia,
Volta, and Niger–Benue rivers. The high areas of Darfur in Sudan (more than
10,000 feet) and of Mount Cameroon(13,435 feet) are volcanic in origin and
are evidence of the same tensions that have resulted in rifting and volcanism
in East Africa.



 The Atlas Mountains.Encyclopædia Britannica, Inc.

Algeria: geographyThe Ahaggar Plateau rises from the barren landscape of the Sahara in southern
Algeria.Geoff Renner/Robert Harding Picture Library

The East African Rift System constitutes the most striking and distinctive relief
feature of the continent. Associated with its formation was the volcanic
activity responsible for most of the higher peaks of East Africa,
including Kilimanjaro. Seismic and volcanic disturbances are still recorded in
the western portions of the rift valley system. In the Virunga Mountains,
northeast of Lake Kivu, there are periodic outbursts (about every 10 or 12
years) that have created a series of lava flows. One of these volcanoes
dammed the rift valley and converted a large area, formerly drained by a
tributary of the Nile, into Lake Kivu.
The rift valley extends for about 4,000 miles, its course being clearly marked
by many of the lakes of East Africa as well as by the adjacent volcanic peaks.
From the Gulf of Aqaba it can be traced southward along the Red Sea and
into the Ethiopian Plateau to Lakes Rudolf, Naivasha, and Magadi in Kenya.
Farther south, through Tanzania, the line of the rift is not quite so obvious.
The walls that constitute the eastern rim have been more easily eroded, while
the lakes of this area are generally smaller and not in line, and some of them
are only waterless salt beds. The largest of these lakes
are Natron and Manyara, with Eyasi in a side branch of the main rift. The
edges are obvious enough to the south in Malawi, where a huge crusted block
collapsed along the parallel faults that constitute the steeply rising slopes
of Lake Nyasa (Malawi). The lake is 360 miles long but never more than 50
miles wide; it has a maximum depth of 2,310 feet. The rift then follows the line
of the Shire Valley to reach the Indian Ocean near Beira, Mozambique.



 Mountains and lakes of East Africa.Encyclopædia Britannica, Inc.

Fishing boat on Lake Nyasa (also called Lake Malawi).Neil Cooper—Panos Pictures

The western branch, or Western Rift Valley, extends from the northern end of
Lake Nyasa in a great arc, taking in Lakes Rukwa, Tanganyika (after Lake
Baikal in Siberia the deepest lake in the world), Kivu, Edward, and Albert.
Subsidiary branches of this valley include the basins in which lie Lakes Mweru
and Upemba.

Lake Kivu is one of the great lakes of East Africa. It lies between Rwanda and the Democratic Republic of
the Congo.Kay Honkanen/Ostman Agency
Most of the lakes that occur along the course of the rift valley lie well below
the general level of the plateau, ranging from about 1,300 to 3,000 feet above
sea level. They are generally very deep and bear a striking resemblance to
fjords; some have floors that are below sea level, even though their surfaces
are hundreds of feet above sea level.

In complete contrast is Lake Victoria, the largest of all African lakes, which
occupies a shallow depression on a plateau 3,720 feet above sea level
between the major branches of the rift valley. Its greatest depth is only 270
feet, but, with an area of 26,828 square miles, it is the third largest of the
world’s lakes, after the Caspian Sea and Lake Superior.
See individual articles for a detailed discussion of the Atlas Mountains, East
African mountains, Ituri Forest, Kalahari, Namib, Sahara, and veld.
Robert Walter Steel

Drainage

The uplifting and warping of the surface of the African continent that occurred
during the Pliocene and Pleistocene epochs produced a number of structural
basins; these are now either individually occupied by, or are linked up with,
drainage systems. With the exception of the Chad basin, all the major
drainage basins have outlets to the sea. In addition, minor drainage basins,
similar to that of Lake Chad, are situated in the East African Rift Valley. Some,
again like Lake Chad, constitute the focus of centripetal drainage (drainage
directed toward the centre), while others are linked to river systems. Although
the East African lakes are climatically and economically important, relatively
little is known of their hydrological characteristics.
Climate, geology, and the history of tectonic activity have imparted certain
common characteristics to African rivers. Spatial variations in the incidence
and amount of rainfall are reflected in their hydrological regimes. In areas that
have one rainfall season, for example, and have pronounced drought
throughout the rest of the year, the rivers flood in the rainy season and shrink
in the dry season.

Whatever their hydrological regimes, all the important African rivers are
interrupted by rapids, cataracts, and waterfalls. This is explained by several
factors, the most important of which is the past tectonic activity, or regional
land movements, that caused ridges to be formed across the courses of the
major rivers. Waterfalls are often found where the rivers are still engaged in
cutting downward as they flow across these ridges; Cahora Bassa (falls) on
the Zambezi and the Augrabies Falls on the Orange River are examples.
Another factor that contributes to the creation of rapids or falls is the incidence
of rock strata that have proved resistant to the erosive effect of the rivers’ flow.
(Tropical rivers do not generally carry large quantities of stone or rock; instead,
they have a tendency to carry loads of fine silt, produced by chemical
weathering.)
Although the Nile, the Zambezi, and the Niger rivers have large deltas, their
size does not compare with, for example, the enormous delta region of the
Ganges and Brahmaputra rivers. In Africa the generally poor development of
deltas is mainly because of the restricted extent of the coastal plain, together
with the relatively narrow continental shelf, which provides neither sufficient
room nor shallow enough water for the deposition of delta-forming material.
The great speed with which most of the rivers flow into the sea is another
factor inhibiting delta formation.
The major drainage basins of Africa are those of the Nile, the Niger, the
Congo, the Zambezi, and the Orange rivers and of Lake Chad.

Nile basin
There are two theories concerning the development of the Nile, which, it
appears, originally consisted of two sections. The first theory is that the lower
Nile had its source at about latitude 20° N, whence it flowed directly into the
sea, while the upper Nile, issuing from Lake Victoria, flowed into an inland
lake that covered the Al-Sudd region in what is now South Sudan. The lake
became filled with water, which then spilled over at its northern end and
flowed into what is now the lower Nile. According to the second theory, the
upper section originally flowed into a vast lake between Mount Al-Silsilah
(near Luxor, Egypt) and what is now Aswān; this was tapped by the lower
section of the Nile after the so-called Sebile erosion (which takes its name
from the fact that the breakthrough by the lower Nile was identified at Sebile).
 The Nile River basin and its drainage network.Encyclopædia Britannica, Inc.

The Nile, which is about 4,132 miles long, is the longest river in the world.
From Lake Victoria it flows, as the Victoria Nile, into Lake Albert, from which it
emerges as the Albert Nile. Farther north it is known as the Al-Jabal River.
Thereafter, having received several tributaries, it becomes the White Nile and
finally the Nile, emptying at last into the Mediterranean Sea. Its major left-bank
tributary is the Al-Ghazāl, and the largest right-bank tributaries are the Sobat,
Blue Nile, and Atbara. Because of the numerous rapids and waterfalls, the
Nile descends fairly rapidly from source to mouth, as do its major right-bank
tributaries. This is especially true of the Blue Nile, which, after issuing
from Lake Tana on the Ethiopian Plateau at a height of approximately 6,000
feet, flows for most of its length through a steep gorge. Swamps also interrupt
the river’s course. Of these the largest is Al-Sudd, a vast area of floating
swamp reeds, mostly papyrus.
White Nile RiverVillage along the White Nile River in Al-Sudd region, South Sudan.© Klaus D. Francke/Peter
Arnold, Inc.

The river’s regime is now controlled by a series of dams situated on the Nile
itself or on one of its various tributaries; of these, the largest is the Aswan
High Dam on the main Nile.
Niger basin
The Niger basin is the largest river basin of western Africa. The Niger River,
which rises in the mountains of Guinea and enters the sea through its delta in
southern Nigeria, is about 2,600 miles in length. Rapids interrupt its course at
several points, although some of these (such as below Bamako, Mali) have
been submerged in waters impounded by dams.
 The Niger and Sénégal river basins and the Lake Chad basin and their drainage networks.Encyclopædia
Britannica, Inc.

The Niger receives its largest tributary, the Benue, which flows in from its left
bank, in Nigeria. The valleys of both the Niger downstream from Taoussa and
the Benue appear to be faulted troughs dating from the early Cretaceous
Period. Originally, the middle Niger was separate from the upper Niger, which
flowed into an inland lake, the remnants of which now form the inland Niger
delta. The middle Niger flowed southeastward to the sea; its valley eroded
toward its headwaters, eventually tapping the inland lake and linking the
middle with the upper Niger.
West Africa: The Niger RiverThe Niger River in the western region of Africa is used for irrigation, power
production, and transportation.Encyclopædia Britannica, Inc.

Congo basin
With a total area of about 1,335,000 square miles, the Congo basin consists
of a vast shallow depression that rises by a series of giant steps to an almost
circular rim of highlands through which the river has cut a narrow exit into
the Atlantic Ocean. The present exit is geologically relatively recent; the
previous exit was to the north of the present one.
 The Congo River basin and its drainage network.Encyclopædia Britannica, Inc.

The Congo River is some 2,900 miles in length. Its many waterfalls and rapids
cause its valley, like that of the Nile, to lose elevation quickly. The river’s
course is often constricted by gorges. The best-known are
the Boyoma (Stanley) Falls at Kisangani, where the river swings through an
arc to flow westward; in fact, the Boyoma Falls are no more than a series of
unevenly spaced rapids at no great height, extending along a 60-mile stretch
of the river. Downstream from Kisangani, the Congo is joined first by the
Ubangi from the right and then by the Kasai—which rivals the Ubangi in the
size of its drainage basin—from the left. Below its confluencewith the Kasai,
the main river cuts through the Cristal Mountains in a deep gorge, which at
one point expands into Malebo (Stanley) Pool, a shallow lake measuring 22
miles in length and 14 miles in width. The Congo enters the sea through a
swampy estuary that is about 6 miles wide at its mouth.
 Enya (Wagenia) fishing in the rapids of the Congo River near Kisangani, Democratic Republic of the
Congo.SuperStock

Zambezi basin
The Zambezi River is about 2,200 miles in length and occupies a basin with
an approximate area of 463,000 square miles. Originally, there were two
rivers, corresponding to the upper and lower courses of the present river; the
valley of the lower section eroded toward the headwaters until it captured the
waters of the upper section. Although there are stretches of the river where
the gradient is very gentle—a drop of only about three inches to the mile—the
valley as a whole has a fairly steep gradient. There are numerous waterfalls,
the most spectacular of which is the Victoria Falls. After these falls, the river
winds through a number of deep gorges cut out of basalt and, after flowing
through a broad valley, enters Kariba Gorge, which is more than 16 miles in
length and is cut through paragneiss (a gneiss, or coarse-grained rock, in
which bands rich in granular minerals alternate with bands containing
schistose minerals, formed out of sedimentary rock). The Kafue and the
Luangwa, the two main tributaries, which both flow through gorges, join the
Zambezi on its left bank downstream from Kariba. At the mouth of the main
river is a delta about 37 miles wide.
 The Zambezi River basin and its drainage network.Encyclopædia Britannica, Inc.

Orange basin
The Orange River is the longest in South Africa. Flowing across almost the
entire width of the country, it makes its way from the highlands in the east
through the Kalahari depression in the west to empty into the South Atlantic
Ocean. Its major tributary, the Vaal River, is one of its northern headwaters;
the two rivers together have a combined length of about 1,300 miles. Together
with other major rivers on the continent, the Orange–Vaal river system shares
the characteristic of flowing over steep gradients for numerous stretches of its
course. The largest drop (about 400 feet) occurs at the Augrabies Falls.
 The Orange River basin and its drainage network, one of the prominent physical features of southern
Africa.Encyclopædia Britannica, Inc.

Chad basin
The Chad basin constitutes the largest inland drainage area in Africa. Lake
Chad, a large sheet of fresh water with a mean depth between 3.5 and 4 feet,
lies at the centre of the basin but not in its lowest part. Lake Chad is fed by
three major streams, the Komadugu Yobe, Logone, and Chari, but these are
in danger of having their waters captured by the drainage systems of rivers
that flow in opposite directions. Lake Chad itself, with an area of only some
5,000 square miles, was formerly much more extensive.
For a detailed discussion of Lake Chad, the Congo River, the East African
lakes, the Niger River, the Nile River, the Orange River, the Sénégal River,
the Suez Canal, and the Zambezi River, see individual articles.
Soils

Soil types
In general, soil types on the African continent may be divided into five or six
broad categories. There are desert soils; chestnut-brown soils, which border
the deserts; and chernozem-like soils (dark black soils rich in humus and
carbonates), which are found immediately south of the chestnut soils from
Sudan westward to just beyond the Niger Bend (the bend in the middle course
of the Niger River) and pockets of which are also found in East
Africa, Zambia, Zimbabwe, and South Africa. In addition, there are black soils
(often grouped with chernozems), and found on the Accra Plains of Ghana;
red tropical soils and laterites (leached red iron-bearing soils), which occur in
the tropical wet-and-dry and equatorial climatic zones; and Mediterranean
soils, found in the Atlas Mountains of North Africa and the Cape region
of South Africa.

Distribution of African soil groups as classified by the Food and Agriculture Organization
(FAO).Encyclopædia Britannica, Inc.

The most important factors that affect soil formation are climate, parent
material, relief, drainage, vegetation cover, and the passage of time. Where
the land has been generally stable and fairly flat for prolonged periods, as in
Africa, the climate becomes the major determinant of the soil groups. The
different rocks are deeply weathered and are broken down into their common
component elements to produce broadly similar soils under the same climatic
conditions. Given sufficient time under a tropical climate, the differences in
humus content of the great soil groups, which are introduced by vegetation
types, are minimized. But within these groups there will naturally be
differences in soil types as a function of local differences in physical factors.

Desert soils
These soils are characterized by the general lack of organic content; by the
types of rock reflected in them, the chemical weathering of which has
been inhibited by the lack of water; and by the crusts or concretions of soluble
salts on or just below their surface. While these crusts are in general thought
to have been formed as a result of evaporation, it is nevertheless possible that
they may have been formed under a wetter climate during the Pleistocene
Epoch.
Chestnut-brown soils
In the semiarid areas bordering the desert, increased rainfall makes grass
vegetation more plentiful, results in rocks becoming more weathered than in
the desert, and produces better developed soils with a higher humus content.
It is the humus content that, according to the amount present, gives the
chestnut soils their characteristic light or dark brown colour. Chestnut soils
also differ from desert soils because they receive enough water to wash out
some of the salt accumulations either on the surface or immediately below it.
Chernozem-like and black soils
An unfailing characteristic of the chernozem is the presence of a subsurface
zone of calcium carbonate, sometimes accompanied by calcium sulfate, which
is left behind after all the soluble salts have been washed out. Grouped with
them are the black soils, which should, perhaps, be differently classified, for
their black colour is not necessarily due to high humus content but rather to
the presence of certain minerals, as in the black soils of the Accra Plains,
in Ghana.
Red tropical soils and laterites
The majority of tropical soils have shades of colour varying from yellow and
brown to red. The reddish colour reflects the presence of iron oxides that form
as a result of chemical weathering. At one time all tropical red earths or soils
were indiscriminately referred to as laterites, but it is now clear that the term
laterite should be confined to those tropical soils with large concentrations of
iron and aluminum sesquioxides (insoluble compounds) that have formed a
hard pan at or just below the surface. At the most advanced state of
laterization, bauxite, from which aluminum is extracted, is formed. Most
tropical soils are in varying stages of laterization, which is to say they are at
various stages of accumulating insoluble compounds as the soluble elements
are leached out. The compounds accumulate more readily in areas with a
pronounced dry season and where the water table is not too far below the
surface. If the top horizons (layers) of the soils should erode, the subsurface
concentrations of sesquioxides are then exposed to the atmosphere,
whereupon they crystallize irreversibly to form true laterite concretions.
Mediterranean soils
Mediterranean soils are generally deficient in humus, not so much because of
sparse vegetation cover as because of the slowness of the chemical
processes that convert the vegetable matter to humus. Low rainfall, occurring
when temperatures are lowest, retards chemical weathering. The uneven
surface relief of the regions where these soils occur also makes it difficult for
mature soils to develop, since the land, except in the valley bottoms, is not
sufficiently flat over wide enough areas to allow the soil-forming (parent)
materials to remain in place and thus to be thoroughly weathered.

Soil problems

Soil is the foundation of Africa’s economic life, and as such its detailed study
is most important. Failure to appreciate the physical and chemical properties
of the soils has led to disastrous results for several projects for agricultural
improvement.

In studying the soils of Africa, it is essential not to lose sight of the importance
of such social factors as the ability or inability of mostly uneducated farmers to
judge the quality of the soil. Thus, schemes for transforming traditional
systems of farming that are based on soil classification but that do not take
into account local perception may have little chance of success.

For desert soils to be productive they must be irrigated, as they are on the
desert margins of North Africa; their excessive salinity or alkalinity must also
be reduced. Compared to desert soils, the chestnut-brown soils are easier to
work and are more productive under irrigation. Black soils tend to have a
markedly crumbly structure and are sometimes difficult to plow. In the wet
season, the black soils of the Accra Plains swell and become slippery, while in
the dry season they shrink once more and crack to such an extent that they
are said to plow themselves. Red tropical soils need careful handling. Despite
their luxuriant vegetation cover, high temperatures coupled with humidity
promote the rapid decay of organic matter and keep the humus content low.
Erosion is a constant threat if the soils are exposed to the elements for any
length of time; the soils remain cultivable only if the sesquioxides remain
below the surface.

In the Atlas and Cape regions, there is a clearer relationship between soil
characteristics and parent material than in the humid tropical areas. Over
expanses of limestone, for example, the soils contain large amounts of
calcium compounds, some of which must be washed away or neutralized
before the soils can become fully productive.

Climate

Factors influencing the African climate

A number of factors influence the climate of the African continent. First, most
of the continent—which extends from 35° S to about 37° N latitude—lies
within the tropics. Second, the near bisection of the continent by
the Equator results in a largely symmetrical arrangement of climatic zones on
either side. This symmetry is, however, imperfect because of a third factor—
the great east–west extent of the continent north of the Equator, in contrast to
its narrow width to the south. In consequence, the influence of the sea
extends farther inland in Southern Africa. Moreover, a quasi-permanent
subtropical high-pressure cell (the Saharan anticyclone) develops in the heart
of northern Africa, while in Southern Africa the belt of high pressure on land
weakens during the time of high sun (the season when the Sun is overhead—
in December and January in the south). A fourth factor consists of the
cool ocean currents, which chill the winds that blow over them and thereby
influence the climate of the neighbouring shores. Fifth, because of the
extensive plateau surfaces of the continent and the absence of high and long
mountain ranges comparable to, for example, the Andes in South America or
the Himalayas in Asia, climatic zones in Africa tend to shade into one another,
rather than change abruptly from place to place. Finally, the high mountains
have climatic zones of their own that vary with altitude.
While these factors help to account for the broad climatic patterns of the
African continent, there are nevertheless numerous local variations to be
found from place to place within the same climatic zone. Urban areas, for
example, have climates that often differ in many respects from those of the
surrounding countryside. Typically experiencing higher average temperatures,
urban areas also frequently have less wind and lower relative humidity; there
is too little relevant data from Africa, however, to permit a detailed study of
urban climates.

The most important differentiating climatic element is rainfall; this, together

with several other climatic elements, depends upon the characteristics of the
dominating air mass. The air masses of relevance to the African climate may
be broadly classified as maritime tropical, maritime equatorial, continental
tropical, maritime polar, and continental polar. Of these, the least important
are the continental polar air masses, which may occasionally bring intense
cold to northern Egypt in December and January, and the maritime polar air
masses, which are associated with rain-bearing depressions over the northern
and southern extremities of the continent during the winter. With the exception
of these, the continent is affected both by a continental tropical air mass to the
north and by maritime tropical and maritime equatorial air masses to the south.
These northern and southern air masses meet at the intertropical
convergence zone (ITCZ). The hot, dry continental tropical air mass, which is
present in the upper levels of the atmosphere, descends to the ground only at
the convergence zone. Less hot than the continental tropical are the maritime
tropical and maritime equatorial air masses, which originate from the Indian
and South Atlantic oceans, respectively; they differ only in that the maritime
equatorial air mass is unstable and brings rain while the maritime tropical air
mass, when fully developed, is stable and does not normally bring rain unless
it is forced to rise by a high mountain.
In July the ITCZ—following the sun—moves northward toward the area of low
pressure over the Sahara; there the maritime and continental tropical air
masses converge, with the maritime air masses swinging inland from the sea.
There is no rainfall on the northern side of the convergence zone, since the
region is completely under the dry continental tropical air mass originating
over the Sahara. At the ITCZ itself, however, precipitation is prolonged and
intense as air converges between the maritime and continental air masses
and is forced aloft. Immediately south of the convergence zone, rainfall is
heavy because of the unstable nature of maritime tropical air over a heated
land surface. South of the Equator, at yet greater distance from the
convergence zone, the maritime air masses are less-heated, thick, and stable,
and they bring hardly any rainfall, except over some of the East African
highlands. Only the southern tip of South Africa receives rainfall at this time,
from winter cyclones.
During the period of low sun in the Northern Hemisphere (from December to
January, when the sun has moved to its southern limit), the situation
described above is reversed. The convergence zone moves southward,
dipping into Southern Africa. At this season the whole of northern Africa
(except the Atlas Mountains) is under the dry continental tropical air mass,
while Southern Africa receives rainfall except in the Cape region and on the
southwest coast, where the maritime air mass remains stable offshore over
the cool Benguela Current.
Climatic regions

When considered in detail, the movement of air masses and their effects
provide the basis for a division of the continent into eight climatic regions.
These are the hot desert, semiarid, tropical wet-and-dry, equatorial (tropical
wet), Mediterranean, humid subtropical marine, warm temperate upland, and
mountain regions.

Camel caravan in the Sahara, Morocco.© Vladimir Wrangel/Shutterstock.com

The hot desert region consists of the Sahara and Kalahari deserts, which are
always under the influence of dry continental tropical air masses, and the
northern Kenya–Somali desert, the aridity of which is principally caused by the
stable nature of the maritime air masses that pass over it throughout the year.
The stability of these maritime air masses is induced by their passing over the
cool body of water offshore. In addition to aridity, the desert climate is
characterized by high mean monthly temperatures; the diurnal (daily)
temperature range is, however, greater than the annual range of the mean
monthly temperature.

Africa: major climate regionsAfrica's climate is dominated by desert conditions along vast stretches of
its northern and southern fringes. The central portion of the continent is wetter, with tropical rainforests,
grasslands, and semi-arid climates.Encyclopædia Britannica, Inc./Kenny Chmielewski

Semiarid climatic regions fringe the desert areas and include the greater part
of the land south of the Zambezi River. They differ from true desert regions in
being just within reach of the ITCZ in the course of its seasonal movement
and therefore receiving more rainfall. Temperatures are about the same as
those in the desert regions.
The tropical wet-and-dry region is often called the savanna climatic region;
this implies, incorrectly, that all areas with savanna vegetation have this type
of climate. This region covers a little less than half of the total surface area of
the continent, extending toward the Equator from the semiarid areas. The
great distinguishing feature of this climatic region is the seasonal character of
its rainfall. During the period of high sun, the maritime air masses produce up
to six months of rainfall, the length of the rainy season depending on nearness
to the Equator. The rest of the year is dry. In a few places—for example, on
the coast of Mauritania and Senegal—there is also a little rainfall in the period
of low sun. As in the desert and semiarid climatic zones, mean monthly
temperatures show less variation than daily temperatures. In western Africa
the period of low sun corresponds to the harmattan season. The harmattan is
a warm, dry, northeasterly or easterly wind that blows out of the southern
Sahara and is frequently laden with large quantities of sand and dust.
Regions with the equatorial, or tropical wet, type of climate, or variants thereof,
are the wettest in Africa. There are two peak periods of rainfall corresponding
to the double passage of the ITCZ. Because areas with an equatorial climate
are constantly covered by warm maritime air masses, variations in their
monthly and daily temperatures are less pronounced than in the tropical wet-
and-dry regions.
Marked variations in the rhythm of equatorial climate sometimes occur. For
example, the rainfall may be monsoonal and the second rainy season may be
all but nonexistent. But the most notable anomaly can be observed on the
western African coast from around Cape Three Points, Ghana, eastward
to Benin, where, although the bimodal rainfall regime prevails, the total annual
precipitation is less than 40 inches (1,000 millimetres). Among the many
explanations that have been suggested are that the presence of a cold body
of water offshore chills the lower layers of the maritime air mass and makes it
stable, that the body of cold air that forms offshore diverts the incoming
airstreams to the west and east of the anomalously dry area, that there is a
strong tendency for the winds to blow parallel to the shore during the rainy
seasons, that the absence of highlands deprives the region of orographic
(mountain) rainfall, that fluctuations in the offshore moisture-bearing winds
occur during the rainy season and reduce rainfall, and that local
meteorological peculiarities of thunderstorms contribute to the reduction in
rainfall.
In the northern and southern extremities of the continent, there is a dry
summer subtropical, or Mediterranean, type of climate. Rain falls only in
winter (December–January in North Africa, June–July in Southern Africa),
although in some localities it may fall in autumn (September in North Africa,
April in Southern Africa). Mean monthly temperatures are lower than in
tropical climates, dropping to about 50 °F (10 °C) in winter, while summer
(June–July in North Africa, and December–January in Southern Africa)
temperatures may sometimes exceed those of tropical climates. Clear blue
skies are characteristic.
The humid subtropical marine climate is restricted to the southeast coast of
Africa. This region is characterized by rainfall throughout the year, but it is
heaviest in summer. In South Africa, south of KwaZulu-Natal, the winter
rainfall is more pronounced, and the temperatures are a little lower than in the
north. Thus, at Port Elizabeth there are six months when temperatures are
below 62 °F (17 °C), while at Durban mean monthly temperatures do not fall
below 64 °F (18 °C).
The warm temperate upland climatic region is found on the Highveld of
Southern Africa. Its rainfall regime is similar to that of the tropical wet-and-dry
climate, but temperatures are greatly modified by the altitude; frost, for
example, occasionally occurs in Lesotho. Toward the coast the climate shows
maritime characteristics, and there is a tendency toward winter rainfall.
The mountain climatic region includes the high mountain areas of Ethiopia
and the lake region of East Africa. In some respects the climate is similar to
the warm temperate upland climate, except that temperatures are even lower
and snow occurs on the tops of the highest peaks, such as Kilimanjaro. The
rainfall regime is similar to that of the adjacent lowland areas.
Kwamina Busumafi Dickson

Plant life

African vegetation develops in direct response to the interacting effects of

rainfall, temperature, topography, and type of soil; it is further modified by the
incidence of fire, human agriculture, and grazing and browsing by livestock. Of
the total land area of the continent, forests cover about one-fifth; woodlands,
bushlands, grasslands, and thickets about two-fifths; and deserts and their
extended margins the remaining two-fifths.
Ecological relationships

Until about two million years ago Africa’s vegetation had always been
controlled by the interactions of climate; geology, soil, and groundwater
conditions (edaphic factors); and the activities of animals (biological factors).
The addition of humans to the latter group, however, has increasingly
rendered unreal the concept of a fully developed “natural” vegetation—i.e.,
one approximating the ideal of a vegetational climax. Nevertheless, in broad
terms, climate remains the dominant control over vegetation. Zonal belts of
precipitation, reflecting latitude and contrasting exposure to the Atlantic and
Indian oceans and their currents, give some reality to related belts of
vegetation. Early attempts at mapping and classifying Africa’s vegetation
stressed this relationship: sometimes the names of plant zones were derived
directly from climates. In this discussion the idea of zones is retained only in a
broad descriptive sense.

As more has become known of the many thousands of African plant species
and their complex ecology, naming, classification, and mapping have also
become more particular, stressing what was actually present rather than
postulating about climatic potential. In addition, over time more floral regions
of varying shape and size have been recognized. Many schemes have arisen
successively, all of which have had to take views on two important aspects:
the general scale of treatment to be adopted and the degree to which human
modification is to be comprehended or discounted.

Once, as with the scientific treatment of African soils, a much greater

uniformity was attributed to the vegetation than would have been generally
acceptable in the same period for treatments of the lands of
western Europe or the United States. Quite the opposite assumption is now
frequently advanced. An intimate mosaic of many species—in complex
associations and related to localized soils, slopes, and drainage—has been
detailed in many studies of the African tropics. In a few square miles there
may be a visible succession from swamp with papyrus, through swampy
grassland and broad-leaved woodland and grass, to a patch of forest on richer
hillside soil, and finally to succulents on a nearly naked rock summit.
The span of human occupation in Africa is believed to exceed that of any
other continent. All the resultant activities have tended, on balance, to reduce
tree cover and increase grassland, but there has been considerable dispute
among scholars concerning the natural versus human-caused development of
most African grasslands at the regional level. Correspondingly, classifications
have differed greatly in their principles for naming, grouping, and describing
formations: some have chosen terms such
as forest, woodland, thornbush, thicket, and shrub for much of the same broad
tracts that others have grouped as wooded savanna, savanna, and steppe.
This is best seen in the nomenclature adopted by two of the
most comprehensive and authoritative maps of Africa’s vegetation that have
been published: R.W.J. Keay’s annotated Vegetation Map of Africa South of
the Tropic of Cancer (1959) and its more widely based successor, The
Vegetation Map of Africa (1983), compiled by Frank White. In the Keay map
the terms savanna and steppe were adopted as precise definitions of
formations, based on the herb layer and the coverage of woody vegetation.
The White map, however, discarded these two categories as specific
classifications. Yet any rapid demise of savanna in its popular and more
general sense (i.e., as dry tropical grassland or mixed woods and grassland)
is doubtful.
The vegetational map of Africa and general vegetation groupings used in this
article mainly follow the White map and its extensive annotations, although
some 100 specific types of vegetation identified on the source map have been
compressed into 14 broader classifications.
Vegetational zones

Lowland rainforest

African lowland rainforests occur along the Guinea Coast of western Africa
and in the Congo basin. The full development of this tropical formation
requires continuously warm conditions and an annual rainfall exceeding 50 to
60 inches (1,270 to 1,520 millimetres) distributed fairly evenly over the year.
The vertical limit is about 3,500 to 4,000 feet. This multistoried, highly diverse,
extensive, and potentially self-perpetuating assemblage has been described
by some as the source of virtually all tropical floristic diversity. No other part of
the world sustains a greater biomass (total weight of organic matter in a given
surface area) than lowland tropical rainforests. Even though the speciation
(proliferation of distinct types of plant) within the African rainforests is notably
poorer than that of its counterparts in Southeast Asia and the Amazon basin
of South America, these forests sustain a huge multiplicity of life-forms,
occupying different strata (generalized levels of plant height)
and niches (separate, small-scale habitats).
 Tropical forests in Africa.Encyclopædia Britannica, Inc.

Characteristically, tropical rainforest is composed of a ground story, from 6 to

10 feet tall, of shrubs, ferns, and mosses; a middle story of trees and palms
20 to 60 feet in height; and a dominant top canopy consisting of trees up to
150 feet high with straight unbranched trunks, buttressed roots, and spreading
crowns of perennial leafage. The large branches of these crowns provide
niches for epiphytes, including orchids, ferns, and mosses. Lianas tie trees to
one another, parasitic species cling to trunks and branches, and strangler figs
(Ficus pretoriae) put down aerial taproots. Nevertheless, these are not
“impenetrable” jungles. It has been suggested that some early European
travelers and pioneer botanists may have exaggerated the difficulties of
human penetration because they journeyed along atypical waterways and
along tracks where disturbance of the original vegetation had thickened the
regenerating ground layer. In true rainforests, grasses are adventitious
(occurring in consequence of fortuitousintrusions). Elephant
grass (Pennisetum purpureum) can grow abundantly in areas where the
vegetation has been disturbed, providing good fodder for grazing animals
when young but quickly becoming rank, coarse, and a refuge for insects.
Cogon grass (Imperata cylindrica) is a troublesome grass on depleted and
fire-seared ground.
Eastern African forest and bush

Lowland forests and evergreen bushland form a long belt of land some 125
miles broad along the Indian Ocean. From various causes—notably the
monsoonal climate, freely draining soils, and long historical impact of
humans—these forests are much more limited in their structure (physical
form), speciation, and robustness. On more favoured terrain—such as
estuarine fringes, the seaward flanks of the islands of Zanzibar and Pemba,
and hill masses athwart the rain-bearing southeast monsoon—forest and a
close broad-leaved woodland are still dominant. Where land is in a rain
shadow, in areas of unfavourable geology (e.g., raised coral reefs), and near
cities and small ports, thorny bush, succulent shrubs, and scrawny grassland
prevail. Nevertheless, the region now sustains a number of economically
important domesticated trees—both indigenous and exotic—such as
the coconut palm, cashew, mango, and (especially on Zanzibar and
Pemba) clove.
Mangrove swamp
Mangroves include a variety of species of broad-leaved, shrubby trees (10–40
feet high) that fringe muddy creeks and tidal estuaries. They require warm
saline water—hence their distribution along tropical coastlines. Often they
form nearly impenetrable stands, for which the easiest access is by sea. The
trunks and roots are termite-resistant, and they have long been favoured as a
building material and for making charcoal.

Broad-leaved woodland and grassland

This classification constitutes one of the most extensive composite categories

now recognized and includes much of the land formerly labeled as savanna.
Two broad bands extend across the continent, one from about 7° to 12° N
latitude and the other from about 8° to 22° S latitude. Structure and
floristic composition vary greatly with the increase of latitude, both in the north
and the south. Annual rainfall averages 35 to 45 inches, with marked
seasonality of occurrence and considerable fluctuations from year to year,
both in total rainfall and in the onset of rainy periods. The woodlands of
western Africa strikingly resemble those south of the Equator. In both areas,
undulating wooded interfluves on light soils successively alternate with
swampy, clay-based valley grasslands (called fadamas in Nigeria and dambos
in Zambia and Malawi) in a topographically linked sequence of soils called a
catena.
Trees, 30 to 50 feet high, are typically deciduous and often fire-resistant, since
much of this land is burned annually. Common western African species
include types of Isoberlinia (a spreading leguminous tree of the pea
family), Daniellia (a leguminous tree with white bark), and Lophira (a tree with
strap-shaped leaves that is said to yield the most durable timber in the region).
Other hardwoods, forming distinct communities,
are Combretumand Terminalia, which are better suited to the drier areas.
Prevalent southern equivalents include Brachystegia (a leguminous hardwood,
the bark of which formerly was used to make cloth) and Julbernardia (another
plant of the pea family resembling Isoberlinia). Over much of the interior of
Tanzania, in areas of reduced rainfall and poorer soils, a light-canopied,
sustained woodland called Miombo forest rises above a rather scrawny
ground layer. This is an excellent habitat for bees, and honey has long been
gathered there.
Because of periodic burning, tall grasses have become dominant over large
expanses of plateau land, which sometimes contains few, if any, of its original
trees. The tall, coarse red grass Hyparrhenia can form prominent stands, but it
makes poor grazing land and often harbours insects that spread disease.
Much better for the pastoralists are induced swards of Themeda.
For centuries humans have selectively retained certain economically
important tree species in areas cleared for farming; the effect has been to
create what is called “farmed parkland,” in which a few favoured trees rise
above the fields. Examples include the shea butter nut tree (Butyrospermum),
common in Ghana and Côte d’Ivoire; Acacia albida, found in Senegal and
Zambia; and the truly domesticated baobab (Adansonia digitata), which is
perhaps the most widely distributed.
Thorn woodland, grassland, and semidesert vegetation

Toward the margins of the tropics, the vegetation cover becomes lower and
thinner as the fluctuating transition to desert vegetation ensues. In the same
progression the concept of an annual rainfall (nominally 5 to 20 inches) yields
to the reality of extreme unreliability in both incidence and expectation. Under
such restraints a definitive “boundary” with the desert becomes meaningless.
Moreover, there appears to have been a trend toward declining precipitation in
the last half of the 20th century, and human impact certainly
has enhanced the natural deprivation of plant life in the marginal regions. The
southern margin of the Sahara—roughly between the latitudes of 15° and
20°—is called the Sahel (Arabic: Sāḥil; meaning “shore” or “edge”), the word
being extended by implication to comprehend the fluctuating margins of the
great sand seas of the Sahara to the north. The southern equivalent covers
much of the Kalahari, which is often called a desert but is more properly a
thirstland.
Thorn woodland displays a predominance of xerophytic, sometimes succulent
or semisucculent trees, such as acacia, Commiphora (the myrrh tree),
or Boscia (an evergreen hard-leaved tree). The occurrence of the bunched
and thorny desert date (Balanites) seems to accompany land impoverishment.
A relatively luxuriant shrub layer, often forming dense thickets, is found in
conjunction with succulents, such as aloes, Sansevieria(a fibrous species),
and Adenium, or desert rose (a succulent shrub with smooth gray bark, a
huge water-storing base, and beautiful red or pink flowers), and smaller
euphorbias.
Farther toward the desert, tree growth and perennial grass—surviving in
narrow strips along watercourses—separate much larger areas of sparse
annual grasses (Cenchrus in western Africa, Eragrostis south of the Equator,
and Chrysopogon on the margins) and scattered low shrubs, often mainly
acacias. Shrubs may often be salt-tolerant. While shrubs may die from
inadequate moisture, they are little affected by the rare fires that occur.
Afromontane vegetation
All high mountains exhibit azonality; i.e., their vegetation differs from that
found in the climatic zones from which they rise. The
differences manifestthemselves as progressive modifications, which are
usually well stratified and reflect altitude-dependent climatic changes.
Generally, as elevation increases, temperature decreases (to the point where
frost and even glaciation can occur) and precipitation increases (although
above a certain level precipitation decreases markedly). Mountainous terrain
can retain ancient climatic conditions—making possible, for example, the
survival of relict species—and the relative inaccessibility of the higher
elevations to humans has helped preserve more of the vegetal patterns of the
past.
Vegetation strata typically are skewed with regard to slope orientation (aspect).
This is mainly due to a contrast between exposure to rain-bearing winds and
shadowing from them but may also reflect long-term history. If lower slopes
rise abruptly from the base, as they often do in Africa, then a distinct boundary
between vegetation formations may be clearly distinguished; if the rise is
gentle, vegetations merge (as in the western Kenyan highlands). (All the
circumstances mentioned above are represented in the African mountain
systems, but for purposes of illustration the vegetational map identifies only
areas of altitudinal modification. Thus, some areas that are included are not
tropical, such as parts of the Red Sea Hills and the mountains of South Africa
and Lesotho.)
Altitudinal modifications of vegetation are clearly discernible on the high East
African peaks near the Equator (e.g., Kilimanjaro and Mounts Kenya and
Elgon), and a rich forest belt—much reduced upslope by human activities,
except where the land has been reserved—clothes the zone that receives the
maximum rainfall and is free of frosts (up to about 5,000 to 6,000 feet). Such
mountains have great human importance as watersheds and as repositories
of native plants.

Desert vegetation
The Sahara has one of the lowest species densities in the world, and a
sustained vegetation cover (which can include trees and bushes) occurs only
in the massifs and oases. Elsewhere the vegetation is discontinuous and
consists of two main types: perennials with huge root systems and sparse
aerial parts, often protected by waxy cuticles, thorns, and hairs;
and ephemerals with slight root systems and little foliage but with the ability to
flower profusely immediately after occasional storms and then to seed quickly
and abundantly. The stony and rocky expanses give more hold for plants than
do the vast areas of shifting sands. In some areas with slightly more rainfall,
grass tufts may grow 50 yards apart. Aristida is the dominant grass, and for
brief periods it can yield a nutritious forage called ashab.
The Namib is one of the world’s driest deserts. The area along the coast,
however, is almost always foggy, and succulent shrubs (such as aloes)
manage to survive on this moisture. The Namib also contains the strange
tumboa, or welwitschia (Welwitschia mirabilis), which may live 100 years or
more.
Karoo-Namib shrubland
In this drought-prone land, soils are often shallow, even saline. The low
shrubs that grow there can be divided into two groups: woody plants, such as
species of Acacia and Pentzia and the saltbush (Atriplex); and succulents,
including aloes, euphorbias, and Mesembryantheum.
Aristidaand Themeda are characteristic grasses. Every year the blossoms of
bulbous plants lay short-lived carpets of colour. Being both drought-resistant
and high in minerals, many of the shrubs can provide useful grazing for goats
and sheep.
 Tree aloes and other succulents growing in the Karoo-Namib shrubland in Namaqualand, S.Af.Carol
Hughes/Bruce Coleman Ltd.

Highveld grassland
The grassland classification is restricted to regions with 10 percent or less
woody plant cover. The Highveld meets this definition and probably owes
much to unaided nature for its creation and perpetuation, since fires caused
by lightning strikes are relatively frequent. Its extent has always been fairly
precisely defined: areas with more than 15 inches of rainfall during the
summer. Highveld vegetation, though modified considerably by human activity,
traditionally has been differentiated into sweet veld (dominated by Themeda)
or sour veld (Andropogon and Eragrostis), the latter making poorer pasturage.
 Highveld grassland near Heidelberg, S.Af., southeast of Johannesburg.Gerald Cubitt—Bruce Coleman Ltd.

Mediterranean vegetation
This zone is determined chiefly by its climate, which is characterized by very
dry summers and mild, rainy winters, but it has long been much differentiated
by its inhabitants. Large tracts have been degraded into maquis (macchie),
garigue, or dry semidesert (steppe) vegetation. Maquis consists of dense
scrub growths of xerophytic (drought-resistant) and sclerophyllous (leathery)
shrubs and small trees, which are often fire-resistant. Garigue
characteristically is found on limestone soils and has more woody growth,
including evergreen and cork oaks (Quercus suber). The higher slopes of the
Atlas Mountains once carried large stands of pine and cedar, but they have
been much depleted. Typical grasses, progressing from the coast to the
desert, are Ampelodesmos, Phalaris, and Stipa.
Cape shrub, bush, and thicket

This region constitutes the southern counterpart of the Mediterranean zone,

although (with the exception of the Atlas Mountains) it is richer in its
vegetation potential. There were once considerable enclaves of true
evergreen bushland, which have reverted to shrubland (fynbos).
Sclerophyllous foliage and proteas abound. Although grassy tracts occur on
the mountains, they are characteristically unusual lower down. Beyond the
Cape Ranges, fynbos grades into karoo.
Madagascar
Physically and biologically, Madagascar has long formed a separate entity.
White has identified eastern and western regions of endemic (unique)
vegetation. In the eastern centre, about one-sixth of the plant genera and
more than three-fourths of the thousands of species are regarded as endemic.
The Madagascar rainforest has shorter trees and a somewhat drier climate
than its equatorial counterpart and contains its own dwarf palms (Dypsis) and
bamboos (Ochlandra). The western deciduous foreststands in the rain
shadow; some of its trees resemble Mediterranean oaks. The southern
thickets have prominent euphorbias and species of the Didiereaceae family.
The island has much degraded secondary forest (locally called savoka) along
the eastern and northern coasts.
Sudd
In addition to the major types of vegetation described above, a special
vegetation called sudd (literally meaning “barrier”) occurs in the great Nile,
Niger, and Zambezi drainage systems of the African interior plateau. Sedges
(especially papyrus), reeds, and other water plants—including the floating Nile
cabbage (Pistia stratiotes)—form masses of waterlogged plant material that
are largely unproductive and are a nuisance to fishing and
navigation. Pistia has become an unwelcome invader of Lake Kariba, the
body of water formed by the impounding (1959) of the Zambezi River in the
Kariba Gorge.

Lake KaribaLake Kariba, located between Zambia and Zimbabwe in central Africa.© Adam Ojdahl

Long-term changes in vegetation

Africa’s basic vegetational zones are believed to have existed in
approximately the same climatically controlled series and with the same
characteristically developed species for a long period of time; indeed, some
ancient African plant families—such as the cycads, which evolved some 200
million years ago—still have living representatives. Nonetheless, the
continent’s vegetation has been altered continuously by geologic and climatic
changes and by the movement of the caloric (heat) Equator. The past million
years have been a time of unusually rapid changes, with major consequences
for Africa’s vegetation.

The vegetational history of Africa is of great scientific relevance. Studying the

lichens growing in the high East African mountains, for example, may yield a
better understanding of the continent’s climatic trends, and a knowledge of
past conditions in the Sahel might help explain what influence natural
phenomena have had on the disastrous droughts of the region since the late
1960s.

Geologic influences

The two most important geologic modifications of vegetation have been the
very ancient separation of Madagascar from the mainland, which gave rise to
the distinct speciation of the island’s flora, and the long-continuing faulting and
volcanism along East Africa’s huge rift system that has thrown up high ranges
(e.g., the Ruwenzori between Uganda and the Democratic Republic of the
Congo) and great volcanoes (Kilimanjaro) and has thus created and reshaped
Afromontane flora.
 Thicket of members of the Didiereaceae family near the Mandrare River, southern Madagascar.© Mark
Pidgeon/Oxford Scientific Films Ltd.

Climatic influences

The repercussions of the great Pleistocene Ice Ages of Europe

have constituted the most notable climatic influence on African flora in
relatively recent geologic history. These consist of a succession of colder
periods marked by glacial advances, interrupted by warmer, drier interglacials;
the last series of these ended between about 5,000 and 10,000 years ago.
Tropical Africa experienced contemporaneous fluctuations in its climate,
although it is misleading to infer any simple equivalences between these
fluctuations and the European periods of glacial advances and retreats.
During the wetter times (pluvials) in Africa, equatorial forests spread,
separating northern woodlands from their southern counterparts (with
consequent species differentiation); mountain vegetation descended onto the
plateaus; and there is evidence that the Saharan climate was
greatly ameliorated, much to the advantage of humans. During the warmer,
drier interpluvials the existing vegetation was degraded in many zones. Dunes
spread from the Sahara and over the Kalahari, for example, and their
fossilized alignments—now vegetated—can be traced across the thorny
woodlands and grasslands of Niger, Nigeria, Namibia, and Botswana.
Human influences

The greater part of the reduction of Africa’s natural vegetation has happened
in the last 2,000 years—probably since the late 19th century for the tropical
portions—the time during which humans have been most numerous and
active. Pastoralism, agriculture, the rapid growth of human and livestock
populations, the expansion of cities and towns, and the external demands for
primary resources have made ever-greater demands upon the land for
sustenance and perceived economic betterment. Much is known of the
detailed processes of vegetation modification along the Mediterranean, since
they have been observed and studied since Classical times, and a good deal
is also known from the more than three centuries of study of the Cape area of
South Africa, but until the late 19th century very little was understood about
these processes in tropical Africa. Indeed, the timescale of actual human
impact on African vegetation may be causally linked to the awareness of it by
Europeans.

Within the tropical forests and woodlands, fire undoubtedly has been the great
human agent of clearance and degradation, of far greater efficacythan felling,
bark-ringing, or uprooting—at least until the introduction of modern plantation
agriculture and logging. Hunters, pastoralists, and cultivators have all fired the
land for centuries and have gathered wild foodstuffs, thatch timber for
construction, and fuelwood from the volunteer (i.e., uncultivated or self-
generating) vegetation. The long-term effects of such activity bear directly
upon the debated question of the origin of the savannas.
In earlier times, African cultivators found the fabric of the tropical rainforest
comparatively difficult to modify substantially. In the 20th century, however, it
was greatly reduced in extent (such as in Sierra Leone), patched and frayed
(Nigeria), and exploited for timber exports (Gabon). Moreover, many of
tropical Africa’s largest cities and busy seaports are in this zone. The most
diverse and seemingly inexhaustible floral realm in Africa has therefore
become a cause for widespread concern.

Conserving the vegetation

Perceptions of the need for environmental conservation in Africa held by those

outside the continent are sometimes expressed in terms that seem opposed
to the legitimate priorities and aspirations of African peoples (in meeting which
agriculture and livestock management must remain crucial). It is not surprising
that projections based upon the assumptions from these external sources
frequently end in pessimism. A more constructive approach is to identify ways
in which to more fully integratewild plant life, crops, and animals, which can be
expressed in the concept of productive countryside. The capacity and
precision of resource surveys have been greatly enhanced by remote sensing,
and this has been coupled with the worldwide transmissibility of information.
Research and interest in agroforestry have expanded and become
institutionalized. Above all, however, confidence must be put in the capacities
of many millions of African farmers to expand agriculture while working toward
reintegration with wild plant life.
Animal life

Africa includes two regions of the zoographic area known as the Paleotropical
realm: the Afrotropical region, which comprises the continent south of the
Sahara and the southwestern part of Arabia, and the Madagascan region. The
continent also includes a southern part of the Palaearctic (Old World) region
of the Holarctic realm (i.e., the lands of the Northern Hemisphere), consisting
of northwestern and North Africa south to roughly the Tropic of Cancer.

animal life at African watering holeA look at the diversity of animal life at a single watering hole at the
Mashatu Game Reserve, a privately owned reserve in eastern Botswana.© Martin Harvey (A Britannica
Publishing Partner)

Genera and distribution

Africa is best known for the enormous diversity and richness of its wildlife. It
has a greater variety of large ungulates, or hoofed mammals (some 90
species), and freshwater fish (2,000 species) than any other continent.
Mammals
The main group of herbivores are the African antelope, which belong to four
subfamilies of the ox family (Bovidae). The first subfamily is the oxlike Bovinae,
which is further subdivided into the African buffalo and the twist-horned
antelope, including the eland (the largest of all antelope), kudu, nyala, and
bushbuck. The second subfamily is the duiker, a small primitive bovid that
lives in the thickets, bush, and forests. Third is the “horse antelope,” further
divided into sabre-horned sable, roan, and oryx antelope; the “deer antelope,”
kongonis, hartebeest, topi, gnu (wildebeest), and blesbok, all mostly
inhabitants of the open plains; and the “marsh antelope,” waterbuck, lechwe,
kob, puku, and reedbuck. The fourth subfamily is the antelope proper, divided
into two distinct tribes, the first of which includes royal, dik-dik, klipspringer,
oribi, steenbok, and grysbok and the second of which includes gazelle,
impala, springbok, and gerenuk. Other well-known large African herbivores
include the zebra, giraffe, hippopotamus, rhinoceros, and African elephant.

Cape, or African, buffalo (Syncerus caffer).Mark Boulton—The National Audubon Society Collection/Photo
Researchers

Probably no group of animals is more identified with Africa than

its Carnivora (the order of flesh-eating mammals), of which there are more
than 60 species. In addition to the better-known big (or roaring) cats—
the lion, leopard, and cheetah—are the wild dog, hyena, serval (a long-limbed
cat), wildcat, jackal, fox, weasel, civet, and mongoose. These predators and
scavengers are vital in maintaining the ecological equilibrium of the areas that
they inhabit.
The primates include some 45 species of Old World monkeys, as well as two
of the world’s great apes—the chimpanzee and the world’s largest ape, the
gorilla. Presimian primates—such as pottos (African lemurs) and galagos
(bush babies, or small arboreal lemurs), as well as Lorisidae (a family of
arboreal lemurs, moving with a slow, delicate crawl)—are mainly small and
nocturnal, but in Madagascar, where there are no true monkeys, the world’s
most diverse assemblage of large and small diurnal and nocturnal presimian
lemurs survives.



 West African, or masked, chimpanzee (Pan troglodytes verus).Helmut Albrecht/Bruce Coleman Ltd.

Red-bellied lemur (Eulemur rubriventer) in the eastern Madagascar rainforest near Ranomafana.© David
Curl/Oxford Scientific Films Ltd.

Marine mammals include one Mediterranean and one South African seal (the
Cape fur seal) and two Sirenia (an order of aquatic herbivores)—the dugong
and the manatee. In addition, whales, porpoises, and dolphins frequent
Africa’s coastal waters.

Africa’s large number of endemic mammal species is second only to that of

South America. They include several families of the ungulate order
Artiodactyla (composed of mammals with an even number of toes), such as
giraffes and hippopotamuses. Some families of Carnivora—such as civets (of
the Viverridae family), their smaller relations the genets, and hyenas—are
chiefly African. The rodent family of jumping hares (Pedetidae) is endemic,
and one order, the aardvark (Tubulidentata)—a large nocturnal burrowing
mammal, with one species—is exclusively African. Madagascar also has a
remarkable insect-eating family, the tenrecs (animals with long pointed snouts,
some of which are spiny and tailless).

Streaked tenrec (Hemicentetes semispinosus).H. Uible/Photo Researchers

Birds
South of the Sahara the birdlife includes nearly 1,500 resident species, to
which must be added another 275 species that are either resident in
northwestern Africa or else are Palaearctic winter migrants; the migrants once
totaled perhaps two billion individuals, but their numbers have been reduced
considerably by severe droughts and by human land use and predation. Birds
are mainly of Old World families, but of those that are endemic the most
noteworthy are perhaps the ostrich, shoebill, hammerkop (a brown heronlike
bird), and secretary bird (a large long-legged predatory bird) and the touracos
(brightly coloured birds, some with helmetlike crests). Other families, such as
bustards, sand grouse, honey guides (small dull-coloured birds, several
species of which are noted for leading people to the nests of honeybees, in
order to feed on them after the nests have been broken), and larks, are
predominantly African. There are many avian predators of land mammals,
including eagles, hawks, and owls; more of fish, such as storks, waders, and a
few species of kingfishers; and even more of insects, this latter group usually
being of benefit to humans. Scavengers include vultures and the
large marabou stork.

Ostriches (Struthio camelus); at left is the male.David C. Houston—Bruce Coleman Ltd.

Reptiles and amphibians

Reptiles, of which there are few endemic families, have mainly Old
World affinities. Those most likely to be seen include lizards of the agamid
family, skinks (a family of lizards characterized by smooth overlapping scales),
crocodiles, and tortoises. Endemic reptiles include girdle-tailed and plated
lizards. Within the African realm, lizards of the iguana family and boa
constrictors occur only in Madagascar. Large vipers are abundant and varied;
certain species have extremely toxic venom, but they are seldom encountered.
A wealth of both colubrine snakes (with fangs at the posterior end of the upper
jaw) and elapine snakes (with fixed poison fangs at the front of the upper jaw)
include such highly venomous elapine species as mambas.
Amphibians also belong mainly to Old World groups. Salamanders and hylid
tree frogs (having teeth in the upper jaw) are confined to the Palaearctic
northwest. Abundant commoner frogs and toads include such oddities as the
so-called hairy frog of Cameroon, whose hairs are auxiliaryrespiratory organs.
The frog subfamily Phrynomerinae is exclusively African.
Arthropods
Africa possesses an abundant and varied population of arthropods (which
include insects and other segmented invertebrates). Among them are found
large butterflies of the Charaxes (brush-footed) and Papilio (swallow-tailed)
genera, stick insects, and mantises, grasshoppers, driver, or safari, ants
(tropical ants that travel in vast, serried ranks), termites, and dung beetles.
Spiders abound throughout the continent, and scorpions and locusts can also
be plentiful locally. Periodically, huge swarms of locusts spread over wide
areas, causing enormous destruction to vegetation. Other serious pests are
mosquitoes, which act as vectors in the spread of such human diseases as
malaria, and tsetse flies, which transmit the parasite that causes African
trypanosomiasis (sleeping sickness) in humans and nagana in livestock.
Aquatic life

Freshwater fish include both remarkable archaic forms and examples of rapid
recent evolution. Among the ancient forms are lungfish (Protopterus), bichirs,
or lobefins (Polypterus), and reedfish (Calamoichthys), all of which can
breathe air—a property also possessed by certain catfish (Clariidae), which
are able to travel overland for some distance in wet weather. Characteristic of
more recent evolutionary trends are the approximately 200 species of fish
found in Lake Nyasa, four-fifths of which occur only there.

African lungfish (Protopterus annectens).Copyright Tom McHugh—Steinhart Aquarium/Photo Researchers

The coelacanth, an archaic marine form believed extinct for more than 60
million years, was discovered to be alive off the east coast of South Africa in
1938, and since then many others have been found. A rich and varied
invertebrate animal life on the east and west coasts includes marine
organisms typical of the Indo-Pacific and Atlantic oceans. Coral reefs and
associated organisms are mainly found in the warm waters of Africa’s east
coast, while the southwest and west coasts—washed, respectively, by the
cold Benguela and Canary currents—abound in fish.

Coelacanth (Latimeria chalumnae)Peter Green—Ardea Photographics

Origin and adaption of African fauna

At one time most African fauna was thought to derive from elsewhere. There
is no doubt, however, that as little as 15,000 years ago an amelioration of the
present Saharan climate enabled such typical Ethiopian forms as clariid
catfish to reach the river systems of North Africa. Likewise, Palaearctic animal
life and vegetation appear to have extended far south into the Sahara, and
the white rhinoceros apparently lived beside elklike, typically Palaearctic deer.
Within the Ethiopian region, repeated climatically controlled expansion and
contraction of vegetational zones resulted first in organisms establishing
themselves in numerous specialized ecological communities (niches) of plants
and animals and second in the proliferation of those species that successfully
adapted themselves to the prevailing conditions. The spread of forests during
the pluvials, separating northern and southern wooded grasslands, led to the
evolution of such closely related northern and southern species of antelope as
the kob and puku, the Nile and common lechwe, and the northern and
southern forms of white rhinoceros.

Some subfamilies of Bovidae, like the spiral-horned antelope (Tragelaphinae),

have adapted to almost every ecological environment—forest, woodland,
grassland, Afro-Alpine zones, and even to sudd vegetation. Others, like the
hartebeests (Alcelaphinae), which inhabit savannas and grasslands, are less
adaptable.

Freshwater fishes demonstrate the existence of the relation to one another of

former river systems and lakes. Large rivers containing Ethiopian fish
evidently existed quite recently in the northern Sahara. The fish life of the
now-isolated Lake Rudolf (Lake Turkana), in East Africa, demonstrates that
the lake was once connected to the Nile, though Lake Victoria, the present
source of the White Nile, was not. Lake Kivu too was formerly connected with
the Nile, but, as a result of volcanic activity, it is now part of the Congo
drainage system.
In earlier periods the animal life was even more remarkable than today. Fossil
deposits have revealed sheep as big as present-day buffalo, huge
hippopotamuses, giant baboons, and other types similar to existing species.
These huge types probably lived in pluvial periods, dying out as aridity
increased. Smaller types survived.

The effects of humans

Until they acquired firearms, humans made relatively little impact on animal
numbers or—with some exceptions—their range. From the last half of the
19th century, however, and particularly since 1940, direct or indirect
human wastage of Africa’s animal life has been intense and has reduced
stocks considerably. The antelope known as the Zambian black lechwe, for
example, believed to have numbered 1,000,000 in 1900, had been reduced to
less than 8,000 by the late 20th century, and the population of African
elephants declined from 2,000,000 in the early 1970s to some 600,000 by
1990, largely because of poaching for the ivory trade. The African white
rhinoceros reached the verge of extinction in 1980.
Though European hunters and colonists were rightly blamed for much of the
decline at its onset, hunting and destruction and the disturbance of habitats by
Africans have become more important. Rinderpest, an acuteand usually
fatal infectious disease of livestock, entered Africa with domestic stock in the
1890s and ravaged herds of indigenous ungulates. The accelerated spread of
agriculture and stock raising involving the destruction of forests, as well as
heavy grazing and burning of vegetation, eliminated large animals from wide
tracts. In South Sudan, for example, political strife and warfare in the 1960s
entirely eliminated wildlife from some areas. The demand for fancy leather
and fur has also endangered the Nile crocodile and the leopard.
Humans, however, have been of benefit to many smaller species. Dams and
irrigation schemes, for example, have provided habitats for waterfowl, frogs,
and fish, and the spread of grain crops has encouraged certain pests. Even
the patchy cultivation of forests has resulted in the development of a mosaic
of habitats that can provide new, if small, niches for some species.

Ecology

There are still sufficiently large tracts of relatively unspoiled country in which
animal life may be studied in its environment. The complementary roles of wild
ungulates, for example, show that in any area inhabited by a wide variety of
species, the grass is grazed in regular succession and at different stages of
growth—for example, by zebra, gnu, hartebeest, and gazelle—while
specific adaptations enable a still greater variety to survive. A much smaller
variety of domestic stock cannot duplicate such effects. Overpopulation by
domestic or wild species may upset the delicate natural balance, as may be
seen by the example of elephant overpopulation in Murchison Falls (Kabalega)
National Park, Uganda, and in Tsavo National Park, Kenya; whether the
elephants survive or not, they have ineradicably altered the environment to
the detriment of many other typical species.
Animal life of particular interest

Animal life of particular interest to humans includes four main groups that are
not mutually exclusive. They are: (1) species potentially or actually useful to
humans as food (large ungulates), (2) dangerous or pest species that may
have to be controlled or eliminated (locusts, tsetse flies, Quelea finches—
which do immense damage to grain crops—and some ungulates or
carnivores), (3) species that provide a spectacle and bring economic benefit
(elephants, the larger plain ungulates, primates, or carnivores), and (4)
endangered, rare, or unique species.

 

red-billed queleaA flock of red-billed queleas (Quelea quelea), Etosha National Park, Namibia.©
EcoView/Fotolia
 red-billed queleaMale (right) and female red-billed queleas (Quelea quelea).© Johan
Swanepoel/Shutterstock.com

Much of the study of African wildlife has been addressed to the first two
groups described above. For example, after it was learned that the feeding
habits of domesticated livestock and wild ungulates are complementary, it
became possible to incorporate the ungulates into pastoral and mixed-farming
systems. This has happened on limited scales with the oryx (which was
domesticated by the ancient Egyptians), the springbok (which has been run
with cattle for decades in Southern Africa), and the African buffalo and eland.
Similarly, much attention has been given to controlling pests. In the 1950s
and ’60s considerable progress was made in the control of mosquitoes and
locust swarms, although these achievements have been partially lost by
governmental instability and mismanagement and by warfare between states.
Infestation by the tsetse fly remains as one of tropical Africa’s most critical
problems, not only because the tsetse spreads disease but also because—by
effectively restricting livestock farming—it denies relief of the chronic protein
shortage of many African peoples. Control of the tsetse is possible, but it is
complex and requires a coordinated effort within and between countries.
Much research has also been carried out on animals in the third and fourth
groups. Studies of predators, such as the lion, for example, have shown that
they do not generally control the numbers of ungulates to the same degree as
do disease or starvation. It has also been established that the hyena is as
much a potent predator as a scavenger. Intensive studies have been made of
such primates as baboons, Ethiopian geladas (to which baboons are related),
and especially chimpanzees and gorillas; of great interest has been learning
what associations there are between human and other primate behaviour and
psychology.

Conservation
Many countries have now set aside large tracts as national parks, game
reserves, or forest reserves. Of these parks, only some are large enough to
be self-contained ecosystems, and most have been set aside to
accommodate large mammals. In East Africa there are also sanctuaries for
birds and marine organisms. The conservation of vegetation is undertaken
mainly in forest reserves but also in national parks. In addition, a number of
countries are attempting to conserve wildlife by refusing export licenses for
certain kinds of skins, especially those of the leopard, cheetah, and zebra.
Conservation efforts in Southern Africa have been aided by the creation of
transfrontier parks and conservation areas, which link nature reserves and
parks in neighbouring countries to create large international conservation
areas that protect biodiversity and allow a wider range of movement for
migratory animal populations. One such park is the Great Limpopo
Transfrontier Park (GLTP), where representative populations of most savanna
species are maintained. The GLTP links one of Africa’s oldest and best-known
national parks, Kruger National Park, with Mozambique’s Limpopo National
Park and Zimbabwe’s Gonarezhou National Park. Another is Kgalagadi
Transfrontier Park, which links South Africa’s Kalahari Gemsbok National Park
with Botswana’s Gemsbok National Park; it conserves a tract of arid country
with such associated types of antelope as springbok and gemsbok; smaller
reserves and parks conserve particular species. Only one large mammal
species, the blaubok (or blaauwbok), has become extinct, though several
subspecies have nearly disappeared; one such subspecies—the quagga, a
race of zebra—has vanished.

Encyclopædia Britannica, Inc.

East and central African countries have large national parks, which have been
expanded in size or have increased in number as a result of the economic
benefits of tourism. Kenya’s parks include Tsavo, one of the largest, with an
area of more than 8,000 square miles, Lake Nakuru National Park for
flamingos, several montane parks, and a marine park. Uganda has several
national parks. Tanzania has the famous Serengeti National Park, with its
unrivaled populations of plains ungulates, and the parks of Ngorongoro, Lake
Manyara, Arusha, and others. Other countries with notable national parks and
game reserves are Botswana, Malawi, Namibia, Zambia, and Zimbabwe. All
parks in these countries preserve representative woodland, thornbush,
grassland, and succulent-desert habitats and species.
Elsewhere the situation is less satisfactory. In the Democratic Republic of the
Congo, national parks were all seriously depleted after independence. Congo
now has several major national parks, including the Virunga National
Park (3,100 square miles), but in the late 20th century many suffered
from deforestation and poaching, as well as general human encroachment,
due to conflicts and warfare in the region. Ethiopia has several parks
developed largely during the 1970s, while Somalia has only
a rudimentary system consisting mostly of game reserves and one area (Luc
Badana) nominally a national park but failing to meet UN criteria for such
parks. The “W” park is shared between Burkina Faso, Niger, and Benin, but
most western African countries have only small national parks if any at all.
Animals not protected in parks are not necessarily threatened. Many large
species are still plentiful in forest or game reserves or in controlled-hunting
areas. Well-managed forest reserves in particular provide secure habitats for
many smaller unprotected forms.

Animals affecting land usage

Historically, the abundance of elephants and other large ungulates may have
stimulated some individuals—notably western African hunters in the forests
and Europeans in Southern Africa—to occupy certain areas. Trade routes
were established and early hunter-explorers were influenced by the availability
of elephants, whose ivory tusks slaves could carry.
Large and small animals now affect humans by competing with them or with
their livestock. They may prey on people or on livestock or carry diseases
affecting either. The bilharzia snail and the Simulium fly (host to an organism
causing blindness), the tsetse fly, and the mosquito collectively affect human
beings and their livestock far more than do such individually large
or formidable species as lions or elephants.
 The larger ungulates may compete with domestic livestock for forage, but they
are more keenly resented and hunted by those agriculturists whose crops they
eat. Pastoralists are much more concerned about lions that occasionally kill
cattle than they are about locusts or rats, which, by depleting forage, indirectly
cause the death of much livestock; such perceptions may hinder eradication
or better control of these pests.

Danger to humans from large animals—carnivorous or otherwise—has been

greatly exaggerated, but disease carried by living organisms has remained a
serious problem. Diseases have reduced crop productivity, spoiled harvests,
and acted as a curb on the better integration of land use and on the extension
of pastoralism and mixed farming into underused areas.
David N. McMaster

SIMILAR TOPICS
 Europe
 Antarctica
 North America
 Asia
 South America

People
Africa is now widely recognized as the birthplace of the Hominidae, the
taxonomic family to which modern humans belong.
Archaeological evidence indicates that the continent has been inhabited by
humans and their forebears for some 4,000,000 years or more. Anatomically
modern humans are believed to have appeared as early as 200,000 years
ago in the eastern region of sub-Saharan Africa. Somewhat later those early
humans spread into northern Africa and the Middle East and, ultimately, to the
rest of the world.
 Kenya: traditional clothingWomen in traditional clothing, Kenya, East Africa.© Goodshoot/Thinkstock

Africa is the most tropical of all the continents; some four-fifths of its territory
rests between the Tropics of Cancer and Capricorn. As a consequence,
the cultures and the physical variations of the peoples reflect adaptation to
both hot, dry climates and hot, wet climates. Dark skin is the dominant
characteristic of indigenous African peoples, but skin colour is not uniform.
Skin colour shows a clinal variation from a light or tan colour in the northern
fringe of the continent, which has a Mediterranean climate, to very dark skin in
certain Sudanic regions in western and East Africa, where radiation from the
Sun has been most intense. Africa has the most physically varied populations
in the world, from the tallest peoples to the shortest; body form and facial and
other morphological features also vary widely. It is the continent with the
greatest human genetic variation, reflecting its evolutionary role as the source
of all human DNA.
Throughout human history there have been movements of peoples
(seehuman migration) within, into, and out of Africa along its northern coasts,
across the Sinai Peninsula, along the Red Sea, and especially in the Horn of
Africa and coastal areas as far south as Southern Africa. North Africa from
the Strait of Gibraltar to the Nile River delta has been the site of conquests
and movements of peoples for thousands of years. Along the east coast,
trading cities arose and fell, cities that had overseas contacts during the past
two millennia with peoples of southern Arabia and as far east as Indiaand
Indonesia. Internal movements during that time contributed to the
heterogeneity and complexity of native African societies. The greatest
movement of peoples out of the continent was a result of the Atlantic slave
trade that lasted from the 16th to the 19th century and involved the transport
of an estimated 10,000,000 people to the New World. Such a loss of people,
together with the devastating warfare and raiding associated with it, was the
major cause of the subsequent weakness and decline of African societies.
Whereas the majority of Africa’s peoples are indigenous, European colonial
settlers constitute the largest majority of new peoples, with substantial
numbers in Kenya, South Africa, Zimbabwe, Zambia, Namibia,
and Mozambique. Dutch settlers first arrived in South Africa in 1652; their
descendants now constitute the main Afrikaner, or Boer, population. The vast
majority of European settlers arrived after the 1885 Berlin West Africa
Conference and the resulting “scramble for Africa,” during which European
leaders carved out spheres of influence. Attendant, but unassociated, with the
scramble, French and Italian settlers also established new communitiesin
North Africa and, to some extent, western Africa. Much earlier, in several
waves of migrations beginning in the 7th century, Arabs spread across
northern Africa and, to a lesser extent, into western Africa, bringing a new
religion (Islam) and a new language (Arabic), along with some new cultural
and political institutions. They also spread Islam southward along the east
coast, largely through trading and kinship relationships. (More detail is given
in the regional history articles North Africa, Central Africa, Southern
Africa, Western Africa, and Eastern Africa.) The colonial era began to
disintegrate in the 1950s.
Culture areas

Although the precise number is unknown, there are several thousand different
societies or ethnic groups in Africa. They are identified by their recognition of
a common culture, language, religion, and history. But in some areas the
boundaries among ethnic groups and communities (villages, towns, farm
areas) may not always be clear to the outsider. Most Africans speak more
than one language, and frequent migrations and interactions, including
intermarriage, with other peoples have often blurred ethnic distinctions. There
are an estimated 900 to 1,500 different languages, but many distinct political
units share a common or similar language (as among the Yoruba, Hausa,
and Swahili-speaking peoples). Complicating the situation in the 20th century
was the creation of new “tribes” (such as the Zande [Azande] and Luo) that
had not been distinct polities before the colonial era. Ethnic (cultural) identities
in modern times have often been heightened, exacerbated, or muted for
political reasons.
In their attempts to comprehend such a huge heterogeneous continent,
scholars have often tried to divide it into culture areas that represent important
geographical and ecological circumstances. Those areas reflect differences in
the cultural adaptation of traditional societies to varying natural habitats. For
the purposes of this discussion, the principal regions are northern, western,
west-central, eastern, and Central and Southern Africa; Madagascar is also
included.
Audrey Smedley
Northern Africa
Africa north of the Sahara is differentiated from the rest of the continent by its
Mediterranean climate and by its long history of political and cultural contacts
with peoples outside of Africa. It is physically separated from the rest of the
continent by the Atlas Mountains and is inhabited primarily by peoples who
speak languages that belong to the Afro-Asiatic group. Those peoples include,
for example, the Imazighen (Berbers) of Morocco, Algeria, and Tunisia. The
Berbers are most numerous in Morocco and least in Tunisia, where, as a
result of culture contact and intermarriage, they have become
largely assimilated with Arabs, who speak a Semitic language. The Arabs
migrated into North Africa from Arabia in a number of waves; the first of those
waves occurred in the 7th century CE. The distinctive nature of Maghrebian, or
western Arab, culture resulted from that admixture. In the Sahara such Arab
peoples as the Shuwa live side by side with such Berber peoples as
the Tuareg. See also Islamic world.

Tuareg man; camelA Tuareg man and a camel in the Sahara, Algeria, North Africa.© Claire.B/Fotolia

Western Africa
Western Africa contains a remarkable diversity of ethnic groups. It can be
divided into two zones, the Sudanic savanna and the Guinea Coast. The
savanna area stretches for some 3,000 miles (4,800 km) east to west along
the southern Saharan borderland. Its vegetation consists of extensive
grasslands and few forests, and little rain falls there. The savanna supports
pastoralism and horticultural economies dependent on grain. In contrast, the
Guinea Coast experiences heavy rainfall and is characterized by hardwood
tropical forests and dense foliage. It produces primarily root crops (various
yams).

Malinke villageMalinke village near Tambacounda, Senegal.N. Cirani/DeA Picture Library

Among the more important of the savanna peoples are the three main clusters
known as Mande in Senegal and Mali and including the Bambara, Malinke,
and Soninke; the Gur-speaking group in the savanna zone to the east that
includes the Senufo, Lobi, Dogon, and Moore; and in northern Nigeria, Niger,
and Cameroon the many small, mainly non-Muslim tribes of the plateau and
highland areas. Throughout the region live the many groups of the Fulani, a
cattle-keeping Muslim people who either have conquered indigenous peoples
(such as the numerous Hausa) or live in a symbiotic relationship with
agricultural peoples. In the Sahara fringe are the many Berber-speaking
groups (collectively known as the Tuareg), the Kanuri of Lake Chad, and
the Bedouin Arab peoples. Many of the kingdoms are successor states to
those of Ghana and Mali.
The larger societies in the coastal zone are also mostly kingdoms. In Nigeria
are the Igbo and Ibibio, organized into many autonomous polities; the Tiv;
the Edo; and the several powerful kingdoms of the Yoruba. Westward are
the Fon of Benin; the various peoples of the Akan confederacy, mostly in
Ghana, the largest group being the Asante; the Ewe, Ga, Fante, and Anyi of
the coast; the Mende and Temne of Sierra Leone; the Kru of Liberia;
the Wolof, Serer, Dyula, and others of Senegal; and the Creoles of Sierra
Leone and Liberia, descendants of freed slaves from the New World or of
those who were on their way there.
West-central Africa

West-central Africa may be considered as an eastern extension of western

Africa: in the north are the savannas of Chad, the Central African
Republic, Sudan, and South Sudan, stretching to the Nile River, and in the
south is the largely forested area of the Congo River basin. The Congo area,
in the centre of the continent, is an extension of the wet forestlands of the
Guinea Coast; it extends to the lacustrine area of eastern Africa. That region
is the largest area of secondary tropical forest in the world; only South
Americahas more primary (i.e., undisturbed by humans) tropical forests. The
vast majority of peoples speak related languages of the Bantu family.
The Luba, Lunda, Fang, Mongo, Kuba, Songe, and Chokwe are among the
larger ethnic groups of west-central Africa. The Bambuti (Pygmy) peoples live
in the eastern forests, and smaller groups of Pygmy peoples live in the
western forests of Gabon.
Ituri Forest: Efe campEfe camp in the Ituri Forest, Democratic Republic of the Congo. The Efe are one
of the Bambuti (Pygmy) peoples of west-central Africa.Robert C. Bailey

Eastern Africa
Eastern Africa can also be divided into several regions. The northern
mountainous area, known as the Horn of
Africa, comprises Djibouti, Ethiopia, Eritrea, and Somalia. In the east is the
arid Somali desert. The coastal area extends from Kenya to Southern Africa,
where numerous trading cities arose beginning in the 10th century. The East
African Rift System intersects eastern Africa, running from north to south. The
region, particularly the areas of the East African lakes—
Victoria, Albert, Tanganyika, and Nyasa (Malawi)—contains some of the most
fertile land in Africa, and during the colonial period it attracted settlers
from Europe and Asia. Vast areas of savanna support pastoralists and
peoples with mixed economies.
 Maasai menMaasai men in traditional attire, Kenya, East Africa.© Herby ( Herbert ) Me/Fotolia

Ethnically complex, eastern Africa includes the Eastern Sudanic-speaking

pastoralists of the Nile valley (e.g., Shilluk, Dinka, Luo, and Lango), those of
the central plains (Maasai, Nandi, and others), and the Somali and Oromo of
the Horn of Africa, who speak Cushitic languages. In Ethiopia also are
the Amhara, Tigre, and others who speak Semitic languages. Most of the
remaining peoples of the region are Bantu speakers who, although they vary
widely in other ways, are all subsistence farmers. Near the East African
lakes are several formerly powerful Bantu kingdoms
(Ganda, Nyoro, Rwanda, Rundi, and others). In the highlands of Kenya are
the Kikuyu, Luhya, and others. On the coast are the various Swahili-speaking
tribes, while in Tanzania are the Bantu-
speaking Chaga (Chagga), Nyamwezi, Sukuma, and many more. There are
also remnants of other groups: the hunting Okiek (Dorobo), Hadza, and some
Pygmies. And on the coast are the remnants of the once politically powerful
Arabs, formerly based on the island of Zanzibar.
Central and Southern Africa
Central and Southern Africa may be considered as a single large culture area.
Most of it consists of open and dry savanna grasslands: the northwest
contains the edges of the Congo forests; the southwest is very arid; and the
coastline of South Africa and Mozambique is fertile, most of it with a
subtropical or Mediterranean climate.
 Botswana: SanTwo San men in Botswana demonstrating the traditional method of starting a fire.Ian
Sewell

The region was once populated by Khoisan-speaking peoples. The San are
today restricted to the arid areas of southwestern Africa and Botswana, and
most of the Khoekhoe are found in the Cape region of South Africa. The other
indigenous groups are all Bantu-speaking peoples, originally from the area of
Cameroon, who dispersed across the region some 2,000 years ago. The
vanguard, known linguistically as the Southern Bantu, drove the Khoekhoe
and San before them and adopted some of the typically Khoisan click sounds
into their own languages. Over the past several hundred years, Bantu-
speaking people who had mixed economies with large numbers
of cattle began massive movements, mostly northward. A major cause of that
displacement of peoples (which together with a series of related wars is
known as the Mfecane) was the search for new grazing lands. A number of
conquests resulted in the establishment of the states of
the Zulu, Swazi, Tswana, Ndebele, Sotho, and others.
Madagascar
The island of Madagascar forms a distinct culture area. The
various Malagasy ethnic groups, of which the politically most important is
the Merina, are mainly of Indonesian origin, following migrations across
the Indian Ocean probably during the 5th and 6th centuries CE. The Malagasy
language, spoken by virtually all of the island’s population, is classified
as Austronesian.
John F.M. MiddletonJohn Innes ClarkeAudrey Smedley
Cultural patterns

Languages

The knowledge of most of the individual languages of Africa is still very

incomplete, but there are known to be in excess of 1,500 distinct languages.
Many attempts to classify them have been inadequate because of the great
complexity of the languages and because of a confusion relating language,
“race,” and economy; for example, there was once a spurious view of
pastoralism as related to cultures whose members spoke “Hamitic” languages
and were descendants of ancient Egyptians. One of the more recent attempts
to classify all the African languages, prepared by the American linguist Joseph
Greenberg, is based on the principles of linguistic analysis used for Indo-
European languages rather than on geographic, ethnic, or other
nonlinguistic criteria. The four main language families, or phyla, of the
continent are now considered to be Niger-Congo, Nilo-Saharan, Afro-Asiatic,
and Khoisan.
 Africa: languages and peoplesMajor languages and peoples of Africa.Encyclopædia Britannica, Inc.

Niger-Congo is the most widespread family and consists of nine

branches: Kordofanian, Mande, Ijoid, Atlantic, Benue-Congo, Kru, Kwa, Gur,
and Adamawa-Ubangi. Those languages cover most of Central and Southern
Africa; they are found from Senegal to the Cape of Good Hope, with a
geographically widespread extension due to relatively recent migrations.
Kordofanian includes subgroups all spoken within a small area of southern
Sudan. The most original point in that classification is the group called Benue-
Congo, which linguistically subsumes all the Bantu languagesfound dispersed
over most of eastern, Central, and Southern Africa. That dispersal is
attributable to the rapid expansion of people from the area of the Bight of
Benin from the beginning of the 2nd millennium CE onward: the vanguard, the
Southern Bantoid speakers, had not reached the Cape of Good Hope when
the Dutch arrived there in the 17th century. The close linguistic similarity
among the Bantu languages points to the speed of that vast migration. Swahili,
grammatically Bantu but with much Arabic in its vocabulary, is widely used as
a lingua franca in eastern Africa; as the language of the people of Zanzibar
and the east coast, it was spread by 19th-century Arab slavers in the
hinterland as far as what is now the Democratic Republic of the Congo. Fula,
an Atlantic language of the Niger-Congo family, also is used as a lingua
franca in West Africa.
The Nilo-Saharan family classification is perhaps the most controversial—
because of inadequate research—and the family is the most scattered. It
comprises languages spoken along the savanna zone south of the Sahara
from the middle Niger River to the Nile, with outlying groups among the
pastoralists of eastern Africa. Its subgroups are Songhai, Saharan, Maban,
Fur, Eastern Sudanic, Central Sudanic, Kunama, Berta, Komuz, and Kadu.
The Afro-Asiatic family includes languages from both Africa and the Middle
East: Semitic (including Arabic, Amharic, and Tigrinya), Egyptian (extinct),
Amazigh (Berber), Cushitic, Chadic (e.g., Hausa), and Omotic. It is found over
much of northern Africa and eastward to the Horn of Africa. Arabic is both an
official and an unofficial language in states north of the Sahara, as well as in
Sudan. In many other countries it is the language of Islam. Amharic is one of
the two principal languages of Ethiopia. Hausa also is spoken widely as a
lingua franca along the northern fringe of sub-Saharan western Africa, a wide
area that encompasses many ethnic and political boundaries.
The Khoisan family comprises the languages of the aboriginal peoples of
Southern Africa, who now are limited largely to the arid parts of southwestern
Africa, and perhaps of the outlying Hadza and Sandawe peoples of northern
Tanzania.
The Austronesian language family is represented by the various languages
of Malagasy in Madagascar.
There are many widespread trade languages and lingua francas in addition to
those mentioned above. Some, including English and French, were imported
and used by administrators, missionaries, and traders during the colonial
period. Some of those languages have become the national languages of
independent nation-states, and, with the spread of formal education, they are
gaining greater acceptance. Between the Sahara and the Zambezi River,
either English or French is widely understood. French is an official language in
the states that formerly made up French West Africaand French Equatorial
Africa, as well as in Madagascar (Malagasy is also an official language) and
the Democratic Republic of the Congo. Similarly, English is the official
language or is widely spoken in the states of western, central, and eastern
Africa formerly under British administration and is also the official language in
Liberia. Portuguese is used officially and otherwise in the countries formerly
under Portugal. In South Africa, English and Afrikaans (which developed from
17th-century Dutch by way of the descendants of European [Dutch, German,
and French] colonists, indigenous Khoisan-speaking peoples, and African and
Asian slaves) are among the many official languages. Hindi, Gujarati, Urdu,
and other languages of the Indian subcontinent are spoken in the Asian
communities. In western Africa, forms of creole (Krio) and pidgin are
widespread in the coast towns of very heterogeneous ethnic composition. In
Southern Africa, Fanagalo, a mixture of English and local Bantu tongue
(notably Zulu), is still spoken in some mining areas.
The great majority of African languages have no indigenous forms of writing.
Several of them, however, were transcribed in the 20th century by missionary
linguists, native speakers, and others. Many African languages (such as
Swahili) have for centuries been written in Arabic script. The best-known
exceptions to the Arabic writing system are those of the Vai of Liberia and
Sierra Leone, the Mum of Cameroon, and the Tuareg and other Berber
groups of the southern Sahara, all of whom invented their own scripts.
Religions
In general, the peoples of northern Africa adhere predominantly to Islamand
those in Southern Africa largely to Christianity, although their distributions are
not discrete. For example, the Coptic church is found in Egypt and Ethiopia,
and Islam is common along the coast of eastern Africa and is expanding
southward in western Africa. Many of the Sudanicpeoples—such as the
Malinke, Hausa, Songhai, and Bornu—are Islamized, and the religion has also
achieved substantial gains among such Guinea Coast people as the Yoruba
of Nigeria and the Temne of Sierra Leone. Much conversion to Christianity
also has occurred, most notably to Roman Catholicism and in the coastal
regions of sub-Saharan Africa.

Dejenné, Mali: mosqueMosque at Dejenné, Mali, designated a UNESCO World Heritage site in 1988.©
jean claude braun/Fotolia

In most of the rest of sub-Saharan Africa the people practice a variety of

traditional religions, which have certain common features. All of those known
include the notion of a high or creator God, remote from humans and beyond
their comprehension or control. That God typically is not attributed a gender
but in some cases is male or female; often God is given an immanent and
visible aspect as well. The most important “spiritual” powers are usually
associated with things or beings with which people have day-to-day contact or
that they know from the past. Thus, there may be many kinds and levels of
spirits of the air, of the earth, of rivers, and so on. There may be ancestors
and ghosts of the dead who have achieved a partial divinity, or there may be
mythical heroes who led the people to their present land and founded their
society as it is known today.
 Yoruba in Nigeria performing a dance in honour of the god Shango.Frank Speed

The ritual functionaries found in most African societies include priests, lineage
and clan elders, rainmakers, diviners, prophets, and others. Very few of those
people are specialists; typically they hold ritual authority by virtue of age,
genealogy, or political office and are primarily responsible for the ritual well-
being only of the members of the social groupings that they head; their
congregations consist of their joint families, lineages, clans, local village
communities, chieftaincies, or the like. Their ritual authority is thus a sanction
for their secular and domestic authority.
A central element of every indigenous African religion is its cosmology—which
tells of tribal origins and early migrations and explains the basic ideological
problems of any culture, such as the origin of death, the nature of society, the
relationship of men and women and of living and dead, and so on. Social
values are typically expressed in myths, legends, folktales, and riddles; the
overt meanings of those various oral statements frequently conceal
sociological and historical meanings not easily apparent to outsiders.
In the past, witchcraft and sorcery were given widespread credence and
served to explain or control the misfortunes of people who were aware of their
lack of mastery and understanding of nature and society. Travelers’ tales of
African people living in fear of witchcraft, however, were, of course, grossly
exaggerated; the colonial powers usually assumed (incorrectly) that witch
doctors were socially harmful and prohibited them. Although belief in
witchcraft is receding, it is still important in both rural and urban areas, often
serving as a means of explaining the misfortunes that beset urban dwellers
and labour migrants who find themselves in new and confusing social milieus.
There have been many cases in modern times of “epidemics” of beliefs in
witches, and there have arisen a number of evanescent religions led by
various kinds of prophets and evangelists. Such manias arise in periods of
radical change and their resultant uncertainty and stress.
Social and religious changes in Africa have often been accompanied by the
appearance of prophets who advocate the expulsion of the Europeans or the
eradication of epidemic diseases threatening the traditional ways of life. More
recently, also, the spread of Christianity and, to a lesser extent, Islam has
given rise to Christian prophets and to leaders of separatist
movements repudiating European-controlled mission churches for nationalistic,
tribalistic, or racial reasons. Such prophets lead their own groups and
establish their own churches, typically gaining new political power sanctioned
by their presumed direct links with God. The new churches have been
reported in almost all parts of the continent.
Domestic groupings

The forms of the family found in Africa are consistent with the forms of
economic production. Throughout most of the rural areas the typical domestic
group is the joint or extended family consisting of several generations of kin
and their spouses, the whole being under the authority of the senior male. The
size of the group varies, but it typically consists of three to five generations of
kin. It provides a stable and long-lasting domestic unit able to work as a single
cooperative group, to defend itself against others, and to care for all of its
members throughout their lifetimes. Polygyny is traditionally widespread as an
ideal, its extent depending on the status and wealth of the husband: chiefs
and rulers need many wives to give them a mark of high position and to
enable them to offer hospitality to their subjects.
In most of Africa those residential groups are based on descent groups known
as clans and lineages, the latter being segments of the former. The
significance given to descent groups varies, but they are important in
providing for heirs, successors, and marital partners.
In the second half of the 20th century that pattern began to change—rapidly in
the urban and poverty-stricken areas, more slowly in those areas less affected
by economic and political development. In cities and in major labour-supplying
areas, such as most of Southern Africa, the joint or extended family gave way
to the independent nuclear family of husband, wife, and children. There is also
a tendency toward the breakdown of family structure because of labour
migration—the younger men moving to the cities, leaving women, older men,
and children in the impoverished homelands.
John F.M. MiddletonJohn Innes ClarkeThe Editors of Encyclopaedia Britannica
Demographic patterns

Africa has the most rapidly expanding population of any region in the world,
even though the continent’s birth and death rates are also the world’s highest.
There was some decline in overall death rates in the latter half of the 20th
century, but infant and child mortality rates remained high, and average life
expectancy at birth actually declined somewhat during the 1990s. On average,
Africa’s population is increasing at about 3 percent per annum, and that
growth rate is associated with an increasingly youthful population: in nearly
every African country more than two-fifths of the population is younger than 15
years of age.
The great majority of the working population is still engaged in subsistence
agriculture and in the production of cash crops. In most countries the
proportion of the total population dependent on agriculture is at least three-
fifths.

The remainder of the working population is divided mainly between a rapidly

growing service sector (including civil servants, members of the armed forces,
police, teachers, health workers, and those engaged in commerce and
communications) and an increasing number of mining and industrial projects;
in only a few countries, however, do those latter activities employ more than
one-tenth of the workforce. Underemployment, particularly in the agricultural
sector, is widespread, and unemployment has risen, especially in urban areas.

Participation in labour by women varies considerably from country to country.

There are generally fewer women in paid employment than men, though a
large proportion of women in sub-Saharan countries are engaged in
subsistence agriculture—if only part of the time. Women are also employed in
the civil service, trading (especially in western Africa), domestic service, and
to an increasing extent in light industry.
Population distribution

Africa has more than one-eighth of the total population of the world,
distributed over a land area representing slightly more than one-fifth of the
land surface. Such desert areas as the Sahara, Kalahari, and Namib, however,
have reduced the amount of habitable land, and such factors as climate,
vegetation, and disease have tended to limit the evolution of densely
populated areas where agriculture is practiced. With the advent of the colonial
era, the African continent was divided into small geographically and politically
based units that took little or no account of ethnic distribution. Those political
boundaries persisted, and the continent continued to be characterized by a
large number of countries with predominantly small populations.

Population density of Africa.Encyclopædia Britannica, Inc.

Wide variations in density occur from country to country in Africa and within
countries. In general, the most densely populated areas are found bordering
the lakes, in the river basins (especially those of the Nile and Niger), along the
coastal belts of western and North Africa, and in certain highland areas, while
settlement is the most sparse in the desert and savanna areas. Thus, Rwanda
and Burundi, situated in the East African highlands, are the most densely
populated countries in Africa, while Western Sahara, Mauritania, and Libya in
the Sahara and Botswana and Namibia in the Kalahari and Namib are the
least densely populated.
Settlement patterns

Traditional African patterns of settlement vary with differences in landscape

and ecology, communications, and warfare. The most widespread pattern has
been that of scattered villages and hamlets—the homesteads of joint and
extended families—large enough for defense and domestic cooperation but
rarely permanent because of the requirements of shifting cultivation and the
use of short-lived building materials. Large mud-adobe villages are traditional
in much of the western African savanna, but over most of Africa housing
consists of mud and wattle with roofs of thatch or palm leaves.

Mauritania: hutMud-and-thatch hut, Mauritania, West Africa.© Kirsz Marcin/Shutterstock.com

Large towns were not widespread in the continent until the 20th century.
Towns dating from precolonial times are found mainly along the Nile valley
and the Mediterranean fringe of North Africa—where many date from
Classical times (e.g., Alexandria, Egypt) and the late 18th century (e.g., Fès,
Morocco)—and also in western Africa, in both forest and savanna zones,
where they were the seats of governments of kingdoms. Timbuktu (Mali), Ile-
Ife (Nigeria), Benin City (Benin), and Mombasa (Kenya) all date from the 12th
century, while the Nigerian city of Kano has prehistoric origins. Two other
Nigerian cities, Ibadan and Oyo, became important cities only in the 19th
century.
The more-traditional towns differ in form, function, and even population
characteristics from the many towns and cities established under colonial rule
as administrative, trading, or industrial centres and ports. The latter cities are
found throughout Africa and
include Johannesburg, Lusaka, Harare, Kinshasa, Lubumbashi, Nairobi, Daka
r, Freetown, Abidjan, and many others; often, as in the case of Lagos or Accra,
they are built onto traditional towns. Typically the focus of in-migration from an
impoverished hinterland, they are ethnically heterogeneous. Many have grown
to become the largest cities in their respective countries, dominating their
national urban hierarchies in size as well as in function.
Mostly rural for centuries, Africa has rapidly become more urbanized.
Although it is still the least urbanized of the continents, Africa has one of the
fastest rates of urbanization. Thus, the total population living in towns—which
was only about one-seventh in 1950—grew to about one-third by 1990 and
about two-fifths in the year 2010. Generally, the level of urbanization is
highest in the north and south, and it is higher in the west than in the east and
nearer the coasts than in the interior.

The largest cities include Cairo, Alexandria, and Al-Jīzah, Egypt; Kinshasa,
Democratic Republic of the Congo; Lagos, Nigeria; Casablanca, Morocco;
Johannesburg, South Africa; Addis Ababa, Ethiopia; and Algiers, Algeria.
Many other large cities are seaports along the coasts or central marketing
towns, linked by rail or river with a coast. Examples of seaports are Accra,
Ghana; Lagos; and Cape Town, South Africa. Examples of large inland cities
are Ibadan and Ogbomosho, Nigeria; Nairobi, Kenya; and Addis Ababa.

Cape Town, South Africa.© Digital Vision/Getty Images

Migrations

There have been many movements of population within the African continent,
from outside into the continent and from the continent outward. The major
movement within the continent in historic times has been that of the Bantu-
speaking peoples, who, as a result of a population explosion that is not fully
understood, spread over most of the continent south of the Equator.

Maison des Esclaves (“Slave House”), Gorée Island, Senegal.© GoLo/Fotolia

The major movements into the continent in the past few centuries have been
of European settlers into northern Africa and of European and Asian settlers in
Southern Africa. The Dutch migrations into Southern Africa began in the mid-
17th century. Originally settling on the coast, the Dutch—or Boers—later
moved inland to the Highveld region, where a series of military conflicts
occurred between them and the Bantu speakers in the 19th century. Other
European settlement took place mainly in the 19th century: the British
particularly in what is now KwaZulu-Natal province of South Africa but also
inland in what are now Zambia and Zimbabwe and in the East African
highlands, the Portuguese in Angola and Mozambique, and the Germans in
what is now Namibia.
The presence of large settler populations delayed the achievement of self-
government by the African peoples of South Africa, Namibia, Zimbabwe,
Angola, and Mozambique and resulted in much bitterness between the
indigenous peoples and settlers. In North Africa, by contrast, where the
extensive settlement of Europeans from France, Italy, and Spain occurred, the
growth of Arab nationalism and the emergence of independent states such as
Morocco, Algeria, and Tunisia led to the return of between one and two million
colonists to their homelands in the late 1950s and early 1960s and to the
political dominance of the indigenous peoples.
The greatest outward movement of people was that of Africans—particularly
from western Africa and, to a lesser extent, Angola—to the Americas and the
Caribbean during the period of the slave trade from the 16th to the 19th
century. (For further discussion of the phenomenon, seeslavery.) Earlier
estimates that between 15 and 20 million Africans were transported across
the Atlantic have been revised to a figure of 10 million, which appears more
realistic. While their contribution to the development of the New World was of
crucial importance, the effect of the loss of manpower to the African continent
was considerable and has yet to be satisfactorily analyzed. The slave trade
was also active on the east coast of Africa, where it was centred on the island
of Zanzibar.
There were few permanent population movements in Africa during the 20th
century, although an extensive settlement of Hausa from northern Nigeria took
place in what is now Sudan. Warfare produced some significant population
displacements, usually of minority groups fleeing the dominant majority. In
1966 the Igbo people of northern Nigeria, for example, returned en masse to
their homeland in eastern Nigeria, the number of refugees being estimated at
more than 500,000. The conflicts in the Horn of Africa since the 1960s have
caused similar displacements. Indeed, Africa has millions of refugees. Such
refugees are among the poorest and most vulnerable people in the world, and
their numbers are substantially augmented by those fleeing drought and
famine. The countries to which those people flee often find it extremely difficult
to cope with them.
 Somali refugeesSomali refugees in Ethiopia, 2011.Carola Frentzen—DPA/Landov

Most movement occurs across uncontrolled borders and between people of

the same tribal groups. Much is seasonal, in any case, and is restricted to
migrant labourers and nomadic herdsmen. Controlled immigration and
emigration are generally negligible; contemporary examples, however, include
the employment of mine workers in South Africa, the forced emigration of
Asians from East Africa, and the expulsion of people from neighbouring
western African states caused by such actions as the enforcement of the Alien
Compliance Order of 1969 in Ghana.
Robert K.A. GardinerDavidson S.H.W. NicolJohn F.M. MiddletonJohn Innes ClarkeThe
Editors of Encyclopaedia Britannica
MORE ABOUT THIS TOPIC
 Education: Africa
 Roman Catholicism: Missions in Africa
 History of publishing: Africa
 History of Latin America: Africans
 Coin: Coins of Africa
 Coin: Coinage in western continental Europe, Africa, and the Byzantine
Empire
 Western colonialism: Partition of Africa
 Police: Police organizations in Africa
 Anthropology: Anthropology in Africa
 South America: Africans
Economy
With the exception of South Africa and the countries of North Africa, all of
which have diversified production systems, the economy of most of Africa can
be characterized as underdeveloped. Africa as a whole has abundant natural
resources, but much of its economy has remained predominantly agricultural,
and subsistence farming still engages more than 60 percent of the population.
Until the beginning of the 20th century this system of farming relied on simple
tools and techniques, as well as on traditional organization of the family
or community for its labour. Because of poor transport and communications,
production was largely for domestic use. There was little long-distance trade,
and wage labour was virtually unknown. The small size and vast
heterogeneity of polities at that time also made exchanges very limited. There
were, however, notable exceptions, especially in western Africa, where for
many centuries societies had engaged in long-distance trade and had
elaborate exchange and craft facilities, communications, and a
political infrastructure to maintain their trade routes.
Africa experienced considerable economic development during the 20th
century, and, while this provided many benefits, it also gave rise to a number
of serious problems. The first significant changes occurred under colonial rule
in the first half of the century: wage labour was introduced, transportation and
communications were improved, and resources were widely developed in the
colonial territories. The legacy of this, however, has been that the export of
two or three major agricultural products or minerals—such as
peanuts, petroleum, or copper—has come to provide most of the foreign-
exchange earnings for nearly all African countries. Fluctuations in the prices of
these commodities have made the economies of these
countries vulnerable and fragile. The situation has been exacerbated in
countries in the marginal dryland zones, where the increasing frequency of
drought conditions have undermined agricultural productivity.
The second major change was the vigorous promotion of industrial
development, often with foreign assistance, that took place in the two decades
(1960–80) following the political independence of most African countries. The
political fragmentation of the continent, however, also became a major
constraint to industrial growth, because it created numerous small markets.
Consequently, most African countries became saddled with excess industrial
capacity, coupled with enormous foreign debts incurred in large part to build
this capacity.
In nearly all African countries a poor economic situation has been aggravated
by rapid population growth, which has kept per capita gross domestic
product low or in some cases caused it to decline. Thus, any hope for
improving economic conditions in most of Africa rests on two factors:
population control within individual countries to give their economies the
chance to grow; and the organization of groups of states into regional
economic blocs in order to create internal markets large enough to sustain
growth.
Resources

Mineral resources

Africa’s known mineral wealth places it among the world’s richest continents.
Its very large share of the world’s mineral resources includes coal,
petroleum, natural gas, uranium, radium, low-cost thorium, iron
ores, chromium, cobalt, copper, lead, zinc, tin, bauxite, titanium, antimony,
gold, platinum, tantalum, germanium, lithium, phosphates, and diamonds.
Major deposits of coal are confined to four groups of coal basins—in Southern
Africa, North Africa, the Democratic Republic of the Congo, and Nigeria.
Proven petroleum reserves in North Africa occur in Libya, Algeria, Egypt,
and Tunisia. Exploration has been concentrated north of the Aïr–Ahaggar
massifs; there may also be major Saharan reserves to the south. The other
major oil reserves are in the western coastal basin—mainly in Nigeria and
also in Cameroon, Gabon, Equatorial Guinea, and the Republic of the
Congo—and in Angola and South Sudan. Natural gas reserves are
concentrated in basins of North Africa and coastal central Africa.
Southern Africa is said to be one of the world’s seven major uranium
provinces. In South Africa the unusual degree of knowledge of reserves
derives from the joint occurrence of uranium with gold, a condition that also
decreases the cost of production. Other countries with significant uranium
deposits are Niger, Gabon, the Democratic Republic of the Congo,
and Namibia.
Metallic deposits

In North Africa reserves of iron ore are concentrated in the Atlas

Mountainsand in the western Sahara. Egypt, however, has medium-grade
reserves, of which the most important are at Al-Baḥriyyah Oasis. The ore
deposits in Morocco and Tunisia, which were once of considerable importance,
have been severely depleted. Africa’s most significant iron reserves are to be
found in western and Southern Africa. It is the sedimentary Precambrian rocks,
particularly in western Africa, that have proved the basis of Africa’s role as a
major world producer of iron ore. The most significant deposits are
in Liberia in the Bomi Hills, Bong and Nimba ranges, and Mano valley; in the
extension into Guinea of the Nimba–Simandou ranges, where hematites have
been located; in Nigeria and Mauritania, which have large deposits of low-
grade ore; and in Gabon, where extensive reserves are present in the
northeast. In Southern Africa most iron ore reserves lie in South Africa itself.
The chief deposits are at Postmasburg, in the Bushveld Complex, at
Thabazimbi, and in the vast low-grade deposits of Pretoria. There are also
substantial reserves in Zimbabwe.
Africa’s reserves of minerals used as ferroalloys in the steel industry are even
more striking than its enormous share of world iron ore reserves. This is
particularly true of chromium. Almost the entire world reserve of chromium is
found in Southern Africa and, to a much lesser extent, in western and
northeastern Africa. The highest concentrations are found in Zimbabwe,
at Great Dyke. South Africa contains the largest deposits of chromite. As
compared with these two sources, reserves elsewhere in Africa are relatively
small.
Manganese reserves are also considerable. In South Africa reserves of
contained manganese are found in the Kalahari Manganese Field and
elsewhere. The Mouanda deposit in southeastern Gabon is thought to be
among the largest in the world. Ghana is another important source of
manganese, having both low-grade and high-grade reserves. Elsewhere in
western Africa, manganese deposits are situated in Burkina Faso and Côte
d’Ivoire, as well as in the Democratic Republic of the Congo and in Cameroon.
In North Africa manganese is found in Morocco and Algeria.
Africa’s contribution to world resources of other ferroalloys is, by comparison,
insignificant. Nickel is of some importance, occurring in other metalliferous
ores in Southern Africa.

Most of Africa’s copper is contained in the Central African Copperbelt,

stretching across Zambia and into the Katanga (Shaba) area of the
Democratic Republic of the Congo. Accompanying minerals vary with the
geologic layer, but cobalt dominates. Outside the Copperbelt a number of
countries have lesser but still significant reserves of copper.
Only Nigeria, the Democratic Republic of the Congo, and South Africa contain
tin reserves of any significance. Although it is difficult to consider Africa’s
reserves of lead and zinc separately, of the two, lead ores are considerably
more widespread. North Africa is the largest traditional producing region.
African reserves of zinc metal are located along the Moroccan-Algerian
frontier, in the Copperbelt in the Democratic Republic of the Congo, in Nigeria,
in Zambia, and in Namibia.

Africa has about one-fourth of the world’s reserves of bauxite, the chief
aluminum ore. Virtually all of this occurs in a major belt of tropical laterite
stretching some 1,200 miles from Guinea to Togo. The largest reserves are in
Guinea.
Half of the world reserves of cobalt can be found in the Democratic Republic
of the Congo. A continuation of the geologic formation into Zambia gives the
country sizable reserves of cobalt content. The only other deposit of any
importance is found in Morocco.
The titanium ores, ilmenite and rutile, are widely distributed in Africa but are
rarely considered as minable reserves. A major source is the Sherbro deposit
in Sierra Leone. Almost all of Africa’s antimony resources lie in the Murchison
Range of South Africa. The major concentrations of beryllium are
in Madagascar, Mozambique, the Democratic Republic of the Congo,
Zimbabwe, Rwanda, Uganda, and South Africa. The principal sources of
cadmium are in Namibia and the Democratic Republic of the Congo. Deposits
of mercury are restricted to North Africa, notably to Tunisia and, more
particularly, Algeria.
Gold and allied metals are widely disseminated, reaching their greatest
concentrations in South Africa, where reserves of gold
probably constituteabout half of the world total. Gold is also found in
Zimbabwe, in the Democratic Republic of the Congo, and in Ghana. There are
numerous alluvial sources of gold in Burundi, Côte d’Ivoire, and Gabon. South
Africa has the most important deposit of platinum of the world’s market
economies. Silver reserves of the continent are not important.
Africa contains a major share of world reserves of tantalum, and the
Democratic Republic of the Congo has most of these reserves. African
reserves of niobium (columbium; a steel-gray metallic element resembling
tantalum in its chemical properties that is used in alloys) are relatively small.
Nigeria, however, is an important world producer.

One of Africa’s many sources of zirconium (a metallic element resembling

titanium chemically) is the Jos Plateau in Nigeria. Greater reserves, however,
are contained in deposits on the Senegal coast; on the east coast of South
Africa; in Madagascar; at Sherbro, Sierra Leone; and in the Nile delta.
Another rare metal of which Africa contains a majority of world reserves is
germanium, concentrated in the Democratic Republic of the Congo and in
Namibia. Africa also has large deposits of lithium, the largest of which are
found in the Democratic Republic of the Congo.

Nonmetallic deposits

Clays are widespread and are found in North Africa, where brick and pottery
clays occur in Algeria and Morocco; in western and central Africa, where clays
are located in Togo (ceramic), the Central African Republic, and Côte d’Ivoire
(ceramic); and in East and Southern Africa.
Kaolin (china clay) occurs in Algeria. Outside North Africa it is widespread. In
western Africa it occurs most notably in Nigeria’s Jos Plateau, as well as
in Mali, Ghana, and Guinea. Similar deposits occur in central and East Africa,
as well as in Southern Africa.
Bentonite (a clay formed from decomposed volcanic ash, which is able to
absorb large quantities of water and to expand to several times its usual size)
is found in the Moroccan Atlas Mountains and in Tanzania, Kenya, and South
Africa. The continent’s principal reserve of fuller’s earth (an absorbent clay) is
in Morocco.
Economically important mica deposits occur primarily in Southern Africa
(South Africa, Zimbabwe, and Tanzania) and in Madagascar.

Africa has none of the world’s major reserves of sulfur. It reaches economic
concentrations only in South Africa’s Witwatersrand, in Zambia’s Copperbelt,
and in Morocco. Large quantities of sodium deposits remain to be evaluated.
Sodium chloride is the principal salt, the largest deposit being in the Danakil
Plain of Ethiopia. The principal sources of salt in Africa, however, are inland or
coastal basins, from which it is extracted by the evaporation of salt water.
Major coastal reserves of this type lie along the North African Mediterranean
coast and along the Red Sea and Indian Ocean coasts of East Africa and
Madagascar. Inland, the chief reserves are in the Oran Sebkha, a salt
pan region in Algeria; in Botswana around Lake Makarikari; and in Uganda.
Another important sodium mineral is natron, or sodium carbonate. Natron is
more limited in occurrence, but Africa contains several significant deposits. It
is found in Lake Magadi, Kenya, and in Lake Natron, Tanzania, as well as in
western Africa, where beds have been deposited from the waters of Lake
Chad.
North Africa has been a traditional exporter of phosphates, and western Africa
has large reserves. Morocco and Western Sahara together have vast
reserves. The Río de Oro region in Western Sahara contains huge deposits,
and a major development at Bu-Craa has been established. Algeria and
Tunisia also have reserves. To the east, phosphate-bearing sediments
outcrop on the Red Sea coast. The Thiès deposit in Senegal is of particular
interest in constituting the world’s only source of aluminum (as opposed to
calcium) phosphate. Other phosphate deposits occur in Togo, Nigeria,
Tanzania, Uganda, and Malawi.
The potash deposits in the Republic of the Congo are the largest in Africa.
The other large reserve is in Ethiopia.
Madagascar has the world’s largest known accumulation of flake graphite
deposits. Continuations of these high-quality deposits in Mozambique and
southeastern Kenya contain further reserves of graphite.

While deposits of low-grade sand suitable for construction and engineering

work are widely distributed, reserves of sands with a sufficiently high silica
content for glass manufacture are more localized. There are deposits in
western Africa (Côte d’Ivoire, Liberia, Nigeria, and Ghana), East Africa
(Uganda and Tanzania), and South Africa. Glass sands are also found in
Egypt.

Kyanite (cyanite), a mineral aluminum silicate used as a refractory, occurs

most typically in Southern Africa. Apart from South African reserves, there are
deposits in Kenya, Malawi, Ghana, Cameroon, and Liberia.

Of the abrasive substances, industrial diamonds are most closely associated

with Africa. The continent contains some 40 percent of the total world
reserves. The stones are found in a number of major belts south of the
Sahara. The principal known reserves of diamonds in their primary form are in
the South African Vaal belt. Elsewhere in Africa, primary deposits are found in
Tanzania, Botswana, and Lesotho.
Another major belt of diamondiferous rocks encircles the Congo River basin
and includes the world’s largest deposit, located in the Democratic Republic of
the Congo, which contains the majority of Africa’s reserves of industrial
diamonds. The same belt has secondary deposits that occur elsewhere in that
country as well as in the Central African Republic and Angola. In western
Africa known reserves are located primarily in alluvial gravel fields. They are
found in Sierra Leone, Guinea, Côte d’Ivoire, Liberia, and Ghana.
A considerable proportion of the world reserves of corundum (a common
mineral, aluminum oxide, notable for its hardness) is located in Southern
Africa. The principal deposits are in Zimbabwe, South Africa, Mozambique,
Madagascar, and Malawi.
Pumice is found in areas of volcanic activity such as the Atlantic islands, the
coastal Atlas Mountains of northeastern Morocco, and the East African Rift
System, notably in Kenya, Tanzania, and Malawi. Joint reserves, however,
constitute only a small percentage of the world total.
Reserves of building materials are characterized by their wide distribution, to
such an extent that the commercial status of such deposits depends more on
their location relative to areas of development than on their extent and quality.
While almost all African countries have reserves of building materials,
knowledge of such reserves is strictly related to the country’s level of
development, and no meaningful estimate of the size of reserves can be
made.

Granite is located in Morocco and Nigeria, and there are vast reserves in
Burkina Faso. Quartzite (a granular rock, consisting essentially of quartz) is
important as a building stone in Uganda and the Democratic Republic of the
Congo. Dolerite (a coarse-grained basalt) is produced in South Africa and
basalt, which is crushed for use in road construction, in Senegal. Marble is
found in Mali, Togo, Nigeria, and South Africa.
Limestone is important because of its use in the cement industry, and
deposits are fairly widespread. North Africa is a particularly important source.
In western Africa a belt of limestone runs from the Central African Republic to
the Atlantic coasts, with major outcrops in northern Nigeria, Niger, Burkina
Faso, and Mali. Elsewhere there are deposits in Nigeria, Benin, Togo, and
Ghana. East African deposits include those in Kenya, Tanzania, Uganda, and
Zambia; there are also deposits in South Africa.
North Africa has major reserves of gypsum on the Mediterranean coast, as
well as in outcrops along the Gulf of Suez and the Red Sea. Somalia has one
of the largest known deposits. Eastern Africa and Madagascar have further
reserves, and in western and Southern Africa superficial deposits are
particularly important—for instance, north of Nouakchott, Mauritania.
Many of the major deposits of the most important commercial gem mineral,
the diamond, have already been described above in the discussion of
industrial diamonds. One major deposit, however—that of Namibia—consists
almost entirely of gem diamonds.
There is no other gem mineral in Africa of comparable importance to these
diamond reserves. Deposits of a number of such stones are found, however,
especially in Southern and eastern Africa, where diamond fields contain beryl,
garnets, amethyst, rose quartz, topaz, opal, jasper, emeralds, and other
stones. Madagascar contains a large deposit of garnet. Tourmaline is found in
Madagascar and Namibia. Agate is particularly associated with the volcanic
areas of eastern and Southern Africa and malachites with the Katanga
Copperbelt, while sapphires are found with diamonds in Ghana.
Africa contains no major world deposits of talc, but the mineral is found in
Morocco, Nigeria, Sudan, Zimbabwe, and South Africa. Reserves of asbestos
are much more important, and Southern Africa has a number of deposits of
world significance.
Major deposits of fluorite, or fluorspar (a common mineral, calcium fluoride,
used as a flux in metallurgy), are particularly associated with deposits of lead
and zinc. In South Africa the chief deposit is in the northeastern part of the
country. North African reserves lie primarily in Tunisia and Morocco.

Africa produces a very small share of the world supply of diatomite (a fine
siliceous earth, used as an abrasive). The most important deposit is in Kenya.

Water resources

In general, the seasonal distribution of river flow in Africa reflects the seasonal
rainfall pattern; the amount of groundwater entering the river channels during
the dry season is comparatively small. Important modifications in the flow of
some rivers are caused by the presence of large lakes and swamps, which act
as natural storage reservoirs, by the construction of dams on their courses,
and by the incidence and severity of drought.

Surface water

Although the surface area of Africa is about one-fifth of Earth’s land surface,
the combined annual flow of African rivers is only about 7 percent of the
world’s river flow reaching the oceans.
North Africa’s few perennial rivers originate in the mountains of the Maghrib,
and their water is used extensively for irrigation. The large number of wadis,
or ephemeral watercourses, to be found throughout the Sahara and the
eastern Mediterranean coastal lands become filled with water as a result of
the rare and erratic storms that occur over mountainous areas; otherwise they
remain dry.
From the relatively well-watered areas of western and equatorial Africa, the
Sénégal, the Niger, the Logone–Chari, and the Nile rivers flow through the
drier inland zones. Of these, the Niger River, originating in the Fouta
Djallonregion of Guinea, is retarded in the lake and swamp area south
of Timbuktuin Mali, and the Logone–Chari feeds Lake Chad.
The Nile, the world’s longest river, receives more than 60 percent of its water
from the Ethiopian Plateau, although its source is much farther south in the
mountains of Burundi. Since the completion of the Aswan High Dam, only a
small proportion of the river’s total flow reaching Egypt enters
the Mediterranean Sea.
A number of rivers flowing in a more or less southerly direction into
the Atlantic Ocean drain the southern part of western Africa. Many flow rapidly
over bedrock before entering the coastal plains, draining into the system of
lagoons and creeks along the coast. During the dry season the upper reaches
of these rivers are without water, but in Guinea, Sierra Leone, and Liberia,
where the dry season is fairly short, the rivers flow throughout the year.
In the well-watered western part of equatorial Africa the total average annual
flow of the Congo River is enormous: some 44 trillion cubic feet. River flow at
the lower end of the basin has two maxima: one that corresponds with the
rainy season north of the equator, the other with the rainy season that occurs
when it is summer in the Southern Hemisphere. The waters in the lower
reaches of the river are slightly acid after traversingthe large swamps situated
in the centre of the basin.
East Africa’s many lakes stretch along the East African Rift Valley from the
Red Sea to the mouth of the Zambezi River. Evaporation from most of them
exceeds their surface rainfall, and in consequence their outflow is less than
the quantities brought in annually by their tributaries. They often govern river
flow by acting as storage reservoirs—decreasing the flood flow and increasing
the dry-season flow. A number of the rift valley lakes are situated in closed
basins and contain high percentages of dissolved salts. The largest of these
are Lakes Rudolf (Turkana), Natron, and Eyasi.
Rainfall over much of Southern Africa is small, and the majority of the rivers
originating there have an intermittent flow. Some large perennial rivers (e.g.,
the Okavango, the Zambezi, and the Orange) flow from areas of abundant
rainfall into the drier zones.
Groundwater

The conditions under which groundwater is found and the quantity and quality
of groundwater reserves are closely related to geologic structure. Large inland
depressions in Africa’s basement rock, having been filled with sedimentary
layers of continental origin, sometimes form important groundwater reservoirs,
notably those in the Taoudeni–Niger region, in the central Sahara between the
Atlas and Ahaggar mountains; in the Libyan Desert; and in Chad, the Congo
basin, the Karoo area of South Africa, and the Kalahari.
The East African plateaus usually contain little or no quantities of groundwater,
and aquifers (geologic formations containing water)—generally of local
importance—are found only in humid areas where the crystalline rock is
weathered or fractured.
The chalky shales (rocks of laminated structure formed by the consolidation of
clays) and dolomitic limestones (those containing calcium magnesium
carbonate), which sporadically cover the basement rock, may contain
important aquifers; those in Zambia and South Africa are major sources of
water.

In the Sahara a rock stratum called the Continental Intercalary series, which
dates from the early Cretaceous Period and which includes the Nubian
sandstones of southern Egypt, is the most important water-bearing layer. It
extends over very large areas and reaches a thickness of more than 3,000
feet; in Egypt and Algeria it is a major source of artesian water. In Sudan it
sometimes lies directly on the Precambrian bedrock and contains
underground water layers of local importance. Overlaying the Continental
Intercalary series, but generally separated from it by a thick marine deposit, is
a younger Tertiary layer called the Continental Terminal, which is the second
largest aquifer in this area. Both these layers contain “fossil” water—i.e., water
that entered the layers when rainfall in and around the Sahara was much
more abundant than today. Near the surface, aquifers are found in such
geologically recent deposits as alluvial deposits and sand dunes.
In the coastal areas of Senegal, Côte d’Ivoire, Ghana, Togo, Benin, Nigeria,
Cameroon, Gabon, the Republic of the Congo, Angola, Mozambique, the East
African countries, and Madagascar, aquifers are found in sandstone,
limestone, and sand and gravel sediments. Intensive exploitation, however,
may result in saltwater intrusions.

The Jurassic limestones of the mountainous area of the Maghrib are much
more abundant in water sources than are dolomitic limestones. Around the
cape in South Africa, sandstones and limestones contain very little water.

Yields from aquifers with good porosity, such as coastal sedimentary rocks or
alluvial deposits, vary from a few cubic feet per hour in the fine-grained sands
found in many parts of the continent to 35,000 cubic feet (990 cubic metres)
per hour in the coarse gravels of the Nile delta. The capacity of wells in the
Continental Terminal is generally somewhat lower, and those in the
Continental Intercalary and the Karoo formations can also deliver moderate to
high yields.
In North Africa limestones containing many cracks and fissures may yield
thousands of cubic feet of water per hour, while in the Democratic Republic of
the Congo, Zambia, and South Africa large yields are drawn from dolomitic
limestones.
The harder sandstones, sandy shale, and quartzites of Precambrian and
Paleozoic age are not generally very porous, and water is obtained only from
fractured or weathered deposits. Western African, Angolan, and Tanzanian
wells in these formations produce only a few cubic feet per hour. Crystalline
and metamorphic rocks are almost impermeable except where fractured or
weathered. Volcanic rock, especially the basalts, may yield up to 1,060 cubic
feet per hour.

Most of the exploited groundwater is generally fit for consumption, because

the dissolved minerals in water from shallow wells, particularly in the sandy
aquifers of western Africa, are quite low. Groundwater from deeper marine
layers, however—such as occurs in parts of North Africa, Mozambique,
Ethiopia, and South Africa—may have a high content of dissolved salts. In
moist tropical countries the water from Precambrian rocks generally contains
only small amounts of dissolved minerals, whereas in the volcanic areas of
East Africa groundwater may have so high a content of fluorine as to make it
unfit for human consumption. There, and elsewhere in Africa, hot (possibly
medicinal) springs with high mineral contents occur.
Availability for human use

The pronounced seasonal character of rainfall and the fact that many rivers
stop flowing during the dry season have necessitated the development of
groundwater for human use, and the tapping of local aquifers has become
important in many parts of the continent.

Large-scale irrigation has long been practiced mainly in North Africa, Egypt,
Sudan, South Africa, Mali, Zimbabwe, and Mozambique. Medium-scale
irrigation projects have been operated in Madagascar, Senegal, Somalia, and
Ethiopia. In Côte d’Ivoire, Burkina Faso, Kenya, Nigeria, Ghana, and Zambia,
medium- to small-scale projects have been constructed.

More than 50 river and lake basins are shared by two or more countries, and
the development of their resources requires the cooperation of the basin
states and several intergovernmental agencies—such as the Organization for
the Development of the Sénégal River, the Niger Basin Authority, and
the Lake Chad Basin Commission.
Several large reservoirs were built in the late 20th century, such as the Aswan
High Dam, Roseires, and Khashm al-Qirbah reservoirs in the Nile basin, Kainji
on the Niger, Akosombo on the Volta, Kariba on the Zambezi, Cahora
Bassa on the Zambezi in Mozambique, Kossou on the Bandama in Côte
d’Ivoire, Kafue on the Kafue in Zambia, and Inga I and II on the Congo River
in the Democratic Republic of the Congo. At a number of man-made lakes,
research centres have been set up to study resettlement problems, the full
use of ecological conditions, and the control of health hazards that sometimes
occur.
Biological resources

Africa’s naturally occurring biological resources—its immensely varied

vegetational cover, vast insect life, and diverse animal life—have been
described above. When combined with cultivated crops and domestic animals,
these resources represent the great bulk of the continent’s economic wealth.
Botanical resources

The two most economically important types of vegetation are forests and
grasslands. Among the forested areas, the tropical forests contain much of the
valuable timber. The vast equatorial lowland rainforest has the greatest variety
of tree species, but the species most commercially in demand are found in the
zones of broad-leaved woodlands and tropical highland forests. The true
value of the forested areas, however, cannot be ascertainedexactly, as
original forests are progressively being converted to farming areas, and few
governments have undertaken comprehensive land-use surveys to determine
their present extent.
A large proportion of the land surface of Africa bears vegetation in
which grass is an essential feature. This abundance of grass has made
possible the continent’s enormous and varied populations of herbivorous
mammals, both wild and domesticated. The tall and fibrous invasive grasses
in forest environments and in large tracts of wooded grasslands are seldom
very palatable to livestock, but, in those parts of the continent where good
forage grows naturally or has been introduced, livestock raising is of great
economic importance.
The Albida acacia tree of the “farmed parkland” areas of western Africa is of
special economic importance. Unlike almost all other dry woodland trees,
whose leaf shedding normally occurs at the onset of the dry season, the
Albida appears to have a period of partial dormancy during the rainy season
and springs to life only at the beginning of the dry season. At such periods its
foliage is abundant and—being a palatable leguminous species—is much
prized as browse for sheep, goats, and cattle. The smaller leafy branches are
frequently fed to stock. The tree flowers and produces fruits, which are
harvested, dried, and fed as a protein concentrate to stock at the height of the
dry season.
Animal resources

Water buffalo, oxen, horses, mules, donkeys, and camels are used primarily
as draft, pack, or riding animals in Africa, and they also provide milk, meat,
hides, or skins. Because of its intractability and wild nature, however,
the African elephant—unlike the Asian elephant—is not used for draft or
haulage purposes.
The water buffalo is an offshoot of the Asiatic buffalo (Bubalus bubalis); it
arrived in Africa in relatively recent times and is now found almost exclusively
in Egypt. The domesticated African water buffalo is used to cultivate irrigated
land (mainly in the Nile delta) and to provide milk and meat.
Oxen are widely used in Africa for agricultural purposes, especially for plowing
and cultivation; they are also trained to thresh grain, pump water, and act as
pack animals. Bullock (castrated oxen) plowing is well developed in the
countries of North Africa, in Ethiopia and Sudan, and farther west in Chad, in
northern Nigeria, and in the savanna climatic zone of western Africa. Plowing
and cultivation by oxen is also well developed in areas of eastern and
Southern Africa that are free of the deadly tsetse fly. Females used for work
may also be milked. Work oxen are often used for meat and to provide hides.
Horses and ponies are principally found in Morocco, Algeria, Tunisia, Chad,
Ethiopia, Mali, Niger, Nigeria, Senegal, Burkina Faso, Egypt, South Africa,
and Lesotho. Horses are used as riding or pack animals and in a number of
areas are bred with donkeys to produce mules. Few are kept in areas where
tsetse flies are present. Five main types of horses inhabit Africa:
the Darfurpony, the Dongola horse, the Ethiopian-Galla horse, the Somalia
pony, and the South African horse (including the Basuto pony). In North Africa,
types also have evolved as a result of selection and crossing with exotic Arab,
Barb (Barbary), and Thoroughbred horses. Arab and Thoroughbred influence
may also be noted in Southern Africa.
The distribution of the ass roughly corresponds to that of the horse, except
that it also extends into the livestock areas of eastern and central
Africa. Mules are found in Algeria, Ethiopia, Morocco, Somalia, South Africa,
and Tunisia, where they provide farm draft power and are used as pack
animals and for riding. The ability of mules to perform work in hot, dry climates
is superior to that of most other farm animals.
The Arabian camel, or dromedary, is widely dispersed in the drier regions of
northern and eastern Africa. Although used principally as a pack animal, it
also is used for land cultivation, water pumping, and human transportation.
The camel is essentially a bush browser and, if reasonably well fed and
watered, may produce about 11 to 13 pounds (5 to 6 kilograms) of milk daily,
in addition to that fed to the calf. The milk is prized by the camel herders and
their families. Camel meat and camel hides find a ready market among
Muslim communities.
Cattle provide hides, and sheep, goats, and pigs provide skins. Skins of the
Maradi, Sokoto, and Kano red goats from Niger and Nigeria are greatly prized
by the Morocco leather trade. In the areas north and south of the tropical zone,
African sheep are covered with wool, but in the tropics they are hairy. In
elevated areas, such as Ethiopia, where temperatures are modified by altitude,
some sheep may be partially wooled, at least on the back and buttocks. The
wooled sheep of North Africa are largely of the woolly Barbary type, which
was originally introduced to Africa from the Middle East.
The great herds of wild African herbivores include the principal game animals.
African antelope have been important throughout human history as sources of
meat and such by-products as hides and bone, and they, along with other
large mammals, became prized by trophy hunters. For centuries African
elephants were sought for the ivory in their tusks, but the severe reduction of
their numbers by the late 20th century led to a total ban on hunting them in
most African countries.
The most economically useful fishes found in African waters include many
freshwater species. Important among the marine fishes are flounder, halibut,
sole, redfish, bass, conger, jack, mullet, herring, sardine, and anchovy.
Crustaceans are important for local consumption and for export, as are
oysters (for pearls), trochus shells, corals, and sponges. The most
economically important aquatic mammal is the Southern, or Cape, fur seal.
Agriculture

Agriculture is by far the single most important economic activity in Africa. It

provides employment for about two-thirds of the continent’s working
population and for each country contributes an average of 30 to 60 percent of
gross domestic product and about 30 percent of the value of exports.
Nonetheless, arable land and land under permanent crops occupy only about
6 percent of Africa’s total land area.
Northern Africa: Irrigation of LandIn the dry regions of northern Africa many different methods are used
to irrigate the land so it can be used for farming.Encyclopædia Britannica, Inc.

Except for countries with sizable populations of European descent—such as

South Africa, Zimbabwe, and Kenya—agriculture has been largely confined to
subsistence farming and has been considerably dependent on the inefficient
system of shifting cultivation, in which land is temporarily cultivated with
simple implements until its fertility decreases and then abandoned for a time
to allow the soil to regenerate. In addition, over most of Africa arable land
generally has been allocated through a complex system of
communal tenure and ownership rather than through individually acquired title,
and peasant farmers have had rights to use relatively small and scattered
holdings. This system of land ownership has tended to keep the intensity of
agricultural production low and has inhibited the rate at which capital has been
mobilized for modernizing production. A number of countries have made
efforts to raise productive levels by selecting better varieties of seeds and
planting materials, using tractors and other mechanized equipment, or
increasing the use of mineral fertilizers and insecticides. Such measures,
however, have been relatively limited, and they have raised concerns about
their part in accelerating soil erosion and desertification. In areas of cash crop
production, land has become private rather than community property, and
cultivation is intensive.
The persistence of relatively low-productivity agricultural systems over large
parts of the continent also stems from a lack of integration between crop
production and animal husbandry. Traditionally, sedentary cultivators like the
Hausa in Nigeria and the Kikuyu in Kenya live apart from their nomadic
herdsmen neighbours (the Fulani and Maasai, respectively), with the result
that over large areas of the continent farmers do not have access to animals
for draft power or to manure for fertilizer. The incidence of such insect pests
as the tsetse fly also discourages mixed farming in many areas.
The need to sharply increase food production to meet the demands of a
rapidly growing population, however, has remained paramount. Intense
research at such centres as the International Institute of Tropical Agriculture
in Ibadan, Nigeria, has been directed at developing high-performing varieties
of crops and designing more appropriate cropping systems. One product of
such research is a genetically improved strain of corn (maize). Corn is not in
itself a balanced food, being deficient in some amino acids, but a scientific
breakthrough in the mid-1960s resulted in an increase of the amino acids
lysine and tryptophan in certain new varieties of corn called opaque, or high-
lysine, strains. These varieties initially produced low yields, were more prone
to disease and vermin, and had a soft texture that was not desirable. Breeding
programs, however, corrected these defects, and the new strains began to
improve the nutritional value of diets in Africa (which consist mainly of corn
preparations).
Principal crops

Cereals and grains

Africa produces all the principal grains—corn, wheat, and rice—in that order of
importance. Corn has the widest distribution, being grown in virtually all
ecological zones. Highest yields per acre are recorded in Egypt and on the
Indian Ocean islands of Réunion and Mauritius, areas where production is
under irrigation. Millet and sorghum are also produced but principally in the
savanna regions of the continent. Rice production and consumption have
become increasingly important and are closely associated with areas of rapid
urbanization. The most important rice-producing countries are Egypt, Guinea,
Senegal, Mali, Sierra Leone, Liberia, Côte d’Ivoire, Nigeria, Tanzania, and
Madagascar. Wheat production was once restricted to South Africa, the
countries of North Africa, and the highland zones of Ethiopia and Kenya, but
new varieties have extended cultivation (under irrigation) to countries in the
savanna region such as Nigeria.
Legumes and fodder

Fodder crops are not widely grown except in subtropical areas of North Africa
and the highland zones of East and Southern Africa, where pure stands of
alfalfa (lucerne) are raised. Berseem (a type of clover used for forage) is also
grown in Egypt and Sudan under irrigation. Protein-rich legumes are produced
widely, usually sown together with other crops. They include velvet beans,
cowpeas, soybeans, and lablab (hyacinth beans). In North Africa broad beans
and vetches are also produced. Peanuts (groundnuts) are grown widely in
western Africa, both for domestic consumption and for export.

Tubers and root crops

Cultivation of the hardy cassava has expanded tremendously, particularly in

western and central Africa; it has displaced the cultivation of yams in many
areas and has ceased to be regarded as just famine reserve. Potatoes are
cultivated in the higher elevations of such countries as Ethiopia, Kenya, and
Madagascar, as well as in areas of Mediterranean climates in North and
South Africa. Sweet potatoes have a more tropical and subtropical distribution,
while the plantain is grown extensively in the tropical forest zones.

Fruits and vegetables

Among the important fruits are bananas, pineapples, dates, figs, olives, and
citrus; the principal vegetables include tomatoes and onions.

The banana is well distributed throughout tropical Africa, but it is intensively

cultivated as an irrigated enterprise in Somalia, Uganda, Tanzania, Angola,
and Madagascar. Also widely cultivated is the pineapple, which is produced
as a cash crop in Côte d’Ivoire, the Congo basin, Kenya, and South Africa.

A typical tree of desert oases, the date palm is most frequently cultivated in
Egypt, Sudan, and the other countries of North Africa. The fig and olive are
limited to North Africa, with about two-thirds of the olive production being
processed into olive oil.
The principal orange-growing regions are the southern coast of South Africa
and the Mediterranean coast of North Africa, as well as Ghana, Swaziland,
Zimbabwe, the Democratic Republic of the Congo, and Madagascar. The
largest yields are produced in countries where basin irrigation is practiced.
South Africa is the largest producer of grapefruit, followed by Sudan.
Tomatoes and onions are grown widely, but the largest-producing areas
border the Mediterranean. Large vegetables, such as cabbages and
cauliflowers, are grown in the same region, from where it is possible to export
some quantities to southern Europe. Important vegetables of tropical Africa
include peppers, okra, eggplants, cucumbers, and watermelons.
Beverage crops
Tea, coffee, cocoa, and grapes are all grown in Africa. Kenya, Tanzania,
Malawi, Zimbabwe, and Mozambique are the largest producers of tea, while
Ethiopia, Uganda, Côte d’Ivoire, Tanzania, and Madagascar are the major
producers of coffee. Cocoa is essentially a tropical forest crop. Its cultivation is
concentrated in western Africa, with the principal producers being Côte
d’Ivoire, Ghana, Nigeria, and Cameroon. All these crops are largely grown for
export. Sharp price fluctuations caused African countries to form international
cartels with other producing countries in an effort to regulate the market and
negotiate better prices. Grapes are produced in northern Africa and in South
Africa, essentially for the making of wine for European markets.

Fibres

Large areas of Africa raise cotton for textile manufacture. The principal
producing countries include Burkina Faso, Nigeria, Egypt, Zimbabwe, and
Mali. Sisal production is also important, especially in the eastern African
countries of Ethiopia, Tanzania, Kenya, and Madagascar, as well as in
Mozambique, Angola, and South Africa. Some countries, notably Nigeria,
promote the cultivation of kenaf (one of the bast fibres).

Other cash crops

The oil palm, producing palm oil and palm kernels, grows widely in secondary
bush in the tropical forest zones. There are large plantations in Nigeria, Côte
d’Ivoire, and the Democratic Republic of the Congo. Coconuts are important in
the Comoros, Ghana, Côte d’Ivoire, Mozambique, Nigeria, and Tanzania. Kola
nuts are grown principally in the forested regions of Nigeria, Ghana, Côte
d’Ivoire, Sierra Leone, and Liberia. The cashew tree is grown to a limited
extent in East Africa and to a lesser extent in the coastal countries of western
Africa. Rubber is produced principally in Nigeria and Liberia. Tobacco is
widely cultivated as an export crop in Zimbabwe, Malawi, Tanzania, Nigeria,
and South Africa. Sugarcane is also widely grown but largely for domestic
consumption. Major producers include South Africa, Egypt, Mauritius, and
Sudan.
Livestock and fishing
Cattle, sheep, and goats form the bulk of livestock raised. Except in South
Africa, most of these animals are raised essentially for meat. Sheep in the
north and south are also kept for their wool; South Africa alone produces half
of the entire continental production, much of the clip from Merino or crossbred
Merino sheep. In the tropical areas, however, other livestock products include
hides and skins. It is estimated that the annual output of hides is in the range
of 10 percent of the total population of cattle, while that of sheepskins and
goatskins is approximately 25 percent. The number of game hides and skins
processed and sold annually is not accurately known. Except in South Africa,
Zimbabwe, and Kenya, production of milk and milk products is grossly
insufficient to meet domestic needs. Poultry production, however, has
increased tremendously, and everywhere stocks have nearly doubled since
the 1960s. Nigeria, Ethiopia, Morocco, South Africa, and Sudan are the
countries with the largest poultry stocks.

Fishing is important on the local level in all countries bordering the sea or
inland bodies of water. Commercial ocean fishing is practiced most widely by
the countries near the rich fishing grounds of the west coast—South Africa,
Namibia, Angola, Nigeria, Ghana, Senegal, and Morocco. Herring, sardines,
and anchovies contribute most to the ocean catch, followed by jack, mullets,
sauries, redfish, bass, and conger in tropical waters and cod, hake, haddock,
tuna, bonitas, and bullfish in northern and southern waters. Inland countries
with well-developed fisheries include Malawi, Uganda, Chad, Côte d’Ivoire,
and Mali; tilapia and other cichlids constitute the largest catch in inland waters.
Some countries, such as Nigeria, have developed both marine and freshwater
fishing industries. A number of commissions have been established to monitor
and control fishery development on the continent.
Industry

The countries of North Africa, unlike those of the rest of the continent, have
wide-ranging and ancient traditions of manufacture. At the end of the 19th
century, however, Africa as a whole was regarded solely as a potential source
of raw materials or as a natural market for Europe. In the course of time,
limited industrialization tended to converge around the relatively large
expatriate settlements, where technical considerations operated in favour of
the industrialization of some areas and transport costs constitutedthe
dominant development factor in others. Though World War II led to
acceleration in the process of industrial development, by 1950 the total factory
output of manufacturing industries (excluding South Africa) still remained
small.
After 1950 output rapidly increased. The substantial increase and its range
were attributable to such factors as increased demand, the substitution of
home-produced for imported goods, the encouragement of manufacturing by
individual African administrations, and an influx of development capital and
petrodollars. Major weaknesses nevertheless were evident, among them high
capital costs, the political division of Africa into more than 50 countries, which
inhibited mass production and mass marketing, and a scarcity of skilled
personnel.
Despite its expansion since about 1950, the relative significance of
manufacturing remains considerably smaller than in the more-advanced
countries and smaller also than in continental Asia and in Latin America.
Furthermore, the share of manufacturing in the gross domestic product varies
widely in different African countries. At the lower end of the spectrum are
countries such as Equatorial Guinea, Guinea, and Niger, and at the upper end
of the spectrum are countries such as Egypt, Algeria, and South Africa. The
total output of manufacturing in South Africa alone, however, is nearly 50
percent of the output in the remainder of the continent.
Manufacturing in Africa tends to concentrate on comparatively simple items
and on those where some special advantage is available to the African
producer, although the range of products has widened. Industrial production
includes electric motors, transport equipment, and tractors, while airplanes are
also assembled. The leading heavy industries are chemical and petroleum,
coal, rubber, and metal manufacture. Most industrial plants, however, are of
the relatively simple kind, being engaged in food processing or in
manufacturing textiles, leather products, and cement or other building
materials.
The mining industry is an increasingly significant source of national income,
foreign exchange, and raw materials for the development of local processing
industries. The industry is very unevenly distributed: more than half of mineral
earnings came from North Africa alone, and nearly one-fourth came from
Southern Africa.
Except in South Africa, iron and steel are used mostly for construction rather
than for engineering. There are integrated iron and steel plants in Algeria,
Tunisia, Egypt, Zimbabwe, and South Africa, while smaller production
facilities—often based on the transformation of scrap—exist in several other
countries.
Petroleum-refining capacity is based on domestic crude oil output in a few
cases and on imported crude oil in others. In some countries the development
of the petrochemical industry followed the establishment of refineries. In 1965
there were only three major petrochemical complexes in Africa—in Zimbabwe,
Egypt, and South Africa. By the late 20th century several more countries had
large refinery capacities, including Algeria, Ghana, Kenya, Libya, Morocco,
Nigeria, Senegal, Sudan, and Tunisia.
Most of the textiles are processed in bleaching, dyeing, and printing
establishments that form an integral part of composite spinning and weaving
units. With the exception of Egypt, producers have concentrated on the home
market and on the manufacture of cotton textiles. Although African countries
export textiles, their imports are usually larger. Rayon–synthetic and woolen
materials are, for the most part, imported. Ready-made clothing, both
domestic and imported, has emerged as a major market factor.
Most African countries have cement plants, the leading producers being South
Africa and Algeria. The transport costs of cement make its price variable.
Prices are lowest on the North African coast, somewhat higher on the west
and east coasts, and highest in the inland countries.

By far most of Africa’s wood output is used for fuel. Sawmills, however, are
distributed throughout the continent. Plants for the manufacture of plywood,
particleboard, and fibreboard have a considerable amount of excess capacity.
The pulp and paper industry is concentrated in North Africa and in Southern
Africa, although a number of small paper mills have been established in other
parts of the continent. The main products of the paper industry
proper comprise newsprint, printing and writing papers, paper and paperboard,
and industrial paper. The bulk of the output of all paper products is directed to
national markets.
Power

A spectacular development in the use of electric energy took place in the

second half of the 20th century, partly because of the growth of the petroleum
industry and partly because of the establishment of large hydroelectric plants
and some thermoelectric plants. The increased quantity and quality of electric
energy gave rise to problems of transmission and distribution. Unlike
thermoelectric plants, which may be sited where the consumer demand is
greatest, sites of hydroelectric installations are not flexible, and the type of
transmission lines in use has therefore changed. Although in the 1950s it was
common practice to use lines with transmission voltages of less than 220
kilovolts, transmission lines were later built that could handle higher voltages.
In Nigeria, for example, 330-kilovolt lines were strung; similar lines were used
in Zimbabwe’s system, which feeds Harare and Bulawayo in Zimbabwe, as
well as the Copperbelt in Zambia. This same system is interconnected in the
north with the large Katanga (Shaba) region hydroelectric power stations in
the Democratic Republic of the Congo. The construction of high-tension lines
to supply power to the Katanga Copperbelt was completed in 1982. Much of
the power for Egypt’s population centres is supplied by lines from such
hydroelectric power stations as that at the Aswan High Dam. Construction of
533-kilovolt lines to transmit power from the Cahora Bassa hydroelectric
station in Mozambique to South Africa was completed in 1974. The possibility
of supplying landlocked states with energy from the large hydroelectric plants
in the coastal states is more likely to be considered in the future.
A number of steam power stations are located in ports and cities near the
coasts. The largest installations of this kind operate in Tunis,
Tunisia; Casablanca and Oujda, Morocco; Dakar, Senegal; Abidjan, Côte
d’Ivoire; and Lagos, Nigeria. Steam power stations using coal are by far the
most common, especially in South Africa.
Electric energy consumption in large urban centres, especially when they are
near coastal towns and mining areas where industrial activity has taken shape,
has increased considerably. Although some countries have extended
networks to the rural areas or increased the numbers of isolated low-powered
stations and independent networks, progress in rural electrification has not
been especially noteworthy.
Trade

Internal trade

Intra-African trade records frequently understate the amount of trade—partly

because of the lack of adequate statistics and partly because of the high rate
of smuggling, which allows a substantial amount of traditional border trade to
continue unrecorded. Apart from this, commerce between African states has
been handicapped by a tendency for trade to remain concentrated within the
common-currency areas and trade zones that developed among African
countries during the colonial era, by the often inadequate means of transport
and communication, by the lack of complementary agricultural or other
products, and by the limited development of manufacturing industries.

Much of the intra-African trade consists of consumables—food, drinks,

tobacco, sugar, cattle, and meat. The growth of industrialization in some
countries, however, has been accompanied by an increase in the trade of
durable and nondurable manufactured goods. There has also been a large
amount of reexport trade between the coastal and inland states, especially in
machinery, transport equipment, and spare parts.
Common-currency and trade zones that have evolved through the granting of
preferences or the operation of common currencies inherited from former
colonial powers include: the Economic and Monetary Community of Central
Africa (CEMAC), which comprises Cameroon, Gabon, the Central African
Republic, Equatorial Guinea, Chad, and the Republic of the Congo and is part
of the larger Economic Community of Central African States (CEEAC), which
also includes Angola, Burundi, the Democratic Republic of the Congo,
and Sao Tome and Principe; the Economic Community of West African
States (ECOWAS), consisting of Benin, Burkina Faso, Cape Verde, Côte
d’Ivoire, The Gambia, Ghana, Guinea, Guinea-Bissau, Liberia, Mali, Niger,
Nigeria, Senegal, Sierra Leone, and Togo; the Common Market for Eastern
and Southern Africa (COMESA), consisting of Burundi, Comoros, the
Democratic Republic of the Congo, Djibouti, Egypt, Eritrea, Ethiopia, Kenya,
Libya, Madagascar, Malawi, Mauritius, Rwanda, Seychelles, Sudan,
Swaziland, Uganda, Zambia, and Zimbabwe; the East African
Community, comprising Kenya, Uganda, Tanzania, Rwanda, and Burundi;
the Southern African Development Community (SADC), comprising Angola,
Botswana, the Democratic Republic of the Congo, Lesotho, Madagascar,
Malawi, Mauritius, Mozambique, Namibia, Seychelles, South Africa,
Swaziland, Tanzania, Zambia, and Zimbabwe; and the Arab Maghreb
Union (UMA), grouping Algeria, Libya, Mauritania, Morocco, and Tunisia.
External trade

Since the outbreak of World War II there has been a considerable expansion
in Africa’s overall external trade. The growth compares favourably with that of
the other developing regions, such as Latin America. The value of imports,
however, has outweighed exports for some time, resulting in huge trade
imbalances for most African countries. The large expansion in African exports
is generally attributed to the increase in the demand for primary commodities
during World War II and in the immediate postwar reconstruction period.
Subsequently the attainment of independence by a large number of African
countries, especially in the early 1960s, followed by a bid for economic
development, strengthened the export-expansion drive. Another reason for
the rapid growth in African exports was the temporary increase in the price of
primary commodities, although subsequently the general trend, except for
petroleum, has been toward depressed commodity prices. The persistence of
this situation has been part of the reason the economies of many African
countries have become crippled by huge foreign debts.
Exports

An important factor that influenced the growth of African exports was the
discovery of petroleum in several countries, notably Libya, Algeria, Nigeria,
Gabon, Angola, the Republic of the Congo, and Cameroon, and the dramatic
price increases brought about by the Organization of Petroleum Exporting
Countries (OPEC) in the 1970s. Other factors include the discovery and the
increased exploitation of minerals that are in high demand, such as
diamonds—especially in Sierra Leone, the Republic of the Congo, the Central
African Republic, and the Democratic Republic of the Congo—and the
exploitation of other minerals, such as uranium ore.

Since achieving independence, many African countries have made attempts

to diversify external trade relations. The record of achievement has been poor,
however, because Africa’s trade patterns continued to reflect the influence of
traditional links with the countries of western Europe. These links were further
consolidated through a series of agreements, collectively called the Lomé
Conventions, that guaranteed preferential access to the European Economic
Community (precursor to the European Community and, later, the European
Union) for various export commodities from African states and that provided
European aid and investment funding. Nonetheless, a significant export trade
developed with the United States and Japan.
In most African states one or two primary commodities dominate the export
trade—e.g., petroleum and petroleum products in Libya, Nigeria, Algeria,
Egypt, Gabon, the Republic of the Congo, and Angola; iron ore in Mauritania
and Liberia; copper in Zambia and the Democratic Republic of the Congo;
cotton in Chad; coffee in Burundi, Uganda, Rwanda, Ethiopia, Madagascar,
Kenya, and Côte d’Ivoire; and sugar in Mauritius.

Imports

The tremendous increase of Africa’s import trade has meant that the import
bill of most African states has exceeded their export earnings; in consequence,
many governments have established import restrictions or subsidized many of
the required imports. The bulk of imports comes from western Europe,
especially countries of the European Union, with strong trade ties persisting
along former colonial lines. There has, however, been a substantial increase
in imports from the United States, Japan, and South Africa. Imports are
needed primarily to develop manufacturing industries and are, therefore,
confined for the most part to mineral fuels, industrial goods, machinery,
transport equipment, and durable consumer goods.
Transportation

There were highly developed transport networks in many parts of Africa in

precolonial times, and, during the colonial era that followed, these networks
were restructured to penetrate into the interior from the seaports and, in the
main, to serve the commercial and administrative needs of the colonial
powers. Their fragmentation, which led to interregional links being but thinly
developed, resulted from the juxtaposition of varied and difficult terrains, the
economic artificiality of certain national frontiers, the lack of a developed intra-
African trade, and the strong orientation of commodity trade with the
administering countries. All of this was further complicated by the existence of
vast unpopulated areas lying between the main centres.
The emergence in the 1960s of independent African governments who
recognized the need to lift economies from their generally very low levels and,
above all, to develop agriculture and embark on industrialization heralded
improvements in economic planning, the development of transport networks,
and the introduction of cheaper freight rates. But there remained a serious
shortage of qualified African labour to plan and manage transport systems at
the national or multinational level and, simultaneously, to keep up with the
rapid development of transport technology outside Africa.
Animal transport

There is some evidence that before the arrival of the camel, which was
introduced into Africa via Egypt at the time of the Arab conquest, bullocks
were used either as pack animals or to draw carts from the northern countries
across the Sahara to the gold-producing areas of the ancient Sudan. From the
16th century onward the Portuguese developed transport inland from the
coast at Mozambique, and from the 17th century first the Dutch and then
British settlers from the Cape trekked northward and northeastward with their
wagons. Except in such highland areas as Ethiopia, where pack animals were
and still are used, the tsetse fly often prevented the use of animal transport.
With the steady progress in the development of transport infrastructure in
many African countries, the use of bullocks in Southern Africa, donkeys in
western and North Africa, horses in northern Nigeria, and camels in western
and North Africa and the Horn of Africa has been reduced, but the extent of
this reduction cannot be accurately gauged.
Motor transport

The arrival and rapid development of the internal-combustion engine in the

1920s transformed the collection and distribution of goods and personal travel.
Roads were built, particularly in North and Southern Africa but also in parts of
the west and east. World Bank loans since the 1950s, supplementing
contributions to road and highway development from national budgets, have
financed the building and improvement of road networks in many African
countries.
Rail transport

The early railways were constructed partly to facilitate the administration of

interior regions and to bring supplies from ports to central consumption or
distribution points and partly—especially in the south—to enable valuable
minerals or commodities to reach the coast for export. In Africa, as in Europe
and North America, the major period of railway development extended from
the end of the 19th century to the end of World War I. This expansion,
however, was not coordinated: railways with different gauges of track were
built and were operated with rolling stock of different braking and coupling
systems. Thus, the colonizing powers left a difficult and costly legacy for
independent African countries who wished to link themselves together. As
with roads, rail networks have been improved considerably since the 1960s
and, as a result, there has been a lowering of transport costs.
Air transport

Air transport is well suited to Africa’s geographic vastness, and it has become
the primary means of international and sometimes of national travel in Africa.
During the late 1940s and the ’50s, as great advances were made in the
extension and improvement of rail and road services, a new transport factor
emerged in the introduction of internal and international scheduled air services.
The rapid development of air transport increased the movement of goods and
people and began to open up the hitherto largely closed interior of the
continent. Transport became much quicker and usually cheaper. Since then,
internal air services have steadily increased, and intercontinental air transport,
especially of passengers, has developed greatly. The largest international
airports include those at Casablanca, Morocco; Las Palmas, Canary
Islands; Cairo, Egypt; Dakar, Senegal; Abidjan, Côte d’Ivoire; Lagos, Nigeria;
Douala, Cameroon; Addis Ababa, Ethiopia; Nairobi, Kenya;
and Johannesburg, South Africa.
Navigation

Historically, throughout the vast interior between the Sahara and the Zambezi
River, people or goods were transported by canoe or boat on the great river
systems of the Nile, Sénégal, Niger, Congo, Ubangi, and Zambezi rivers and
on the few but very large lakes. Where conditions allowed, engine-powered
craft later supplemented or displaced canoes, but further development of
water transport has been slight. Also notable were the construction of lake
ports and the installation of rail ferries across Lake Victoria.
Meanwhile, on the coasts, artificial harbours have been developed. New
berths have been added to established port facilities, and a number of ports
have been constructed. In planning new ports, the choice of site, probable
costs, and the possibilities of using containers or other unitized loads have
been taken into consideration.