Africa's ecosystem

The ecosystems of Africa range from the desolate expanses of the Sahara to the dense confines of equatorial rain forests. Threats to the plant and animal life found across the continent have placed Africa in the forefront of global environmentalist campaigns, some of which aim not only to save menaced species but also to conserve other natural resources, including soils and minerals.

The image of the African continent containing primarily dense tropical jungles holds true for limited regions only—those near the equator and subject to heavy seasonal rainfall. In fact, Africa has several different environmental regions. These correspond mainly, but not only, to relative latitudinal position north or south of the equator. Geographers generally separate the continent into five zones: North, South, East, West, and Central. The environmental conditions that are found in the zones vary widely.

General Environmental Characteristics

In comparison to other continents, Africa possesses relatively few major mountain ranges. The most important tectonic upliftings are in South Africa—notably the Drakensberg range, which is 1,000 kilometers (620 miles) long, with elevations reaching in places nearly 3,500 meters (11,500 feet)—and in the northwestern and northeastern areas of the continent (the Aurès and Atlas mountains in Tunisia and Morocco, and the Simyen and Bale mountains in Ethiopia). The geology of the Ethiopian ranges, which boast peaks such as Ras Dashen in the Simyens, more than 4,500 meters (14,800 feet) high, and many volcanic peaks, is closely connected with the tectonic phenomena that created the Great Rift Valley running north to south from the Red Sea to Malawi in Southern Africa.

Whereas these long ranges contribute to extensive regional environmental patterns—combining patterns of flora and fauna that determine the livelihoods of entire sections of Africa—other quite different mountains (mostly volcanic “monoliths”) lend themselves to more localized environmental, and therefore human cultural, settings. Prototypical examples would be Mount Kenya and Mount Kilimanjaro in Tanzania (the latter being the highest mountain in Africa—reaching almost 6,000 meters, or 19,700 feet) and Mount Cameroon near the Gulf of Guinea coast in West Africa. Mount Kenya became the site of one of Africa’s earliest national parks, founded in 1949. Each of these famous mountains is associated with indigenous legends tying them to local religious beliefs. High levels of rainfall close to such prominent peaks often combine with fertile volcanic soil to create not only lush natural vegetation but also fairly high levels of domestic and commercial agricultural productivity (both Kenya and Tanzania, for example, produce famous coffee strains).

Africa contains the most extensive and arid expanse in the world: the Sahara. This desert region, which covers most of North Africa, is bordered on the south by the Sahel, a region that forms a broad continental dividing line between North Africa (where basic environmental characteristics are shared among the five modern countries of Morocco, Algeria, Tunisia, Libya, and Egypt) and sub-Saharan Africa. Much of North Africa (except for Egypt’s Nile River Valley, which runs south to north between desolate desert littorals, reaching to the Red Sea in the east and to Libya’s Fezzan desert region to the west) is characterized by rain-fed coastal plains bordered by the higher altitudes of the Aures and Atlas mountain chains. Once the Sahara begins, however, vegetation is very scant or nonexistent, except in oasis areas, where subsurface water sources are available. The estimated average annual rainfall for the Sahara is approximately 25 millimeters (about 1 inch).

Another major desert in Africa is the Kalahari, which, in combination with the contiguous Namib Desert, covers much of the land area of South Africa from the Orange River into modern Angola and Namibia. The Kalahari is not nearly as arid as the Sahara, having widely dispersed thorny trees and bushes.

The greatest territorial expanses of Africa are characterized by semiarid savanna conditions; their includes extensive grasslands with widely dispersed trees. Savannas, which receive quite limited and seasonally specific rainfall, are typically located between desert expanses and tropical zones near the equator. African savannas are found in the immediate sub-Saharan zones of Senegal, Mali, Niger, Chad, and Sudan, and in Central and Southern Africa stretching eastward to the Indian Ocean. Because of their extensive grasslands, these zones form (or formed) the habitats of many of Africa’s famous wild animal herds (especially in the Serengeti of Tanzania) and areas of Zambia, Zimbabwe, and South Africa. Rains totaling as much as 635 millimeters (25 inches) come from May into the summer, but then disappear by early fall.

Clearly, the major factor contributing to dense vegetation in Africa is rainfall, as the label “tropical rain forest” suggests. Regions close to the equator (including in Guinea, southern Côte d’Ivoire, and Ghana, but especially in Cameroon, Equatorial Guinea, Gabon, and the Congo) receive the highest rainfall, and their environments support extensive multitiered forests that are habitats for many animal species, including primates such as gorillas and chimpanzees. The extensive and complicated of the Congo basin produces vegetation necessary to support both human and animal life and is the source of the Congo River. Another very long African river, the Niger, has its sources in the West African tropical zone of Guinea.

Africa’s major inland lakes are found in different environmental settings. What was once the continent’s largest lake, Lake Chad, is located in the middle of the dry interior of what was formerly part of French West Africa and French Equatorial Africa. This lake is probably the remnant of an ancient inland sea. Although it is still fed by the Chari River and its tributary the Logone (which carry water from equatorial Africa), its shores have receded considerably. This is part of the increasing desiccation of the African Sahel, which has caused major environmental problems for inhabitants of the region.

By contrast, many of the main lakes of East Africa—including Lake Tanganyika and Lake Malawi, also known as Lake Nyasa—are formed by water from the high elevations surrounding the Great Rift Valley. The more centrally located Lake Victoria, also known as Victoria Nyanza, is an exception. Lake Malawi is the largest East African lake (covering nearly 70,000 square kilometers, or 27,000 square miles), and Lake Tanganyika (covering almost 34,000 square kilometers, or 13,000 square miles) is the longest and second-deepest lake in the world (some 680 kilometers, or 420 miles, long, with a maximum depth of almost 1,500 meters, or 5,000 feet). Although all major and lesser East African lakes provide natural for cichlid fish populations, Lake Malawi has a greater variety of such fish than any other place in the world, including many species that are unknown anywhere else.

In addition to the obvious environmental features of Africa’s vast landmass and its lakes and rivers, the continent’s natural resources are tied to its Mediterranean Sea, Atlantic Ocean, and Indian Ocean coastal waters and estuaries. Beyond their value for commercially viable fishing (and fishing for domestic consumption), some coastal regions of Africa offer features that began to attract particular attention during the late decades of the twentieth century.

Environmental Issues

Among the environmental issues affecting Africa are concerns about declining numbers and even extinctions of indigenous plant and animal species. The list of menaced African species ranges from the cichlid tropical fish populations in East Africa’s freshwater lakes through the African elephant.

Various factors have caused a sharp decline in what was once a thriving habitat for more than five hundred species of cichlids in Lake Victoria. It is estimated that almost half of the cichlids have disappeared as the result of the decision to introduce Nile perch into the lake waters to increase local fishing harvests for food and commercial sale. The nonnative perch proved to be predatory and fed off the local cichlid populations.

There are many other examples of rising concerns among environmentalists who study declining numbers of animal species that were once very numerous in different areas of Africa. Those that have drawn the greatest attention are the large mammals, including mountain gorillas, elephants, and members of the great cat family (lions, leopards, and cheetahs). Questionable human actions—including poaching for food or trophies—are generally behind the threats to these species.

By the end of the twentieth century, organized conservation efforts were on the rise in Africa. The obvious importance of saving large game species led, for example, to safari tourism in protected parks. Among the best known of these parks is the Selous Game Reserve in Tanzania, which covers more than 54,000 square kilometers (21,000 square miles) and is home to an incredibly diverse array of animals, including elephants, black rhinoceroses, giraffes, and crocodiles.

Some environmental activists have attempted to create programs to promote the conservation of both animal and plant species. Some support environmental conservation efforts that can benefit not only flora and fauna but also local African populations that depend directly on the for their livelihoods. For example, some help develop skills among Africans that will benefit both the local environment and the Africans’ material welfare. Examples include the development of apiculture (beekeeping), the training of Africans in the careful selection of tree and medicinal plant species for cultivation, and the promotion of ecotourism. The Green Belt Movement, for example, has four main focuses: climate change, gender livelihood and advocacy, mainstream advocacy, and tree planting and water harvesting. Women are the primary workers who are paid to grow seedlings and plant trees. These trees are sources of firewood and food, reduce erosion, and retain rainwater.

The African Conservation Foundation (ACF) coordinates the sharing of information among conservation groups working in Africa and posts alerts concerning alarming developments. A prime example of an ACF alert is one stating the organization’s opposition to illicit mining (particularly in the violence-torn eastern Congo) of what the ACF calls the “Three T’s”—tin, tantalum, and tungsten (all minerals in great demand because of their use in developed countries’ high-technology industries).

In some cases, efforts to protect the environment in Africa are complicated by various political factors. For example, pressures toward economic development conflict with concerns about the environment in decisions regarding offshore drilling, particularly along the coasts of West Africa (extending from the Niger Delta through Cameroon, Equatorial Guinea, and Gabon). The potential threat that such drilling poses for marine life and vegetation, particularly in environmentally unique coastal mangrove ecosystems, may rank as high as inland and extraction concerns as major African environmental issues in the twenty-first century.

Some areas of Africa face environmental concerns stemming from natural causes tied to global warming. This is particularly the case in the Sahel region to the south of the Sahara. Beginning during the mid-1970s and intermittently since then, drought conditions have caused major crop shortages as well as widespread losses in animal herds that provide the only means of survival for many Sahel populations, as well as for inhabitants of other arid regions of Africa. By the 2020s, more than 750 million people lived in ecozones classified as unsustainable. As human migration out of such stricken zones rises, environmental problems are often seen in the areas receiving the migrants; these problems include urban sprawl, shortages of supplies, and the spread of communicable animal and human diseases. In 2022, African nations called on United Nations member nations to address climate change that was having a significant and increasing impact on the continent.

Bibliography

"The Degradation of Ecosystems in Africa." Agence Francaise de Developpement, 10 Apr. 2024, www.afd.fr/en/actualites/degradation-ecosystems-africa. Accessed 11 July 2024.

Doyle, Shane. Crisis and Decline in Bunyoro. London: British Institute in Eastern Africa, 2006.

Goldblatt, Peter, ed. Biological Relationships Between Africa and South America. New Haven, Conn.: Yale University Press, 1993.

Higgins, Steven I., Timo Conradi, Laurence M. Kruger, Robert B. O'Hara, and Jasper A. Slingsby. "Limited Climatic Space for Alternative Ecosystem States in Africa." Science, vol. 380, no. 6649, 2023, pp. 1038-1042. DOI: 10.1126/science.add5190. Accessed 11 July 2024.

"Home-Grown Organizations Working to Restore Africa's Environment." Philanthropy Circuit, 22 Oct. 2021, philanthropycircuit.org/insights/home-grown-organizations-working-to-restore-africas-environment/. Accessed 12 July 2024.

"In the Face of Climate Change, Migration Offers an Adaptation Strategy in Africa." International Organization for Migration, 5 Sept. 2022, www.iom.int/news/face-climate-change-migration-offers-adaptation-strategy-africa. Accessed 12 July 2024.

Maddox, Gregory H. Sub-Saharan Africa: An Environmental History. Santa Barbara, Calif.: ABC-CLIO, 2006.

Shorrocks, Bryan. The Biology of African Savannahs. New York: Oxford University Press, 2007.

United Nations Environment Programme. Africa: Environment Outlook. Nairobi: Author, 2006.