Africa, the second-largest continent, is bounded by the Mediterranean Sea, the Red Sea, the Indian Ocean, and the Atlantic Ocean. It is divided in half almost equally by the Equator.

Africa has eight major physical regions: the Sahara, the Sahel, the Ethiopian Highlands, savannas, the Swahili Coast, rainforests, the African Great Lakes, and Southern Africa. Some of these regions cover large bands of the continent, such as the Sahara and the Sahel, while others are isolated areas, such as the Ethiopian Highlands and the Great Lakes. Each of these regions has unique animal, plant, and human communities.

Sahara

The Sahara is the world’s largest hot desert. It covers 8.5 million square kilometers (about 3.3 million square miles), making it about the size of Brazil. This desert region makes up 25 percent of Africa and defines the continent’s northern bulge.

The Sahara has a number of distinct physical features, including ergs, regs, hamadas, and oases. Ergs, which cover 20 percent of the Sahara, are sand dunes that stretch for hundreds of kilometers and reach heights of more than 300 meters (1,000 feet). Ergs cover most of Algeria and Libya as well as parts of Mali and Nigeria. These ergs can contain large quantities of salt, which is harvested and sold for industrial and food use. People of the Sahara have been producing salt for thousands of years by creating pits and filling them with water to leach out the salt. The water is then heated to a boil; as it evaporates, the salt is left behind. Salt production remains is a major industry and job source in this part of Africa.

Regs, which make up 70 percent of the Sahara, are plains of sand and gravel. The gravel can be black, red, or white. Regs are the remains of prehistoric seabeds and riverbeds, though they are now nearly waterless.

Hamadas are elevated plateaus of rock and stone. They include the Atlas Mountains, which stretch from southwestern Morocco to northeastern Tunisia; the Tibesti Mountains of southern Libya and northern Chad; and the Ahaggar Mountains in southern Algeria.

An oasis is a hub of water in the desert, often in the form of springs, wells, or irrigation systems. There are over 90 oases throughout the Sahara Desert, and many of them have enough water and other resources to support human life. People of various cultures and traditions have been living in and around these oases since the sixth century B.C.E.

Animal and plant communities have also adapted to the region’s extremely dry conditions. The kidneys of the jerboa, a type of rodent, produce highly concentrated urine that minimizes water loss. A dromedary camel conserves water by changing its body temperature so it does not sweat as the day gets hotter. The scorpion limits its activities to night, burrowing into the cooler sands beneath the surface during the day. It also absorbs water from the flesh of its prey.

Saharan plants, meanwhile, survive thanks to root systems that plunge deep into the ground. In parts of the Sahara, however, plants cannot take root at all.

Sahel

The Sahel is a narrow band of semi-arid land that forms a transition zone between the Sahara to the north and the savannas to the south. It is made up of flat, barren plains that stretch roughly 5,400 kilometers (3,300 miles) across Africa, from Senegal to Sudan.

The Sahel contains the fertile delta of the Niger, one of Africa’s longest rivers. The Sahel’s fertile land is rapidly becoming desert as a result of drought, deforestation, and intensive agriculture. This process is known as desertification. Desertification is occurring in the Sahel for a variety of reasons, with the increasing temperatures associated with climate change being a primary contributing factor. Other causes include economic factors, such as cattle raising. While the practice is encouraged by several national governments in the region as a way to combat poverty, years of overgrazing has caused the quality of the soil to decline, expanding the size of the desert. Additionally, the area near the Sahel has been plagued by political unrest and armed conflict between ethnic and tribal groups, which has made it challenging for local governments and international donors alike to prioritize and support conservation efforts. International organizations and governments are often reluctant to provide aid to countries to combat desertification, because they worry that the funds may be diverted to other causes or used to fuel further political instability.

Sahel animals have adaptations that help them scavenge for scarce water and vegetation resources. The Senegal gerbil—the most common mammal in the Sahel—measures only a few centimeters but consumes as much as 10 percent of the Sahel’s plants.

The Sahel’s green vegetation emerges only during the rainy season, and farmers must work quickly to take advantage of the short growing season. Sahel farmers grow cotton, nuts, and grains. Among the most common trees found in the Sahel are baobabs, a type of drought- and fire-resistant tree that can grow to be as tall as 26 meters (85 feet) with trunks that are often 15 meters (50 feet) wide, and acacia, whose deep root systems are ideal for semi-arid climates. Cram-cram, a prickly grass, is the primary fodder for Sahel herds such as zebu cattle.

Ethiopian Highlands

The Ethiopian Highlands began to rise 75 million years ago, as magma from the Earth’s mantle uplifted a broad dome of ancient rock. This dome was later split as Africa’s continental crust pulled apart, creating the Great Rift Valley system. Today, this valley cuts through the Ethiopian Highlands from the southwest to the northeast. The Ethiopian Highlands are home to 80 percent of Africa’s tallest mountains.

The highland’s craggy landscape is perfect for nimble animal species. Native species, such as the walia ibex, an endangered wild goat, and the gelada baboon, live in the ledges and rocky outposts of the Simien Mountains. The most emblematic highland species is the Ethiopian wolf. Found only in Ethiopia, this wolf is a rare predator and unique part of the Ethiopian Highland ecosystem. The encroachment of humans on the wolves’ habitat has caused them to become endangered, and despite their endangered status, farmers sometimes hunt the wolves to protect their livestock. Ethiopian wolves also are susceptible to rabies and other diseases that can be passed to humans, making advocacy for their protection even more challenging.

Plant species native to the Ethiopian Highlands include the Ethiopian rose (Africa’s only native rose) and the ensete, a tall, thick, rubbery plant that is a close relative of the banana.

Savannas

Savannas, or grasslands, cover more than 13 million square kilometers (5 million square miles), comprising almost half of Africa. These grasslands make up most of central Africa, beginning south of the Sahara and the Sahel and ending north of the continent’s southern tip.

Among Africa’s savanna regions, the Serengeti Plains is the best known. The Serengeti is a vast, undulating plain that stretches 30,000 square kilometers (11,583 square miles) from Kenya’s Massai-Mara game reserve to Tanzania’s Serengeti National Park.

The Serengeti is home to one of the continent’s highest concentrations of large mammal species, including lions, hyenas, zebras, giraffes, and elephants. Each year, more than one million wildebeest travel in a circular migration, following seasonal rains, across the Serengeti Plains. Their grazing and trampling of grass allows new grasses to grow, while their waste helps fertilize the soil.

Residents of savanna regions have been capitalizing on the unique wildlife to support the economy through ecotourism. However, people in the savannas are facing similar challenges to those in the Sahel, as economic pressure to increase agricultural output is driving loss of savanna lands.

Swahili Coast

The Swahili Coast stretches about 2,900 kilometers (1,800 miles) along the coastlines of Kenya, Mozambique, and Tanzania. The nearby coral reefs and barrier islands protect the coast from severe weather. For centuries, the areas along the Swahili Coast, such as the island of Kilwa Kisiwani off the coast of Tanzania, have been centers for trade and water travel. This tradition has continued as the people of the Swahili Coast have built several major international ports, including Dar es Salaam and Mombasa.

There is not a lot of animal life on the sandy Swahili Coast. The golden-rumped elephant shrew, an insect-eating rodent with a long snout, is common. A small species of primate known as the bush baby or galago inhabits vegetated areas of the Swahili Coast. Bush babies feed primarily on insects, fruit, and leaves. Their distinctive enormous eyes allow them to hunt at night.

The vegetated areas of the Swahili Coast are located on a narrow strip just inland from the coastal sands. Mangrove forests are the most common vegetation. Mangroves have exposed root systems, which allow the trees to absorb oxygen directly from the air, as well as from the nutrient-poor soil.

Rainforest

Africa’s rainforests have a rich variety of animal life; a 6-kilometer (4-mile) patch could contain up to 400 bird species, 150 butterfly species, and 60 amphibian species. Important mammals include African forest elephants, gorillas, the black colobus monkey, and the okapi, a donkey-like giraffe.

The driver ant is one of Africa’s most aggressive rainforest species. Driver ants move across the rainforest floor in columns of up to 20 million and will eat anything from toxic millipedes to small reptiles and mammals.

The African rainforest’s plant community is even more diverse, with an estimated 8,000 plant species documented. More than 1,100 of these species are endemic, meaning they are found nowhere else on Earth. Only 10 percent of the plants in the African rainforest have been identified.

Several nomadic indigenous rainforest groups have lived off the forest’s resources for centuries, including the Mbuti, the Twa, the Baka, and the Aka (with the latter two sometimes being grouped together). These tribes have historically had little contact with the outside world, but as rural populations just beyond the rainforest have continued to grow and encroach on these areas, their traditional way of life has begun to face serious threat.

African Great Lakes

The Great Lakes are located in ten countries that surround the Great Rift Valley: Burundi, the Democratic Republic of Congo, Ethiopia, Kenya, Malawi, Mozambique, Rwanda, Tanzania, Uganda, and Zambia. As the African continent separated from Saudi Arabia, large, deep cracks were created in the Earth’s surface. These cracks were later filled with water. This geologic process created some of the largest and deepest lakes in the world.

There are seven major African Great Lakes: Lake Albert, Lake Edward, Lake Kivu, Lake Malawi, Lake Tanganyika, Lake Turkana, and Lake Victoria. Lake Victoria, the largest lake in Africa, is the southern source of the Nile River, the longest river in the world. Due to the water resources, local governments in Burundi, Rwanda, and Tanzania, as well other countries, are working to build more hydroelectric power plants to harness the potential energy.

The African Great Lakes region has a diverse range of aquatic and terrestrial animal life. Fish include the Nile perch, which can weigh as much as 45 kilograms (100 pounds) or more. There are also fish as small as the 2.5-centimeter (1-inch) cichlid. Migrating savanna animals, such as wildebeest, use the lakes as watering holes. Hippos and crocodiles also call the region their home.

The Great Lakes border everything from rainforest to savanna plant communities. However, invasive species like the water hyacinth and papyrus have begun to take over entire shorelines, endangering animals and plants.

Southern Africa

The region of Southern Africa is dominated by the Kaapvaal craton, a shelf of bedrock that is more than 2.6 billion years old. Rocky features of Southern Africa include plateaus and mountains, such as the Drakensberg range.

Southern Africa is the epicenter of Africa’s well-known reserves. Reserves in South Africa in particular benefit local populations by providing jobs and supporting communities with the earned revenue. The reserves also protect animal species such as lions, elephants, baboons, white rhinos, and Burchell’s zebras. Other important animal species include the impala, a type of deer, and the springbok, a type of gazelle that can spring several feet into the air to avoid predators.

Southern Africa’s Cape Floral Region is one of the richest areas for plants in the world. While the Cape Floral Region covers less than 0.5 percent of Africa, it is home to nearly 20 percent of the continent’s flora. The giant protea, South Africa’s national flower, is found in the Cape Floral Region.