Afrotropical realm

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Afrotropics
)
The Afrotropical realm (in green)

The Afrotropical realm is one of the Earth's eight biogeographic realms. It includes Sub-Saharan Africa, the southern Arabian Peninsula, the island of Madagascar, and the islands of the western Indian Ocean.[1] It was formerly known as the Ethiopian Zone or Ethiopian Region.

Major ecological regions

Most of the Afrotropical realm, except for Africa's southern tip, has a tropical climate. A broad belt of deserts, including the Atlantic and Sahara deserts of northern Africa and the Arabian Desert of the Arabian Peninsula, separate the Afrotropic from the Palearctic realm, which includes northern Africa and temperate Eurasia.

Sahel and Sudan

South of the Sahara, two belts of

forest-savanna mosaic is a transitional zone between the grasslands and the belt of tropical moist broadleaf forests near the equator
.

Southern Arabian woodlands

South Arabia, which includes

forests.

Forest zone

The

Congolian forests of the Congo Basin
in Central Africa.

A belt of tropical moist broadleaf forest also runs along the Indian Ocean coast, from southern Somalia to South Africa.

Somali–Masai region

In northeastern Africa, semi-arid Acacia-Commiphora woodlands, savannas, and bushlands are the dominant plant communities. This region is called the Somali-Masai center of endemism or Somali-Masai region. It extends from central Tanzania northwards through the Horn of Africa, and covers portions of Tanzania, Kenya, Ethiopia, Somalia, Djibouti, and Eritrea. Thorny, dry-season deciduous species of Vachellia and Senegalia (formerly Acacia) and Commiphora are the dominant trees, growing in open-canopied woodlands, open savannas, and dense bushlands and thickets. This region includes the Serengeti ecosystem, which is renowned for its wildlife.[2]

Eastern Africa's highlands

The

Drakensberg Mountains of South Africa, including the East African Rift. This region is home to distinctive flora, including Podocarpus and Afrocarpus, as well as giant Lobelias and Senecios
.

Zambezian region

The

Miombo woodlands, drier mopane and Baikiaea woodlands, and higher-elevation Bushveld. It extends from east to west in a broad belt across the continent, south of the rainforests of the Guineo-Congolian region, and north of the deserts of southeastern Africa, the countries are Malawi, Angola, Botswana, Mozambique, Zambia and Zimbabwe, and the subtropical.[3]

Deserts of Southern Africa

Southern Africa as described in Plant Taxonomic Database Standards No. 2. Approximate locations of deserts are overlaid in red.

Southern Africa contains several deserts. The

Tankwa Karoo is a more arid sub-region known for harsher conditions and starker landscapes. Further to the west, the Richtersveld, a mountainous desert in the northwestern corner of South Africa, presents a rugged landscape. It is celebrated as a UNESCO World Heritage Site for its unique biodiversity and cultural significance to the local Nama people
.

Cape floristic region

The

taxa, as well as to plant families like the proteas (Proteaceae) that are also found in the Australasian realm
.

Madagascar and the Indian Ocean islands

Madagascar and neighboring islands form a distinctive sub-region of the realm, with numerous endemic taxa, such as lemurs. Madagascar and the Granitic Seychelles are old pieces of the ancient supercontinent of Gondwana, and broke away from Africa millions of years ago. Other Indian Ocean islands, like the Comoros and Mascarene Islands, are volcanic islands that formed more recently. Madagascar contains various plant habitats, from rainforests to mountains and deserts, as its biodiversity and ratio of endemism is extremely high.

Endemic plants and animals

Plants

The Afrotropical realm is home to several endemic plant families.

Oliniaceae
.

Animals

The East African Great Lakes (Victoria, Malawi, and Tanganyika) are the center of biodiversity of many freshwater fishes, especially cichlids (they harbor more than two-thirds of the estimated 2,000 species in the family).[3] The West African coastal rivers region covers only a fraction of West Africa, but harbours 322 of West Africa's fish species, with 247 restricted to this area and 129 restricted even to smaller ranges. The central rivers fauna comprise 194 fish species, with 119 endemics and only 33 restricted to small areas.[4]

The Afrotropic has various endemic

rockfowl
(Picathartidae).

Africa has three endemic orders of mammals, the

are well known for their diversity of large mammals.

Four species of

common chimpanzee, Pan troglodytes, and bonobo, Pan paniscus). Humans
and their ancestors originated in Africa.

Afrotropical terrestrial ecoregions

mangroves
Albertine Rift montane forests Democratic Republic of the Congo, Burundi, Rwanda, Tanzania, Uganda
Atlantic Equatorial coastal forests Angola, Cameroon, Democratic Republic of the Congo, Republic of the Congo, Equatorial Guinea, Gabon
Cameroonian Highlands forests Cameroon, Nigeria
Central Congolian lowland forests Democratic Republic of the Congo
Comoros forests Comoros
Cross–Niger transition forests Nigeria
Cross–Sanaga–Bioko coastal forests Cameroon, Equatorial Guinea, Nigeria
East African montane forests Kenya, South Sudan, Tanzania, Uganda
Eastern Arc forests Tanzania, Kenya
Eastern Congolian swamp forests Democratic Republic of the Congo
Eastern Guinean forests Benin, Ghana, Ivory Coast, Togo
Ethiopian montane forests Eritrea, Ethiopia, Somalia, Sudan
Granitic Seychelles forests
Seychelles
Guinean montane forests Guinea, Ivory Coast, Liberia, Sierra Leone
Knysna–Amatole montane forests South Africa
KwaZulu–Cape coastal forest mosaic South Africa
Madagascar lowland forests Madagascar
Madagascar subhumid forests Madagascar
Maputaland coastal forest mosaic Eswatini (Swaziland), Mozambique, South Africa
Mascarene forests
Mauritius, Réunion
Mount Cameroon and Bioko montane forests Cameroon, Equatorial Guinea
Niger Delta swamp forests Nigeria
Nigerian lowland forests Benin, Nigeria
Northeastern Congolian lowland forests Cameroon, Central African Republic, Gabon, Republic of the Congo
Northern Zanzibar–Inhambane coastal forest mosaic Kenya, Somalia, Tanzania
Northwestern Congolian lowland forests Cameroon, Central African Republic, Gabon, Republic of the Congo
São Tomé, Príncipe, and Annobón forests Equatorial Guinea, São Tomé and Príncipe
Southern Zanzibar–Inhambane coastal forest mosaic Malawi, Mozambique, Tanzania, Zimbabwe
Western Congolian swamp forests Democratic Republic of the Congo, Republic of the Congo
Western Guinean lowland forests Guinea, Ivory Coast, Liberia, Sierra Leone
Cape Verde Islands dry forests Cape Verde
Madagascar dry deciduous forests Madagascar
Zambezian Cryptosepalum dry forests
Zambia, Angola
Angolan miombo woodlands Angola
Angolan mopane woodlands Angola, Namibia
Ascension scrub and grasslands Ascension Island
Central Zambezian miombo woodlands Angola, Burundi, Democratic Republic of the Congo, Malawi, Tanzania, Zambia
East Sudanian savanna Cameroon, Central African Republic, Chad, Democratic Republic of the Congo, Eritrea, Ethiopia, South Sudan, Sudan, Uganda
Eastern miombo woodlands Mozambique, Tanzania
Guinean forest–savanna mosaic
Guinea Bissau, Ivory Coast, Nigeria, Senegal, Togo
Itigi–Sumbu thicket Tanzania, Zambia
Kalahari Acacia-Baikiaea woodlands
Botswana, Namibia, South Africa, Zimbabwe
Mandara Plateau mosaic Cameroon, Nigeria
Northern Acacia–Commiphora bushlands and thickets Ethiopia, Kenya, South Sudan, Uganda
Northern Congolian forest–savanna mosaic Cameroon, Central African Republic, Democratic Republic of the Congo, South Sudan, Uganda
Sahelian Acacia savanna
Burkina Faso, Cameroon, Cape Verde, Chad, Eritrea, Ethiopia, Mali, Mauritania, Niger, Nigeria, Senegal, South Sudan, Sudan
Serengeti volcanic grasslands Kenya, Tanzania
Somali Acacia–Commiphora bushlands and thickets Eritrea, Ethiopia, Kenya, Somalia
South Arabian fog woodlands, shrublands, and dune Oman, Saudi Arabia, Yemen
Southern Acacia–Commiphora bushlands and thickets Kenya, Tanzania
Southern Africa bushveld
Botswana, South Africa, Zimbabwe
Southern Congolian forest–savanna mosaic Angola, Democratic Republic of the Congo
Southern miombo woodlands Malawi, Mozambique, Zambia, Zimbabwe
Saint Helena scrub and woodlands Saint Helena
Victoria Basin forest–savanna mosaic Burundi, Democratic Republic of the Congo, Ethiopia, Kenya, Rwanda, South Sudan, Tanzania, Uganda
West Sudanian savanna
Western Congolian forest–savanna mosaic Angola, Democratic Republic of the Congo, Republic of the Congo
Western Zambezian grasslands Angola, Zambia
Zambezian and mopane woodlands Botswana, Eswatini, Malawi, Mozambique, Namibia, South Africa, Zambia, Zimbabwe
Zambezian Baikiaea woodlands Angola, Botswana, Namibia, Zambia, Zimbabwe
Al Hajar montane woodlands Oman, United Arab Emirates
Amsterdam and Saint-Paul Islands temperate grasslands Amsterdam Island, Saint-Paul Island
Tristan da Cunha–Gough Islands shrub and grasslands Tristan da Cunha, Gough Island
East African halophytics
Kenya, Tanzania
Etosha Pan halophytics
Namibia
Inner Niger Delta flooded savanna
Mali
Lake Chad flooded savanna Cameroon, Chad, Niger, Nigeria
Saharan flooded grasslands
South Sudan
Zambezian coastal flooded savanna Mozambique
Zambezian flooded grasslands Angola, Botswana, Democratic Republic of the Congo, Malawi, Mozambique, Tanzania, Zambia
Zambezian halophytics
Botswana
Angolan montane forest–grassland mosaic Angola
Angolan Scarp savanna and woodlands Angola
Drakensberg alti-montane grasslands and woodlands
Lesotho, South Africa
Drakensberg montane grasslands, woodlands and forests
Lesotho, South Africa, Eswatini (Swaziland)
East African montane moorlands Kenya, Sudan, Tanzania, Uganda
Eastern Zimbabwe montane forest–grassland mosaic
Mozambique, Zimbabwe
Ethiopian montane grasslands and woodlands Ethiopia, Sudan
Ethiopian montane moorlands Ethiopia, Sudan
Highveld grasslands
Lesotho, South Africa
Jos Plateau forest–grassland mosaic
Nigeria
Madagascar ericoid thickets Madagascar
Maputaland–Pondoland bushland and thickets Mozambique, South Africa, Eswatini (Swaziland)
Rwenzori–Virunga montane moorlands Democratic Republic of the Congo, Rwanda, Uganda
South Malawi montane forest–grassland mosaic Malawi, Mozambique
Southern Rift montane forest–grassland mosaic Malawi, Tanzania
Albany thickets South Africa
Lowland fynbos and renosterveld
South Africa
Montane fynbos and renosterveld
South Africa
Arabian Peninsula coastal fog desert Oman, Saudi Arabia, Yemen
Aldabra Island xeric scrub
Seychelles
East Saharan montane xeric woodlands Chad, Sudan
Eritrean coastal desert Djibouti, Eritrea
Ethiopian xeric grasslands and shrublands
Djibouti, Eritrea, Ethiopia, Somalia, Sudan
Gulf of Oman desert and semi-desert Oman, United Arab Emirates
Hobyo grasslands and shrublands Somalia
Ile Europa and Bassas da India xeric scrub
Bassas da India, Europa
Kalahari xeric savanna
Botswana, Namibia, South Africa
Kaokoveld desert
Angola, Namibia
Madagascar spiny thickets
Madagascar
Madagascar succulent woodlands Madagascar
Masai xeric grasslands and shrublands Ethiopia, Kenya
Nama Karoo Namibia, South Africa
Namib desert
Namibia
Namibian savanna woodlands Namibia
Socotra Island xeric shrublands Yemen
Somali montane xeric woodlands Somalia
Southwestern Arabian foothills savanna Saudi Arabia, Yemen
Southwestern Arabian montane woodlands Saudi Arabia, Yemen
Succulent Karoo South Africa
Central African mangroves Angola, Cameroon, Democratic Republic of the Congo, Equatorial Guinea, Gabon, Ghana, Niger Delta
East African mangroves Kenya, Mozambique, Tanzania
Guinean mangroves
Madagascar mangroves Madagascar
Southern Africa mangroves Mozambique, South Africa

Habitats

The tropical environment is rich in terms of biodiversity. Tropical African forest is 18 percent of the world's total and covers over 3.6 million square kilometers of land in West, East, and Central Africa. This total area can be subdivided to 2.69 million square kilometers (74%) in Central Africa, 680,000 square kilometers (19%) in West Africa, and 250,000 square kilometers (7%) in

Sanaga river
.

Ituri Rainforest

Semi-deciduous rainforests in West Africa began at the fringed coastline of

hydrological cycles, release vast amounts of greenhouse gases into the atmosphere, and lessen the planet's ability to store excess carbon
.

The rainforest vegetation of the Guinea-Congolian transition area, extending from

Eastern Nigeria
to Gabon, and with some large patches leaning to the west from Ghana to Liberia and to the east of Zaïre-Congo basin.

Among rainforest areas in other continents, most of the African rainforest is comparatively dry and receives between 1600 and 2000 mm of rainfall per year. Areas receiving more rain than this mainly are in coastal areas. The circulation of rainfall throughout the year remains less than in other rainforest regions in the world. The average monthly rainfall in nearly the whole region remains under 100  mm throughout the year. The variety of the African rainforest flora is also less than the other rainforests. This lack of flora has been credited to several reasons such as the gradual infertility since the Miocene, severe dry periods during Quaternary, or the refuge theory of the cool and dry climate of tropical Africa during the last severe ice age of about 18,000 years ago.[6]

Fauna

African forest elephant

The Tropical African rainforest has rich fauna, commonly smaller mammal species rarely seen by humans. New species continually are being discovered. For instance, in late 1988 an unknown shrub species was discovered on the shores of the Median River in Western Cameroon. Since then many species have become extinct. However, undisturbed rainforests are some of the richest habitats for animal species. Today, undisturbed rainforests are remnant but rare.

Timber extraction not only changes the edifice of the forest, but it also affects the tree species spectrum by removing economically important species and terminating other species in the process. The species that compose African rainforests are of different evolutionary ages because of the contraction and expansion of the rainforest in response to global climatic fluctuations.[6]

The

insectivores, rodents, bats, tree frogs, and bird species inhabit the forest. These species, along with a diversity of fruits and insects, make a special habitat that allows for a diversity of life. The top canopy is home to monkey species like the red colobus
, Black-and-white Colobus, and many other Old-World monkey species. Many of these rare and unique species are endangered or critically endangered and need protection from poachers and provided ample habitat to thrive.

Flora

In Tropical Africa, about 8,500 plant species have been documented, including 403 orchid species.[citation needed]

Species unfamiliar with the changes in forest structure for industrial use might not survive.[6] If timber use continues and an increasing amount of farming occurs, it could lead to the mass killing of animal species. The home of nearly half of the world's animals and plant species are tropical rainforests. The rainforests provide economic resources for over-populated developing countries. Despite the stated need to save the West African forests, there are varied opinions on how best to accomplish this goal. In April 1992, countries with some of the largest surviving tropical rainforests banned a rainforest protection plan proposed by the British government. It aimed at finding endangered species of tropical trees to control their trade. Experts estimate that the rainforest of West Africa, at the present rate of deforestation, may disappear by the year 2020.[6]

Africa's rainforest, like many others emergent in the world, has a special significance to the indigenous peoples of Africa who have occupied them for millennia.[6]

Region protection

Many African countries are in economic and political change, overwhelmed by conflict, making various movements of forest exploitation to maintain forest management and production more and more complicated.

Forest legislation of ATO member countries aims to promote the balanced utilization of the forest domain and of wildlife and fishery to increase the input of the forest sector to the economic, social, cultural, and scientific development of the country.[6]

Deforestation

Tropical rainforests are distributed across West African countries. However, it is becoming clear that the area is experiencing a high rate of deforestation. The term deforestation refers to the complete obstruction of the forest canopy cover for means of agriculture, plantations, cattle-ranching, and other non-forest fields. Other observed changes in these forests are forest disintegration (changing the spatial continuity and creating a mosaic of forest blocks and other land cover types), and selective logging of woody species for profitable purposes that affect the forest subfloor and the biodiversity.[6]

Several conservation and development

deforestation in Africa
are less known than in other regions of the tropics.

One reason for forest depletion is agriculture of

forest loss of 7,200 km2 (2,800 sq mi) was noted down along the Gulf of Guinea, a figure equivalent to 4-5 percent of the total remaining rainforest area.[6] By 1985, 72% of West Africa's rainforests had been transformed into fallow lands and an additional 9% had been opened up by timber exploitation.[6]

Tropical timber became a viable choice for European wood following

conservationists blamed the timber industry and the farmers for felling trees, others believe rainforest destruction is connected to the problem of fuel wood.[6] The contribution of fuel wood consumption to tree stock decline in Africa is believed to be significant. It is generally believed that firewood provides 75% of the energy used in sub-Sahara Africa.[6] With the high demand, the consumption of wood for fuel exceeds the renewal of forest cover
.

African Pygmies living in the Dzanga-Sangha Special Reserve

The rainforests that remain in West Africa now greatly differ in condition from their state 30 years ago. In Guinea, Liberia, and the Ivory Coast, there is almost no primary forest cover left unscathed; in Ghana, the situation is much worse, and nearly all of the rainforest is being removed.

Cote d'Ivoire
. The remaining tropical forests still cover major areas in Central Africa but are abridged by patches in West Africa.

The African Timber Organization member countries eventually recognized the cooperation between rural people and their forest environment. Customary law gives residents the right to use trees for firewood, fell trees for construction, and collect of forest products and rights for hunting or fishing and grazing or clearing of forests for maintenance agriculture. Other areas are called "protected forests", which means that uncontrolled clearings and unauthorized logging are forbidden. After World War II, commercial exploitation increased until no West African forestry department was able to make the law. By comparison with rainforests in other places of the world in 1973, Africa showed the greatest infringement though in total volume means, African timber production accounted for just one-third compared to that of Asia.[6] The difference was due to the variety of trees in Africa forests and the demand for specific wood types in Europe.

United Nations Development Program, and the World Bank with hopes of halting tropical forest destruction.[6] In its bid to stress forest conservation and development, the World Bank
provided $111,103 million to developing countries, especially in Africa, to help in developing long-range forest conservation and management programs meant for ending deforestation.

Historical temperature and climate

In early 2007, scientists created an entirely new proxy to determine the annual mean air temperature on land—based on molecules from the cell membrane of soil-inhabiting bacteria. Scientists from the NIOZ, Royal Netherlands Institute for Sea Research conducted a temperature record dating back to 25,000 years ago.[7]

In concordance with their German colleagues at the

molecular fossils of soil bacteria. When applying this to the outflow core of the Congo River, the core contained eroded land material and microfossils from marine algae. That concluded that the land environment of tropical Africa cooled more than the bordering Atlantic Ocean during the last ice age. Since the Congo River drains a large part of tropical central Africa, the land-derived material gives an integrated signal for a very large area. These findings further enlighten natural disparities in climate and the possible costs of a warming earth on precipitation in central Africa.[7]

Scientists discovered a way to measure sea temperature—based on organic molecules from algae growing off the surface layer of the Ocean. These organisms acclimatize the molecular composition of their cell membranes to ambient temperature to sustain regular physiological properties. If such molecules sink to the sea floor and are buried in sediments where

last ice age, the land climate in tropical Africa was drier than it is now, whereas it favors the growth of a lush rainforest.[7]

See also

References

  1. .
  2. .
  3. ^ .
  4. Springer Link
    .
  5. ^ Eric Dinerstein, David Olson, Anup Joshi, Carly Vynne, Neil D. Burgess, Eric Wikramanayake, Nathan Hahn, Suzanne Palminteri, Prashant Hedao, Reed Noss, Matt Hansen, Harvey Locke, Erle C Ellis, Benjamin Jones, Charles Victor Barber, Randy Hayes, Cyril Kormos, Vance Martin, Eileen Crist, Wes Sechrest, Lori Price, Jonathan E. M. Baillie, Don Weeden, Kierán Suckling, Crystal Davis, Nigel Sizer, Rebecca Moore, David Thau, Tanya Birch, Peter Potapov, Svetlana Turubanova, Alexandra Tyukavina, Nadia de Souza, Lilian Pintea, José C. Brito, Othman A. Llewellyn, Anthony G. Miller, Annette Patzelt, Shahina A. Ghazanfar, Jonathan Timberlake, Heinz Klöser, Yara Shennan-Farpón, Roeland Kindt, Jens-Peter Barnekow Lillesø, Paulo van Breugel, Lars Graudal, Maianna Voge, Khalaf F. Al-Shammari, Muhammad Saleem, An Ecoregion-Based Approach to Protecting Half the Terrestrial Realm, BioScience, Volume 67, Issue 6, June 2017, Pages 534–545, [1].
  6. ^ a b c d e f g h i j k l m n o p "Study of Land-Use and Deforestation In Central African Tropical Forest Using low-Resolution SAR Satellite Imagery". Archived from the original on 1997-10-18. Retrieved 2007-08-24.
  7. ^ a b c "Microfossils Unravel Climate History Of Tropical Africa". Science Daily. 2007-03-26. Archived from the original on 2011-06-07. Retrieved 2024-03-08.

Bibliography

Further reading

External links