Afrotropical realm
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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
Southern Arabian woodlands
South Arabia, which includes
Forest zone
The
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
- Ethiopian Highlands
- Albertine rift montane forests
- East African montane forests and Eastern Arc forests
Zambezian region
The
Deserts of Southern Africa
Southern Africa contains several deserts. The
Cape floristic region
The
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.
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
Africa has three endemic orders of mammals, the
Four species of
and their ancestors originated in Africa.Afrotropical terrestrial ecoregions
Cape Verde Islands dry forests | Cape Verde |
Madagascar dry deciduous forests | Madagascar |
Zambezian Cryptosepalum dry forests
|
Zambia, Angola |
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 |
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
Semi-deciduous rainforests in West Africa began at the fringed coastline of
The rainforest vegetation of the Guinea-Congolian transition area, extending from
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
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.
The
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
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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
One reason for forest depletion is agriculture of
Tropical timber became a viable choice for European wood following
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.
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.
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
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
See also
References
- ISBN 978-1-55963-364-2.
- ISBN 92-3-101955-4.
- ^ .
- Springer Link.
- ^ 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].
- ^ 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.
- ^ 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
- Burgess, N., J.D. Hales, E. Underwood, and E. Dinerstein (2004). Terrestrial Ecoregions of Africa and Madagascar: A Conservation Assessment. Island Press, Washington, D.C.
- Thieme, M.L., R. Abell, M.L.J. Stiassny, P. Skelton, B. Lehner, G.G. Teugels, E. Dinerstein, A.K. Toham, N. Burgess & D. Olson. 2005. Freshwater ecoregions of Africa and Madagascar: A conservation assessment. Washington D.C.: World Wildlife Fund.