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The Afromontane regions are subregions of the Afrotropical realm, one of the Earth's eight biogeographic realms, covering the plant and animal species found in the mountains of Africa and the southern Arabian Peninsula. The Afromontane regions of Africa are discontinuous, separated from each other by lower-lying areas, and are sometimes referred to as the Afromontane archipelago, as their distribution is analogous to a series of sky islands.
Afromontane communities occur above 1,500–2,000 metres (4,900–6,600 ft) elevation near the equator, and as low as 300 metres (980 ft) elevation in the Knysna-Amatole montane forests of South Africa. Afromontane forests are generally cooler and more humid than the surrounding lowlands.
The Afromontane archipelago mostly follows the East African Rift from the Red Sea to Zimbabwe, with the largest areas in the Ethiopian Highlands, the Albertine Rift Mountains of Uganda, Rwanda, Burundi, Democratic Republic of the Congo, and Tanzania, and the Eastern Arc highlands of Kenya and Tanzania. Other Afromontane regions include the Drakensberg range of southern Africa, the Cameroon Highlands, and the Cameroon Line volcanoes, including Mount Cameroon, Bioko, and São Tomé.
Although some Afromontane enclaves are widely separated, they share a similar mix of plant species which are often distinct from the surrounding lowland regions. [1] Podocarps, of genera Podocarpus and Afrocarpus , are a characteristic tree, along with Prunus africana , Hagenia abyssinica , Juniperus procera , and Olea spp.. In the higher mountains, the Afromontane forest or woodland zone transitions to a higher Afroalpine zone of grasslands, shrublands, or moorlands. [2] [3]
The plant families Curtisiaceae and Oliniaceae are Afromontane endemics and family Barbeyaceae is a near-endemic. The tree genera Afrocrania, Balthasaria, Curtisia, Ficalhoa, Hagenia, Kiggelaria, Kuloa, Leucosidea, Platypterocarpus, Trichocladus, Widdringtonia , and Xymalos are Afromontane endemics or near-endemics, as are the plant genera Ardisiandra, Cincinnobotrys, and Stapfiella . [1]
Afromontane areas have a wide range of plant communities, including intermediate types. These include:
In South Africa, Afromontane forests cover only 0.5% of the country's land area. The Afromontane forests occur along the mountainous arc of the Drakensberg Range, from Limpopo Province in the northeast to the Western Cape Province in the southwest. The Afromontane forests generally occur in well-watered areas, including ravines and south-facing slopes. The Afromontane forests are intolerant of fire, and the frequent fires of the surrounding fynbos, savanna, and grassland limit the expansion of the forests. Despite their small area, the Afromontane forests of South Africa produce valuable timber, particularly the real yellowwood (Podocarpus latifolius), Outeniqua yellowwood (Afrocarpus falcatus), and stinkwood (Ocotea bullata).
A woodland is, in the broad sense, land covered with trees, or in a narrow sense, synonymous with wood, a low-density forest forming open habitats with plenty of sunlight and limited shade. Some savannas may also be woodlands, such as savanna woodland, where trees and shrubs form a light canopy.
The Global 200 is the list of ecoregions identified by the World Wide Fund for Nature (WWF), the global conservation organization, as priorities for conservation. According to WWF, an ecoregion is defined as a "relatively large unit of land or water containing a characteristic set of natural communities that share a large majority of their species dynamics, and environmental conditions". For example, based on their levels of endemism, Madagascar gets multiple listings, ancient Lake Baikal gets one, and the North American Great Lakes get none.
The Ethiopian Highlands is a rugged mass of mountains in Ethiopia in Northeast Africa. It forms the largest continuous area of its elevation in the continent, with little of its surface falling below 1,500 m (4,900 ft), while the summits reach heights of up to 4,550 m (14,930 ft). It is sometimes called the Roof of Africa due to its height and large area. Most of the Ethiopian Highlands are part of central and northern Ethiopia, and its northernmost portion reaches into Eritrea.
Forest–savanna mosaic is a transitory ecotone between the tropical moist broadleaf forests of Equatorial Africa and the drier savannas and open woodlands to the north and south of the forest belt. The forest–savanna mosaic consists of drier forests, often gallery forest, interspersed with savannas and open grasslands.
Hagenia is a monotypic genus of flowering plant with the sole species Hagenia abyssinica, native to the high-elevation Afromontane regions of central and eastern Africa. It also has a disjunct distribution in the high mountains of East Africa from Sudan and Ethiopia in the north, through Kenya, Uganda, Rwanda, Burundi, Democratic Republic of Congo, and Tanzania, to Malawi and Zambia in the south. A member of the rose family, its closest relative is the Afromontane genus Leucosidea.
Mount Rungwe is a volcanic mountain in Mbeya Region, in Tanzania's Southern Highlands. At an altitude of 2,981 metres (9,780 ft), it is southern Tanzania's second-highest peak. Rungwe's volcano is currently inactive.
Podocarpus milanjianus is a species of conifer in the family Podocarpaceae. It is native to the highlands and mountains of tropical Africa.
The South Malawi montane forest–grassland mosaic is an ecoregion of Malawi.
The Angolan montane forest-grassland mosaic ecoregion is located on the east-facing inland side of the belt of mountains that stands parallel to the coast of Angola, 50–100 km inland.
The Ethiopian montane moorlands is a montane grasslands and shrublands ecoregion in Ethiopia. It lies above 3,000 meters elevation in the Ethiopian Highlands, the largest Afroalpine region in Africa. The montane moorlands lie above the tree line, and consist of grassland and moorland with abundant herbs and shrubs adapted to the high elevation conditions.
Ilex mitis is a tall, dense, evergreen tree that is indigenous to Sub-Saharan Africa and Madagascar. It makes an excellent fast-growing hedge for gardens - growing tall, straight and dense.
The Southern Highlands is a highland region in southwestern Tanzania, at the northern end of Lake Malawi. The highlands include portions of Mbeya, Njombe, Rukwa, Ruvuma, and Songwe regions, bordering Malawi, Mozambique, and Zambia. Mbeya is the largest city in the highlands.
The East African montane forests is a montane tropical moist forest ecoregion of eastern Africa. The ecoregion comprises several separate areas above 2000 meters in the mountains of South Sudan, Uganda, Kenya, and Tanzania.
The Ethiopian montane forests is a tropical moist broadleaf forest ecoregion in eastern Africa. It covers the middle elevations of the Ethiopian Highlands in Ethiopia and extends into neighboring Eritrea, Sudan, Djibouti, and Somaliland. The ecoregion includes distinctive Afromontane forests, woodlands, grasslands, and shrublands. The ecoregion's biodiversity is threatened by deforestation, conversion to agriculture, and overgrazing.
The Victoria Basin forest–grassland mosaic is an ecoregion that lies mostly in Uganda and extends into neighboring countries. The ecoregion is centered north and west of Lake Victoria, with an outlier on the border of Ethiopia and South Sudan.
Cassipourea malosana is a species of plant native to tropical Africa.
Galiniera saxifraga is a species of tree or small shrub native to the highlands of eastern and central Africa.