The Coastal forests of eastern Africa, also known as the East African Coastal Forests or Zanzibar–Inhambane forests, is a tropical moist forest region along the east coast of Africa. The region was designated a

biodiversity hotspot A biodiversity hotspot is a ecoregion, biogeographic region with significant levels of biodiversity that is threatened by human habitation. Norman Myers wrote about the concept in two articles in ''The Environmentalist'' in 1988 and 1990, after ...

by Conservation International.

Geography

The forests extend in a narrow band along the coast of the

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or approximately 20% of the water area of Earth#Surface, Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia (continent), ...

, from southern

Somalia Somalia, officially the Federal Republic of Somalia, is the easternmost country in continental Africa. The country is located in the Horn of Africa and is bordered by Ethiopia to the west, Djibouti to the northwest, Kenya to the southwest, th ...

in the north, through coastal

Kenya Kenya, officially the Republic of Kenya, is a country located in East Africa. With an estimated population of more than 52.4 million as of mid-2024, Kenya is the 27th-most-populous country in the world and the 7th most populous in Africa. ...

and

Tanzania Tanzania, officially the United Republic of Tanzania, is a country in East Africa within the African Great Lakes region. It is bordered by Uganda to the northwest; Kenya to the northeast; the Indian Ocean to the east; Mozambique and Malawi to t ...

to the mouth of the

Limpopo River The Limpopo River () rises in South Africa and flows generally eastward through Mozambique to the Indian Ocean. The term Limpopo is derived from Rivombo (Livombo/Lebombo), a group of Tsonga settlers led by Hosi Rivombo who settled in the mou ...

in southern

Mozambique Mozambique, officially the Republic of Mozambique, is a country located in Southeast Africa bordered by the Indian Ocean to the east, Tanzania to the north, Malawi and Zambia to the northwest, Zimbabwe to the west, and Eswatini and South Afr ...

. The forest belt is 50 to 200 km wide, and extends further west along river valleys. They are bounded on the west by drier grasslands and savannas. Pockets of coastal forest grow on the windward eastern slopes of mountains further inland, including the

Eastern Arc Mountains The Eastern Arc Mountains are a chain of mountains found in Kenya and Tanzania. The chain runs from northeast to southwest, with the Taita Hills being in Kenya and the other ranges being in Tanzania. They are delimited on the southwest by the fau ...

of Tanzania and Kenya and some

inselberg An inselberg or monadnock ( ) is an isolated rock hill, knob, ridge, or small mountain that rises abruptly from a gently sloping or virtually level surrounding plain. In Southern Africa, a similar formation of granite is known as a koppie, an ...

s in northern Mozambique, where rainfall and dry-season humidity are higher than the adjacent lowlands. The

World Wildlife Fund The World Wide Fund for Nature (WWF) is a Swiss-based international non-governmental organization founded in 1961 that works in the field of wilderness preservation and the reduction of human impact on the environment. It was formerly named the ...

divides the coastal forests into two ecoregions: the Northern Zanzibar-Inhambane coastal forest mosaic, which extends from southern Somalia through coastal Kenya to southern Tanzania, and includes the islands of

Zanzibar Zanzibar is a Tanzanian archipelago off the coast of East Africa. It is located in the Indian Ocean, and consists of many small Island, islands and two large ones: Unguja (the main island, referred to informally as Zanzibar) and Pemba Island. ...

and Pemba, and the Southern Zanzibar-Inhambane coastal forest mosaic, which extends from southern Tanzania along the Mozambique coast to the mouth of the Limpopo.

Climate

Rainfall averages from 800 and 1200 mm per year in most of the coastal belt, with a well-defined dry season. Rainfall is similar to the interior savannas, but humidity in the coastal belt is higher during the dry season. A few places have higher rainfall, including the islands of islands of Unguja (Zanzibar) and Pemba and the eastern slopes of the East Usambara Mountains, and are home to rain forests.

Flora

Forest was once the primary climax vegetation across most of the region. Most primary forest has been replaced by secondary wooded grassland, agriculture, and forest plantations. Frank White (1983) identified ten characteristic plant communities:Kindt R, van Breugel P, Orwa C, Lillesø JPB, Jamnadass R and Graudal L (2015) Useful tree species for Eastern Africa: a species selection tool based on the VECEA map. Version 2.0. World Agroforestry Centre (ICRAF) and Forest & Landscape Denmark. //vegetationmap4africa.org * Zanzibar-Inhambane lowland rain forest It found mostly in Tanzania, on the windward (east-facing) slopes of the Uluguru, Nguru, and Usambara Mountains, and in parts of Ulanga and Iringa districts. Trees form a closed evergreen canopy up to 20 meters tall, with emergent trees up to 40 meters tall. It is now reduced to small remnant patches. * Transitional rain forest grows at middle elevations (above 800 meters) in the Usambara and other nearby mountains. It is a transition between lowland and montane forests, and includes a mix of lowland and Afromontane species, along with many endemic species. The Amani Forest in Tanzania's Usambara mountains is the most intact remnant of this forest type. * Zanzibar-Inhambane undifferentiated forest varies in form and species composition based on rainfall and soils. In moister areas, trees form a canopy 15-20 meters high, with emergents of 30 or 35 meters. Many trees are evergreen, while others are briefly deciduous. * Zanzibar-Inhambane scrub forest. In Somalia and Kenya, scrub forest grows in a band between coastal forests and the drier bushlands of the interior. It is also found near the coast in Kenya and Tanzania, often on coral rag.Kindt, R., van Breugel, P., Lillesø, J-P. B., Bingham, M., Demissew, S., Dudley, C., ... Graudal, L. O. V. (2011). ''Potential natural vegetation of Eastern Africa (Ethiopia, Kenya, Malawi, Rwanda, Tanzania, Uganda and Zambia): Volume 2: description and tree species composition for forest potential natural vegetation types.'' Forest & Landscape, University of Copenhagen. Forest & Landscape Working Papers, No. 62/2011 * Swamp forest grows in limited areas in the coastal lowlands, often inland from coastal mangroves and exending along the lower reaches of rivers. '' Barringtonia racemosa'' is the predominant tree. Swamp forests of Raffia palm grow in low-lying areas of Pemba Island. * Zanzibar-Inhambane transition woodland * Zanzibar-Inhambane woodland and scrub woodland * Zanzibar-Inhambane evergreen and semi-evergreen bushland and thicket * Zanzibar-Inhambane edaphic grassland * Zanzibar-Inhambane secondary grassland and wooded grassland White (1983) estimated 3000 plant species were native to the region, of which several hundred are endemic. Of 192 native forest trees recorded by White, 90, or nearly half, are endemic.

Gallery

File:Dense forest in doline (9710746328).jpg, A moist forested gulley at Pemba, Mozambique File:Deciduous forest with Hyphaene petersiana.jpg, Deciduous forest on the Yoloko inselberg near Pemba, Mozambique File:Hildegardia migeodii - blue sky (8131504138).jpg, '' Hildegardia migeodii'',

Malvaceae Malvaceae (), or the mallows, is a family of flowering plants estimated to contain 244 genera with 4225 known species. Well-known members of economic importance include Theobroma cacao, cacao, Cola (plant), cola, cotton, okra, Hibiscus sabdariffa, ...

, a rare endemic of these forests

References

External links