The Eastern Arc forests is a

montane Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures lapse rate, fall as elevation increases, causing the ecosystem to stratify. This stratification is ...

ecoregion An ecoregion (ecological region) is an ecological and geographic area that exists on multiple different levels, defined by type, quality, and quantity of environmental resources. Ecoregions cover relatively large areas of land or water, and c ...

of eastern

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

. The ecoregion comprises several separate highland areas above 800 meters in

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 (mostly)

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 ...

Setting

The Eastern Arc forests extend across a total of 23,800 km² (9,200 sq. mi.) of mountainous landscape from the

Taita Hills The Taita Hills, sometimes also spelled as Teita Hills, are a mountain range located in the Taita-Taveta County in south-eastern Kenya. The hills consist of three massifs: Dawida Massif, Dawida, Sagalla Massif, Sagalla in the southern side of Vo ...

on Kenya-Tanzania border through central Tanzania to the

Udzungwa Mountains The Udzungwa Mountains are a mountain range in south-central Tanzania. The mountains are mostly within Iringa Region, south of Tanzania's capital Dodoma. The Udzungwa Mountains are part of the Eastern Arc Mountains, and are home to a biodiverse ...

in the southwest. The ecoregion includes numerous mountain blocks separated by lowland areas. The mountain form a broad arc curving to the northwest and southwest, and include the Taita Hills, North and South Pare Mountains, East and West

Usambara Mountains The Usambara Mountains of northeastern Tanzania in tropical East Africa, comprise the easternmost ranges of the Eastern Arc Mountains. The ranges are approximately long and about half that wide, and they are situated in the Lushoto District ...

, Nguu Mountains, North and South

Nguru Mountains The Nguru Mountains are a mountain range in Morogoro Region, Tanzania, Africa. They are part of the Eastern Arc Mountains. The mountains are predominantly covered with rainforest, home to 83 species of birds and African violets. Several forest res ...

, Ukaguru Mountains,

Uluguru Mountains The Uluguru mountains are a mountain range in eastern Tanzania, named after the Luguru people, Luguru tribe. The main portion of the Uluguru mountains is a ridge running roughly north-south and rising to altitude at its highest point. On the ma ...

Rubeho Mountains The Rubeho Mountains are a mountain range in central Tanzania. The mountains in Dodoma and Morogoro regions, southeast of Tanzania's capital Dodoma. The Rubeho Mountains are part of the Eastern Arc Mountains, and are home to a biodiverse community ...

Uvidunda Mountains The Uvidunda Mountains are a mountain range in Tanzania's Morogoro Region Kilosa district. The Mountains named after the Vidunda people native to the Mountains. Uvidunda Mountains located with more than 6 untouched waterfalls trail.The Uvidunda ...

, and

. The ecoregion includes two outlying mountains, the

Mahenge Mountains The Mahenge Mountains are a mountain range in Ulanga District, Morogoro Region, Tanzania. The town of Mahenge is located in the northeastern mountains. The mountains are southeast of Iringa, in the Eastern miombo woodlands ecoregion. Geograph ...

south of the Udzungwas and Malundwe Mountain in

Mikumi National Park Mikumi National Park is a national park in Tanzania located near the city of Morogoro, with an area of that was established in 1964. It is the fourth largest in the country. Territory Mikumi National Park borders Selous Game Reserve on the so ...

."Eastern Arc Forests". WWF ecoregion profile. Accessed 18 September 201

/ref> At lower elevations, the mountain forests are mostly surrounded by Eastern miombo woodlands, Miombo woodlands. The southeastern-facing slopes, which receive more moisture-laden winds off the Indian Ocean, are home to transitional forests from 250 to 350 meters elevation up to 800 meters elevation. These transitional forests more closely resemble the lowland coastal forests to the east, and are considered part of the

Northern Zanzibar–Inhambane coastal forest mosaic Northern Zanzibar–Inhambane coastal forest mosaic, also known as the Northern Swahili coastal forests and woodlands, is a tropical and subtropical moist broadleaf forests, tropical moist broadleaf forest ecoregion of coastal East Africa. The ec ...

ecoregion."Northern Zanzibar-Inhambane Coastal Forest Mosaic". WWF ecoregion profile. Accessed 18 September 2019

/ref> To the southwest, the Makambako Gap, a region of Miombo woodland, separate the Eastern Arc forests from the

Southern Rift montane forest–grassland mosaic The South Malawi montane forest-grassland mosaic is a montane grasslands and shrublands ecoregion of Tanzania, Malawi, Mozambique, and Zambia. The ecoregion encompasses several high mountains and plateaus north and east of Lake Malawi. Climate T ...

ecoregion in Tanzania's Southern Highlands.

Flora

The main plant communities are upper montane forests (2635–1800 m), lower montane forests (1250–1800 m) and submontane forests (800–1250 m). The upper montane forests are dwarfed and lichen-covered at the highest elevations. The ecoregion also includes areas of high-elevation grassland, heathland, and bamboo forest. The forests are home to many endemic species including over 800 plants, and are the original homeland of the

African violet ''Streptocarpus'' sect. ''Saintpaulia'' is a section within ''Streptocarpus'' subgenus ''Streptocarpella'' consisting of about ten species of herbaceous perennial flowering plants in the family Gesneriaceae, native to Tanzania and adjacent sout ...

(''Saintpaulia'') and the Busy Lizzie (''Impatiens'').

Fauna

The ecoregion is rich in wildlife with many endemic species of birds, and some mammals, while endemic amphibians include five species of reed frogs (''

Hyperolius ''Hyperolius'' (commonly known as the African reed frogs or reed frogs) is a large genus of frogs in the family Hyperoliidae from Sub-Saharan Africa. The genus is known to exhibit Sexual dichromatism, a trait that is otherwise rare in frogs. Spe ...

''), two species of forest treefrogs (''

Leptopelis ''Leptopelis'' is a genus of frogs in the family Arthroleptidae. They are found throughout Sub-Saharan Africa Sub-Saharan Africa is the area and regions of the continent of Africa that lie south of the Sahara. These include Central Afric ...

''), five tree toads (''

Nectophrynoides ''Nectophrynoides'' is a genus of true toads, family Bufonidae. They are endemic to Eastern Arc forests and wetlands in Tanzania,Channing and Howell. (2006). ''Amphibians of East Africa.'' Pp. 104–117. and all except '' N. tornieri'' are thr ...

''), four species of

Microhylidae The Microhylidae, commonly known as narrow-mouthed frogs, are a geographically widespread family (biology), family of frogs. The 683 species are in 57 genera and 11 subfamilies. Evolution A molecular phylogenetic study by van der Meijden, et al. ...

, and five

Caeciliidae Caeciliidae is the family of common caecilians. They are found in Central and South America. Like other caecilians, they superficially resemble worms or snakes. Although they are the most diverse of the caecilian families, the caeciliids do ha ...

. Endemic reptiles include ten species of chameleons (seven ''

Chamaeleo ''Chamaeleo'' is a genus of chameleons in the Family (biology), family Chamaeleonidae. Most species of the genus ''Chamaeleo'' are found in sub-Saharan Africa, but a few species are also present in northern Africa, southern Europe, and southern ...

'' and three ''

Rhampholeon ''Rhampholeon'' (from , 'bird's bill' and , 'lion') is a genus of small chameleons, commonly known as pygmy chameleons or African leaf chameleons, found in East Africa and Central Africa. They are found in forests, woodlands, thickets, and sava ...

''), three worm snakes (''

Typhlops ''Typhlops'' is a genus of blind snakes in the family Typhlopidae. The genus is endemic to the West Indies. Some species which were formerly placed in the genus ''Typhlops'' have been moved to the genera ''Afrotyphlops, Amerotyphlops, Anilios, ...

''), and six

Colubridae Colubridae (, commonly known as colubrids , from , 'snake') is a family of snakes. With 249 genera, it is the largest snake family. The earliest fossil species of the family date back to the Late Eocene epoch, with earlier origins suspected. C ...

snakes. Invertebrates show very high levels of endemism too. Furthermore, study of the wildlife on these isolated hills is important for research into evolutionary pathways.

Threats and conservation

These wet hillsides are highly populated with farming communities and most forest has been lost, especially on the lower slopes.

Protected areas

20.31% of the ecoregion is in protected areas. The largest protected area is Udzungwa Mountains National Park. Other protected areas include Mkomazi National Park, Tsavo West National Park, Amani Nature Forest Reserve, Chome Nature Forest Reserve, Nilo Nature Forest Reserve, Mkingu Nature Forest Reserve, and Uluguru Nature Forest Reserve. There are also protected areas around a number of reservoirs, as this region is central to Tanzania's water supply.

References

External links

* {{WWF ecoregion, name=Eastern Arc forests, id=at0109 Afromontane ecoregions Afrotropical ecoregions Eastern Arc Mountains Ecoregions of Kenya Ecoregions of Tanzania Rainforests of Africa Tropical and subtropical moist broadleaf forests