The Eastern Arc Mountains is a chain of mountains found in

Kenya ) , national_anthem = "Ee Mungu Nguvu Yetu"() , image_map = , map_caption = , image_map2 = , capital = Nairobi , coordinates = , largest_city = Nairobi , ...

and

Tanzania Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands and ...

. 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 fault complex represented by the Makambako Gap that separates them from the

Kipengere Range The Kipengere Range, also known as the Livingstone Mountains, lies entirely in Njombe Region in southwest Tanzania at the northern end of Lake Nyasa. Near Lake Nyasa they are known as the Kinga Mountains. It is a plateau-like ridge of mountains r ...

. To the northeast, they are delimited by more recent

volcanism Volcanism, vulcanism or volcanicity is the phenomenon of eruption of molten rock (magma) onto the surface of the Earth or a solid-surface planet or moon, where lava, pyroclastics, and volcanic gases erupt through a break in the surface called ...

represented by

Mount Kilimanjaro Mount Kilimanjaro () is a dormant volcano in Tanzania. It has three volcanic cones: Kibo, Mawenzi, and Shira. It is the highest mountain in Africa and the highest free-standing mountain above sea level in the world: above sea level and ab ...

. The chain is considered a Tentative World Heritage Site.

Mountain ranges

The Eastern Arc Mountains forms a roughly crescent-shaped arc and consists of: #

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, Sagalla in the southern side of Voi township and Kasigau in t ...

# North and South

Pare Mountains The Pare Mountains are a mountain range in northeastern Tanzania, located north of the Usambara Mountains. The mountains are administratively located in the Kilimanjaro Region, specifically in the Mwanga District and Same District. The North an ...

# 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 of approximately long and about half that wide, are situated in the Lushoto District of the Tang ...

Nguru Mountains The Nguru Mountains are a mountain range in Morogoro Region, Tanzania, Africa. The Nguru Mountains are part of the Eastern Arc Mountains. The mountains are predominantly covered with rainforest, home to 83 species of birds (Romdal 2001) and Africa ...

Ukaguru Mountains The Ukaguru Mountains are a mountain range in central Tanzania. The mountains are in Morogoro region, east of Tanzania's capital Dodoma. The mountains are named for the Kaguru people. The Ukaguru Mountains are part of the Eastern Arc Mountains, an ...

Uluguru Mountains The Uluguru mountains are a mountain range in eastern Tanzania, named after the 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 main Uluguru rang ...

# Uvidunda Mountains #

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 communi ...

Malundwe Mountain Malundwe Mountain, also known as Malundwe Hill, is a mountain in Tanzania. It is located in Mikumi National Park in Morogoro Region. Geography Malundwe consists of three peaks along a ridge running north and south. Malundwe's south peak is the hi ...

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 ...

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. Geography ...

Geology

These mountain ranges are the oldest in East Africa, and though physically separated from each other, share a similar

geomorphology Geomorphology (from Ancient Greek: , ', "earth"; , ', "form"; and , ', "study") is the scientific study of the origin and evolution of topographic and bathymetric features created by physical, chemical or biological processes operating at or n ...

and

ecology Ecology () is the study of the relationships between living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere level. Ecology overlaps wi ...

. They were formed at least one hundred million years ago along a fault lying to the east of the

East African Rift The East African Rift (EAR) or East African Rift System (EARS) is an active continental rift zone in East Africa. The EAR began developing around the onset of the Miocene, 22–25 million years ago. In the past it was considered to be part of a ...

, which is a more recent structure. About thirty million years ago, all this area was covered by extensive

rainforest Rainforests are characterized by a closed and continuous tree canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforest can be classified as tropical rainforest or temperate rainfores ...

. During a period some ten million years ago, when the climate was cooler and drier, the lowland forests were converted to

savanna A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to ...

, leaving the mountain ranges as "islands" where the tropical forests continued to flourish, fed by moisture-laden winds from the Indian Ocean. This isolation of each mountain range has led to a great deal of

endemism Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

, and a very diverse flora and fauna, The Eastern Arc becoming known as one of the world's top twenty biodiversity hotspots.

Flora and fauna

Seventy-five species of vertebrate are endemic to the Eastern Arc, as well as thousands of species of invertebrates. Fifteen plant

genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...

are endemic to these mountains, as well as ''Streptocarpus'' sect. ''Saintpaulia'', the African violet, now used as a

houseplant A houseplant, sometimes known as a pot plant, potted plant, or an indoor plant, is an ornamental plant that is grown indoors. As such, they are found in places like residences and offices, mainly for decorative purposes. Common houseplants are us ...

around the world. Many of these endemics have evolved recently, but some are remnants of populations that were at one time more widespread. The Uluguru Mountains and the eastern Usambara Mountains have the greatest degree of biodiversity. Many endemic species are found on a single mountain range. Four of the endemic birds are similar to Asian species, and may have evolved at a time when the

Arabian Peninsula The Arabian Peninsula, (; ar, شِبْهُ الْجَزِيرَةِ الْعَرَبِيَّة, , "Arabian Peninsula" or , , "Island of the Arabs") or Arabia, is a peninsula of Western Asia, situated northeast of Africa on the Arabian Plate ...

had a coastal fringe of vegetation to act as a passageway; the

Udzungwa forest partridge The Udzungwa forest partridge (''Xenoperdix udzungwensis''), also known as the Udzungwa partridge, is a small, approximately long, boldly barred, brownish partridge with rufous face, grey underparts, olive-brown crown and upperparts. It has a red ...

(''Xenoperdix udzungwensis'') is a

relict A relict is a surviving remnant of a natural phenomenon. Biology A relict (or relic) is an organism that at an earlier time was abundant in a large area but now occurs at only one or a few small areas. Geology and geomorphology In geology, a r ...

and example of this, it is found only on the Rubeho Mountains and Udzungwa Mountains, and its closest relatives appear to be the hill partridges of Asia.

References

External links

Eastern Arc Mountains Conservation Endowment Fund
* {{Authority control Mountain ranges of Tanzania

Mountain ranges

Geology

Flora and fauna

See also

References

External links