The Nimba Range forms part of the southern extent of the Guinea Highlands. The highest peak is Mount Richard-Molard on the border of

Côte d'Ivoire Ivory Coast, also known as Côte d'Ivoire, officially the Republic of Côte d'Ivoire, is a country on the southern coast of West Africa. Its capital is Yamoussoukro, in the centre of the country, while its largest city and economic centre is ...

and

Guinea Guinea ( ),, fuf, 𞤘𞤭𞤲𞤫, italic=no, Gine, wo, Gine, nqo, ߖߌ߬ߣߍ߫, bm, Gine officially the Republic of Guinea (french: République de Guinée), is a coastal country in West Africa. It borders the Atlantic Ocean to the we ...

, at 1,752 m (5,750 ft). "Mount Nimba" may refer either to Mount Richard-Molard or to the entire range. Other peaks include Grand Rochers at 1694 m (5558 ft), Mont Sempéré at 1682 m (5518 ft), Mont Piérré Richaud at 1670 m (5479 ft), Mont Tô at 1675 m (5495 ft), and Mont LeClerc 1577 m (5174 ft), all of them are located in Guinea. Mount Nimba Strict Nature Reserve of Guinea and Côte d'Ivoire covers significant portions of the Nimba Range.

Geology

The Nimba Range is a narrow ridge extending approximately 40 km long, with an orientation of northeast-southwest. It is composed mostly of

Precambrian The Precambrian (or Pre-Cambrian, sometimes abbreviated pꞒ, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the ...

rock, including granite and quartzite which contain deposits of

iron ore Iron ores are rocks and minerals from which metallic iron can be economically extracted. The ores are usually rich in iron oxides and vary in color from dark grey, bright yellow, or deep purple to rusty red. The iron is usually found in the fo ...

. Mining of top-quality iron-ore poses the major threat to the unique geomorphology and wildlife. There are about fifty springs, including the origins of the Cavally,

Cestos Cestos is a settlement in Rivercess County in central Liberia. Located along the Cestos River, it lay at the heart of a heavily contested region during the First Liberian Civil War: the National Patriotic Front of Liberia derived vast amounts of r ...

, and Sassandra Rivers.

Climate

Rainfall varies greatly with elevation and season. About 3,000 mm of rain falls at the highest altitudes, and between 700-1,200 mm at the lower elevations. In fact, some parts of the mountain receive less precipitation, due to rain-shadow effect of the high ridge. Most of the rainfall occurs between May and October.

Ecology

The Nimba Range harbours an especially rich flora and fauna, and it is the home of more than 2000 vascular plant species, 317 vertebrate species, 107 of which are

mammal Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...

s, and to more than 2,500 invertebrate species. Notably endemic vertebrates are Nimba viviparous toad (''Nimbaphrynoides occidentalis''), Lamotte's roundleaf bat (''Hipposideros lamottei''), '' Myotis nimbaensis'', and Nimba otter shrew (''Micropotamogale lamottei''). Other rare and endangered animals are West African lion (''Panthera leo senegalensis''), pygmy hippopotamus (''Choeropsis liberiensis''), zebra duiker (''Cephalophus zebra''), and western chimpanzee (''Pan troglodytes verus'') that uses stones as tools. Terrestrial ecoregions include

Western Guinean lowland forest The Western Guinean lowland forests ecoregion (WWF #AT0130) is a tropical moist broadleaf forest ecoregion of West Africa. It is centered on Liberia, with portions in surrounding countries. It is the westernmost tropical rainforest in Africa, an ...

, Guinean montane forest, Guinean forest-savanna mosaic, and West Sudanian savanna. The Nimba Range is a part of a distinct freshwater ecoregion with a high portion of endemic aquatic species.

Terrestrial

The plant communities vary with altitude and cardinal orientation. The Guinean montane forests ecoregion covers the portion of the range above 600 meters elevation. Major plant communities in the ecoregion include montane grasslands and savannas, cloud forests, and lower montane forests. High-altitude grasslands and montane savannas cover the highest peaks, dominated by the grass ''

Loudetia kagerensis ''Loudetia'' is a genus of African, Arabian, and South American plants in the grass family.Asplenium schnellii ''Asplenium'' is a genus of about 700 species of ferns, often treated as the only genus in the family Aspleniaceae, though other authors consider ''Hymenasplenium'' separate, based on molecular phylogenetic analysis of DNA sequences, a different ...

'', and two endemic flowering plants, '' Osbeckia porteresii'' and '' Blaeria nimbana''. Shrubs, including ''

Protea occidentalis ''Protea'' () is a genus of South African flowering plants, also called sugarbushes (Afrikaans: ''suikerbos''). Etymology The genus ''Protea'' was named in 1735 by Carl Linnaeus, possibly after the Greek god Proteus, who could change his form a ...

'', inhabit the slopes."Mount Nimba Strict Nature Reserve, Guinea and Côte d'Ivoire". Encyclopedia of Earth. Accessed November 10, 2012

/ref> The endemic frog species '' Nimbaphrynoides occidentalis,'' which inhabits the montane grasslands of the range, is totally viviparous. The Guinea Screeching Frog (''

Arthroleptis crusculum ''Arthroleptis crusculum'' is a species of frog in the family Arthroleptidae. It is found in southern Guinea, Liberia, Sierra Leone, and Côte d'Ivoire, at elevations of above sea level. Its natural habitats are high-altitude grassland, galler ...

'') is a threatened species found on Mt. Nimba and other peaks in the Guinea Highlands. It is found in high-altitude grassland and in gallery forests during the dry season. ''

Ptychadena submascareniensis ''Ptychadena submascareniensis'' (common name: Guinea grassland frog) is a species of frog in the family Ptychadenidae. This West African frog is found on the Nimba Range of Ivory Coast, Guinea, and Liberia, and on the Loma Mountains of Sierra Le ...

'' is another frog species that has been found only on Mount Nimba and in the

Loma Mountains The Loma Mountains are the highest mountain range in Sierra Leone Sierra Leone,)]. officially the Republic of Sierra Leone, is a country on the southwest coast of West Africa. It is bordered by Liberia to the southeast and Guinea surround ...

of Sierra Leone. Below the highest peaks, montane grasslands interspersed by gallery forests, between 1,200-1,400 meters. Above 900 meters elevation, near-daily mist and clouds support

cloud forest A cloud forest, also called a water forest, primas forest, or tropical montane cloud forest (TMCF), is a generally tropical or subtropical, evergreen, montane, moist forest characterized by a persistent, frequent or seasonal low-level cloud c ...

s, dominated by the Guinea Plum tree (''

Parinari excelsa ''Parinari excelsa'', the Guinea plum, is a species of large, evergreen tree in the family Chrysobalanaceae. It has a very wide distribution in tropical Africa and South America. This species grows to tall while the trunk is up to in diameter. ...

''), trees of the Myrtle family (

Myrtaceae Myrtaceae, the myrtle family, is a family of dicotyledonous plants placed within the order Myrtales. Myrtle, pōhutukawa, bay rum tree, clove, guava, acca (feijoa), allspice, and eucalyptus are some notable members of this group. All speci ...

), including ''

Syzygium guineense ''Syzygium guineense'' ( bm, Kokisa) is a leafy forest tree of the family Myrtaceae, found in many parts of Africa both wild and domesticated. Both its fruits and leaves are edible; the pulp and the fruit skin are sucked and the seed discarded. I ...

'', and species of '' Ochna'' and ''

Gaertnera ''Gaertnera'' is a genus of flowering plants in the family Rubiaceae. There are at least 85 species distributed across the Old World tropics from Africa to Asia.

''. The moist climate supports many

epiphyte An epiphyte is an organism that grows on the surface of a plant and derives its moisture and nutrients from the air, rain, water (in marine environments) or from debris accumulating around it. The plants on which epiphytes grow are called phoroph ...

s, including an endemic orchid, '' Rhipidoglossum paucifolium''. Lower montane forests of ''

Lophira procera ''Lophira'' is a genus of plants in the family Ochnaceae. Almost every part of ''Lophira'' (bark, root bark, leaves, and leafy shoots) is used for various medicinal purposes. Species include: * ''Lophira alata'' Banks ex C.F.Gaertn. * ''Lophi ...

'', '' Tarrietia utilis'', ''

Mapania ''Mapania'' is a genus of plants in the family Cyperaceae. It contains around 60-70 species, distributed in tropical regions of Africa, India, southern China, Southeast Asia, New Guinea, Australia, Central America, northern South America ...

'' spp., ''

Chlorophora regia ''Milicia regia'' is a species of tropical tree in the family Moraceae. It grows in a belt on the west coast of Africa that extends from the Gambia to Ghana. It is threatened by habitat loss and logging. Description ''Milicia regia'' has a wide ...

'', ''

Morus mesozygia ''Morus mesozygia'', known as black mulberry or African mulberry, is a small- to medium-sized forest tree of Tropical Africa. Its leaves and fruit provide food for the mantled guereza, a colobus monkey native to much of Tropical Africa, and for t ...

'', and '' Terminalia ivorensis'' occur between 600 and 900 meters elevation. Below 600 meters, the montane forests transition to the Western Guinean lowland forests ecoregion. The mountain is surrounded by Guinean forest-savanna mosaic, and West Sudanian savanna.

Freshwater

Swift-running streams descend steep slopes of the range, and often experience torrential floods during the rainy season. Rheophytes, plants that can live in running water, dominate the aquatic vegetation. The endemic aquatic animals in the Nimba Range includes frogs, fish, the Nimba Stream Crab ''(Liberonautes nimba)'', and the endangered Nimba otter shrew ''(Micropotamogale lamottei)''. The African clawless otter ''(Aonyx capensis)'' also inhabits the mountain streams. Species richness is high among aquatic invertebrates, including 81 species of dragonflies. The WWF designates the Nimba Range a distinct freshwater ecoregion because of its moderate species richness and high proportion of endemic aquatic species, particularly among fish and amphibians. The Nimba Range's high elevation, its rapids and waterfalls that isolate habitat areas, and the stability of the aquatic environment, have promoted

speciation Speciation is the evolutionary process by which populations evolve to become distinct species. The biologist Orator F. Cook coined the term in 1906 for cladogenesis, the splitting of lineages, as opposed to anagenesis, phyletic evolution within ...

. The

Guinean Highlands The Guinea Highlands is a densely forested mountainous plateau extending from central Guinea through northern Sierra Leone and Liberia to western Ivory Coast. The highlands include a number of mountains, ranges and plateaus, including the Fouta Dj ...

, of which the Nimba Range are part, separate the coastal rivers and streams of Upper Guinea from the upper Niger River basin. The highlands form a barrier to movement of aquatic species between these freshwater regions. The fish fauna of the Nimba Range shares affinities with that of Upper Guinea."Mount Nimba". Freshwater Ecoregions of the World, accessed November 10, 201

/ref>

Mount Nimba Strict Nature Reserve

In 1943, the colonial government established a Strict Nature Reserve in the Côte d'Ivoire section of the range. It was extended into Guinea the following year. The area remained protected after Guinea and Côte d'Ivoire became independent. UNESCO declared Mount Nimba a biosphere reserve in 1980, and a World Heritage Site shortly thereafter.

References

External links

Mount Nimba (Freshwater Ecoregions of the World)

Guinean Montane Forests (Encyclopedia of Earth)

Western Guinean lowland forests (Encyclopedia of Earth)

Guinean forest-savanna mosaic (Encyclopedia of Earth)

Mount Nimba Strict Nature Reserve, Guinea and Côte d'Ivoire (Encyclopedia of Earth)

Mount Nimba Strict Nature Reserve, Guinea and Côte d'Ivoire (UNESCO)

Mount Nimba Strict Nature Reserve, Guinea and Côte d'Ivoire (UNESCO MAB Biosphere Reserves Directory)

{{Coord, 7, 34, N, 8, 28, W, display=title, region:LR_type:mountain_source:GNS-enwiki Afromontane Ecoregions of Guinea Ecoregions of Ivory Coast Ecoregions of Liberia Freshwater ecoregions of Africa Guinean montane forests Mountain ranges of Guinea Mountain ranges of Ivory Coast Mountain ranges of Liberia Montagnes District