The Nimba Range forms part of the southern extent of the

Guinea 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 ...

. The highest peak is

Mount Richard-Molard Mount Richard-Molard, also known as Mount Nimba, is a mountain along the border of Ivory Coast and Guinea in West Africa. The highest peak for both countries and the Nimba Range is at . The mountain is a part of the Guinea Highlands, which straddl ...

on the

border Borders are usually defined as geographical boundaries, imposed either by features such as oceans and terrain, or by political entities such as governments, sovereign states, federated states, and other subnational entities. Political borders c ...

of Côte d'Ivoire and Guinea, 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 Mount Nimba Strict Nature Reserve is a protected area and UNESCO World Heritage Site located in both Guinea and Côte d'Ivoire, extending over a total of area of 17,540 hectares, with 12,540 hectares in Guinea, and 5,000 hectares in Côte d'Ivoi ...

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 rock, including

granite Granite () is a coarse-grained ( phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies under ...

and

quartzite Quartzite is a hard, non- foliated metamorphic rock which was originally pure quartz sandstone.Essentials of Geology, 3rd Edition, Stephen Marshak, p 182 Sandstone is converted into quartzite through heating and pressure usually related to tec ...

which contain deposits of iron ore. 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, and

Sassandra River The Sassandra River is a river of western Côte d'Ivoire in West Africa. It is formed by the confluence of the Tienba River, which originates in the highlands of northwestern Côte d'Ivoire, and the Gouan River (also known as the Bafing Sud Riv ...

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 Vascular plants (), also called tracheophytes () or collectively Tracheophyta (), form a large group of land plants ( accepted known species) that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. They ...

species, 317

vertebrate Vertebrates () comprise all animal taxa within the subphylum Vertebrata () (chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, with c ...

species, 107 of which are mammals, and to more than 2,500

invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...

species. Notably

endemic 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 else ...

vertebrates are Nimba viviparous toad (''Nimbaphrynoides occidentalis''),

Lamotte's roundleaf bat Lamotte's roundleaf bat (''Hipposideros lamottei'') is a species of bat found only at Mount Nimba on the border of Côte d'Ivoire, Guinea and Liberia. It is critically endangered. Taxonomy It was described as a new species in 1984 by French ...

(''Hipposideros lamottei''), ''

Myotis nimbaensis The Nimba myotis (''Myotis nimbaensis''), also known as the orange-furred bat or Nimba Mountain bat, is a species of bat in the family Vespertilionidae. The species is endemic to the Nimba Mountains in Guinea, West Africa West Africa or We ...

'', and

Nimba otter shrew The Nimba otter shrew (''Micropotamogale lamottei'') is a dwarf otter shrew and belongs to the mammal family Potamogalidae. Otter shrews are shrew-like afrotherian mammals found in sub-Saharan Africa. They are most closely related to the tenrecs ...

(''Micropotamogale lamottei''). Other rare and endangered animals are

West African lion ''Panthera leo leo'' is a lion subspecies, which is present in West Africa, northern Central Africa and India. In West and Central Africa it is restricted to fragmented and isolated populations with a declining trajectory. It has been referred to ...

(''Panthera leo senegalensis''),

pygmy hippopotamus The pygmy hippopotamus or pygmy hippo (''Choeropsis liberiensis'') is a small hippopotamid which is native to the forests and swamps of West Africa, primarily in Liberia, with small populations in Sierra Leone, Guinea, and Ivory Coast. It has ...

(''Choeropsis liberiensis''), zebra duiker (''Cephalophus zebra''), and

western chimpanzee The western chimpanzee, or West African chimpanzee, (''Pan troglodytes verus'') is a Critically Endangered subspecies of the common chimpanzee. It inhabits western Africa, specifically Côte d'Ivoire, Guinea, Liberia, Mali, Senegal, Ghana, ...

(''Pan troglodytes verus'') that uses stones as tools. Terrestrial ecoregions include Western Guinean lowland forest, Guinean montane forest,

Guinean forest-savanna mosaic 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 ...

, and

West Sudanian savanna The West Sudanian savanna is a tropical savanna ecoregion that extends across West Africa. Geography The ecoregion stretches east and west across West Africa, from the Atlantic coast of Senegal to the Mandara Mountains on Nigeria's eastern borde ...

. The Nimba Range is a part of a distinct

freshwater ecoregion An ecoregion (ecological region) or ecozone (ecological zone) is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas of l ...

with a high portion of endemic aquatic species.

Terrestrial

The plant communities vary with altitude and cardinal orientation. The

Guinean montane forests The Guinean montane forests are a tropical moist broadleaf forest ecoregion of West Africa. The ecoregion occupies the portions of the Guinea Highlands lying above 600 meters elevation, extending across portions of Guinea, Sierra Leone, Lib ...

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''. The grasslands are home to one endemic fern, '' Asplenium schnellii'', and two endemic flowering plants, ''

Osbeckia porteresii ''Osbeckia'' is a genus of plants in the family Melastomataceae. It was named by Carl Linnaeus for the Swedish explorer and naturalist Pehr Osbeck (1723–1805). Distribution Osbeckias are native to Eastern Asia — China, Japan, Malaysia, Ind ...

'' and '' Blaeria nimbana''. Shrubs, including '' Protea occidentalis'', 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 Among animals, viviparity is development of the embryo inside the body of the parent. This is opposed to oviparity which is a reproductive mode in which females lay developing eggs that complete their development and hatch externally from the ...

. The Guinea Screeching Frog ('' Arthroleptis crusculum'') 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'' is another frog species that has been found only on Mount Nimba and in the Loma Mountains of

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 surrounds the northern half of the nation. Covering a total area of , Sierr ...

. 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 forests, dominated by the Guinea Plum tree ('' Parinari excelsa''), trees of the Myrtle family ( Myrtaceae), including '' Syzygium guineense'', and species of ''

Ochna ''Ochna''Linnaeus C (1753) ''Sp. Pl.'' 1: 513. is a genus comprising 86 species of evergreen trees, shrubs and shrublets belonging to the flowering plant family ''Ochnaceae''. These species are native to tropical woodlands of Africa, the Mascare ...

'' and '' Gaertnera''. The moist climate supports many epiphytes, including an endemic

orchid Orchids are plants that belong to the family Orchidaceae (), a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant. Along with the Asteraceae, they are one of the two largest families of flowerin ...

, '' Rhipidoglossum paucifolium''. Lower montane forests of '' Lophira procera'', '' Tarrietia utilis'', '' Mapania'' spp., '' Chlorophora regia'', '' Morus mesozygia'', and ''

Terminalia ivorensis ''Terminalia ivorensis'' is a species of tree in the family Combretaceae, and is known by the common names of Ivory Coast almond, idigbo, black afara, framire and emeri. Description ''Terminalia ivorensis'' is found in Cameroon, Ivory Coast, Gh ...

'' occur between 600 and 900 meters elevation. Below 600 meters, the montane forests transition to the

Western Guinean lowland forests 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 ...

ecoregion. The mountain is surrounded by Guinean forest-savanna mosaic, and

Freshwater

Swift-running streams descend steep slopes of the range, and often experience torrential floods during the rainy season.

Rheophyte A rheophyte is a plant that lives in fast moving water currents in an environment where few other organisms can survive. Rheophytes tend to be found in currents that move at rates of one to two meters per second and that are up to 1 to 2 m deep. Th ...

s, 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

''(Micropotamogale lamottei)''. The

African clawless otter The African clawless otter (''Aonyx capensis''), also known as the Cape clawless otter or groot otter, is the second-largest freshwater otter species. It inhabits permanent water bodies in savannah and lowland forest areas through most of sub- ...

''(Aonyx capensis)'' also inhabits the mountain streams. Species richness is high among aquatic invertebrates, including 81 species of

dragonflies A dragonfly is a flying insect belonging to the infraorder Anisoptera below the order Odonata. About 3,000 extant species of true dragonfly are known. Most are tropical, with fewer species in temperate regions. Loss of wetland habitat threa ...

. The WWF designates the Nimba Range a distinct

because of its moderate species richness and high proportion of

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. The Guinean Highlands, of which the Nimba Range are part, separate the coastal rivers and streams of

Upper Guinea Upper Guinea is a geographical term used in several contexts: # Upper Guinea (french: Haute-Guinée) is one of the four geographic regions of the Republic of Guinea, being east of Futa Jalon, north of Forest Guinea, and bordering Mali. The popula ...

from the upper

Niger River The Niger River ( ; ) is the main river of West Africa, extending about . Its drainage basin is in area. Its source is in the Guinea Highlands in south-eastern Guinea near the Sierra Leone border. It runs in a crescent shape through ...

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

."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 The United Nations Educational, Scientific and Cultural Organization is a specialized agency of the United Nations (UN) aimed at promoting world peace and security through international cooperation in education, arts, sciences and culture. It ...

declared Mount Nimba a

biosphere reserve A nature reserve (also known as a wildlife refuge, wildlife sanctuary, biosphere reserve or bioreserve, natural or nature preserve, or nature conservation area) is a protected area of importance for flora, fauna, or features of geological or ...

in 1980, and a

World Heritage Site A World Heritage Site is a landmark or area with legal protection by an international convention administered by the United Nations Educational, Scientific and Cultural Organization (UNESCO). World Heritage Sites are designated by UNESCO for h ...

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