Mont Eloumden

CMNTIPA010
Mont Eloumden

Country: Cameroon

Administrative region: Centre (Region)

Central co-ordinates: 3.82830 N, 11.43880 E

Area: 13km²

Qualifying IPA Criteria

A(i)Site contains one or more globally threatened species

IPA assessment rationale

Mont Eloumden qualifies as a potential IPA on the basis of several records of globally threatened species that are known from few other sites and are mostly nationally endemic. These include Eugenia kameruniana (CR), Psychotria yaoundensis (CR), Pterorhachis zenkeri (VU), Anisotes zenkeri (VU) and Crossopetalum serrulatum (VU). Psychotria yaoundensis is known only from Yaoundé and Anisotes zenkeri only from Centre Region. Pararistolochia ceropegioides (VU) is recorded from Nkol Ngoaékélé which is included as part of this suggested IPA.

Site description

Mount Eloumden and the associated peaks of Mount Zokye, Mount Ekanga and Nkol Ngoaékélé are located about 10 km west of central Yaoundé. Together with the Mount Kala massif further west they extend in an east-west orientation, forming the southernmost of the various hills reaching over 1,000 m that dominate the western approach to the capital. Mount Zokye, Mount Ekanga and Nkol Ngoaékélé continue the Eloumden massif to the west and should arguably be included in the IPA designation since intact vegetation appears to persist. This chain comprises an area of approximately 10 km2. A wider valley and road with settlements separates it from Mount Kala.

Botanical significance

Many botanical collections were made in the Yaoundé area by Zenker and Staudt in the 1890s (Cheek et al., 2011). While unfortunately most of these can not be precisely located, the western hills are the main surviving areas were some natural habitat remains. These are forested inselbergs and provide an interesting flora differing from the lower surrounding areas. Subsequent collections have recorded several globally threatened taxa at Eloumden, including Pterorhachis zenkeri (VU) which was first recorded from Yaoundé in 1894. Psychotria yaoundensis (CR) has only been recorded from this site and two other nearby hills in Yaoundé (Lachenaud et al., 2013; Lovell & Cheek, 2021). Anisotes zenkeri (EN) is also known only from Yaoundé and one other site also in centre region.

Habitat and geology

The hills around Yaoundé rise from the South Cameroon Plain between the Sanaga fault and the north-thrusting Congo craton. They are formed from high grade metamorphic rocks, mainly granulites and migmatites also referred to as embrichite gneiss (Achoundog,1985), formed from sedimentary and igneous protoliths and apparently dating from around 600 mya (Nzenti et al.,1988; Tchouatcha et al., 2018; Ngnotue et al., 2012).
Preciptiation in Yaoundé is 1,605 mm per annum, falling in a bimodal pattern with a small (March-June) and greater (September-November) wet season interspersed with a drier period (July-August) and then a second more severe dry period between December and February. During the latter period mean monthly rainfall drops below the relatively flat mean monthly temperature curve (range: 22.8–25.47 °C) on a Walter-Leith type chart (Simo et al., 2009; Bissaya et al., 2014; Madiapevo et al., 2015). The overall precipitation is below the level of rainfall normally thought necessary to sustain evergreen tropical forest (Cheek et al., 2011), although the level may be higher on the summits due to orographic precipitation (Noumi, 2014; Simo et al., 2009). The original forest was probably semi-deciduous (Achoundong et al., 1985; Letouzey, 1985) but has been heavily degraded through timber and wood extraction and cultivation.

Conservation issues

The site does not have protected status. Quarries are evident on the southern faces of Mount Eloumden and Mount Zokye. Elsewhere in Yaoundé a larger quarry has destroyed much of the northeast summit of Mount Minloa.
Yaoundé is expanding in size and there is considerable pressure on undeveloped land for fuelwood, cultivation and building (Nkwemoh et al., 2017; Tiafack & Mbon, 2017; Nkwemoh & Tchindjang, 2018). The lower flanks show clear signs of settlement and cultivation up to about 900 m, particularly on the eastern side nearer to Yaoundé where it is feared there may be very little original vegetation surviving.
As well as potentially forming part of a network of inselberg sites around Yaoundé, the adjacent proposed IPAs of Mt Kala, Eloumden and Colline Mbokdoum offer a potential for a large connected habitat.

Ecosystem services

As is the case with the other hills around Yaoundé, there is a high risk of landslides due to steep terrain and impervious clay beneath permeable laterite soil (Zogning et al., 2007; Mukenga, 2016). This is likely exacerbated by quarrying activity and cultivation. Preservation of existing forest and primary vegetation is important to preventing such disasters and flash flooding. The site provides a recreational and educational opportunity for the city's residents, as well as improving air quality.

Site assessor(s)

Bruce Murphy, Royal Botanic Gardens, Kew

Dr Vincent Droissart, Institute of Research for Development. Marseille

Professor Bonaventure Sonke, University of Yaounde I

IPA criterion A species

Species Qualifying sub-criterion ≥ 1% of global population ≥ 5% of national population 1 of 5 best sites nationally Entire global population Socio-economically important Abundance at site
Anisotes zenkeri (Lindau) C.B.Clarke A(i) True True True False True
Eugenia kameruniana Engl. A(i) True True True False False
Pterorhachis zenkeri Harms A(i) True True True False False
Callichilia monopodialis (K.Schum.) Stapf A(i) True False False False False
Crossopetalum serrulatum (Loes.) I.Darbysh. A(i) True True False False False
Psychotria yaoundensis O.Lachenaud A(i) True True True False False
Pararistolochia ceropegioides (S.Moore) Hutch. & Dalziel A(i) True False True False False
Oxyanthus doucetii Sonké & O.Lachenaud A(i) True True True False False
Crossopetalum serrulatum (Loes.) I.Darbysh. A(i) False False True False False

Anisotes zenkeri (Lindau) C.B.Clarke

Qualifying sub-criterion:
A(i)
≥ 1% of global population:
True
≥ 5% of national population:
True
1 of 5 best sites nationally:
True
Entire global population:
False
Socio-economically important:
True
Abundance at site:

Eugenia kameruniana Engl.

Qualifying sub-criterion:
A(i)
≥ 1% of global population:
True
≥ 5% of national population:
True
1 of 5 best sites nationally:
True
Entire global population:
False
Socio-economically important:
False
Abundance at site:

Pterorhachis zenkeri Harms

Qualifying sub-criterion:
A(i)
≥ 1% of global population:
True
≥ 5% of national population:
True
1 of 5 best sites nationally:
True
Entire global population:
False
Socio-economically important:
False
Abundance at site:

Callichilia monopodialis (K.Schum.) Stapf

Qualifying sub-criterion:
A(i)
≥ 1% of global population:
True
≥ 5% of national population:
False
1 of 5 best sites nationally:
False
Entire global population:
False
Socio-economically important:
False
Abundance at site:

Crossopetalum serrulatum (Loes.) I.Darbysh.

Qualifying sub-criterion:
A(i)
≥ 1% of global population:
True
≥ 5% of national population:
True
1 of 5 best sites nationally:
False
Entire global population:
False
Socio-economically important:
False
Abundance at site:

Psychotria yaoundensis O.Lachenaud

Qualifying sub-criterion:
A(i)
≥ 1% of global population:
True
≥ 5% of national population:
True
1 of 5 best sites nationally:
True
Entire global population:
False
Socio-economically important:
False
Abundance at site:

Pararistolochia ceropegioides (S.Moore) Hutch. & Dalziel

Qualifying sub-criterion:
A(i)
≥ 1% of global population:
True
≥ 5% of national population:
False
1 of 5 best sites nationally:
True
Entire global population:
False
Socio-economically important:
False
Abundance at site:

Oxyanthus doucetii Sonké & O.Lachenaud

Qualifying sub-criterion:
A(i)
≥ 1% of global population:
True
≥ 5% of national population:
True
1 of 5 best sites nationally:
True
Entire global population:
False
Socio-economically important:
False
Abundance at site:

Crossopetalum serrulatum (Loes.) I.Darbysh.

Qualifying sub-criterion:
A(i)
≥ 1% of global population:
False
≥ 5% of national population:
False
1 of 5 best sites nationally:
True
Entire global population:
False
Socio-economically important:
False
Abundance at site:

General site habitats

General site habitat Percent coverage Importance
Forest - Subtropical/Tropical Moist Montane Forest No value
Forest - Subtropical/Tropical Dry Forest No value
Rocky Areas - Rocky Areas [e.g. inland cliffs, mountain peaks] No value

Forest - Subtropical/Tropical Moist Montane Forest

Percent coverage:
No value
Importance:

Forest - Subtropical/Tropical Dry Forest

Percent coverage:
No value
Importance:

Rocky Areas - Rocky Areas [e.g. inland cliffs, mountain peaks]

Percent coverage:
No value
Importance:

Land use types

Land use type Percent coverage Importance
Extractive industry No value
Agriculture (arable) No value
Harvesting of wild resources No value

Extractive industry

Percent coverage:
No value
Importance:

Agriculture (arable)

Percent coverage:
No value
Importance:

Harvesting of wild resources

Percent coverage:
No value
Importance:

Threats

Threat Severity Timing
Residential & commercial development - Housing & urban areas High Ongoing - increasing
Agriculture & aquaculture - Annual & perennial non-timber crops - Small-holder farming High Ongoing - increasing
Energy production & mining - Mining & quarrying High Ongoing - increasing
Biological resource use - Logging & wood harvesting High Ongoing - trend unknown
Geological events - Avalanches/landslides Medium Ongoing - trend unknown

Residential & commercial development - Housing & urban areas

Severity:
High
Timing:
Ongoing - increasing

Agriculture & aquaculture - Annual & perennial non-timber crops - Small-holder farming

Severity:
High
Timing:
Ongoing - increasing

Energy production & mining - Mining & quarrying

Severity:
High
Timing:
Ongoing - increasing

Biological resource use - Logging & wood harvesting

Severity:
High
Timing:
Ongoing - trend unknown

Geological events - Avalanches/landslides

Severity:
Medium
Timing:
Ongoing - trend unknown

Conservation designation

Designation name Protected area Relationship with IPA Areal overlap
Mbam Minkom-Kala IBA Important Bird Area protected/conservation area encompasses IPA 100
Mbam Minkom-Kala IBA Key Biodiversity Area protected/conservation area encompasses IPA No value

Mbam Minkom-Kala IBA

Protected area:
Important Bird Area
Relationship with IPA:
protected/conservation area encompasses IPA
Areal overlap:
100

Mbam Minkom-Kala IBA

Protected area:
Key Biodiversity Area
Relationship with IPA:
protected/conservation area encompasses IPA
Areal overlap:
No value

Management type

Management type Description Year started Year finished
No management plan in place No value No value

No management plan in place

Year started:
No value
Year finished:
No value

Bibliography

Cheek, M., Harvey, Y. & Onana, J.M., 2011

The Plants of Mefou Proposed National Park, Yaoundé, Cameroon

Letouzey, R., 1985

Notice de la carte phytogéographique du Cameroun au 1: 500,000.

BirdLife International, 2020

Important Bird Areas factsheet: Mbam Minkom - Kala.

Available online

Zogning, A., Ngouanet, C. & Tiafack, O., 2007

The catastrophic geomorphological processes in humid tropical Africa: A case study of the recent landslide disasters in Cameroon

Sedimentary Geology, Vol 199, page(s) 13 – 27 Available online

Mukenga, W,. Havenith, H.B., Dewitte, O. & R.M. Eko, 2016

Spatial Analysis of the Landslide Risk in the Cameroon Volcanic Line (CVL)

Available online

Bissaya, R., Ghogomu, R.T., Moundi, A., Njom, B. & N.S. Kanouo, 2014

Utilisation des données géologiques et gestion des informations multi-sources pour l’analyse de l’aléa glissement de terrain/éboulement dans le secteur Nord-Ouest de la région de Yaoundé

Afrique SCIENCE, Vol 10(3), page(s) 113 - 133

Tiafack, O. & Mbon, A.M., 2017

Urban Growth and Front Development on Risk Zones: GIS Application for Mapping of Impacts on Yaounde North Western Highlands, Cameroon

Current Urban Studies, Vol 5(2), page(s) 217-235

Nkwemoh, C.A.; Tchindjang, M., 2018

Urban sprawl and agriculture: A case study of the Yaounde metropolis (Cameroon)

Revue Scientifique et Technique Forêt et Environnement du Bassin du Congo, Vol 10, page(s) 45-58.

Nkwemoh, C.A., Tchindjang, M. & Afungang, R.N., 2017

The Impact of Urbanization on the Vegetation of Yaounde, (Cameroon)

International Journal of Innovative Research & Development, Vol 6(5), page(s) 6-18

Noumi, E., 2015

Floristic structure and diversity of a tropical sub-montane evergreen forest, in the Mbam minkom massif (Western Yaoundé).

Journal of Biology and Life Science, Vol 6(1), page(s) 149-193

Nzenti, J.P., Barbey, P., Macaudiere, J. & Soba, D., 1988

Origin and evolution of the late Precambrian high-grade Yaounde gneisses (Cameroon).

Precambambrian Research, Vol 38, page(s) 91-109

Tchouatcha, M.S., Kouske, A.P., Njiosseu, E.L.T., Ngouem, P.A., Ngnotue, T., Njinchuki, D.N. & Nzenti, J.P., 2018

Preserved Sedimentary Features in the Pan-African High-Grade Metamorphic Rocks from the Yaoundé Series (Cameroon)

Journal of Geosciences and Geomatics, Vol 6(3), page(s) 94-102

Ngnotué, T., Ganno, S., Nzenti, J.P., Schulz, B., Tchaptchet T.D. & Suh, C.E., 2012

Geochemistry and geochronology of Peraluminous High-K Granitic Leucosomes of Yaoundé Series ) Cameroon. Evidence for a Unique Pan-African Magmatism and Melting Event in North Equatorial Fold Belt.

International Journal of Geosciences, Vol 3, page(s) 525-548

Madiapevo, S.N., Makemteu, J. & Noumi, E., 2017

Plant Woody Diversity of the Highest Summit Forest (1156 m), in the Kala Massif, Western Yaoundé

International Journal of Current Research in Biosciences and Plant Biology, Vol 4(10), page(s) 1-30

Recommended citation

Bruce Murphy, Dr Vincent Droissart, Professor Bonaventure Sonke (2024) Tropical Important Plant Areas Explorer: Mount Eloumden massif (Cameroon). https://tipas.kew.org/site/mont-eloumden-2/ (Accessed on 21/05/2024)