Mount Oku and the Kilum-Ijim forests

CMNTIPA037
Mount Oku and the Kilum-Ijim forests

Country: Cameroon

Administrative region: Northwest (Region)

Central co-ordinates: 6.22000 N, 10.44000 E

Area: 289km²

Qualifying IPA Criteria

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

IPA assessment rationale

Mount Oku and the Ijim Ridge qualifies as a potential IPA under criterion A(i) through the occurrence of numerous globally threatened species, several of which are narrowly endemic. It would likely qualify also under criterion B(ii) due to a high diversity of restricted or nationally endemic species, and also under criterion C(iii) as one of the top national sites for montane forest, subalpine vegetation or montane sphagnum bog.

Site description

Rising to around 3,000 m, Mt Oku is the second highest peak in Cameroon. Situated along the Cameroon Volcanic Line 280 km northeast of Mount Cameroon and the Gulf of Guinea coast, and 175-150 km northeast of Mt Kupe and Mount Manenguba, it is part of the Bamenda Highlands, an area which has been intensively populated and largely deforested. The proposed IPA is based on the Oku Ijim IBA (150 km2) which is similar to the core area surveyed by Cheek et al. (2000), both having been based on the the Kilum Forest Project Area (c. 200 km2 Maisels et al. 2000) which approximately follows the 2,000 m contour line. However, the area has been extended here, bringing the total area up to 289 km2. Communities surround the site, including the villages of Elak (where the headquarters of the Kilum Project was based), Oku and Jikijem to the northeast, Njinikom and Fundong to the west and northwest, Ibal to the south, and the suburbs of the larger town of Kumbo spreading from the east. Laikom, where the Fon of Kom's palace is sited, lies within the Ijim project area and within the proposed TIPA zone at the western tip of the Ijim Ridge. At the centre of the area at approximately 2,240 m lies lake Oku, a large crater lake.

Botanical significance

Mount Oku and the Ijim ridge is one of a handful of key sites for afromontane and subalpine vegetation outside of east Africa (Cheek et al., 2000; White, 1986). Cheek et al. (2000) recorded 850 species within a zone similar to the IPA proposed here. While the flora has natural affinities with other sites along the Cameroon line (Mt Cameroon, the Bakossi mountains, Mt Kupe, Tchabal Mbabo), it is also notably different, peaking at higher altitude than all but Mt Cameroon and largely limited to the montane and upper submontane altitudinal bands. Mt Cameroon and Mt Oku are the only two sites reaching sufficient altitude for Afro-alpine vegetation (above 2,800 m) but Letouzey (1985) showed forest extended higher at Oku (to 3,000 m) than at Mt Cameroon. The site is the largest remaining and best preserved part of the formerly forested Bamenda Highlands, which have lost c. 95% of their original forest cover above 1,500 m (Cheek et al., 2000). Other remaining submontane forest patches in this area include the forests of Dom and Bali Ngemba, both also proposed as IPAs but both much smaller in size. The previously important forest at Bafut Ngemba has been all but obliterated, with 99% of the canopy estimated to have been lost or replaced by Eucalyptus; a similar fate is suspected at Kejodsam (Cheek et al., 2000).
The summit area of Mt Oku also features the highest known sphagnum bog in West Africa at 2,900 m, surveyed in 1997 (Maisels et al., 2000), as well as other rare natural habitat types (Cheek et al., 2000).
Around 50 globally threatened species are listed here, with nearly half estimated to have 10% or more of their global population at the site, an indication of the rarity of this habitat. Seven taxa are noted as narrowly endemic, including Alchemilla fischeri subsp. camerunensis (CR), which occurs only at the summit of Mt Oku itself, creating a silver carpet visible on satellite imagery. It is threatened by grazing and fire (Cheek et al., 2000). Other notable taxa include the two separate subspecies of Bafutia tenuicaulis, a genus confined to the Bamenda highlands area and named after Bafut Ngemba reserve where it is likely extinct; subsp. zapfackii is considered endemic to the Oku IPA. Newtonia camerunensis (CR) was feared extinct until rediscovered here and at one other site. Prunus africana has been heavily impacted by collection but Oku remains an important site.
The Oku-Ijim area is the sole location for Scleria cheekii (VU), although not all the records are quite within the IPA boundary (Bauters et al., 2019; Larridon et al., 2019). The same is true for Ledermanniella keayi (CR) (Diop, 2010). The site is one of only two locations where the medicinally important Ternstroemia cameroonensis (CR) has been recorded, although the collecting location was deforested and it has not been rediscovered at the site (Cheek et al., 2004). Angraecopsis lisowskii (EN) is only otherwise recorded from a few collections near Bamenda (Simo et al., 2018). Crotalaria bamendae is worthy of mention as it appears rare despite having a large range of occurrence extending to Angola and an IUCN status of Least Concern (Cheek, 2015); if threatened at Oku then it might qualify as threatened. Saxicolella ijim (provisionally CR) is known only from a waterfall close to the edge of the TIPA site at 1300 m. Saxicolella marginalis (CR) is also recorded nearby but not within the IPA boundaries. Polystachya anthoceros (EN) is known from Bali Ngemba and Baba II forests and from Oku village where it was collected from a coffee plantation, epiphytic on a coffee plant. This location is outside the IPA proposed here. A second location in the area of Oku-Ijim is also indicated by Simo-Droissart et al. (2020) but the specimen was not located and also appears to be outside the boundary. Schefflera hierniana (VU) is recorded along the route from Belo to Oku (Keay & Lightbody, 28519) but it is unclear if it occurs within the IPA.
A further eight undescribed species are thought likely to be threatened (Cheek et al., 2000), including apparently endemic Xyris and Gladiolus species, and an Oncoba sp. which has now also been collected at Bali Ngemba and which, it is is feared, may be extinct at the Oku site.

Habitat and geology

The Mount Oku massif is a Tertiary era stratovolcano complex, approximately 100 km in diameter, consisting of mainly trachyte and basalt lava overlying granite and migmatite basement rocks (Wooley, 2001). It consists of four individual stratovolcanoes, Mt Oku itself, the highest, reaching over 3,000 m, Mount Nkambe to the northeast, Mount Babanki to the southwest and Mt Nyos, with it's CO2 emitting lake, to the northwest (Brunt, 2000; Konfor et al, 2007; Djukem et al., 2020). Mount Oku itself shows three periods of volcanic activity: a lower series of trachyte and rhyolite plugs and flows from 24-22 Ma, a middle series from 18-14 Ma of basalt, trachyte and rhyolite lavas intercalated by pyroclastic flows; and an upper series of recent <1 Ma basalt, pyroclasts, scoria and other airfall material leaving volcanic craters and cones prominent in the remaining landscape (Konfor et al., 2007). There is no evidence of volcanic activity between 1 and 14 Ma. The Lake Oku crater originates from the recent series, the eruption leaving basalt lavas on the north flanks and rhyolitic and phonolitic flows to the south (Wooley, 2001). The peaks of Mount Oku, which can be steep and bare of vegetation, are mostly formed of middle series trachyte plugs (Konfor et al, 2007), while mafic rocks are generally hidden by deep lateritic soils and forest but may in places form "inhospitable cliffs" (Konfor et al., 2007).
Brunt (2000) describes the soils as humic ferralitic clay (mainly Gibbsite) with high organic content but low in nutrients due to intensive weathering. Soils are liable to become particularly infertile when the organic content is exhausted. Structurally, they are grainy in the upper layers, free draining and non-plastic when wet (Brunt, 2000). However, according to Djukem et al. (2020), the basalt and trachyte derived clay soils are highly plastic and very susceptible when wet to landslides.
The Bamenda Highlands have a two-season climate with a rainy season from April-May to September-November and a dry season in between (McLeod 1987; Djukem et al., 2020). The montane landscape superimposes further climatic variation on this general pattern, leading Hawkins and Brunt (1965) to distinguish nine climatic zones for the Northwest Region, of which three are relevant to Mount Oku. The major part of the site fits the "Cool and Misty" climate type (zone 7), with rainfall between 1780-2290 mm falling mainly between July and September. A rain shadow effect gives the eastern side lower precipitation, with c.2000 mm at Jakiri (McLeod, 1987) and 2,260 mm at Bamenda (World Meterological Organization, 2021) despite 400 m lower altitude at the latter. Forboseh et al. (2003) cite annual averages of 2,427 mm at Kilum on the north side and 2,242 mm at Ijim to the south. Mean maximum and minimum temperatures are 20-22° C and 13-14° C respectively, with November the coldest month and some ground frost occurring in narrow valleys at night. Humidity averages over 80% in July and August with frequent mist cover. At the summit (zone 8, "Cold, Very Cloudy and Misty"), mist is very common and solar insolation reduced, rainfall is estimated at about 3050 mm and mean temperatures may drop as low as 9 degrees in some months. Climate zone 9 ("variable") may also be applicable to escarpments where strong winds occur.
The site features mainly montane and upper montane forest. The upper montane forest is characterised by 10 species which contribute 90% of the canopy and are also found at other high altitude sites along the Cameroon Volcanic Line: Astropanax abyssinica, A. mannii, Prunus africana, Myrsine melanophloeos, Bersama abyssinica, Syzygium staudtii, Ixora foliosa, Carapa oreophila, Clausena anisata and the bamboo Oldeania alpina (Cheek et al., 2000; Cheek et al., 2021). Podocarpus latifolius is rare and localised and Ficus is absent (Cheek et al., 2000). The understory is rich in herbs, with Acanthaceae prominent, and an interesting mass-flowering phenomenon noted by Cheek et al. (2000). Several other important habitats are also found: Afroalpine, rock ridge and summit grassland (including Alchemilla fischeri subsp. camerunensis); Hyparrhenia grassland which appears to replace montane forest after clearance; upper-montane Sporobolus africanus dominated grassland (which appears to replace burnt and trampled Hyparrhenia grassland); an unusual "basalt pavement grassland" (with Loudetia simplex and Scleria cheekii, annual herbs (including Utricularia spp.) and perrennial geophytes; drier woodland and forest edge with fire resistant shrubs and herbs (including Erica spp., Lasiosiphon glaucus, Dombeya ledermannii, Adenocarpus mannii and Maesa lanceolata); swamp and riverine habitats including sphagnum communities, waterfalls and rapids, and Lake Oku itself.

Conservation issues

Between 1963 and 1986 the forest at Kilum Ijim was estimated to have been reduced by 50% due to conversion for farmland (Macleod, 1987; Maisels & Forboseh, 1999). This sparked involvement by Birdlife International (then ICBP) and, in collaboration with MINEF, the creation of the Kilum and Ijim Forest Projects, which have operated together since 1995 (BirdLife International, 2003). The Projects aimed to prevent further forest loss and provide sustainable alternatives for local people (Maisels & Forboseh, 1999). In 2003 the project was transferred to MINEF and the local communities (Birdlife International, 2003). GIS analysis of the period has shown that the most intense forest loss occurred between 1984-1988, with forest limits being largely preserved from the onset of the Forest Projects, and net forest recovery recorded after 1995 (Baena et al., 2010). Without the change in deforestation trajectory associated with the initiation of the Forest Project it is estimated, based on rates of loss in 1987, that the forest would have completely disappeared by 1998 (Baena et al., 2010). However, threats remain and more recent reports suggest the forest continues to deteriorate due to grazing, burning, edge effects, fuelwood cutting, bark harvesting and building (Forboseh et al., 2003; Doherty-Bone & Gvoždík, 2017; Maisels et al, 2001; Stewart, 2009). Improvements to roads through the forest are likely to further increase pressure on the habitat (Doherty-Bone & Gvoždík, 2017). Grazing is a particular threat; it is not not thought to be a traditional practice (Cheek et al., 2000), and was halted within the forest after the onset of the forest project but has subsequently resumed (Maisels et al., 2001). The extinction of natural seed dispersers (megafauna and birds) is an additional concern to the long-term survival of the plantlife (Maisels et al., 2001). The forest is also used fairly intensively for non-timber forest products. Harvesting of Prunus africana bark constitutes a major threat to one of the key montane forest species at the site (Stewart, 2009) but efforts have been made to promote cultivation and sustainable management of P. africana amongst local communities (Stewart, 2009).
A small part of the site around the lake (10 km2) has been designated a national Plantlife Sanctuary (IUCN category IV). The rest of the site has no formal protection but is managed by local communities in collaboration with MINEF.

Ecosystem services

The site is an IBA and the main site for two bird species endemic to the Bamenda Highlands, Tauraco Bannermani and Platysteira laticincta (both EN). It is also important for amphibians, with 50 species recorded from the Oku Massif and five (or possibly six) endemic to Mount Oku (Doherty-Bone & Gvoždík, 2017). These taxa have helped justify the site becoming part of the Alliance for Zero Extinction network (Key Biodiversity Areas Partnership, 2020). Five small mammals are also apparently globally endemic, Chrysochloris balsaci, Lemniscomys mittendorfi (EN), Hylomyscus grandis, Lophuromys dieterleni and Lamottemys okuensis (EN), the latter a unique genus which is apparently threatened by hunting and sold in tins as "Oku sardines" (Ingram, 2011; Birdlife International, 2021).
The preservation of the montane forest is important to mitigating the risk of landslides, erosion and silting of freshwater supplies, especially given the high population density of the surrounding area with 300,000 people estimated to live within a day's walk (Maisels et al, 2000; Djukem et al., 2020). Overall, 200,000 people have been estimated to depend on the forest for food, water, fuel and tourist income (Forboseh et al., 2003). Prunus africana bark is harvested for pharmaceutical purposes. The area is known for its extensive use of traditional medicines based on plants from the forest (Cheek et al., 2000). Beekeeping has successfully been encouraged as a sustainable source of income, while tourism is also important and has been embraced by local leaders (Doherty-Bone, 2015; Frits, 2017).

Site assessor(s)

Bruce Murphy, Royal Botanic Gardens, Kew

Martin Cheek, Royal Botanic Gardens Kew

Jean Michel Onana, University of Yaounde I, Faculty of Science, Department of Plant Biology; IRAD-Herbier National Camerounais

Kenneth Tah, COMAID (formerly ANCO)

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
Psychotria moseskemei Cheek A(i) True True True False False
Eugenia gilgii Engl. & Brehme A(i) True True True False False
Oxyanthus okuensis Cheek & Sonké A(i) True True True False False
Lefebvrea camerunensis (Jacq.-Fél.) Cheek & I.Darbysh. A(i) True True True False False
Polystachya superposita Rchb.f. A(i) True True True False False
Disperis nitida Summerh. A(i) True True True False False
Habenaria obovata Summerh. A(i) True True True False False
Millettia conraui A(i) True True True False False
Acanthopale decempedalis C.B.Clarke A(i) True True True False True
Scleria cheekii Bauters A(i) True True True True True Abundant
Prunus africana (Hook.f.) Kalkman A(i) True False True False True
Dissotis bamendae Brenan & Keay A(i) True False True False False
Anthocleista scandens Hook.f. A(i) True True True False False
Ixora foliosa Hiern A(i) True False True False False
Tapinanthus letouzeyi (Balle) Polhill & Wiens A(i) True True True False False
Begonia oxyanthera Warb. A(i) True False True False False
Crassocephalum bauchiense (Hutch.) Milne-Redh. A(i) False False True False False
Crotalaria ledermannii Bak.f. A(i) True True True False False
Phyllopentas ledermannii (K.Krause) Kårehed & B.Bremer A(i) True True True False False
Polystachya bicalcarata Kraenzl. A(i) True True True False False
Bidens mannii T.G.J.Rayner A(i) True False True False False
Isoglossa nervosa C.B.Clarke A(i) True True True False False
Ternstroemia cameroonensis Cheek A(i), A(iii) False False True False True Occasional
Wahlenbergia ramosissima (Hemsl.) Thulin subsp. ramosissima A(i) True True True False False
Kniphofia reflexa Hutch. ex Codd A(i) True True True False False
Dombeya ledermannii Engl. A(i) True False True False False
Stachys pseudohumifusa subsp. saxeri A(i) True True True False False
Coleus maculosus (Lam) A.J.Paton subsp. lanatus (J.K.Morton) A.J.Paton A(i) True True True False True
Newtonia camerunensis Villiers A(i) True True True False False
Diaphananthe bueae (Schltr.) Schltr. A(i) True False True False False
Genyorchis macrantha Summerh. A(i) True True True False False
Bafutia tenuicaulis C.D.Adams var. zapfackiana Beentje & B.J.Pollard A(iii) True True True True False
Crotalaria mentiens Polhill A(i) True True True False False
Orbivestus bamendae (C.D.Adams) Isawumi A(i) True True True False False
Alchemilla fischeri subsp. camerunensis Letouzey A(i) True True True True False
Dipsacus narcisseanus Lawalrée A(i) True True True False False
Indigofera patula Baker subsp. okuensis Schrire & Onana A(i) True True True True False
Habenaria maitlandii Summerh. A(i) True True True False False
Dovyalis cameroonensis Cheek & Ngolan A(i) True True True False False Scarce
Afroligusticum townsendii (Charpin & Fern.Casas) P.J.D.Winter A(i) True True True False False
Ledermanniella keayi (G.Taylor) C.Cusset A(iv) True True True False False
Brachystephanus giganteus Champl. A(i) True True True False True
Schefflera mannii (Hook.f.) Harms A(i) False False True False False
Epistemma decurrens H.Huber A(i) True True True False False
Pentarrhinum ledermannii (Schlechter) Goyder & Liede A(i) False True True False False
Deinbollia onanae Cheek A(i) True True True False True
Angraecopsis lisowskii Szlach. & Olszewski A(i) True True True False False
Morella arborea (Hutch.) Cheek A(i) True True True False False
Rhabdotosperma densifolia (Hook.f.) Hartl A(i) True True True False False
Rhabdotosperma ledermannii (Murb.) Hartl A(i) True True True False False
Scleria afroreflexa Lye A(i) True True True False False
Eragrostis camerunensis W.D.Clayton A(i) True True True False False
Pavetta hookeriana Hiern var. hookeriana A(i) True True True False False
Ledermanniella musciformis (G.Taylor) C.Cusset A(iv) True True True False False

Psychotria moseskemei Cheek

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:

Eugenia gilgii Engl. & Brehme

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:

Oxyanthus okuensis Cheek & Sonké

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:

Lefebvrea camerunensis (Jacq.-Fél.) Cheek & I.Darbysh.

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:

Polystachya superposita Rchb.f.

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:

Disperis nitida Summerh.

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:

Habenaria obovata Summerh.

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:

Millettia conraui

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:

Acanthopale decempedalis 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:

Scleria cheekii Bauters

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:
True
Socio-economically important:
True
Abundance at site:
Abundant

Prunus africana (Hook.f.) Kalkman

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:
True
Abundance at site:

Dissotis bamendae Brenan & Keay

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:

Anthocleista scandens Hook.f.

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:

Ixora foliosa Hiern

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:

Tapinanthus letouzeyi (Balle) Polhill & Wiens

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:

Begonia oxyanthera Warb.

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:

Crassocephalum bauchiense (Hutch.) Milne-Redh.

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:

Crotalaria ledermannii Bak.f.

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:

Phyllopentas ledermannii (K.Krause) Kårehed & B.Bremer

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:

Polystachya bicalcarata Kraenzl.

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:

Bidens mannii T.G.J.Rayner

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:

Isoglossa nervosa 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:
False
Abundance at site:

Ternstroemia cameroonensis Cheek

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

Wahlenbergia ramosissima (Hemsl.) Thulin subsp. ramosissima

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:

Kniphofia reflexa Hutch. ex Codd

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:

Dombeya ledermannii Engl.

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:

Stachys pseudohumifusa subsp. saxeri

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:

Coleus maculosus (Lam) A.J.Paton subsp. lanatus (J.K.Morton) A.J.Paton

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:

Newtonia camerunensis Villiers

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:

Diaphananthe bueae (Schltr.) Schltr.

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:

Genyorchis macrantha Summerh.

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:

Bafutia tenuicaulis C.D.Adams var. zapfackiana Beentje & B.J.Pollard

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

Crotalaria mentiens Polhill

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:

Orbivestus bamendae (C.D.Adams) Isawumi

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:

Alchemilla fischeri subsp. camerunensis Letouzey

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:
True
Socio-economically important:
False
Abundance at site:

Dipsacus narcisseanus Lawalrée

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:

Indigofera patula Baker subsp. okuensis Schrire & Onana

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:
True
Socio-economically important:
False
Abundance at site:

Habenaria maitlandii Summerh.

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:

Dovyalis cameroonensis Cheek & Ngolan

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:
Scarce

Afroligusticum townsendii (Charpin & Fern.Casas) P.J.D.Winter

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:

Ledermanniella keayi (G.Taylor) C.Cusset

Qualifying sub-criterion:
A(iv)
≥ 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:

Brachystephanus giganteus Champl.

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:

Schefflera mannii (Hook.f.) Harms

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:

Epistemma decurrens H.Huber

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:

Pentarrhinum ledermannii (Schlechter) Goyder & Liede

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

Deinbollia onanae Cheek

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:

Angraecopsis lisowskii Szlach. & Olszewski

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:

Morella arborea (Hutch.) Cheek

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:

Rhabdotosperma densifolia (Hook.f.) Hartl

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:

Rhabdotosperma ledermannii (Murb.) Hartl

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:

Scleria afroreflexa Lye

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:

Eragrostis camerunensis W.D.Clayton

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:

Pavetta hookeriana Hiern var. hookeriana

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:

Ledermanniella musciformis (G.Taylor) C.Cusset

Qualifying sub-criterion:
A(iv)
≥ 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:

General site habitats

General site habitat Percent coverage Importance
Forest - Subtropical/Tropical Moist Montane Forest 70 Major
Grassland - Subtropical/Tropical High Altitude Grassland 20 Major
Wetlands (inland) - Permanent Rivers, Streams, Creeks [includes waterfalls] No value Unknown
Wetlands (inland) - Permanent Freshwater Marshes/Pools [under 8 ha] No value Major

Forest - Subtropical/Tropical Moist Montane Forest

Percent coverage:
70
Importance:
Major

Grassland - Subtropical/Tropical High Altitude Grassland

Percent coverage:
20
Importance:
Major

Wetlands (inland) - Permanent Rivers, Streams, Creeks [includes waterfalls]

Percent coverage:
No value
Importance:
Unknown

Wetlands (inland) - Permanent Freshwater Marshes/Pools [under 8 ha]

Percent coverage:
No value
Importance:
Major

Land use types

Land use type Percent coverage Importance
Nature conservation 4 Major
Agriculture (arable) No value Minor
Agriculture (pastoral) 20 Major
Harvesting of wild resources No value Unknown

Nature conservation

Percent coverage:
4
Importance:
Major

Agriculture (arable)

Percent coverage:
No value
Importance:
Minor

Agriculture (pastoral)

Percent coverage:
20
Importance:
Major

Harvesting of wild resources

Percent coverage:
No value
Importance:
Unknown

Threats

Threat Severity Timing
Agriculture & aquaculture - Annual & perennial non-timber crops - Small-holder farming High Ongoing - trend unknown
Residential & commercial development - Tourism & recreation areas Medium Ongoing - trend unknown
Agriculture & aquaculture - Livestock farming & ranching - Small-holder grazing, ranching or farming High Ongoing - trend unknown
Natural system modifications - Fire & fire suppression - Increase in fire frequency/intensity High Ongoing - trend unknown
Biological resource use - Gathering terrestrial plants - Intentional use (species being assessed is the target) Medium Ongoing - trend unknown
Biological resource use - Logging & wood harvesting Medium Ongoing - trend unknown

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

Severity:
High
Timing:
Ongoing - trend unknown

Residential & commercial development - Tourism & recreation areas

Severity:
Medium
Timing:
Ongoing - trend unknown

Agriculture & aquaculture - Livestock farming & ranching - Small-holder grazing, ranching or farming

Severity:
High
Timing:
Ongoing - trend unknown

Natural system modifications - Fire & fire suppression - Increase in fire frequency/intensity

Severity:
High
Timing:
Ongoing - trend unknown

Biological resource use - Gathering terrestrial plants - Intentional use (species being assessed is the target)

Severity:
Medium
Timing:
Ongoing - trend unknown

Biological resource use - Logging & wood harvesting

Severity:
Medium
Timing:
Ongoing - trend unknown

Protected areas

Protected area name Protected area type Relationship with IPA Areal overlap
Kilum Ijim, Mont Oku IV: Floral Sanctuary IPA encompasses protected/conservation area 10

Kilum Ijim, Mont Oku

Protected area type:
IV: Floral Sanctuary
Relationship with IPA:
IPA encompasses protected/conservation area
Areal overlap:
10

Conservation designation

Designation name Protected area Relationship with IPA Areal overlap
Mount Oku Alliance for Zero Extinction Site IPA encompasses protected/conservation area 167
Mount Oku Important Bird Area IPA encompasses protected/conservation area 200

Mount Oku

Protected area:
Alliance for Zero Extinction Site
Relationship with IPA:
IPA encompasses protected/conservation area
Areal overlap:
167

Mount Oku

Protected area:
Important Bird Area
Relationship with IPA:
IPA encompasses protected/conservation area
Areal overlap:
200

Management type

Management type Description Year started Year finished
Site management plan in place Kilum and Ijim Forest Project managed by local communities with MINEF. No value No value

Site management plan in place

Kilum and Ijim Forest Project managed by local communities with MINEF.
Year started:
No value
Year finished:
No value

Bibliography

Cheek, M., Onana, J.-M. & Pollard, B.J., 2000

The Plants of Mount Oku and the Ijim Ridge, Cameroon, A Conservation Checklist.

Cheek, M., Tchiengue, B., Tacham, W.N., 2017

Ternstroemia cameroonensis (Ternstroemiaceae), a new medicinally important species of montane tree, nearly extinct in the Highlands of Cameroon

Blumea, Vol 62(1), page(s) 53-57

White, A.F., 1983

The vegetation of Africa. A descriptive memoir to accompany the UNESCO/AETFAT/UNSO vegetation map of Africa

Hawkins, P. & Brunt, M., 1965

The soil and ecology of west Cameroon. Vol. 1, Part 2

Maisels, F., Cheek, M. & Wild, C., 2000

Rare plants on Mount Oku summit, Cameroon

Oryx, Vol 34(2), page(s) 136 - 140

Macleod, H., 1987

Conservation of Oku Mountain Forest, Cameroon. ICBP Report no. 15

Maisels, F., Thomas, D & Forboseh, P., 1998

Conservation of crater lakes and island bogs in Cameroon- scale effects of site assessment, priority setting, monitoring and management

Conference: 2nd International Conference, on Wetlands and DevelopmentAt: Dakar, Senegal

Maisels, F. & Forboseh, P., 1999

The Kilum/ Ijim Forest Project: Biodiversity monitoring in the montane forests of Cameroon.

Bull. African Bird Club, Vol 6(2), page(s) 110-114

BirdLife International, 2003

Mid-term review of the community based conservation in the Bamenda Highlands Project

Available online

Maisels, F., Keming, E, Kemei, M. & Toh, C., 2001

The extirpation of large mammals and implications for montane forest conservation: the case of the Kilum-ljim Forest, North-west Province, Cameroon

Oryx, Vol 35(4)

Stewart, K., 2009

Effects of bark harvest and other human activity on populations of the African cherry (Prunus africana) on Mount Oku, Cameroon

Forest Ecology and Management, Vol 258(7), page(s) 1121-1128

Djukem, W., Braun, A., Wouatong, A., Guedjeo, C., Dohmen, K., Wotchoko, P., Fernandez-Steeger, T., & Havenith, H-B., 2020

Effect of Soil Geomechanical Properties and Geo-Environmental Factors on Landslide Predisposition at Mount Oku, Cameroon

International Journal of Environmental Research and Public Health, Vol 17(8), page(s) 6795

Konfora, N., Temdjima, R., Richard, C., Ghogomub, N., Tchuitchoub, R. & Ajoninac, H., 2006

Geochemistry of tertiary-quaternary lavas of Mt. Oku Northwest Cameroon

Revista Facultad De Ingeniería Universidad De Antioquia, Vol (40), page(s) 59-75 Available online

Forboseh, P., Keming, E., Toh, C. & Wultof, I., 2003

Monitoring of Kilum-Ijim forest bird communities: initial findings

Bird Conservation International, Vol 13, page(s) pp 255271

Ingrim, V., 2011

Non-timber forest products from the cloud forests of the Cameroon Highlands

Baena, S., Moat, J., Forboseh, P., 2010

Monitoring vegetation cover changes in Mount Oku and the Ijim Ridge (Cameroon) using satellite and aerial sensor detection

Systematics and Conservation of African Plants (pub. Royal Botanic Gardens, Kew), page(s) 459-470

Fritts, R., 2017

Nearly half of Mount Oku frogs are in danger of croaking, study finds

Available online

Doherty-Bone, T. (Ed), 2015

A Working Conservation Action Plan for the Mount Oku Summit. Conservation Action Plan Workshop October 2013, Oku Fon’s Palace, Elak-Oku, North West Region, Cameroon.

Key Biodiversity Areas Partnership, 2020

Key Biodiversity Areas factsheet: Mount Oku. Extracted from the World Database of Key Biodiversity Areas. Developed by the Key Biodiversity Areas Partnership: BirdLife International, IUCN, American Bird Conservancy, Amphibian Survival Alliance, et al.

Available online

BirdLife International, 2021

Important Bird Areas factsheet: Mount Oku

Available online

Brunt, M., 2000

Geology and Soils

The Plants of Mount Oku and the Ijim Ridge, Cameroon: a conservation checklist (pub. Royal Botanic Gardens, Kew), page(s) 8-9

Larridon, I., Bauters, K. & Cheek, M., 2019

Scleria cheekii. The IUCN Red List of Threatened Species 2019: e.T123733546A123733850

Available online

Bauters,K., Goetghebeur, P. & Larridon, I., 2018

Scleria cheekii, a new species of Scleria subgenus Hypoporum (Cyperaceae, Cyperoideae, Sclerieae) from Cameroon

Kew Bulletin, Vol 73(27)

Diop, F.N., 2010

Ledermanniella keayi. The IUCN Red List of Threatened Species 2010: e.T39741A10261684

Available online

Simo, M., Stévart, T., Pollard, B.J. & Droissart, V., 2018

Angraecopsis lisowskii. The IUCN Red List of Threatened Species 2018: e.T87583579A87739852

Available online

Recommended citation

Bruce Murphy, Martin Cheek, Jean Michel Onana, Kenneth Tah (2024) Tropical Important Plant Areas Explorer: Mount Oku and the Kilum-Ijim forests (Cameroon). https://tipas.kew.org/site/mount-oku-and-the-kilum-ijim-forests/ (Accessed on 27/05/2024)