Mount Kupe Research Articles

A new coffee species from South-West Cameroon, the principal hotspot of diversity for Coffea L. (Coffeeae, Ixoroideae, Rubiaceae) in Africa

Coffea rizetiana Stoff. & M.Noirot, sp. nov., a diploid species only known from a single wild population in South-West Cameroon, is formally described here. It is probably extinct in the wild, but is present in the germplasm collection in Bassin Martin (Réunion, France) and Meise Botanic Garden (Belgium). Phylogenetic analyses reveal a close relationship with C. montekupensis Stoff., a species endemic to the same region but occurring at higher elevations, and with C. liberica Bull. ex Hiern, a species with a wide Central and West African distribution. The new species can be distinguished from other Coffea species from Central Africa by its large black fleshy fruits with thick mesocarp. It can be differentiated from its close relative C. montekupensis by its larger less obovate leaves, longer corolla tube and larger fruits; and from C. liberica by its shorter petiole, acuminate leaf tip, cuneate leaf base, thinner leaf blade, shorter corolla tube, longer corolla lobes and black fruits with a thick fleshy pericarp. The evolutionary importance of the fruit colour is discussed, as well as the role of Mount Kupe, the Bakossi Mountains and the broader South-West Cameroon region as the principal Coffea diversity hotspot on the African continent.

Twenty-one new species of craneflies (Diptera: Tipulidae and Limoniidae), and a new fold-wing cranefly (Diptera: Ptychopteridae) from Mount Kupe, Cameroon, with notes on eighteen other species new to the country from the same location

Following the award of a Winston Churchill Memorial Trust (WCMT) Fellowship the author was able to visit the Charles P. Alexander (1889–1981) collection at the Smithsonian Institution, Washington D. C. to study craneflies gifted to him from fieldwork in Cameroon. They were collected by Malaise trap in forest clearings near streams on Mount Kupe, near Nyasoso, Cameroon. 21 new species of cranefly (Diptera: Tipulidae and Limoniidae): Dolichopeza (Dolichopeza) vicki sp. n., Nephrotoma mawdsleyi sp. n., Baeoura nyasosoensis sp. n.,Ellipteroides (Ellipteroides) nigromaculatus sp. n., Hovamyia gelhausi sp. n.,Limnophilomyia (Limnophilomyia) alexanderi sp. n., Ormosia (Neserioptera) cameroonensis sp. n., Afrolimnophila mederosi sp. n., A. oosterbroeki sp. n., Neolimnomyia kupensis sp. n., Pseudolimnophila (Pseudolimnophila) staryi sp. n., Achyrolimonia prycei sp. n., Dicranomyia (Dicranomyia) tuberculata sp. n., D. (Idioglochina) stubbsi sp. n., Elephantomyia (Elephantomyia) gilsonae sp. n., Libnotes (Afrolimonia) trimaculata sp. n., Metalimnobia (Tricholimnobia) krameri sp. n., Thaumastoptera (Thaumastoptera) churchilli sp. n., Toxorhina (Ceratocheilus) holvia sp. n., Trentepohlia (Trentepohlia) zorro sp. n., and Trichoneura (Xipholimnobia) jacksoni, and a new species of fold-wing cranefly (Diptera: Ptychopteridae): Ptychoptera (Ptychoptera) fasbenderi sp. n., are described. 18 species of cranefly known from elsewhere in the Afrotropical region are recorded here from Cameroon for the first time: Gonomyia (Leiponeura) hyperion Alexander, 1956, Limnophilomyia (Limnophilomyia) medleriana Alexander, 1976, Styringomyia vittata Edwards, 1914, Afrolimnophila hartwigi (Alexander, 1974), A. urundiana (Alexander, 1955), Austrolimnophila (Phragmocrypta) fulani Alexander, 1974, Hexatoma (Eriocera) brevifurca Alexander, 1956, H. (E.) trichoneura Alexander, 1956, H. (E.) tumidiscapa (Alexander, 1920), Medleromyia nigeriana Alexander, 1974, Achyrolimonia recurvans (Alexander, 1919), Atypopthalmus (Atypopthalmus) submendicus tuberculifer (Alexander, 1956), Dicranomyia (Dicranomyia) redundans (Alexander, 1956), Libnotes (Afrolimonia) rhanteria (Alexander, 1920), L. (A.) illiterata (Alexander, 1937), Limonia woosnami (Alexander, 1920), Orimarga (Protorimarga) bequaertiana (Alexander, 1930) and Toxorhina (Ceratocheilus) nigripleura (Alexander, 1920). In total 40 species are presented as new for Cameroon. A further 23 species already known from Cameroon were identified, and are listed here as some of them have not been recorded since their original description close to, or in some cases over, a hundred years ago.

Effects of Forest Clearance and Cultivation on Bulk Density Variations and Relationships with Texture and Organic Matter in Tephra Soils of Mount Kupe (Cameroon)

ABSTRACTTephra soils around mount Kupe harbor forests which have in the past 30 to 40 years been subject to degradation giving way to continuous cultivation which have the tendency to reduce the yield potentials of the soils. This study was conducted to evaluate the state of degradation following the long periods of cultivation to assist put in place more sustainable management practices. Soil samples from six profiles developed from pyroclastic materials (tephra) of Quaternary age, three from cultivated farms and three from adjacent virgin forests were studied to establish the relationships that exist between bulk density (BD) and organic carbon (OC) content and between BD and particle size. Variations of BD and OC within profiles are erratic. Soil texture is dominated by sand (64.8–81.9%), followed by clay (11.6–32.2%) and then silt (0.8–11.9%). The relationships between BD, OC, and texture indicated that BD correlates negatively with clay (r = −0.68, p < 0.01) and OC (r = −0.15, p < 0.01) contents but inversely with sand (r = 0.43, p < 0.05) and silt (r = 0.33, p < 0.05) contents. Relationships between these properties were better observed in virgin forests than in cultivated farmlands indicating that virgin forest systems are more stable (equilibrium is maintained since they do not incur anthropic perturbations). The high and significantly similar OM contents in both systems indicate that farming practices in the study area are sustainable and need to be maintained since they conserve OM. Results of this study will contribute to management of similar soils in tropical environments.

English

Soils of the western slopes of Kupe Mountain in Cameroon were characterized to understand their proper land use and sustainable management. Evaluation of land suitability for maize (Zea mays), beans (Phaseolus vulgaris) and Irish potatoes (Solanum tuberosum) were assessed, considering the socio-economic importance of these crops in Cameroon. Three sites, representative of the study area were identified following a toposequence; Nyassosso (900 m), Mbule (700 m) and Tombel (500 m) with soils, respectively, classified as: Hyperdystri – humic Leptosol (loami – andic), Skeleti – Umbric Andosol (colluvi – loamic) and Dystri – skeletic Andosol (Colluvi – loamic). Soil properties indicated that colour varies from black and brownish black at the surface to reddish brown in subsurface horizons with some horizons showing varied colours. The soils were friable and granular in structure, had low bulk density ranging from 0.38 to 1.08 g/cm3, and had a loamy texture. Chemically, pH(H2O) ranged from strongly acidic to slightly acidic (4.8 - 6.2), organic carbon ranged from low to very high (0.88 - 7.26%), electrical conductivity was very low (0.02 - 0.29 dS/m), cation exchange capacity ranged from medium to high (20.5 to 38.08 cmol(+)kg-1), total nitrogen from very low to very high (0.09 - 1.7%), available phosphorous from very low to low (7.13 - 19.76 ppm), Ca2+ from very low to high (2.08 - 10.64 cmol(+)kg-1), Mg2+ from very low to medium (0.08 to 2.56 cmol(+)kg-1), K+ from very low to medium (0.01 - 0.31 cmol(+)kg-1) and Na+ was very low (0.01 - 0.05 cmol(+)kg-1). Amorphous iron and aluminum ranged between 0.06 - 1.35 and 0.16 - 1.01%, respectively. Land suitability evaluation indicated that soils of Nyassosso were marginally suitable for rain-fed cultivation of Irish potatoes, beans and maize. Soils of Mbule were marginally suitable for rain-fed cultivation of Irish potatoes and maize but not suitable for beans, while soils of Tombel were marginally suitable for rain-fed cultivation of Irish potatoes and temporarily non suitable for rain-fed cultivation of maize and beans. Key words: Mount Kupe, soil properties, suitability classes, climatic index, land index.

Structure and Floristic Diversity of the Woody Vegetation of the Mount Kupe Submontane Forest (Moungo – Cameroon)

A b s t r a c t A r t i c l e I n f o This study aims to evaluate the vegetation structure and diversity of woody species in the sub mountain forest of Mount Koupe (Moungo-Cameroon) between 1 000 and 1 800 m and to appreciate the index values obtained with those of the tropic, Malagasy and Neotropical region of the world. The basic data have been obtained on inventory of 1-ha plot taking into account all trees whose diameter at breast height (dbh) ≥10 cm. The parameters of floristic diversity were calculated using the standard methodology. A total of 1184 individuals belonging to 156 species, 114 genera and 51 families were inventoried, with the total basal area of 151.44 m²/ha. Most individuals (trees) had between 10 and 20 m height with diameter between 50 and 80 cm, but relatively a significant number of individuals (05) reached even higher values, up to 30 m height and 135 cm of diameter. The five most important families in terms of density, diversity and dominance were Meliaceae, Euphorbiaceae, Rubiaceae, Malvaceae and Burseraceae. They represent 52.53 % of the Family Important Value (FIV). The specific composition revealed that 10 species dominate the submontane forest, 6.41 % of species represent 54.50 % of the Index of Value Importance (IVI). They are Carapa procera, Santiria trimera, Strombosia pustulata, Cola acuminata, Turraeanthus africana, Penianthus longifolius, Allanblackia gabonensis, Drypetes leonensis, Pycnanthus angolensis and Sorindeia grandifolia. A fraction of species (70) then 44.87 % is represented by one individual. In conclusion, the Kupe submontane forest is marked down substantially to the lowland forest. The family of Leguminosae which dominate in these levels does not occur among the 10 important families in FIV; they come in the 14 th position. The Rubiaceae occupies 1 st position in in relative diversity and 2 nd position in FIV mark in this altitudinal stretch.

Seasonality of non-timber forest products in the Kupe mountain region of South Cameroon

Non-timber forest products (NTFPs) are economically-important commodities, especially in the humid and semi-humid regions of many sub-Saharan countries. However, in many of these countries, there is little information on the seasonality characterising their availability and collection, rendering difficult the development of meaningful packages for their sustainable use and valorisation. A study was therefore conducted in randomly selected villages in three zones around the sub-montane forests of Mount Kupe in South West Cameroon, in order to evaluate the effects of seasons on the collection and availability of these products. Data were collected through administration of semi-structured questionnaires and a rapid rural appraisal. Most NTFPs (85%) showed seasonality to different extents, in availability and abundance. Although, considerable differences were observed in the proportion of respondents who collected NTFPs during the dry and rainy seasons, no such difference could be attributed to the climatic or geographical zones. Half of the respondents collected NTFPs during the rainy season when there was relatively less work in their farms. About one-sixth (15.2%) collected NTFPs during the dry season (peak agricultural period) and a third (35%) collected some NTFPs all year round. Key words: Cameroon, humid forest, non-timber, seasonality, collection.

Conservation of Drill Populations in Bakossiland, Cameroon: Historical Trends and Current Status

Very little information is available on the current status of drill populations in Cameroon. We report on drill group sizes and status in Bakossiland, a mountainous area spanning 2000 km2 in the Littoral and South West Provinces of southwestern Cameroon. Between 1970 and 2002 direct visual counts of drill groups (n = 105) yielded group size estimates ranging from 5 to 400 (mean ± S.E.M.; 93.1 ± 8.4). We encountered solitary adult male drills on 8 occasions. Groups were at all elevations (150–2000 m) in 5 habitat types: lowland, premontane, submontane and montane forests and montane savannah at 2000 m). Group sizes did not vary with respect to elevation, habitat type or season (wet and dry mo). However, over the past decade drills have been virtually hunted out of the Mwenzekong Mountains (Banyang Mbo Wildlife Sanctuary), and they are greatly reduced in the southern Bakossi forests of Mwendolengo, Edib Hills and Mungo River. The species became extinct in the Loum Forest Reserve in the late 1970s, and until recently was thought to have become extinct on Mount Mwanenguba. Since 1994 on Mount Kupe, the drill population has begun to recover, largely due to protection afforded by the Bakossi traditional chiefs. Traditional powers and values are still influential in the region. A new national park—Bakossi Mountains National Park— and associated Protected Areas are currently under gazettment. We discuss the effectiveness of conservation strategies in relation to the survival of drills in the area.

Null model analysis of communities on gradients

AbstractAim I employed a novel null model and metric to uncover unusual species co‐occurrence patterns in a herpetofaunal assemblage of 49 species collected at discrete elevations along a gradient.Location Mount Kupe, Cameroon.Methods Using a construction algorithm that started from a matrix of 0s, a sample null space of 25,000 unique null matrices was generated by simultaneously conserving (1) the number of occurrences of each species, (2) site richness and (3) species range spans derived from the observed incidence matrix. I then compared the number of times each pair of confamilial species co‐occurred in the null space with the same number derived from the observed incidence matrix. Two cases dealing with embedded absences in species ranges were tested: (1) embedded absences were maintained, and (2) embedded absences were assumed to be sampling omissions and were replaced by presences.Results In the observed absence/presence assemblage there were 147 possible confamilial species pairs. Therefore, 5% or eight were expected by chance alone to have co‐occurrence patterns that differed from chance expectations by chance alone. Of these confamilial species pairs, 38 were congeneric and so 5% or two were expected to differ from chance expectations. For case (1) 16, and for case (2) 17 confamilial species pairs’ co‐occurrence patterns differed significantly from chance expectations. For case (1) nine congeneric species pairs, and for case (2) 10 congeneric pairs differed significantly from chance expectations. For case (1) four, and for case (2) five congeneric species pairs formed checkerboards (patterns of mutual exclusion). Results from case (1) were a proper subset of case (2) indicating that sampling omissions did not alter greatly the results.Main conclusions I have demonstrated that null models are valuable tools to analyse ecological communities provided that proper models are employed. The choice of the appropriate null space to analyse distributions is critical. The null model employed to analyse birds on islands of an archipelago can be adapted to analyse species along gradients provided an additional range constraint is added to the null model. Moreover, added precision to results can be obtained by analysing each species pair separately, particularly those in the same family or genus, as opposed to applying a community‐wide metric to the faunal assemblage. My results support some of the speculations of previous authors who were unable to demonstrate their suspicions analytically.

Bulbophyllum kupense P. J. Cribb &amp; B. J. Pollard, an Unusual New Orchid from Western Cameroon

Botanical inventories in western Cameroon (SW and NW provinces) have led to the publication of two comprehensive checklists (Cable & Cheek 1998; Cheek et al. 2000). In February 2003, during preparation of "The Plants of Mount Kupe and the Bakossi Mountains", the third in this series, the authors recognised a previously undescribed species of Bulbophyllum Thouars, described in this paper. Other new orchids from this area have been described recently (Cribb 1996; Cribb & Pollard 2002).

Ecology of Three Sympatric Species of the Genus Chamaeleo in a Tropical Upland Forest in Cameroon

The three species of chameleons inhabiting the primary forest on the western slope of Mount Kupe, Cameroon, Chamaeleo montium, Chamaeleo pfefferi, and Chamaeleo quadricornis, are compared with respect to elevational distribution, diet, and body size. Chameleo montium is restricted to lower elevations and markedly separated in elevational distribution from its congeners, which are exclusively found in the submontane forest. The three species prey almost entirely on arthropods, mostly coleopterans, heteropterans, hymenopterans, dipterans, and spiders; niche breadth values that incorpate prey availability are high and suggest opportunistic feeding. Niche overlaps are high with respect to prey type, but the smallest species, C. pfefferi, differs significantly from its congeners in terms of prey volume. Body size difference is largest between the two syntopic species, C. pfefferi and C. quadricornis, and identically low to the allotopic C. montium. The results on dietary segregation and morphological similarity are in accordance with competition limiting elevational distributions of the chameleons on Mount Kupe.

Herpetofaunal Diversity and Abundance in Tropical Upland Forests of Cameroon and Panama1

Abstract Two tropical upland forests, Mount Kupe in Cameroon and Bosque Protector Palo Seco in Panama, were compared in terms of herpetofaunal species richness and density of individuals. Based on rarefaction, whereby samples are standardized for abundance, Palo Seco had significantly more species of frogs and lizards. Extrapolations to total local species richness, by fitting the Michaelis–Menten equation to the species accumulation curves and by using Chao's estimator, yielded divergent results: more lizard species on Mount Kupe, and an equal number of frogs at both sites. These disparities can be accounted for by differences in evenness, which was higher in Palo Seco. Frog density was significantly higher on Mount Kupe, snake density significantly higher in Palo Seco, and lizards exhibited no density difference. Overall, the results revealed a less consistent pattern and more moderate differences than what is known from southeast Asian–Central American comparisons. This outcome is discussed in the ligh...

Ecotones and gradient as determinants of herpetofaunal community structure in the primary forest of Mount Kupe, Cameroon

The relative effects of the elevational gradient and of environmental discontinuities (ecotones) on the structure of a herpetofaunal assemblage in a tropical upland forest were contrasted by means of canonical correspondence analysis. Qualitative descriptors were used to define the elevational positions of the ecotones of interest, namely transitions in forest type and presence/absence of water bodies. The elevational gradient was coded in a form that accommodated different types of community response. Analyses were run for four subsets of the entire assemblage: (1) reptiles, (2) amphibians, (3) amphibians dependent on streams for reproduction, and (4) amphibians that do not use streams for reproduction. All subsets showed a significant relationship with the gradient, which suggested that most species respond to the physical continuum associated with the change in elevation. A response to ecotones was revealed for the amphibian subset only and associated with the presence or absence of watercourses. However, this response disappeared within subsets 3 and 4. A variation partitioning analysis was used to assess the individual and common contributions of gradient and ecotone descriptors to the elevational variation in the structure of subsets 1 and 2. The gradient descriptors explained more variation in the reptile subset than did ecotones, while the reverse was found in the amphibian subset. The dependence of most amphibians on aquatic breeding sites that were not available at all elevations reduced the relative importance of the gradient on the species distributions in subset 2 and accounted for the difference to the reptiles. In all, these findings add to the results of previous null model tests on the same four subsets, where competitive interactions were assigned a minor importance in limiting elevational distributions. The response patterns revealed by the present approach, with ecotones and gradient contrasted in a single analysis, emphasised the role of individual responses to the gradient according to the species' physiological tolerance limits.

SPATIAL ORGANIZATION OF A HERPETOFAUNA ON AN ELEVATIONAL GRADIENT REVEALED BY NULL MODEL TESTS

Five null model tests were applied to the herpetofaunal assemblage on the western slope of Mount Kupe, Cameroon. Based on the pattern of species range boundaries and abundances along the primary forest elevational gradient, ranging from 900 to 2000 m, the relative importance of interspecific competition and ecotones in structuring the assemblage was assessed. Tests were run for (1) all species, (2) amphibians, (3) reptiles, (4) amphibians dependent on streams for reproduction, and (5) amphibians that do not use streams for reproduction. For three null models, the observed patterns did not differ from random expectations. The results indicated that there are very few species whose gradient distributions may be limited by interspecific competition between congeners. Significant discontinuities in abun- dance patterns and range boundary dispersion revealed zonations in all subsets analyzed but neither indicated distinct species groups with sharp exclusion boundaries nor a strong response to vegetational ecotones. Physical factors varying in parallel with the gradient and specific habitat components, particularly water bodies suitable as amphibian breeding sites, are suggested to be the dominant factors limiting gradient distributions of amphibians and reptiles on Mount Kupe. The zonations revealed suggest a pattern of three spatially nonexclusive species groups: physical factors separate distinct lowland and montane species limited by physiological constraints and produce faunal discontinuities in the lower sub- montane forest around 1300 m; this boundary is encompassed by the range of a group of anuran species, whose distributions on the gradient are centered at intermediate elevation and appear to be limited by specific habitat requirements. The response to predominantly abiotic factors suggests a basic difference from endotherms, where biotic factors seem to be of major importance in limiting elevational distributions.

Spatial Organization of a Herpetofauna on an Elevational Gradient Revealed by Null Model Tests

Five null model tests were applied to the herpetofaunal assemblage on the western slope of Mount Kupe, Cameroon. Based on the pattern of species range boundaries and abundances along the primary forest elevational gradient, ranging from 900 to 2000 m, the relative importance of interspecific competition and ecotones in structuring the assemblage was assessed. Tests were run for (1) all species, (2) amphibians, (3) reptiles, (4) amphibians dependent on streams for reproduction, and (5) amphibians that do not use streams for reproduction. For three null models, the observed patterns did not differ from random expectations. The results indicated that there are very few species whose gradient distributions may be limited by interspecific competition between congeners. Significant discontinuities in abundance patterns and range boundary dispersion revealed zonations in all subsets analyzed but neither indicated distinct species groups with sharp exclusion boundaries nor a strong response to vegetational ecotones. Physical factors varying in parallel with the gradient and specific habitat components, particularly water bodies suitable as amphibian breeding sites, are suggested to be the dominant factors limiting gradient distributions of amphibians and reptiles on Mount Kupe. The zonations revealed suggest a pattern of three spatially nonexclusive species groups: physical factors separate distinct lowland and montane species limited by physiological constraints and produce faunal discontinuities in the lower submontane forest around 1300 m; this boundary is encompassed by the range of a group of anuran species, whose distributions on the gradient are centered at intermediate elevation and appear to be limited by specific habitat requirements. The response to predominantly abiotic factors suggests a basic difference from endotherms, where biotic factors seem to be of major importance in limiting elevational distributions.

A New Species of Coffea (Rubiaceae) and Notes on Mount Kupe (Cameroon)

Summary. A new Cameroonian species, Coffea montekupensis (Rubiaceae, Coffeeae) is described and morphological and ecological documentation supplied. C. montekupensis is endemic to the Bakossi Mountains and all but one of the known collections are from Mount Kupe. It resembles the more widely distributed C. brevipes Hiern which also occurs on Mount Kupe, although the two are not sympatric.