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The high mortality and low recruitment of the myrmecophytic Acacia drepanolobium are not consistent with the demographic rates of monodominant species. The positive conspecific density dependence observed from the spatial analysis is consistent with the defensive benefits conferred by symbiotic ants to trees when they grow close to each other. Patches of savanna dominated by Acacia drepanolobium occur throughout East Africa on nutrient-rich vertisols, also known as black cotton soils. We assessed the survival and recruitment for all freestanding trees with diameter at knee height (dkh) ≥ 10 mm in one of such mono-dominated patches (47 ha) at the Mpala Research Centre, Kenya, with the aim of identifying demographic traits that might explain the dominance of this species. Over a mean 6-year interval, mortality and recruitment rates in the habitat were 4.55%/year and 1.42%/year respectively, resulting in a net loss of 17.8% of the initial individuals. Of the 30 species recorded from the first census, 11 decreased in abundance, nine increased, and the remainder 10 did not change in abundance. The monodominant A. drepanolobium had a high mortality (4.69%/year), a low recruitment (1.31%/year), and a 19% population decline. There was no evidence of conspecific negative density dependence for this species. Rather, we found a statistically significant positive correlation between the number of conspecific neighbors and individual-level probability of survival, consistent with the “shared defense” benefits that symbiotic ant colonies occupying multiple trees can confer to these latter in a small neighborhood. Thus, mortality of A. drepanolobium was higher in areas where it occurred in lower densities, which resulted in an increase in the spatial aggregation of conspecifics. Mortality increased with dkh size classes and was mostly caused by elephants and stem-boring beetles. The demographic rates during the study period in theory are inconsistent with those of monodominant species. The protection against herbivory conferred by mutualistic ants associated with this species remains the most probable explanation of its dominance in this habitat.

Stand structure and tree species diversity patterns were examined plot-wide and among four topographically defined habitats (plateau, cliff, low plain and depressions) in a 120-ha permanent plot in an Acacia-dominated savanna in Mpala Ranch, central Kenya. The four habitats were defined by clustering the 3000 quadrats of 20 × 20 m in the plot based on their altitude, slope and convexity. Structural and floristic differences among the four habitats were examined and species-habitat associations were tested for the 30 most abundant species using torus translation randomization tests. The plot included 113 337 trees in 62 species with diameter at knee height ≥ 2 cm (18.4 species ha−1), 41 genera and 23 families. Fabaceae with the genus Acacia were the dominant family, followed by Euphorbiaceae and Ebenaceae. Tree density and basal area were twice as high on low plain and depressions than on the plateau. Species richness was highest in the cliff and was seven times higher than in the adjacent plateau. Half of the species assessed showed significant positive associations with one habitat and 21 showed significant negative associations with at least one habitat. The variation in stand structure and tree species diversity within the Mpala plot shows that topography is among the important drivers of local species distribution and hence the maintenance of tree diversity in savannas.

The Acacia drepanolobium (also known as Vachellia drepanolobium) ant‐plant symbiosis is considered a classic case of species coexistence, in which four species of tree‐defending ants compete for nesting space in a single host tree species. Coexistence in this system has been explained by trade‐offs in the ability of the ant associates to compete with each other for occupied trees versus the ability to colonize unoccupied trees. We seek to understand the proximal reasons for how and why the ant species vary in competitive or colonizing abilities, which are largely unknown. In this study, we use RADseq‐derived SNPs to identify relatedness of workers in colonies to test the hypothesis that competitively dominant ants reach large colony sizes due to polygyny, that is, the presence of multiple egg‐laying queens in a single colony. We find that variation in polygyny is not associated with competitive ability; in fact, the most dominant species, unexpectedly, showed little evidence of polygyny. We also use these markers to investigate variation in mating behavior among the ant species and find that different species vary in the number of males fathering the offspring of each colony. Finally, we show that the nature of polygyny varies between the two commonly polygynous species, Crematogaster mimosae and Tetraponera penzigi: in C. mimosae, queens in the same colony are often related, while this is not the case for T. penzigi. These results shed light on factors influencing the evolution of species coexistence in an ant‐plant mutualism, as well as demonstrating the effectiveness of RADseq‐derived SNPs for parentage analysis.

Rhaptopetalumrabiense Kenfack & Nguema, sp. nov. from the Rabi forest in south-western Gabon is described, illustrated and assigned a provisional conservation status of “Critically Endangered”. An identification key to the five Gabonese species of Rhaptopetalum is also provided.

Gautier, L., O. Lachenaud, X. Van der Burgt & D. Kenfack (2016). Five new species of Englerophytum K. Krause (Sapotaceae) from central Africa. Candollea 71 ≥ : 287–305. In English, English and French abstracts. Five new species of Englerophytum K. Krause (Sapotaceae) are described : Englerophytum paludosum L. Gaut., Burgt & O. Lachenaud, Englerophytum gigantifolium O. Lachenaud & L. Gaut., Englerophytum libenii O. Lachenaud & L. Gaut., Englerophytum sylverianum Kenfack & L. Gaut., and Englerophytum ferrugineum L. Gaut. & O. Lachenaud. All five species are illustrated with line drawings and three of them with field photos. Distribution maps are also provided, and a preliminary extinction risk assessment according to IUCN Categories and Criteria is carried out : Englerophytum paludosum is assessed as “Least Concern”, Englerophytum sylverianum as “Vulnerable”, Englerophytum libenii and Englerophytum ferrugineum as “Endangered”, and Englerophytum gigantifolium as “Critically Endangered”.

The African genus Crotonogynopsis Pax (Euphorbiaceae) is revised to include four species, including two novelties, C. korupensis Kenfack & D. W. Thomas from the Korup National Park, Cameroon, and the Reserva Natural de Rio Campo in Equatorial Guinea; and C. australis Kenfack & Gereau from the southern part of the Eastern Arc Mountains of Tanzania, with a distant outlier in Mozambique. Three of the four species are assigned the IUCN Red List category of Least Concern (LC) on the basis of their occurrence in protected areas with no known threats.

The Neotropics, Afrotropics and Madagascar have different histories which have influenced their respective patterns of diversity. Based on current knowledge of these histories, we developed the following predictions about the phylogenetic structure and composition of rainforest tree communities: (Hypothesis 1) isolation of Gondwanan biotas generated differences in phylogenetic composition among biogeographical regions; (H2) major Cenozoic extinction events led to lack of phylogenetic structure in Afrotropical and Malagasy communities; (H3) greater angiosperm diversification in the Neotropics led to greater phylogenetic clustering there than elsewhere; (H4) phylogenetic overdispersion is expected near the Andes due to the co-occurrence of magnoliids tracking conserved habitat preferences and recently diversified eudicot lineages. Using abundance data of tropical rainforest tree species from 94 communities in the Neotropics, Afrotropics and Madagascar, we computed net relatedness index (NRI) to assess local phylogenetic structure, i.e. phylogenetic clustering vs. overdispersion relative to regional species pools, and principal coordinates of phylogenetic structure (PCPS) to assess variation in phylogenetic composition across communities. We observed significant differences in phylogenetic composition among biogeographical regions (agreement with H1). Overall phylogenetic structure did not differ among biogeographical regions, but results indicated variation from Andes to Amazon. We found widespread phylogenetic randomness in most Afrotropical and all Malagasy communities (agreement with H2). Most of central Amazonian communities were phylogenetically random, although some communities presented phylogenetic clustering (partial agreement with H3). We observed phylogenetic overdispersion near the Andes (agreement with H4). We were able to identify how differences in lineage composition are related to local phylogenetic co-occurrences across biogeographical regions that have been undergoing different climatic and orographic histories during the past 100 Myr. We observed imprints of the history following Gondwana breakup on phylobetadiversity and local phylogenetic structure of rainforest tree communities in the Neotropics, Afrotropics and Madagascar. © 2016 The Authors

Ant-plant interactions mediated by special structures provided by plants such as domatia, extrafloral nectaries (EFNs) and food bodies, are very frequent in tropical ecosystems. To understand why ants are frequently encountered on most species of Carapa Aubl. (Meliaceae), we investigated the presence of extranuptial nectaries (ENNs) in all 27 species of the genus, spanning its entire distributional range in tropical Africa and America. We report for the first time in the genus the occurrence of extrafloral nectaries (at the base of the petiole, along the rachis of the pinnately compound leaf, on bracts) petaline nectaries (on the outer surface of petals), and pericarpial nectaries (on the surface of fruits), and confirm the presence of nectaries on leaflets in Carapa. Petiolar nectaries are the most common, occurring in 85% of the species. Nectaries were mainly active in young developing plant organs. Ants were observed foraging on exudates from these nectaries. The secretions from these glands help to explain the abundance of ants on Carapa trees. Although similar nectaries were also found in other members of the subfamily Cedreloideae, their position and frequency provide new characters for the identification of Carapa species in the field and the herbarium. As in other myrmecophilous plants, ENNs probably confer adaptive advantages to Carapa trees.

Morphometric analysis of Phyllobotryon Muell.Arg. in the Korup Forest Area of Cameroon recognizes three distinct morphospecies (1-3), which show significant variation in several leaf and fruit characters. In order to clarify the taxonomy of Phyllobotryon, we conducted univariate and multivariate analyses on sixteen quantitative and four qualitative characters scored from 111 fresh samples. Analysis of Variance revealed nine significant quantitative characters from which the first three Principal Components accounted for 74.6 % of the total variation. Results from Discriminant Analysis strongly support the existence of two groups (96.2 % and 100 %) representing Morphospecies 2 and 3, but morphospecies 2 is only weakly supported (88.9 %) as distinct from morphospecies 1. Characters such as petiole length, fruit surface ornamentation, style & calyx persistence, flower and fruit orientation and leaf shape are of

Summary. Two new species of Afrothismia are described within the framework of an intended revision of the genus in Cameroon, A. fungiformis from the submontane forest of Mt Kupe and A. pusilla from Mt Kala. The new species are illustrated and the conservation status for both is assessed as Critically Endangered.

Gambeya korupensis Ewango & Kenfack (Sapotaceae: Chrysophylloideae), a new rain forest tree species from the Southwest Region in Cameroon, is described and illustrated. A distribution map is provided. G. korupensis has the leaf blade below pubescent on the midribs and secondary nerves, flowers with a pedicel 0.5 – 1 mm long, and a fruit which is ovoid, attenuate at the apex, 5-ridged, verrucose between the ridges, and bright red at maturity. The conservation status of G. korupensis is assessed as Vulnerable according to IUCN criteria.

Plant species delimitation within tropical ecosystems is often difficult because of the lack of diagnostic morphological characters that are clearly visible. The development of an integrated approach, which utilizes several different types of markers (both morphological and molecular), would be extremely useful in this context. Here we have addressed species delimitation of sympatric tropical tree species that belong to Carapa spp. (Meliaceae) in Central Africa. We adopted a population genetics approach, sampling numerous individuals from three locations where sympatric Carapa species are known to exist. Comparisons between morphological markers (the presence or absence of characters, leaf-shape traits) and molecular markers (chloroplast sequences, ribosomal internal transcribed spacer region (ITS) sequences, and nuclear microsatellites) demonstrated the following: (i) a strong correlation between morphological and nuclear markers; (ii) despite substantial polymorphism, the inability of chloroplast DNA to discriminate between species, suggesting that cytoplasmic markers represent ineffective DNA barcodes; (iii) lineage sorting effects when using ITS sequences; and (iv) a complex evolutionary history within the genus Carapa, which includes frequent inter-specific gene flow. Our results support the use of a population genetics approach, based on ultra-polymorphic markers, to address species delimitation within complex taxonomic groups.

A new species of Cassipourea is described from the banks of the Mana River, in the southeastern boundary of the Korup National Park in Cameroon and placed provisionally within the subgenus Cassipourea. The leaves of the new species are close to those of C. afzelii, but its flowers differ from those of the latter and the rest of the species of the subgenus Cassipourea in having a glabrous ovary and a diplostemonous androceum, with filaments distinctly of two lengths. The illustration of the new species is provided and based on its narrow distribution, the provisional conservation status Vulnerable VU D1 is assigned.

Carapa comprises trees confined to tropical forests in Africa and America. Previous revisions of the genus based primarily on herbarium specimens recognized few variable species, but also stressed the need for further research to clarify and understand the patterns of morphological variation in these species complexes. In the present revision, 27 species are recognized in Carapa of which 16 occur in Africa and 11 in America. Nine new species are described and illustrated, and a new combination is proposed. The remaining 17 species correspond to either recently described species or previously described species that had been placed in synonymy. A key to the 27 species and their distribution maps are provided.

Carapa vasquezii from western Amazonia is described and illustrated. The new species differs from the closely related C. guianensis in having leaflets with an obtuse to rounded apex and a farinose midrib, farinose inflorescence and flower pedicels, 6-ovulate locules, and smaller seeds with a very much reduced hilum.

A taxonomic revision of Carapa (Meliaceae) in Ecuador is provided with the recognition of four species, C. megistocarpa which has cauliflorous inflorescences, C. nicaraguensis previously described and currently placed as synonym of C. guianensis and two new species (C. alticola and C. longipetala). The new species are close to C. guianensis based on their 4-merous flowers borne at the end of the branches. However, C. alticola differs from C. guianensis in having larger leaflets with prominent secondary veins, seeds with rounded edges and short poorly ramified inflorescences, while C. longipetala can be distinguised from C. guianensis in having distinctly pedicellate flowers and 6-ovulate ovary loculi. The new species are described, illustrated, and a key to the four species recognized in Ecuador is provided.

The taxonomy of the amphi-Atlantic tree genus Carapa (Meliaceae) has long been controversial. Of the three species currently recognized in the genus, two are known to present substantial morphological variation that has been used in the past to distinguish several taxa, most of which are currently placed in synonymy. Here, a combination of field observations, univariate analyses of leaf, floral and seed characters and principal coordinate analyses of floral characters in the context of a molecular phylogenetic analysis was used to investigate the patterns of variation and delimit morphological species anew in the genus. These results support the recognition of 27 species in Carapa, of which 16 are previously described and 11 are new. In general, phylogenetically related species occurred in the same geographical area, but were morphologically distinct. © 2011 The Linnean Society of London, Botanical Journal of the Linnean Society, 2011, 165, 186–221.

A distinctive new species of Rubiaceae from Rio Muni, Equatorial Guinea, is described and illustrated. Leptactina rheophytica is the only rheophyte known in the genus. Its diagnostic characters are elucidated, its taxonomic affinities are discussed, and notes on its conservation status are provided. © 2007 The Linnean Society of London.

A new species of Triuridaceae, Kihansia jengiensis Sainge & Kenfack is described from the semi-deciduous forest of Southeastern Cameroon. The new species is illustrated and a key to the identification of the two species in the genus provided. The species constitutes the first record of the genus in central Africa and its conservation status is assessed as Critically Endangered.

The new species Cassipourea korupensis Kenfack & Sainge (Rhizophoraceae) from western Cameroon is described and illustrated, and its conservation status discussed. Unlike other species of subgenus Lasiosepalum Alston, in which it is provisionally placed, the new species has a distinctive glabrous ovary and a cupuliform calyx.

Structural changes in secondary forests are less known in West Africa, and this precludes their management. This study aims at providing quantitative information on floristic composition and structure of the Lama secondary forests (Benin), so as to contribute to their restoration, and fill part of knowledge gaps on West African secondary forests. Data of 77 permanent plots each of 0.5 ha were used to analyze the floristic composition, the trajectory of the recovery and the recovery of stocking in these forests, compared to nearby old-growth forests. The results showed that the forests were less diversified with few species very common in the forest stands; the most dominant were Lonchocarpus sericeus and Anogeissus leiocarpa in the secondary forests, and Dialium guineense , Diospyros mespiliformis and Afzelia africana in the old-growth forests. The secondary forests hold more species than the mature ones. Their compositions will recover that of the original forest because species of the original forest were actively regenerating in the secondary forests. About 28 years after recovery, large trees were insufficient and basal area was about 60% of those of the mature forests. Further studies are needed to elucidate barriers to tree regeneration and dynamics of tree population. © 2016 International Formulae Group. All rights reserved. Keywords: Secondary forest, recovery, diversity, species composition, timber stock, Benin

Tetagastris panamensis is a tropical forest canopy tree that is broadly distributed across Central and South America. We isolated 15 microsatellite loci and characterized them in populations from Panama and Ecuador. The number of alleles per locus in 61 individuals ranged from 4 to 22, and expected heterozygosity ranged from 0.044 to 0.909. The high overall single-parent exclusion probability (P = 1.00) highlights the utility of these loci for parentage-based analyses of gene flow.

L'arbre. Les arbres du genre Carapa (Meliaceae) sont presents dans toutes les forets d'Afrique tropicale au niveau de l'equateur, du rift d'Albertine jusqu'au Senegal et au Mali pour sa distribution la plus septentrionale. En Afrique comme en Amerique tropicale, le carapa est une source importante de Produits Forestiers ligneux (bois) et Non-Ligneux (PFNL). Le fruit et les graines. Le fruit typique de carapa est une capsule a quatre ou cinq valves qui renferment chacune deux a cinq graines, soit un total de huit a vingt graines par fruit. L'extraction de l'huile. Les villageois ramassent les graines tombees au sol avant qu'elles ne soient parasitees ou germees, ce qui est defavorable a la production d'une huile de qualite. L'extraction de l'huile se fait par ebouillantage des graines. L'huile extraite, polyvalente, est la substance issue de la plante qui est la plus utilisee devant les extraits de feuilles, d'ecorce et de racines. Le marche. En Afrique, le commerce de l'huile de carapa est essentiellement local et reste une activite tres marginale. Une demande accrue emane toutefois de l'utilisation de cette huile comme insecticide naturel dans la culture du coton biologique. Discussion. Compte tenu du potentiel economique de l'huile de carapa, sa commercialisation devrait respecter une retribution equitable des paysannes afin de mieux rentabiliser la production. Des mesures de protection des arbres de carapa et de leur habitat doivent egalement etre prises pour permettre une gestion de la production d'huile a long terme. La plantation semble etre une option durable en vue de la conservation des peuplements naturels de carapa. (Resume d'auteur)

Carapa akuri, a new species endemic to central Guyana, is described and illustrated. It is compared to the two other species (C. guianensis and C. surinamensis) occurring in the Guianas.

During the past decade, two long-term studies of tropical forest trees and lianas were initiated in the Korup National Park, Cameroon and in the Reserve de Faune 'a Okapis, Democratic Republic of Congo. These two large forest dynamics programs are part of a global network of research sites coordinated by the Smithsonian Tropical Research Institute, and are leading to the discovery of many new plant species (e.g., Gereau & Kenfack 2000; Ewango & Breteler 2001; Sonk6 et al. 2002). During the study of the Korup plot vouchers at BR, MO, K, SCA and YA, some specimens belonging to the genus Manilkara Adans. could not be matched, and did not fit any of the species described from western and central Africa (Aubreville 1961, 1964; Gautier 1997). Critical examination of the Korup specimens revealed sufficient differences to justify the description of a new species. Further surveys in the Korup area to collect additional specimens of this taxon have so far been unsuccessful. This description is therefore based on a very small number of individuals, and we have little data on intra-specific variation. However, since we have both flowering and fruiting material showing a suite of distinctive characters, there is no reason to delay publication. The new species clearly belongs in the genus Manilkara because of the calyx, which has two whorls of 3 sepals each. Although Manilkara species are often difficult to separate, ours does not resemble any other described species very closely. M. pellegriniana Tisser. & Sillans is the only other species from the region with persistent stipules and glabrous, laciniate staminodes, and the new species can be distinguished from it by a number of well-defined characters. Manilkara lososiana Kenfack & Ewango sp. nov. Manilkarae pellegrinianae Tisser. & Sillans similis, sed stipulis triangularibus non filiformibus, petiolo breviore 5 15 non 20 40 mm longo, pedicello longiore, foliorum indumento brunneo (nec griseoargenteo) distinguitur. Typus: Cameroon, Southwest Province, Korup National Park, Kenfack 625 (holotypus YA; isotypi SCA, MO, K).

Uvariopsis submontana Kenfack, Gosline & Gereau (Annonaceae) is described from premontane habitats in western Cameroon. The new species is morphologically most similar to U. korupensis Gereau & Kenfack, recently described from lower elevations in western Cameroon. The monotypic genus Dennettia Baker f. is completely consistent with the morphological and palynological circumscription of Uvariopsis Engler, and is included in the latter genus under the new combination U. tripetala (Baker f.) G. E. Schatz. A key to the 16 species of this tropical African genus is presented. R1ASUM£. Uvariopsis submontana Kenfacke Gosline & Gereau (Annonaceae) est decrit d'habitats premontagnards de l'Ouest du Cameroun. Quant a sa morphologie, la nouvelle espece ressemble au plus pres 1'U. korupensis Gereau & Kenfack, recemment decrit d'altitudes plus basses de l'Ouest du Cameroun. Le genre monotypique Dennettia Baker f. est tout a fait consistent avec la circonscription morphologique et palynologique d'Uvariopsis Engler et est inclu dans celui-ci sous la nouvelle combinaison Uvariopsis tripetala (Baker f.) G. E. Schatz. Une cle des 16 especes de ce genre de l'Afrique tropicale est presentee.