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L’objectif de cette étude est d’apporter des informations scientifiques nécessaires à la préservation et gestion durable de Khaya anthotheca dans le sud-ouest de la République Centrafricaine via l’amélioration des connaissances sur son écologie. Pour y parvenir, des inventaires forestiers ont été effectués dans les Permis d’Exploitation et d’Aménagement (PEA) des entreprises forestières CentraBois (PEA 192) et Timberland (PEA188). Pour toutes les caractéristiques dendrométriques calculées en fonction des concessions et des classes de diamètre, le PEA 188 de Timberland est largement dominant. La densité moyenne des individus adultes est de 0,10 pieds/ha sur le PEA 192 et de 12 pieds/ha sur le PEA 188 avec le même coefficient de variation (cv) de 112,7%. La surface terrière (m2/ha) varie de 0,86 sur le PEA 192 à 3,78 sur le PEA 188 avec des cv respectifs de 60,2% et 66,4%. La densité de régénération moyenne varie de 3,52 plants/ha sur le PEA 192 à 12,19 plants/ha sur le PEA 188. Les courbes dendrométriques sont exponentielles décroissantes dans les deux concessions. Des travaux de recherches sur la régénération artificielle de K. anthotheca sont importantes pour définir des mesures de préservation dans ces zones.Mots clés : Concessions forestières, inventaires, régénération, gestion durable. English Title: Structural characterisation of natural populations of Khaya anthotheca (Welw.) C.DC in the forest concessions of South-West of Central African RepublicThe objective of this study is to provide scientific information necessary for the preservation and sustainable management of Khaya anthotheca in the south-west of the Central African Republic by improving knowledge of its ecology. To achieve this, forest inventories were carried out in the Logging and Management Permits (PEA) of the forestry companies CentraBois (PEA 192) and Timberland (PEA188). For all dendrometric characteristics calculated according to concessions and diameter classes, Timberland's PEA 188 is largely dominant. The average density of adult individuals is 0.10 tree/ha on PEA 192 and 12 tree/ha on PEA 188 with the same coefficient of variation (CV) of 112.7%. The basal area (m2/ha) varies from 0.86 on PEA 192 to 3.78 on PEA 188 with respective coefficient of variation of 60.2% and 66.4%. The average regeneration density varies from 3.52 plant/ha on the PEA 192 to 12.19 plant/ha on the PEA 188. The dendrometric curves are exponentially decreasing in both concessions. Research on artificial regeneration of K. anthotheca is important to define preservation measures in these areas.Keywords: Forest concessions, inventories, regeneration, sustainable management.

The limited number of studies on mixed plantations makes it difficult to accurately predict success of mixed-species combination especially with regards to growth, undergrowth diversity and carbon sequestration potentials. This study therefore provides information on the effects of Ceiba pentandra, Terminalia superba, Cedrela odorata and Khaya anthotheca in three different stand combinations on growth, undergrowth diversity and carbon sequestration potential. A 15-year-old coupe of 32 ha of mixed tree species stand combinations was selected for the study. The coupe was stratified based on the species combinations. Nested sub-plots (25 m × 25 m) were randomly laid in different species stand combinations for growth data collection. In each nested sub-plot, 1 m × 1 m plots were also randomly laid for undergrowth diversity study. The results revealed that two species stand combination of Ceiba pentandra and Terminalia superba performed better in terms of growth, carbon sequestration and carbon content as compared to the other species stand combinations. The saplings on the other hand, were more diverse under the three species stand combination plots. Also, the effective number of species, species richness, evenness, and dominance were higher in the four species stand combination plots. Generally, Ceiba pentandra and Terminalia superba are compatible as it produced the highest growth and carbon sequestration potential.

Using chemical fingerprints for timber species identification is a relatively new, but promising technique. However, little is known about the effect of pre-processing spectral data parameter settings on the timber species classification accuracy. Therefore, this study presents an extensive and automated analysis method using the random forest machine learning algorithm on a set of highly valuable timber species from the Meliaceae family. Metabolome profiles were collected using direct analysis in real-time (DART™) ionisation coupled with time-of-flight mass spectrometry (TOFMS) analysis of heartwood specimens for 175 individuals (representing 10 species). In order to analyse variability in classification accuracy, 110 sets of data pre-processing parameter combinations consisting of mass tolerance for binning and relative abundance cut-off thresholds were tested. Furthermore, for each set of parameters (designated “binning/threshold setting”), a random search for one hyperparameter of interest was performed, i.e. the number of variables (in this case ions) drawn randomly for each random forest analysis. The best classification accuracy (82.2%) was achieved with 47 variables and a binning and threshold combination of 40 mDa and 4%, respectively. Entandrophragma angolense is mostly confused with Entandrophragma candollei and Khaya anthotheca, and several Swietenia species are confused with each other due to the high similarity of their chemical fingerprints. Entandrophragma cylindricum, Entandrophragma utile, Khaya ivorensis, Lovoa trichilioides and Swietenia macrophylla are easy to discriminate and show less misclassifications. The choice of parameter settings, whether it is in the data pre-processing (binning and threshold) or classification algorithm (hyperparameters), results in variability in classification accuracy. Therefore, a preliminary parameter screening is proposed before constructing the final model when using the random forest algorithm for classification. Overall, DART-TOFMS in combination with random forest is a powerful tool for species identification.

Ethnopharmacological relevance Seven medicinal plants from Ugandan flora, namely Entada abyssinica, Khaya anthotheca, Vernonia amygdalina, Baccharoides adoensis, Schkuhria pinnata, Entandropragma utile and Momordica foetida, were selected in this study. They are used to treat conditions and infections ranging from inflammations, pains and fevers to viruses, bacteria, protozoans and parasites. Two of the plants, V. amygdalina and M. foetida, are also used as human food or relish, while others are important in ethnoveterinary practices and in zoopharmacognosy in the wild. The aim of this study was to evaluate the in vitro antiplasmodial, antitrypanosomal and antileishmanial activities, along with cytotoxicity of the multi-component extracts of these plants. Materials and methods Different parts of the plants were prepared and serially extracted with hexane, petroleum ether, dichloromethane, ethyl acetate, methanol and double distilled water. Solvent free extracts were assayed for in vitro inhibition against four reference parasite strains, Plasmodium falciparum (K1), Trypanosoma brucei rhodesiense (STIB 900), Trypanosoma cruzi (Talahuen C2C4) and Leishmania donovani (MHOM-ET-67/L82) using standard methods. Toxicity was assessed against L6 skeletal fibroblast and mouse peritoneal macrophage (J774) cells and selectivity indices (SIs) calculated for the most active extracts. Results The strongest activities, demonstrating median inhibitory concentration (IC50) values ≤ 2 μg/ml, were observed for the dichloromethane and petroleum ether extracts of K. anthotheca, B. adoensis and S. pinnata. Overall, IC50 values ranged from 90 μg/ml. Out of 22 extracts demonstrating IC50s 3.3 and >10 μg/ml), and nine against P. falciparum (IC50: 0.96 μg/ml to 4.69 μg/ml). Selectivity indices (SI) calculated for the most active extracts ranged from Conclusions The benefits achieved from the seven tested plant species as traditional ethnomedicinal and ethnoveterinary therapies or in zoopharmacognosy against infections and conditions of animals in the wild are strongly supported by results of this study. The synergy of plant extracts, so achieved by concerted actions of the ligands, produces adequate perturbation of targets in the four parasite genera, resulting in the strong potencies exhibited by low IC50 values. The total inhibitory effect, achieved as a sum of perturbations contributed by each participating compound in the extract, minimises toxic effects of the compounds as seen in the high SI's obtained with some extracts. Those extracts demonstrating SI ≥ 4 form promising candidates for further cell-based and system pharmacology studies.

The aim of this study was to fit and select height–diameter and stem volume equations for two African mahogany species (Khaya ivorensis and Khaya anthotheca) in the initial development phase (between 2 and 5 years old), established in agroforestry systems in northeastern Brazil. We used linear and nonlinear models to predict the total height (h) and stem volume (v), based on data from forest inventories and stem measurements of standing trees. We tested the following hypotheses: (1) the simple linear model is the most accurate to estimate the total height of young African mahogany trees in relation to different types of height–diameter models (linearized, nonlinear and those with transformed variables); (2) simple and double-entry stem volume models have the same precision in estimating the individual volume of young African mahogany trees. The results showed that the simple linear height–diameter model was most accurate to estimate the height of both African mahogany species. The age’s effect (young trees) and probably the predominantly monopodial development of the Khaya spp. trees sampled were discussed as the causes of the linear nature of the models that best described the height–diameter relationship. The stem volume equations for Khaya ivorensis and Khaya anthotheca were well adjusted. However, the double-entry Spurr’s model was more accurate than the other models for both species. Furthermore, for the Khaya ivorensis, the one-entry (diameter) Husch’s model generated similar stem volume estimates to Spurr’s model.

Ethnobotanical enquiries have revealed that Khaya anthotheca (Welw.) C.DC (Meliaceae) has anxiolytic properties and is used to alleviate vaginal dryness in postmenopausal women in Cameroon. The aim of this study was to evaluate the ameliorative effects of the aqueous extract of K. anthotheca in vanadium induced anxiety, memory loss and pathologies in the brain and ovary of mice.Forty neonatal female mice were used in this study. All animals received vanadium (3 mg/kg BW/72 h, by lactation and i.p.) for 20 weeks except the Control group. At 16 weeks old, mice were divided into 5 groups (n = 8): Control group received distilled water; V-group received vanadium (V) (3 mg/kg BW every 72 h i.p.), V + Vit E group received vitamin E (500 mg/kg BW/72 h) and vanadium (V) (3 mg/kg BW/72 h i.p, simultaneously). V + KA 125 and V + KA 250 groups received K. anthotheca extract at the doses of 125 and 250 mg/kg BW/day respectively and vanadium (V) (3 mg/kg BW/72 h i.p, simultaneously).The treatment was done per os at 10 mL/kg of volume of administration for 4 weeks. To evalute anxiolytic effects and spatial working memory improved by the extract in mice, the elevated open space test and Y maze test were used respectively. After sacrifice, brains were harvested and pathologies were assessed using cresyl violet stainning and immunohistochemistry (GFAP, Iba-1 and MBP), while pathologies in the ovaries were assessed using immunohistochemistry (Collagen type 1) and HE stainning.Results in the three sessions of elevated open space test showed that vanadium exposure resulted in a significant (p 0.05; p 0.01) increase of the latency of first entry in the slopes and a significant (p 0.05; p 0.01; p 0.001) decrease of the time spent and number of entries in the slopes however, Khaya anthotheca treatment induced a significant (p 0.05; p 0.01) decrease of the latency of first entry in the slopes and a significant (p 0.05; p 0.01) increase of the time spent and number of entries in the slopes. In the Y maze test, vanadium exposure resulted in a significant decrease (p 0.01) in the percentage of correct alternation, K. anthotheca extract at the dose of 250 mg/kg BW however induced a significant (p 0.05) increase of this percentage of correct spontaneous alternation. In the brain, degeneration induced by vanadium exposure was marked by an increase of GFAP-immunoreactive cells, microgliosis and demyelination. The treatment with Khaya anthotheca extract at the dose of 250 mg/kg BW resulted in the preservation of cellular integrity in the same anatomical regions with reduced astroglial and microglial activation and prevented demyelination. In addition, vanadium exposure decreased Collagen type 1 expression in the ovaries and induced a deterioration of tertiary follicle. Khaya anthotheca treatment at the dose of 250 mg/kg BW induced an increase of expression of Collagen type 1 and alleviated deterioration of the microarchitecture of tertiary follicle induced by vanadium.These effects induced by K. anthotheca extract could justify the traditional use of this plant in Cameroonian traditional medicine to manage anxiety. Therefore, to minimise vanadium induced toxicity, the plant should be given more emphasis as a candidate in developing a modern phytodrug.

Khaya anthotheca is a hardwood species from Africa and recently introduced to Brazil. This species yields high-quality wood for diverse applications, but little has been done toward an effective propagation method for large-scale production in nurseries. We evaluated the effects of different concentrations of macro and micronutrients (i.e., 100, 50 and 25% of the concentration of a referenced solution) combined with indole-3-butyric acid (IBA) at 0 and 2 g L−1 on the survival rate of mini-stumps and the survival and adventitious rooting of K. anthotheca mini-cuttings. The mini-stumps were grown from a source of seeds imported from Ghana, West Africa. The mini-stumps survived at a high rate (97%). Consistently high shoot yields were obtained from the mini-stumps (average of 1.8 per mini-stump). High survival percentage of mini-cuttings and adventitious rooting were observed when solutions with 100 and 50% of the nutrients concentration were combined with 2 g L−1 IBA. Histological sections analyzed through optical microscopy indicated the tissues from mini-cutting stems were juvenile, which might have stimulated adventitious rooting. These results have important implications for further work aimed at establishing propagation strategies for K. anthotheca, which are of prime importance for assisting breeding programs of this species.

Carbon (C) dynamics in canopy and roots influence whole-tree carbon fluxes, but little is known about canopy regulation of tree-root activity. Here, the patterns and dynamics of canopy-root C coupling are assessed in tropical trees. Large aeroponics facility was used to study the root systems of Ceiba pentandra and Khaya anthotheca saplings directly at different light intensities. In Ceiba, root respiration (Rr ) co-varied with photosynthesis (An ) in large saplings (3-to-7-m canopy-root axis) at high-light, but showed no consistent pattern at low-light. At medium-light and in small saplings (c. 1-m axis), Rr tended to decrease transiently towards midday. Proximal roots had higher Rr and nonstructural carbohydrate concentrations than distal roots, but canopy-root coupling was unaffected by root location. In medium-sized Khaya, no Rr pattern was observed, and in both species, Rr was unrelated to temperature. The early-afternoon increase in Rr suggests that canopy-root coupling is based on mass flow of newly fixed C in the phloem, whereas the early-morning rise in Rr with An indicates an additional coupling signal that travels faster than the phloem sap. In large saplings and potentially also in higher trees, light and possibly additional environmental factors control the diurnal patterns of canopy-root coupling, irrespective of root location.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2021-09-14T09:23:45Z No. of bitstreams: 1 2019 - Felipe Martini Santos.pdf: 7920872 bytes, checksum: 7822a4c241aa521a69755dc76f3dfefb (MD5) Made available in DSpace on 2021-09-14T09:23:45Z (GMT). No. of bitstreams: 1 2019 - Felipe Martini Santos.pdf: 7920872 bytes, checksum: 7822a4c241aa521a69755dc76f3dfefb (MD5) Previous issue date: 2019-02-27 CAPES - Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior CNPq - Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico EMBRAPA - Empresa Brasileira de Pesquisa Agropecu?ria African mahoganies (Khaya spp.) have high wood quality, especially for uses in the furniture industry, decoration and interior finishes, musical instruments and shipbuilding. Recently, African mahoganies have stimulated the interest of foresters and investors in the tropics. Normally, the African mahoganies stands have been established under monocultures with all trees established at the same time, in densities ranging from 280 to 1100 plants ha-1 with harvest projections to 18 years. Alternatively, there is the possibility of planting African mahogany under different arrangements of agroforestry systems (AFS). When these systems are handled harmonically with the secondary succession, they are called successional agroforestry systems. However, little is known about the growth and production of Khaya spp. in more complex productive systems. In addition, few studies have addressed the management of natural regeneration in successive AFS established in areas abandoned by agricultural activities. The aim of this thesis was to evaluate silvicultural aspects and ecosystem servides in mixed-species plantations and successional AFS with Khaya sp. under different level of diversity and natural regeneration management. The studies were conducted on Fazenda Sucupira, Valen?a, Bahia state, Brazil. A completely randomized block design experiment was established in January 2016 on a production stand of Khaya ivorensis e Khaya anthotheca planted on alternate rows (spacing 7 m x 3 m) in November 2013. The following treatments were established: (T1) mixed plantation of African mahogany without conduction of natural regeneration; (T2) mixed plantation of African mahogany with selective conduction of natural regeneration; (T3) AFS with African mahogany without conduction of natural regeneration; (T4) AFS with African mahogany with selective conduction of natural regeneration (successional AFS). The present thesis was organized in three chapters. In chapter I, the adjustment of hypsometric and volumetric equations for K. ivorensis and K. anthotheca was established in mixed and successional agroforestry systems stands. The selected equations subsided chapter II that evaluated the growth and yield of both Khaya species established in mixed and successional AFS stands with or without selective management of natural regeneration. In chapter III, it was evaluated the recovery of the ecosystem functions resulting from natural regeneration management in Khaya spp. production systems (mixed and agroforestry stands) established in abandoned agricultural area were evaluated. As esp?cies de mogno-africano (Khaya spp.) apresentam madeira de excelente qualidade, especialmente para usos na ind?stria moveleira, decora??o e acabamentos de interiores, instrumentos musicais e constru??o naval. Recentemente, os mognos-africanos t?m despertado o interesse de silvicultores e investidores nas regi?es tropicais. Normalmente, os povoamentos de mognos-africanos t?m sido implantados em monocultivos equi?neos, em densidades que variam de 280 a 1100 plantas ha-1 e expectativa de colheita aos 18 anos. Alternativamente, h? a possibilidade do plantio do mogno-africano sob diferentes arranjos de sistemas agroflorestais (SAFs). Quando esses sistemas s?o manejados harmonicamente com a sucess?o secund?ria, s?o chamados de SAFs sucessionais. No entanto, pouco se sabe a respeito do crescimento e a produ??o de Khaya spp. em sistemas produtivos mais complexos. Ademais, poucos estudos abordaram o manejo da regenera??o natural em SAFs sucessionais estabelecidos em ?reas abandonadas por atividades agropecu?rias. O objetivo desta tese foi avaliar aspectos silviculturais e os servi?os ecossist?micos em povoamentos mistos e SAFs sucessionais com Khaya spp. com diferentes n?veis de diversidade e manejo da regenera??o natural. Os estudos foram conduzidos na Fazenda Sucupira, Valen?a-BA. Um experimento em blocos casualizados foi estabelecido em janeiro de 2016 em ?rea de produ??o de Khaya ivorensis e Khaya anthotheca, plantadas em linhas alternadas (no espa?amento 7 m x 3 m) em novembro de 2013. Os seguintes tratamentos foram estabelecidos: (T1) plantio misto de mogno-africano sem condu??o da regenera??o natural (uso de herbicida); (T2) plantio misto de mogno-africano com condu??o seletiva da regenera??o natural; (T3) SAF com mogno-africano sem condu??o da regenera??o natural; (T4) SAF com mogno-africano com condu??o seletiva da regenera??o natural (SAF sucessional). A presente tese foi organizada em tr?s cap?tulos. No cap?tulo I, realizou-se o ajuste de equa??es hipsom?tricas e volum?tricas para ?rvores de K. ivorensis e K. anthotheca estabelecidas em povoamentos mistos e em SAFs sucessionais. As equa??es ajustadas deram subs?dios ao cap?tulo II, onde avaliou-se o crescimento e produtividade de ambas as esp?cies em plantios mistos e SAFs sucessionais com condu??o seletiva ou n?o da regenera??o natural. J? no cap?tulo III avaliou-se a recupera??o das fun??es ecossist?micas decorrentes do manejo da regenera??o natural em sistemas de produ??o de Khaya spp.(povoamentos mistos e SAFs) estabelecidos em ?rea agr?cola abandonada.

Les espèces du genre Khaya procurent l’un des bois les plus prisés du continent africain. Elles sont commercialisées sous l’appellation « acajou d’Afrique » depuis environ deux siècles. En Afrique continentale, on reconnaît actuellement quatre espèces morphologiquement proches : Khaya anthotheca, K. grandifoliola, K. ivorensis et K. senegalensis. Le nombre de taxons du genre Khaya a varié au cours du temps et la délimitation de ces taxons n’est pas sans avoir des implications sur les stratégies de conservation et de gestion durable des espèces. L’objectif du travail présenté ici est de s’assurer de la délimitation de ces espèces sur la base d’un bilan des connaissances actuelles en taxonomie, génétique, écologie et chimiotaxonomie. Les données disponibles ne permettent pas toujours de séparer sans ambiguïté les quatre acajous d’Afrique continentale. Elles permettent toutefois d’avancer que K. ivorensis, K. grandifoliola et K. senegalensis seraient des espèces à part entière mais dont les limites taxonomiques doivent encore être précisées. Khaya nyasica serait également une espèce qui devrait être séparée de K. anthotheca. Au sein de cette dernière, plusieurs chémotypes ont été identifiés, ce qui suggère que ce taxon pourrait recouvrir un ensemble plus complexe d’au moins deux autres taxons dont le rang spécifique ou sous-spécifique reste à préciser. Des recherches morphométriques, génétiques et écologiques doivent être développées afin de clarifier le statut systématique et l’histoire évolutive de ces divers taxons, en vue de formuler des recommandations appropriées pour la gestion durable des acajous d’Afrique., Species of the genus Khaya produce some of Africa’s most valuable timber. For two centuries, these species have all been traded as “African mahogany”. On the African continent, four different but morphologically similar species are now recognised: Khaya anthotheca, K. grandifoliola, K. ivorensis and K. senegalensis. The number of taxa included in the genus Khaya has varied over time, and the way these taxa are distinguished has implications for the development of sustainable management strategies for the different species. The aim of the study described in this article was to make sure that these species are distinguished on the basis of up-to-date knowledge on taxonomy, genetics, ecology and chemotaxonomy. Although the data available do not always suffice to clearly distinguish between the four mahogany species on the African continent, they do indicate that K. ivorensis, K. grandifoliola and K. senegalensis are probably distinct species whose taxonomic limits are yet to be clearly defined. It also seems that Khaya nyasica should be distinguished from K. anthotheca. Several chemotypes have been identified in the latter, suggesting that it could in fact cover a more complex group including at least two other taxa whose rank as species or sub-species is yet to be determined. Morphometric, genetic and ecological studies need to be developed to clarify the systemic status and evolutionary history of these different taxa, in order to formulate appropriate recommendations for the sustainable management of African mahoganies.

Swietenia macrophylla yields high-quality wood; however, its vulnerability to extinction coupled with challenges for its cultivation have brought attention to its replacement for alternative species such as the Khaya anthotheca. The species has been recently introduced to South America, with potential for the production of high-quality wood. However, limited background on breeding and efficient strategies for its vegetative propagation exist. Here, we achieved significant results with the application of cleft grafting and air layering for the propagation of K. anthotheca plants grown from seeds. First, we analyzed the compatibility of scions and rootstocks for intraspecific and interspecific cleft grafting combinations of K. anthotheca and S. macrophylla. Second, air layering was performed in K. anthotheca seedlings irrigated with three nutrient solution (100%, 50% and 25% of the initial concentration of nutrients) combined with the application of indole-3-butyric acid (IBA) to evaluate adventitious rooting. From cleft grafting, we achieved an overall graft compatibility and survival of 48% after 200 days. However, the interspecific combination of S. macrophylla (scion) and K. anthotheca (rootstock) implicated in no compatibility, while the reciprocal resulted in 52% of compatibility. Through air layering, the irrigation with the nutrient solution with at least 50% of the nutrients concentration and with IBA (3.0 or 8.0 g.L-1) resulted in the best adventitious rooting. Overall, we recommend cleft grafting, except for the combination S. macrophylla(scion) and K. anthotheca (rootstock), with no compatibility. Air layering might also be useful for the propagation of K. anthotheca genotypes in breeding programs.

Khaya anthotheca (Welw.) C.DC (Meliaceae) is a plant used in Cameroon to alleviate vaginal dryness in postmenopausal women and is also known to have anxiolytic properties.This work was designed to evaluate estrogen-like effects of this plant on primary estrogens targets of ovariectomized adult rats, as well as to evaluate its anxiolytic activities in the elevated plus-maze (EPM) test. In the 3-day uterotrophic assay, the extract increased (p < 0.01) the size of the vaginal epithelia and stimulated the acini differentiation of the mammary gland. In the EPM test, the extract increased the percentage of number of entries (p K. anthotheca is endowed with estrogenic and anxiolytic properties, likely due to the presence of some estrogen-like compounds.

Khaya anthotheca (Welw.) C. DC. Monographiae Phanerogamarum 1: 721 (1878); Exell & Mendon��a, Conspectus Florae Angolensis 1 (2): 307 (1951). ��� Garretia anthotheca Welw., Apontamentos Phytogeographicos: 587 (1859), ���anthoteca���, ��Habit. in silvis primitivis District. Golungo Alto, imprimis in Sobato Mussengue.��. ��� Type d��sign�� ici: F.M . Welwitsch 1314, Angola, montagnes de Queta [m. de Queta, fl. IV.1856], fl., IV.1856 (lecto-, BM [BM000799818]!). ANCIENS SYNTYPES. ��� S.loc., s.d., fl. & j. fr., F.M. Welwitsch 1314 (syn-, K[K00432187]!; isosyn-, st., COI[COI00005208!]; st., K[K004321188]!, st., LISU[LISU206318!]; F.M. Welwitsch 1314, Golungo Alto, montagnes de Queta (Golo. Alt. montes Queta), s.d., fl. (syn-, LISU[LISU206312!], excl. frgt. fr.; s.loc., fl. (isosyn-, G [G00382667]!, deux parts, P[P06674532, P06674534]!); F.M.Wel - witsch 1314, Golungo Alto, montagnes de Queta (Golu. Alto. m. d. Queto), s.d., st. (syn-, LISU[LISU206314!]); F.M. Welwitsch 1314, Golungo Alto, [Gol. Alt.], s.d., infl. (syn-, LISU[LISU206317!]; F.M. Welwitsch 1314, for��ts de Queta [sylvis de Queta], fr. et gr., 18.XI.1855 (syn-, LISU[LISU206315!]); F.M. Welwitsch 1314, Golungo Alto, fl. (syn-, 18.XI.1855, II.1856, PRE!; isosyn-, Serra de Alto Queta, II.1856, fl. M[M-0108665!]); F.M.Welwitsch 1314, Golungo Alto, gr., 1857 (syn-, K[K00432186]!); F.M. Welwitsch 1314, Angola, Loanda, XII.1858, gr. (syn-, BM[BM000799819]!; isosyn-, [D. de Gol. o Alto], LISU[LISU206313]!, s.loc., s.d., st. LISU[LISU206319]!); F.M.Welwitsch 1314, Loanda, gtion., XII.1858 (syn-, LISU[LISU206316]!). REMARQUE Le mat��riel original de Welwitsch est largement composite: pas moins de 18 parts sous le m��me num��ro 1314 ont ��t�� rep��r��es dans les herbiers et la banque d���images JSTOR. Comme il n���a pas ��t�� possible d���associer au lectotype tous les doubles d��pos��s dans les herbiers, la principale raison ��tant l���impossibilit�� de les examiner tous, avec de plus des discordances sur les dates, localit��s et ph��nologies, nous les avons consid��r��s comme des syntypes. Nous avons fait le choix, pour des doubles d���un syntype distribu��s entre BM et d���autres herbiers, de privil��gier BM comme lieu de d��p��t du syntype, puisque cet herbier h��berge le premier jeu des parts ayant servi �� la r��daction de Apontamentos Phytogeographicos (Hiern 1896; Albuquerque et al. 2009). Nous faisons de m��me pour LISU, qui est le deuxi��me herbier pour l���importance des collections de Welwitsch.Dans certaines situations d��licates �� trancher �� partir des seules images pour la mise en concordance des parts, �� cause d���informations absentes sur la localit��, la date ou d���un m��lange ��vident du mat��riel collect�� (par exemple, des feuilles d���un jeune pied avec des fleurs ou des fruits), nous avons laiss�� s��par��es de telles parts plut��t que les rassembler �� tort au sein d���un m��me syntype. Par ailleurs, Welwitsch a effectu�� des collectes entre novembre 1855 et d��cembre 1858 et ne les a pas toujours annot��es clairement. De plus, le soin variable apport�� aux collections dans les diff��rents herbiers a pu ajouter �� la confusion. Il ��tait ainsi habituel de renseigner pr��cis��ment une seule ��tiquette, de laisser les doubles avec une information minimale (collecteur et num��ro de collecte) et de n��gliger le report des donn��es originales avant envoi dans d���autres institutions. Il a pu ainsi en r��sulter des planches avec des ��tiquettes aux informations contradictoires sur les localit��s ou les dates. Enfin, pour ne pas alourdir davantage cette op��ration et contrairement aux autres situations, nous avons laiss�� la num��rotation originale en l�����tat, sans y ajouter un suffixe [A], [B], etc., ce qui aurait obscurci �� son tour la situation. Exell & Mendon��a (1951), dans le traitement de Khaya, indiquaient ��BM, tipo��. Dans la mesure o�� il existe deux parts du n��1314 de Welwitsch, l���acte nomenclatural n���est pas effectif. Le choix du lectotype portera donc sur l���une des deux. La part BM000799818 est constitu��e d���une feuille et d���une inflorescence (apparemment incompl��te), on y trouve en haut �� gauche, une ��tiquette avec une longue description sur les caract��res foliaires et floraux, ainsi que la note:�� Hab. in sylvis editior.primit. M. de Queta C. fr. Febr. C. fl. Apr. 1856 ��; une seconde ��tiquette, en bas �� gauche, avec une description plus courte sur les caract��res foliaires et la note: ��Absque floribus in sylvis de Queta editioribus�� et la date 18.11.1855.Ces deux ��tiquettes sont donc dans un conflit de dates et on peut, soit suspecter une planche comprenant une feuille et une inflorescence collect��es �� deux dates diff��rentes, soit consid��rer que la part est homog��ne, mais que l�����tiquette signalant l���absence de fleurs n���appartient pas au mat��riel fix�� sur la planche. La part BM000799819 est constitu��e d���une feuille et de deux graines. Une ��tiquette centr��e vers le haut porte l���indication: �� Anthotheca ��� Folia adulta In sylvis Sobti Mussengue Junio 1856 ��; une seconde ��tiquette, en bas �� gauche: ��Junge Pflanze von Garettia mit noch anh��ngenden Samen.Schalen. ��� Loanda Dcbr. 1858 [Transl. Young plant of Garettia with seed vessels still hanging.��� Loanda Dcbr. 1858]. ��. Sur cette m��me ��tiquette, mais d���une autre ��criture: ��without accompanying specimen; no seed in the study sent specimen ��. On peut attribuer la premi��re ��tiquette �� la feuille et la seconde aux deux graines qui appartenaient �� un fruit dont elles sont le seul ��l��ment restant, ou au contraire, estimer que feuille et graines vont ensemble avec l�����tiquette Loanda d��cembre 1858 et consid��rer l���autre ��tiquette �� Sobti Mussengue juin 1856 �� comme intruse. Pour ces deux parts, il est difficile de choisir parmi toutes les possibilit��s. C���est donc en reconnaissant une part d���arbitraire que nous choisissons BM000799818 comme lectotype, avec l���hypoth��se que la petite ��tiquette du 18.11.1855 est �� exclure de la planche.Pour BM000799819, nous retenons l���hypoth��se d���une part non composite avec la date de d��cembre 1858. Khaya euryphylla Harms, Notizblatt des K��niglichen botanischen Gartens und Museums zu Berlin 3 (28): 169 (1902), �� Kame- run: Johann-Albrechtsh��he. (Staudt n. 677. Bl��hend im M��rz 1896)��. ��� Type d��sign�� ici: A. Staudt 677 (877 �� K), Cameroun, Kumba (Johann-Albrechtsh��he), fl., III.1896 (holo-, B���; lecto-, K[K000094091]!; isolecto-, G [G00414647]!, P[P00453253]!). REMARQUE Les Meliaceae de Berlin ayant br��l��, le type de cette esp��ce a disparu. Nous choisissons la part de K comme lectotype, plus fournie en fleurs que les deux autres. Khaya mildbraedii Harms, Notizblatt des Botanischen Gartens und Museums zu Berlin-Dahlem 7: 223 (1917), �� Kamerun, Weit nach Norden bis in den Bogen des Lom (Sanaga) vor der Vereinigung mit dem Djerem vorgeschobener Auslaufer der geschlossenen Hylaea um Dengdeng etwa 250 Km N O Jaunde��. ��� Type d��sign�� ici: G.W. Mildbraed 8698, Cameroun, en-de���� du confluent de la Sanaga et du Djerem, environ de Dengdeng, 250 km au nord ouest de Yaound��, avanc��e de la for��t dense humide fl., III.1914 (holo-, B���; lecto-, K[K001089643]). REMARQUE La situation est la m��me que pour K. euryphylla: type de Berlin disparu. La seule part retrouv��e est �� K; elle est retenue comme lectotype. Khaya wildemanii Ghesq., Revue zoologique africaine avec Suppl��ment Botanique 13: 29 (1926), ���Wildemanii���. ��� Type d��sign�� ici: J. Ghesqui��re 62, Congo Belge, Kasai, fr., X.1924 (lecto-, BR[BR00000895410]!; isolecto-, BR[BR00000895407,BR00000895440, BR00000895443, BR00000895476, BR00000982535]!). REMARQUE �� BR, on trouve six parts de cette r��colte, dont seules deux, BR00000895410 et BR00000895440 sont not��es comme ��Typus! �� par Ghesqui��re. Nous choisissons comme lectotype la part fructif��re avec des capsules d��membr��es et les graines associ��es. Les autres sont consid��r��es comme doubles, dont BR00000982535, qui est constitu��e de deux fragments d�����corce. Khaya agboensis A. Chev. ex A. Chev., Revue de Botanique appliqu��e et d���Agriculture coloniale 8: 209 (1928), �� C��te d���Ivoire, dans la for��t, assez rare. Agboville, environs du pont de Chemin de fer, km 83. 8 novembre 1909 (en fruits jeunes) ��. ��� Type: A. Chevalier B. 22342, Agboville, environs du pont de chemin de fer, km 82, st., 1-11.XI.1909 (holo-, P[P00453217]!; iso-, K[K001089642]!, SHO!, P[P06674537, P06674539, P06674540, P06674541]!). REMARQUE Chevalier ��crit ��type�� sur une seule part de P, qui est donc l���holotype, toutes les autres parts en sont des doubles, avec les m��mes indications de localit��. Khaya agboensis A. Chev., Exploration botanique de l���Afrique occidentale fran��aise 1: 116 (1920), nom. nudum., Published as part of Dipelet, Ulrich Ga��l Bouka, Florence, Jacques, Doumenge, Charles, Loumeto, Jean Jo��l & McKEY, Doyle, 2017, Khayae (Meliaceae) specierum Nomenclator, pp. 15-30 in Adansonia 39 (1) on pages 17-18, DOI: 10.5252/a2017n1a2, http://zenodo.org/record/4598996, {"references":["HIERN W. P. 1896. - Catalogue of the African Plants Collected by Dr Friedrich Welwitsch in 1853 - 1861. Dicotyledons, Part 1. British Museum (Natural History), London, vol. 1 (1): 26 + 336 p. https: // doi. org / 10.5962 / bhl. title. 10876","ALBUQUERQUE S., BRUMMITT R. K. & FIGUEIREDO E. 2009. - Typification of names based on the Angolan collections of Friedrich Welwitsch. Taxon 58: 641 - 649."]}

Diverse pesticidal activities of anthothecol derived from Khaya anthotheca (Meliaceae) and three limonoids (gedunin, limonin and obacunone) were determined using six phytopathogenic fungi and four insect pests. Anthothecol showed fungicidal activity to Puccinia recondita with control rates of 90, 76 and 53% at concentrations 0.5, 0.25 and 0.1 mg/mL, respectively, while the other limonoids exhibited little inhibitory effect on the fungal survival. The currently used fungicide mancozeb possessed potent fungicidal activity on P. recondite, with 92.3% controlling effect at a concentration of 0.005 mg/mL. Anthothecol exhibited larvicidal activity to Plutella xylostella with 80, 50 and 30% mortality at concentrations of 1.0, 0.5 and 0.25 mg/mL, respectively. Anthothecol showed selective pesticidal activity on P. recondita and P. xylostella. Structural re-examination of anthothecol was conducted and is reported.

Leaf litter is the main and quick source of organic matter and nutrient to the soil compared to other parts of litter. This study focused on the nutrients (N, P and K) leaching from leaf litter of Melia azadirachta, Azadirachta indica, Eucalyptus camaldulensis, Swietenia macrophylla, Mangifera indica, Zizyphus jujuba, Litchi chinensis, Albizia saman, Artocarpus heterophyllus, Acacia auriculiformis, Dalbergia sissoo and Khaya anthotheca as the common cropland agroforest tree species of Bangladesh. About (9 to 35) % of initial mass was lost, while Electric Conductivity (EC) and TDS (Total Dissolved Solid) of leaching water increased to (573 to 3,247) μS/cm and (401 to 2,307) mg/l respectively after 192 hours of leaching process. Mass loss (%) of leaf litter, EC and TDS of leaching water showed significant (ANOVA, p＜0.05) curvilinear relationship with leaching time. Initial concentration of NH4, PO4 and K in leaching water was found to increase significantly (p＜0.05) up to 48/72 hours and then remained almost constant at later stages (48/72 to 192 hours). Mass loss of leaves; EC, TDS, NH4, PO4 and K in leaching water was varied also significantly (ANOVA, p＜0.05) among the studied tree species. All the tree species showed similar pattern of nutrients (K＞N＞P) release during the leaching process. The highest NH4 (4,097 ppm) and potassium (8,904 ppm) concentration was found for M. azadirachta while the highest PO4 (1,331 ppm) concentration was found for E. camaldulensis in the leaching water. Among the studied tree species, M. azadirachta, A. indica, D. sissoo, E. camaldulensis and Z. jujuba was selected as the best tree species with respect to nutrient leaching.

Fourteen (14) medicinal plants used by traditional medical practitioners in treating sexually transmitted diseases and common ailments were selected after an ethno-botanical survey of five districts from Zimbabwe. Plant extracts were screened for phytochemical composition, antioxidant activity by reducing 2,2-diphenyl-picrylhydrazyl (DPPH) free radical with ®-carotene as reference and through total phenolic content (TPC) by Folin-Ciocalteu reagent using gallic acid as reference. Ten (10) of the twenty-eight (28) methanolic extracts exhibited strong antioxidant activity with percentages equal or greater than 90 % compared to reference ®-carotene (99 %). Antioxidant activity for Rhus chirindensis, Khaya anthotheca, Gymnosporia senegalensis and Flacourtica indica was equal or greater than 95 %. Their TPCs ranged from 0.596 mg/mg to 0.105 mg/mg GAE. The TPC in some of the extracts correlate with their antiradical activity (r2=0.57) confirming that the phenolics are the likely cause of the radical scav...

ETHNOPHARMACOLOGICAL RELEVANCE: Khaya species, endemic to Africa and Madagascar, continues to be valuable in indigenous traditional medicine. Their bitter tasting barks are decocted to treat fevers, several febrile conditions, microbial infections and worm infestations. In the Budongo rain forest of Western Uganda, non-human primates, especially chimpanzees and baboons, have been observed to eat the bitter non-nutritious bark and occasionally the seed. MATERIALS AND METHODS: Extracts were prepared by sequential fractionation with solvents of increasing polarities and assayed using standard procedures. Bioassay guided purification of the petroleum ether extract by column chromatography yielded three pure limonoids, Grandifolione (1), 7-deacetylkhivorin (2) and 1,3-deacetyldeoxyhavenensin (3). The antitrypanosomal, antileishmanial and antiplasmodial activities of pure compounds (1) and (2) were evaluated in vitro against Plasmodium falciparum K1, Trypanosoma brucei rhodesiense STIB 900, Trypanosoma cruzi trypomastigotes (Tulahuen C4), and axenic Leishmania donovani MHOMET-67/L82 and for cytotoxicity against L6 rat skeletal myoblast cells, in parallel with standard drugs. RESULTS: Of the four extracts tested, the petroleum ether extract showed activity against Plasmodium falciparum (IC50 0.955?g/ml) and Trypanosoma brucei rhodesiense (IC50 5.72?g/ml). The pure compounds (1) and (2) demonstrated activity against Plasmodium falciparum (KI strain) and marginal activities against Trypanosoma brucei brucei, Trypanosoma brucei rhodesiense, Trypanosoma cruzi and Leishmania donovani. CONCLUSION: The present study provides evidence justifying the use of Khaya preparations in traditional medicine to treat fevers and microbial infections. The observed antiprotozoal activity of grandifolione and 7-deacetylkhivorin from the seed of Khaya anthotheca further confirms the ethnomedicinal potential of this plant and supports the hypothesis that non-human hominids (chimpanzees and baboons) too, eat the bitter bark and seeds for self-medication and in general, the use of Khaya plant material for medication by humans in disease endemic tropical areas. The antiprotozoal activity of gradifolione, and, the antitrypanosomal and antileishmanial activities of 7-deacetylkhivorin are reported here for the first time.

Extracts of plant species, used traditionally to treat malaria, have been extensively investigated for their activity against Plasmodium intraerythrocytic asexual parasites in search of new antimalarial drugs. However, less effort has been directed towards examining their efficacy in blocking transmission. Here, we report the results of the in vitro screening of extracts from eight selected plant species used traditionally to treat malaria in South Africa for activity against Plasmodium falciparum NF54 early and late stage gametocytes. The species used were Khaya anthotheca, Trichilia emetica, Turraea floribunda, Leonotis leonurus, Leonotis leonurus ex Hort, Olea europaea subsp. Africana, Catha edulis and Artemisia afra.To investigate the activities of extracts from plant species traditionally used for malaria treatment against P. falciparum gametocytes.Air-dried and ground plant leaves were extracted using acetone. Primary two point in vitro phenotypic screens against both early and late stage gametocytes were done at 10 and 20µg/ml followed by full IC50 determination of the most active extracts. Inhibition of gametocyte viability in vitro was assessed using the parasite lactate dehydrogenase (pLDH) assay.Of the eight crude acetone extracts from plant species screened in vitro, four had good activity with over 50-70% inhibition of early and late stage gametocytes' viability at 10 and 20µg/ml, respectively. Artemisia afra (Asteraceae), Trichilia emetica (Meliaceae) and Turraea floribunda (Meliaceae) were additionally highly active against both gametocyte stages with IC50 values of less than 10µg/ml while Leonotis leonurus ex Hort (Lamiaceae) was moderately active (IC5020µg/ml). The activity of these three highly active plant species was significantly more pronounced on late stage gametocytes compared to early stages.This study shows the potential transmission blocking activity of extracts from selected South African medicinal plants and substantiates their traditional use in malaria control that broadly encompasses prevention, treatment and transmission blocking. Further studies are needed to isolate and identify the active principles from the crude extracts of A. afra, T. emetica and T. floribunda, as well as to examine their efficacy towards blocking parasite transmission to mosquitoes.

BACKGROUND AND AIMS This study is a first step in a multi-stage project aimed at determining allometric relationships among the tropical tree organs, and carbon fluxes between the various tree parts and their environment. Information on canopy-root interrelationships is needed to improve understanding of above- and below-ground processes and for modelling of the regional and global carbon cycle. Allometric relationships between the sizes of different plant parts will be determined. METHODS Two tropical forest species were used in this study: Ceiba pentandra (kapok), a fast-growing tree native to South and Central America and to Western Africa, and Khaya anthotheca (African mahogany), a slower-growing tree native to Central and Eastern Africa. Growth and allometric parameters of 12-month-old saplings grown in a large-scale aeroponic system and in 50-L soil containers were compared. The main advantage of growing plants in aeroponics is that their root systems are fully accessible throughout the plant life, and can be fully recovered for harvesting. KEY RESULTS The expected differences in shoot and root size between the fast-growing C. pentandra and the slower-growing K. anthotheca were evident in both growth systems. Roots were recovered from the aeroponically grown saplings only, and their distribution among various diameter classes followed the patterns expected from the literature. Stem, branch and leaf allometric parameters were similar for saplings of each species grown in the two systems. CONCLUSIONS The aeroponic tree growth system can be utilized for determining the basic allometric relationships between root and shoot components of these trees, and hence can be used to study carbon allocation and fluxes of whole above- and below-ground tree parts.

Encroachments on Carita Research Forest area have exacerbated the degradation of land due to uncontrolled runoff, erosion and nutrient losses especially on the sloping land with high annual rainfall. To reduce the severity of the degradation the area should be rehabilitated by applying soil and water conservation techniques. The techniques used were the vegetative methods (culture), and a combination of it with mechanical/technical methods. The combination method is expected to be more effective in controlling runoff, erosion and nutrient losses. One important parameter is the efficiency of the distance of the vertical mulch channel, which affects the application cost. This study was aimed to determine the effect of different distances of vertical mulch channels on the plant growth and annual crop yield as well as its effectiveness in controlling runoff, erosion and nutrient losses. The research was conducted in Carita Research Forest from 2005 to 2008, using the randomized block design. Treatments applied were: vertical mulch with six and twelve meter distances of plots of khaya (Khaya anthotheca C.Dc.) and corn ( Zea mays L.) cropping system. Observations included height and diameter growth of khaya, runoff and erosion, and cost per ha. The results showed that six meter of vertical mulch was the most efficient distance. The height and diameter of khaya tree increased by 7% and 31% in six meter distance compared to the control. Moreover, runoff and erosion was reduced by 75% and 37%, and nutrient losses could be trimmed down by three to five times. In addition, six meters distance could also produce corn of 712 kg/ha/year, which was 73% greater than corn production without vertical mulch. On the other hand, the cropping system with six meter distance of vertical mulch required Rp 3,250,000,- per ha, which was Rp 250,000,- more expensive than that without vertical mulch. Normal 0 false false false IN X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi; mso-fareast-language:EN-US;}

An important African timber tree species, white mahogany (Khaya anthotheca), is heavily exploited and vulnerable. Endophytic fungi are thought to have an important role in plant communities, e.g. by increasing the fitness of the host tree. The aim of the present study was to isolate and characterize endophytic fungi collected from K. anthotheca in Ghana. In total, 64 fungal isolates were obtained from symptomless leaf samples. The fungi were grouped according to their morphology, and subjected to DNA sequence comparisons of the ribosomal ITS region. Based on phylogenetic analyses, the fungal isolates were grouped in Sordariomycetes and Dothideomycetes (Ascomycota). Species of Xylariales were the most common fungi associated with K. anthotheca. The results of this study indicate that K. anthotheca serves as a host to numerous endophytic fungi. These fungi could have significance as a source of novel metabolites, and for the fitness of this tree species.

Leaf area, IBA concentration and age of stockplants were all found to be important factors for successful rooting for vegetative propagation using single-node cuttings of the two main African mahogany species: Khaya anthotheca and K. ivorensis. Cuttings with leaf area of 30–50 cm2 had the best rooting percentage and cuttings with about 30 cm2 had the most number of roots per cutting in K. anthotheca. Khaya ivorensis, cuttings with 10–30 cm2 leaf area had the highest rooting percentage. Cuttings collected from 1-year-old stockplants recorded the highest rooting percentage and largest number of roots per cutting. Cuttings from 3-year-old stockplant of the same seeds sources had the lowest rooting suggesting aging negatively impacted rooting ability. The effect of auxin concentration, on rootability was examined with cuttings of K. anthotheca. An IBA concentration of 0.8% was the best exogenous auxin concentration for percentage rooting, number of roots per cutting and the length of the longest root per cutting.

We examined the relative susceptibility of four mahogany species, Khaya ivorensis, Khaya anthotheca, Entandrophragma angolense, and E. utile, to Hypsipyla robusta attack. Seeds were obtained from one to three parent trees for each species. The research was conducted in the moist semideciduous forest zone in Ghana and used a randomized complete block design. Tree height and diameter and height to first branch were measured until 24 months after out-planting in the field. H. robusta damage was assessed by counting the numbers of shoots attacked, branches, and dead shoots. Khaya spp. grew better but experienced more attack than Entandrophragma spp. The relative susceptibility to H. robusta attack, from most to least, of the four species was: K. anthotheca > K. ivorensis > E. angolense > E. utile. At 24 months, the mean number of shoots attacked per tree ranged from 1.0 for an E. utile seed source to 3.6 on for a K. anthotheca seed source. At 15 months, K. anthotheca and K. ivorensis started branching at about 1.5 m, but height of clear trunk increased over time due to self-pruning. As K. anthotheca grew taller, the number of H. robusta attacks per tree declined. This suggested that selection of genotypes and species that are tolerant of H. robusta attack based on infestation of young plants may not be appropriate. Genetic factors more completely reflecting the response of different species and genotypes to H. robusta attack may manifest themselves at later growth stages.

Overexploitation of the African mahoganies, Khaya anthotheca and K. ivorensis, could lead to their commercial extinction in the near future. Efforts to establish plantations to sustain supply have been discouraged by the shoot borer Hypsipyla robusta Moore. We hypothesized that there is a shade level at which Hypsipyla attack and branching are reduced, but height growth is adequate. We report on the growth of these African mahoganies and Hypsipyla attack under three different forest canopy shade levels: open (55% open sky), medium shade (26% open), and deep shade (11% open). Hypsipyla attack on K. anthotheca was 85%, 11%, and 0% attack in the open, medium, and deep shade treatments, respectively. However, growth in medium and deep shade was slow. Mean tree height for K. anthotheca was 413.8, 126.2, and 54.5 cm in the open, medium and deep shade treatments, respectively. K. ivorensis showed similar trends. The reduced growth under these shade levels limit the use of this strategy for controlling Hypsipyla attack.

Questions: Do lianas alter the relative success of tree species during regeneration? Are the effects of lianas on tree seedlings moderated by canopy openness? How are patterns of biomass allocation in tree seedlings affected by liana competition? Location: Tropical moist semi-deciduous forest in Ghana. Methods: Seedlings of the trees Nauclea diderrichii (pioneer), Khaya anthotheca (non-pioneer light demander) and Garcinia kola (non-pioneer shade bearer) were planted with the lianas Acacia kamerunensis (fast growing) and Loeseneriella rowlandii (slow growing) in large and small gaps (ca. 15% and 8% PAR respectively) and in the forest understorey (ca. 4% PAR). Seedling survival, growth and biomass allocation were measured. Results: Canopy openness moderated the interaction between liana and tree seedlings. The nature of the interaction was both liana and tree species specific and displayed temporal variation. Acacia competition effects were stronger in sites with greater canopy openness. In big gap...

Proliferation of lianas in canopy gaps can restrict tree regeneration in tropical forests through competition. Liana effects may differ between tree species, depending on tree requirements for above- and below-ground resources. We conducted an experiment in a shade house over 12 months to test the effect of light (7 and 27% external irradiance) on the competitive interactions between seedlings of one liana species and three tree species and the contribution of both above- and below-ground competition. Seedlings of the liana Acacia kamerunensis were grown with tree seedlings differing in shade tolerance: Nauclea diderrichii (Pioneer), Khaya anthotheca (Non-Pioneer Light Demander) and Garcinia afzelii (Non-Pioneer Shade Bearer). Trees were grown in four competition treatments with the liana: no competition, root competition, shoot competition and root and shoot competition. Both root and root–shoot competition significantly reduced relative growth rates in all three tree species. After one year, root–shoot competition reduced growth in biomass to 58% of those (all species) grown in no competition. The root competition treatment had a more important contribution in the effect of the liana on tree growth. Tree seedlings did not respond to competition with the liana by altering their patterns of biomass allocation. Although irradiance had a great effect on tree growth and allocation of biomass, the interaction between competition treatments and irradiance was not significant. Nauclea diderrichii, the tree species which responded most to the effects of competition, showed signs of being pot-bound, the stress of which may have augmented the competition effects. The understanding of the interaction of above- and below-ground competition between lianas and trees and its moderation by the light environment is important for a proper appreciation of the influence of lianas on tropical forest regeneration.

Khaya anthotheca and Khaya ivorensis (trade name African mahogany) of the family Meliaceae are among the most valuable tropical timber tree species of Africa. Continued supply of these timber species is threatened by over exploitation from natural forest and the difficulties in the establishment of mahogany plantations due to attack of shoot borer Hypsipyla robusta Moore. Hypsipyla attack destroys the growing shoots, causes forking, retards growth and reduces the economic value of the timber. In this study, provenance and within provenance evaluation for pest resistance and growth were studied. The results showed no significant ( P > 0.05) variation in growth among provenances of K. anthotheca and K. ivorensis . Significant variations ( P K. anthotheca had a high heritability ( h 2 = 0.74) for height growth compared to that of K. ivorensis ( h 2 = 0.51) suggesting an inherent degree of higher genetic control in height growth for K. anthotheca than K. ivorensis . The degree of apical dominance and height growth were found to be the most important factors for selection for pest resistance. Backward selection based on the performance of the progenies identified nine and six mother trees of K. anthotheca and K. ivorensis respectively for conservation as seed trees. The results are discussed in relation with productivity in plantations, conservation of genetic resources of mahoganies and the potential of family and or individual selection for quick and high genetic gains.

Valuable timber tree species frequently show poor regeneration after selective logging in tropical forests. Small size of logging gaps, lack of soil disturbance, and limited seed availability have each been blamed for observed regeneration failures. We investigated seed germination and seedling performance using a split-plot factorial design involving light availability and litter removal for six Central African timber tree species, hypothesizing that canopy gaps and litter removal would improve seedling establishment, and that less shade-tolerant species would show stronger responses to both factors. Contrary to our expectations, significantly more germinants established on intact litter than on exposed mineral soil 3 mo after seeding. After 18 mo, seedling survival, height and diameter growth, leaf area, and rooting depth were all much higher in gap plots than in the understory for all species, with the exception of Gilbertiodendron dewevrei, a highly shade-tolerant species whose survival was higher in the understory. Leaf production was negatively influenced by litter removal in the least shade-tolerant species, Nauclea diderrichii, with weak or positive effects in other species. G. dewevrei, while displaying a low-light threshold for growth, exhibited a surprisingly high growth response to increasing light comparable to more shade-intolerant species, a response that may help explain its local competitive dominance in the region. Due to the rapid closure of small gaps, we suggest that shade-intolerant species such as N. diderrichii, Khaya anthotheca, and Entandrophragma utile might benefit from more intensive silvicultural practices that create larger canopy gaps.

Eight limonoids, anthothecanolide (1), 3-O-acetylanthothecanolide (2), 2,3-di-O-acetylanthothecanolide (3), 6R,8alpha-dihydroxycarapin (4), 3beta-acetoxy-3-deoxo-6R-hydroxycarapin (5), methyl angolensate, methyl 6-hydroxyangolensate and khayalactone together with sitosterol glucoside, have been isolated from the extracts of the stem bark of Khaya anthotheca. Compounds 1-4 are described for the first time. Their structures were established by analysis of the high-field NMR and MS data. The structure of compound 4 was confirmed by a single crystal X-ray structure analysis.

The stems of Khaya anthotheca yielded two new limonoids, which were identified on the basis of spectroscopic analysis as 1alpha,8alpha-oxido-3beta-acetoxy-2alpha-acylperoxy-1alpha,14alpha-dihydroxy-[3.3.1(10,2)]-bicyclomeliac-7,19-olide (3) and 3-acetoxy-8,14-dien-8,30-seco-khayalactone (4). Methyl 1alpha,2beta,3alpha,6,8alpha,14beta-hexahydroxy-[4.2.1(10,30).1(1,4)]-tricyclomeliac-7-oate, scopoletin, and 3-O-beta-D-glucopyranosylsitosterol were also isolated. The limonoids were of little value to clarify the basis of the nonresistance against Hypsipyla grandella.

The abundance of forest tree species may be locally limited by the inability of species to disperse to all sites suitable for germination and establishment. This phenomenon of "dispersal limitation" has been suggested to promote the maintenance of high species diversity in tropical forests by slowing down competitive exclusion. We present the first direct experimental evaluation of dispersal limitation in tropical forests, and of its importance relative to other factors affecting recruitment. Seed addition, litter removal and light availability effects on seedling establishment were evaluated in a full factorial experiment on two African mahogany species, Entandrophragma utile and Khaya anthotheca. Seedling recruitment after 18 months, was -22 times greater in seed addition treatments (with addition rates corresponding to the tail of seed shadows of large reproductive trees) compared to controls. This seed addition effect was an order of magnitude greater than either gap or litter removal effects, with similar results observed in both logged and primary forest locations. We conclude that dispersal limitation strongly limits seedling establishment for the two species studied. An important "applied corollary" of this result is that seed supplementation may substantially increase local abundance of valuable or rare species in disturbed or managed tropical forests.