Afzelia bipindensis

About: Afzelia bipindensis is a research topic. Over the lifetime, 8 publications have been published within this topic receiving 179 citations.

Importance of the ectomycorrhizal network for seedling survival and ectomycorrhiza formation in rain forests of south Cameroon

Abstract: An investigation was undertaken at two sites south Cameroon to assess the importance of living roots of adult trees as sources of inoculum for survival, ectomycorrhizal colonisation and growth of seedlings of Paraberlinia bifoliolata. One-month-old seedlings of Paraberlinia bifoliolata, isolated from or in contact with roots of adult target trees, were transplanted in concentric circles 5, 10, 15, and 30 m away from the stem bases of four adult tree species (Afzelia bipindensis, Brachystegia cynometroides, Paraberlinia bifoliolata and Tetraberlinia bifoliolata). After 4 and 8 months, survival, ectomycorrhiza formation and seedling height were observed; plant biomass was determined after 8 months. After 4 months, there was no difference in seedling survival between seedlings in contact with roots of adult trees and isolated seedlings. The number of ectomycorrhizal seedlings was higher among seedlings in contact with adult trees than among isolated seedlings. After 8 months, both seedling survival and ectomycorrhiza formation were higher in seedlings in contact with roots than in isolated seedlings. Seedling survival and ectomycorrhiza formation were highest under Brachystegia. The fraction of surviving seedlings that had formed ectomycorrhizas was lowest under Afzelia. The fraction of surviving seedlings that were ectomycorrhizal declined monotonically towards the edge of the crown projection. Biomass of seedlings in contact with adult trees was significantly higher than that of isolated seedlings. This difference was consistent for all four tree species. The height of seedlings did not vary with the treatment.

Diet and feeding behaviour of the forest elephant in the Santchou Reserve, Cameroon

Abstract: ummary This study reports the diet and feeding behaviour of forest elephants in Western Cameroon. Diet consisted primarily of grass (Pennisetum purpureum). Woody material (leaves and stems) made up the smallest proportion of the diet. Twenty-two species of fruit were eaten of which seven formed a significant component of the diet: Cucurmis manii, Desplatsia subericarpa, Irvingia gabonensis, Parinari excelsa, Strychnos innocuea, Theobroma cacao and Vitex doniana. The greatest variety of fruit was available during the dry season. The frequent presence of crop seeds in the dung piles indicated that elephant incursions into the farms to feed on crops were regular. Elephants removed bark from eight species of tree but concentrated on four: Afzelia bipindensis, Coloncoba welwitschii, Bridelia ferruginea and Terminalia superba. Seventeen species were recorded as browsed. Trees in particular were favoured. Elephants fed mainly by grazing or stripping off fruits. Debarking of trees, breaking of the main stems, and uprooting or pushing over were minor feeding activities. Resume Ce travail decrit le regime et le comportement alimentaire de l'elephant de foret dans l'Ouest du Cameroun. Les elephants se nourissaient surtout d'herbes (Pennisetum purpureum). Le materiel ligneux (feuilles et branches d'arbres) constituait la plus petite proportion du regime alimentaire. Vingt-deux especes de fruit ont ete consommeses dont 7 ont constitute la partie principale de regime: Cucurmis manii, Desplatsia subericarpa, Irvingia gabonensis, Parinari excelsa, Strychnos innocuea, Theobroma cacao et Vitex doniana. C'est pendant la saison seche que les elephants ont dispose de la plus grande variete de fruits. La presence reguliere dans les crottes de graines d'especes cultivees indique que les incursions d'elephants dans les plantations sont frequentes. Les elephants ont enleve l'ecorce de 8 especes d'arbres mais se sont concentres sur 4 d'entre elles: Afzelia bipindensis, Coloncoba welwitschii, Bridelia ferruginia, et Terminalia superba. Dix-sept espees ont ete broutees. Les elephants aimaient specialement les arbres. Les elephants se nourissaient principalement en broutant les herbes ou en depouillant les arbres de leurs fruits. L'ecorcage des troncs d'arbres, le brisage des tiges ou le deracinage des arbres etaient des activites secondaires du comportement alimentaire.

Microsatellite Development and Flow Cytometry in the African Tree Genus Afzelia (Fabaceae, Caesalpinioideae) Reveal a Polyploid Complex

Abstract: Premise of the study: Microsatellites were developed in the vulnerable African rainforest tree Afzelia bipindensis to investigate gene flow patterns. Methods and Results: Using 454 GS-FLX technique, 16 primer sets were identified and optimized, leading to 11 polymorphic and readable markers displaying each six to 25 alleles in a population. Up to four alleles per individual were found in each of the loci, without evidence of fixed heterozygosity, suggesting an autotetraploid genome. Cross-amplification succeeded for all loci in the African rainforest species A. pachyloba and A. bella, which appeared tetraploid, and for most loci in the African woodland species A. africana and A. quanzensis, which appeared diploid, but failed in the Asian species A. xylocarpa. Flow cytometry confirmed the suspected differences in ploidy. Conclusions: African Afzelia species are diploid or tetraploid, a situation rarely documented in tropical trees. These newly developed microsatellites will help in the study of their matin...

Vegetation structure, carbon sequestration potential and species conservation in four agroforestry systems in Cameroon (Tropical Africa)

Abstract: As the rate of forest degradation continues to rise, agroforestry may serve as a way of conserving species and carbon sinks. The aim of this study was to assess agrobiodiversity and carbon sequestration potential in agrosystems in Cameroon. Three age groups of agrosystems were studied. Data were collected in 100x50 m2 quadrates. Density ranged from 53.17±0.08 to 1463±50.11; basal area from 2.07±0.00 to 988.39±16.13 m2/ha; Shannon diversity from 3.3±0.71 to 3.68±0.72; Carbon storage from 12.1±0.27 to 54.65±1.38 t C/ha for 1-10-year-old agrosystems with lowest values in neem; 34.78±0.87 to 71.34±1.6 t C/ha for 10-20-year-old stands with lowest values in cashew; 28.24±0.04 to 108.51±2.46 t C/ha for +20-year-old stands with highest values in eucalyptus; Carbon sequestration potential from 296.7±1.98 to 859.33±10.01 t CO2eq/ha. The highest carbon stocks were found in eucalyptus stands (p<0.05). Several endogenous species, especially Afzelia bipindensis (EN), Leptoderris ledermannii (EN), Mansonia altissima (EN), Entandrophragma cylindricum (VU), Nesogordonia papaverifera (VU), Quassia sanguinea (VU), Vitellaria paradoxa (VU), Afzelia africana (VU), Erythrina senegalensis (LC), Detarium microcarpum (LC), senna spectabilis (LC), were assessed. Other overexploited species, especially Carissa edulis, Zanthoxylum zanthoxyloides, Adansonia digitata, Securidaca longepedonculata, were assessed as well. The studied systems are significant CO2eq sinks and refuge centre for agrobiodiversity.

Removal and predation of aril-covered seeds: the case of Afzelia bipindensis (Fabaceae – Detarioidae)

Abstract: Background and aims – Most tree species with aril-covered seeds are assumed to be dispersed by frugivores. However, the number of studied African rainforest plant species remains low. This study focused on Afzelia bipindensis, an important timber species, which produces seeds partly covered by an aril. Specifically, this study aimed to: (1) identify the dispersers and the predators of A. bipindensis seeds, (2) characterize the role of those dispersers and predators in the regeneration process, and (3) understand the role of the aril in seed germination in relation to the feeding behaviour of the identified dispersers. Methods – The study took place in a Gabonese evergreen rainforest in 2015 and in a Cameroonian semi-deciduous rainforest in 2016 and 2017. We conducted more than 100 hours of direct observations, and used camera traps to monitor animal activities for 3000 hours within the canopy and 10 000 hours on the ground under fruiting trees. Key results – Three rodent taxa (Cricetomys emini, Funisciurus isabella and an undetermined species of Muridae) were mainly observed interacting with the seeds but neither birds nor monkeys were observed. Rodents removed more than 90% of the seeds, after detaching the aril, to probably cache them in burrows or superficial caches. Seeds from which we manually removed the aril (mimicking rodent behaviour) had a higher germination rate.Conclusions – Rodents may play a more important role than expected in the dynamics of tree species producing aril-covered seeds.