References of "Doucet, Jean-Louis"
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See detailIs the western lowland gorilla a good gardener ? Evidence for directed dispersal in Southeast Gabon
Haurez, Barbara ULg; Brostaux, Yves ULg; Petre, Charles-Albert ULg et al

in Bois et Forêts des Tropiques (2015), 324(2), 39-50

In Central African tropical forests, the western lowland gorilla deposits most of the seeds it disperses in well-lit nesting sites that can favour seedling growth. The faecal matrix surrounding the seeds ... [more ▼]

In Central African tropical forests, the western lowland gorilla deposits most of the seeds it disperses in well-lit nesting sites that can favour seedling growth. The faecal matrix surrounding the seeds can act as a fertiliser and further enhance seedling development. This fertilisation effect had never been tested. Our research therefore aimed to determine whether seed deposition by gorillas (i) in faecal matter and (ii) in nest sites is advantageous for seedling development (growth rate and foliation rate) and survival (% of surviving seedlings). To assess the effect of the faecal matrix, seeds of Santiria trimera (Burseraceae), Chrysophyllum lacourtianum (Sapotaceae) and Plagiostyles africana (Euphorbiaceae) collected from gorilla faeces were sown in a nursery with and without a faecal matrix. Seedlings of Santiria trimera and Dacryodes normandii (Burseraceae) were established in nest sites and in closed canopy terra firme forest sites to assess the impact of seed deposition on seedling development and survival. The faecal matrix was observed to positively influence seedling development in the species studied, but showed no effect on survival. Regarding seed deposition sites, the development rates observed were two to ten times higher in the nest sites than in closed-canopy forest. This enhanced seedling development was positively correlated with canopy openness. In situ studies of seed germination, seedling growth and survival are needed to characterise the fate of gorilla-dispersed seeds more precisely. However, our results offer evidence that gorillas provide important directed dispersal services by depositing seeds most frequently in open canopy sites. [less ▲]

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See detailNew data on the recent history of the littoral forests of southern Cameroon: an insight into the role of historical human disturbances on the current forest composition
Biwolé, Achille ULg; Morin-Rivat, Julie ULg; Fayolle, Adeline ULg et al

in Plant Ecology and Evolution (2015), 148(1), 19-28

Background and aims – Prior to European colonisation of Central Africa, human populations were dispersed through the forests, where they practiced slash-and-burn cultivation. From the 19th century they ... [more ▼]

Background and aims – Prior to European colonisation of Central Africa, human populations were dispersed through the forests, where they practiced slash-and-burn cultivation. From the 19th century they were progressively concentrated in villages along roads, leaving large areas of forest derelict. In south-western Cameroon, and elsewhere in Central Africa, forest canopy is dominated by long-lived lightdemanding tree species, suggesting a possible role of human disturbance. The aim of this study was to bring new insights into the possible effect of historical human disturbances in terms of timing and spatial extent on the current forest composition. Location – Wet evergreen littoral forest in south-western Cameroon. Methods and key results – A combined vegetation sampling and archaeobotanical survey were conducted. Potsherds, oil-palm endocarps, and charcoal were found throughout the study area, suggesting generalised human occupation and anthropogenic fire. Human occupancy occurred in two periods: between 2200 and 1500 BP, and, more recently, beginning three centuries ago. High frequency of fire and the presence of Elaeis guineensis both dated recently (between 260 and 145 BP) suggest slash-and-burn shifting cultivation practices. These human-induced disturbances may coincide with the age of the current emergent lightdemanding species, the age of which can be estimated around 200 years, or with the phases of drying climate recorded in the Central African forest in the early 18th century. Conclusions – These results support the idea that historical human disturbances are one of the major factors that shaped the current forest composition in Central Africa. [less ▲]

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See detailGlobally, functional traits are weak predictors of juvenile tree growth, and we do not know why
Paine, C.E. Thimothy; Amissah, Lucy; Auge, Harald et al

in Journal of Ecology (2015), 103(4), 978-989

1. Plant functional traits, in particular specific leaf area (SLA), wood density and seed mass, are often good predictors of individual tree growth rates within communities. Individuals and species with ... [more ▼]

1. Plant functional traits, in particular specific leaf area (SLA), wood density and seed mass, are often good predictors of individual tree growth rates within communities. Individuals and species with high SLA, low wood density and small seeds tend to have faster growth rates. 2. If community-level relationships between traits and growth have general predictive value, then similar relationships should also be observed in analyses that integrate across taxa, biogeographic regions and environments. Such global consistency would imply that traits could serve as valuable proxies for the complex suite of factors that determine growth rate, and, therefore, could underpin a new generation of robust dynamic vegetation models. Alternatively, growth rates may depend more strongly on the local environment or growth–trait relationships may vary along environmental gradients. 3. We tested these alternative hypotheses using data on 27 352 juvenile trees, representing 278 species from 27 sites on all forested continents, and extensive functional trait data, 38% of which were obtained at the same sites at which growth was assessed. Data on potential evapotranspiration (PET), which summarizes the joint ecological effects of temperature and precipitation, were obtained from a global data base. 4. We estimated size-standardized relative height growth rates (SGR) for all species, then related them to functional traits and PET using mixed-effect models for the fastest growing species and for all species together. 5. Both the mean and 95th percentile SGR were more strongly associated with functional traits than with PET. PET was unrelated to SGR at the global scale. SGR increased with increasing SLA and decreased with increasing wood density and seed mass, but these traits explained only 3.1% of the variation in SGR. SGR–trait relationships were consistently weak across families and biogeographic zones, and over a range of tree statures. Thus, the most widely studied functional traits in plant ecology were poor predictors of tree growth over large scales. 6. Synthesis. We conclude that these functional traits alone may be unsuitable for predicting growth of trees over broad scales. Determining the functional traits that predict vital rates under specific environmental conditions may generate more insight than a monolithic global relationship can offer. [less ▲]

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See detailThe role of great apes in seed dispersal of the tropical forest tree species Dacryodes normandii (Burseraceae) in Gabon
Haurez, Barbara ULg; Daïnou, Kasso ULg; Tagg, Nikki et al

in Journal of Tropical Ecology (2015), 31(05), 395-402

The identification of seed dispersers and predators is essential to understand the effect of anthropogenic disturbances, and the associated defaunation process, on tropical forest dynamics in Central ... [more ▼]

The identification of seed dispersers and predators is essential to understand the effect of anthropogenic disturbances, and the associated defaunation process, on tropical forest dynamics in Central Africa. In this study, the animals involved in seed predation and dispersal of Dacryodes normandii (Burseraceae), an endozoochorously dispersed tree species endemic to Gabonese forests, were identified in a site in south-east Gabon using two complementary methods: direct observation and camera-trap monitoring of fruit piles. The combined sampling effort (172 h of direct observations and 796 d of camera trapping) led to the identification of six disperser and eight predator species of D. normandii seeds. With high frequency of consumption (88% and 57% of their visits, respectively) and long visit duration (83 and 23 min, respectively), the western lowland gorilla and central chimpanzee were identified as the main dispersers of this species. Seeds passed through the gorilla gut exhibited high germination success (68%). Rodents were identified as predators of D. normandii seeds, potentially displaying rare secondary dispersal through scatter-hoarding. The results of this study highlight the importance of great apes in the seed dispersal of this tree species. [less ▲]

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See detailLe genre Guibourtia Benn., un taxon à haute valeur commerciale et sociétale (synthèse bibliographique)
Tosso, Dji-ndé Félicien ULg; Daïnou, Kasso ULg; Hardy, J. Olivier et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2015), 19(1),

Known as a genus of great socio-cultural and economical importance, Guibourtia Benn. includes morphologically very similar multipurpose sister species, found in various habitats with different climate and ... [more ▼]

Known as a genus of great socio-cultural and economical importance, Guibourtia Benn. includes morphologically very similar multipurpose sister species, found in various habitats with different climate and soil conditions. In many places, Guibourtia is subject to local overexploitation by forest companies and local communities. As the population density of Guibourtia species is generally very low, it may be necessary to conduct scientific investigations that will provide valuable information for the management of the populations concerned. This paper is based on an extensive literature review and summarizes the available information on the genus Guibourtia, in terms of botany, ecology, genetics, forestry and ethnobotany. Our review provided evidence that, to date, ecological and silvicultural knowledge regarding Guibourtia species is lacking and that it is very difficult to morphologically differentiate very similar sister species. In addition, we provide a new determination key for the genus Guibourtia. Based on the available information, it is difficult to assess the conservation status of these taxa. Further investigations are needed to suggest appropriate management strategies for Guibourtia. Moreover, species diversity within this genus and its distribution in various tropical biomes make it an excellent biological model for understanding the historical, biological and environmental mechanisms that explain the diversity of tropical moist forests. [less ▲]

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See detailWood anatomical characteristics of 600 African tropical species in relationship with their ecology
Morin, Julie ULg; Fayolle, Adeline ULg; Doucet, Jean-Louis ULg et al

Poster (2014, December 16)

The tropical moist forest is a biome with a high number of species that are functionally different. The question arises whether there are patterns in the spectra of wood anatomical features according to ... [more ▼]

The tropical moist forest is a biome with a high number of species that are functionally different. The question arises whether there are patterns in the spectra of wood anatomical features according to functional types. Here we propose to present the main anatomical characteristics of 600 tropical species from the Guineo-Congolian domain in relationship with their ecology. We cross-checked two databases: the anatomical database InsideWood and the CoForTraits database of functional traits produced during the CoForChange project. After characterizing the main trends of the dataset, we performed multivariate analyses between the wood traits (i.e. the anatomical features) and six groups of functional traits: leaf phenology, regeneration guild, dispersal syndrome, life form, plant maximum height, and wood specific gravity. Results showed (i) that several wood features were specific to the tropics, to Africa or only to the Guineo-Congolian region, and (ii) that phylogeny explained the main part of the variation among the traits, whereas (iii) wood structure provided nonetheless interesting functional information related to gradients in plant growth, survival, and dispersal, and (iv) that there was a functional convergence in the study species in response to similar environmental constraints. These observations suggest that certain anatomical features can be used as indicators of functional traits in species-rich biomes. Further research will enable us to increase the input of wood anatomy in explaining the functional trade-offs in African tropical species. [less ▲]

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See detailLe genre Erythrophleum (Fabaceae) en Afrique, un modèle pour l’étude des mécanismes de différenciation de niches climatiques
Gorel, Anaïs ULg; Duminil, Jérôme; Doucet, Jean-Louis ULg et al

Conference (2014, December 16)

Comprendre l’origine des patrons de diversité est un défi en écologie des communautés et en écologie évolutive, notamment dans le contexte du futur changement climatique. Ce poster aura deux objectifs : i ... [more ▼]

Comprendre l’origine des patrons de diversité est un défi en écologie des communautés et en écologie évolutive, notamment dans le contexte du futur changement climatique. Ce poster aura deux objectifs : i) présenter pourquoi le genre Erythrophleum en Afrique est un modèle d’étude idéal à la compréhension des mécanismes de différenciation de niche et de spéciation au sein d’une lignée d’arbre en région tropicale; ii) mettre en lumière les démarches statistiques et expérimentales permettant de valider et de comprendre ces mécanismes. Le genre Erythrophleum, largement distribué en Afrique, est représenté par quatre espèces d’arbre : E. ivorense, E. suaveolens, E. africanum et E. lasianthum. Ces espèces morphologiquement très proches, présentent des aires de distribution géographiques et climatiques adjacentes. Elles sont distribuées de façon parapatrique sur un gradient pluviométrique, du plus humide pour E. ivorense ou plus sec pour E. lasianthum. Ce mode de distribution apparent, combiné à des données issues d’études phylogénétiques, suggère un rôle majeur des gradients climatiques comme pilotes des différenciations spécifiques du genre et pourrait donc confirmer l’hypothèse du gradient écologique (« The ecological gradient hypothesis » suppose que des gradients environnementaux peuvent induire des spéciations parapatriques sans que les populations ne soient isolées géographiquement. Néanmoins, des études sur les niches climatiques et leurs degrés de conservatisme sont indispensables pour valider cette hypothèse. Aujourd’hui, ces études sont rendues plus aisées grâce au développement de nouvelles techniques de modélisation des niches environnementales (Species Distribution Model ou SDM) et de tests statistiques de quantification du conservatisme/divergence de niche (voire Warren et al., 2008). En complément de la modélisation des niches observées (c.à.d. niches réalisées selon la définition de Hutchison (1957)), il est intéressant de comprendre les stratégies fonctionnelles sous-jacentes aux différenciations de niche. Les différenciations de niche au sein des espèces du genre sont probablement issues d’une distinction de leurs stratégies d’utilisation des ressources (lumière/eau) et de leurs différents positionnements au sein du slow-fast continuum (sensu Reich, 2014). Cette hypothèse peut être testée par la mise en place d’expériences en milieu contrôlé mesurant les réponses des individus à des stress environnementaux. [less ▲]

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See detailLes progrès de la foresterie sociale en Afrique centrale
Vermeulen, Cédric ULg; Doucet, Jean-Louis ULg

Conference given outside the academic context (2014)

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See detailIntegrating phylogenetic and environmental niche models to explore speciation mechanisms in the Erythrophleum genus in tropical Africa
Gorel, Anaïs ULg; Fayolle, Adeline ULg; Doucet, Jean-Louis ULg et al

Conference (2014, December 10)

In the context of global climate change, it is of primary importance to understand the species response to climate (habitat tracking or adaptation). In this study we investigated the evolutionary history ... [more ▼]

In the context of global climate change, it is of primary importance to understand the species response to climate (habitat tracking or adaptation). In this study we investigated the evolutionary history of the climatic niche between and within closely related tropical tree species of the Erythrophleum genus (Fabaceae, Caesalpinioideae): E. ivorense, E. suaveolens and E. africanum. Two major hypotheses, the refuge theory and the ecological gradient hypothesis, have been developed to explain the current distribution of tree clades across tropical Africa. To identify the speciation mechanisms, we used a combination of geographic data and environmental factors to quantify the degree of niche conservatism (or divergence). We used two sets of distribution data for the purpose of this study. Species distribution data for the whole of tropical Africa were gathered from herbarium records. Distribution data of the two sister species E. ivorense and E. suaveolens assigned to genetic cluster were available for the lowland tropical forests of western and central Africa. Using a Species Distribution Model (SDM) approach based on MaxEnt algorithm, we tested for the environmental differences (BIOCLIM data) between species and genetic clusters within species. We developed SDMs for each of the three Erythrophleum species (over the whole range) and for each of the five genetic clusters. We quantified the niche overlap using new niche similarity metrics. At species level, the climatic niches differed significantly and overlapped only sligthly, suggesting a parapatric speciation along a climatic gradient. Within the two sister species, the niche of the parapatric central African clusters strongly overlapped, suggesting a secondary contact following the recolonization from different forest refugia. The west African cluster however showed contrasted climatic niches possibly due to either recent (< 100 yrs) climate change in west Africa, or ongoing differentiation on the dry part of the climatic gradient. [less ▲]

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See detailEnrichment of Logging Gaps with a High Conservation Value Species (Pericopsis elata) in a Central African Moist Forest
Ouedraogo, Dakis-Yaoba ULg; Fayolle, Adeline ULg; Daïnou, Kasso ULg et al

in Forests (2014), 5(12), 3031-3047

In central Africa, most of the timber species require high light at the seedling stage for survival and growth. Forest managers face a regeneration shortage of these light-demanding timber species. To ... [more ▼]

In central Africa, most of the timber species require high light at the seedling stage for survival and growth. Forest managers face a regeneration shortage of these light-demanding timber species. To achieve long-term sustainability, there is a need for enrichment methods combining low cost and high species performance. The aim of this study was to assess the performance of Pericopsis elata seedlings in enriched logging gaps in Cameroon. Over five years; the survival and size of each seedling was monitored in 27 logging gaps that were either left without maintenance or cleared. Gaps were relatively small with an average total area of 155 m2. We found that planted seedlings of P. elata performed well in logging gaps. Even without any maintenance 61% of the planted seedlings survived after five years with an average annual diameter increment of 0.28 cm. P. elata appeared to be a good candidate species for enrichment in logging gaps. We demonstrated that the seedlings of P. elata tolerated a wide range of soil conditions but that their performance was strongly influenced by light availability (gap clearance), suggesting potentially improved performance of P. elata in high light environments such as in plantation or larger gaps. [less ▲]

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See detailLate-Holocene moist forests of Central Africa: contribution of charcoal analysis
Morin, Julie ULg; Bremond, Laurent; Gillet, Jean-François et al

Poster (2014, December)

Wood charcoals are often uncovered in the soils of the tropical regions. They remain little studied, however, and this observation is even truer for charcoals coming from the dense humid forests of ... [more ▼]

Wood charcoals are often uncovered in the soils of the tropical regions. They remain little studied, however, and this observation is even truer for charcoals coming from the dense humid forests of Central Africa. Here we aim at showing the interest of the analysis of soil charcoals in this region so as to understand the dynamics of past forest environments during the late-Holocene. Several examples of taxonomical identifications conducted on charcoals sampled in soil pits in Cameroon and in the Republic of the Congo are presented along with radiocarbon dates. These charcoals were hand-split then observed under an incident light microscope. The wood anatomical features that were preserved in charcoals and described according to a standard method were compared to a reference collection of woods. Results demonstrated that past burnings that spanned from 2,500 BP to Recent were human-induced and scattered in the study area. The identified species are still present in the environment today and localized changes in the vegetation occurred over the past two millennia. Charcoal analysis can thus allow a better understanding of the past history of the tropical forests in relationship with the ancient anthropogenic disturbances. [less ▲]

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See detailSoil charcoal to assess the impacts of past human disturbances on tropical forests
Vleminckx, Jason; Morin-Rivat, Julie ULg; Biwolé, Achille et al

in PLoS ONE (2014), 9(11),

The canopy of many central African forests is dominated by light-demanding tree species that do not regenerate well under themselves. The prevalence of these species might result from ancient slash-and ... [more ▼]

The canopy of many central African forests is dominated by light-demanding tree species that do not regenerate well under themselves. The prevalence of these species might result from ancient slash-and-burn agricultural activities that created large openings, while a decline of these activities since the colonial period could explain their deficit of regeneration. To verify this hypothesis, we compared soil charcoal abundance, used as a proxy for past slash-and-burn agriculture, and tree species composition assessed on 208 rainforest 0.2 ha plots located in three areas from Southern Cameroon. Species were classified in regeneration guilds (pioneer, non-pioneer light-demanding, shade-bearer) and characterized by their woodspecific gravity, assumed to reflect light requirement. We tested the correlation between soil charcoal abundance and: (i) the relative abundance of each guild, (ii) each species and family abundance and (iii) mean wood-specific gravity. Charcoal was found in 83% of the plots, indicating frequent past forest fires. Radiocarbon dating revealed two periods of fires: ‘‘recent’’ charcoal were on average 300 years old (up to 860 BP, n = 16) and occurred in the uppermost 20 cm soil layer, while ‘‘ancient’’ charcoal were on average 1900 years old (range: 1500 to 2800 BP, n = 43, excluding one sample dated 9400 BP), and found in all soil layers. While we expected a positive correlation between the relative abundance of light demanding species and charcoal abundance in the upper soil layer, overall there was no evidence that the current heterogeneity in tree species composition can be explained by charcoal abundance in any soil layer. The absence of signal supporting our hypothesis might result from (i) a relatively uniform impact of past slash-and-burn activities, (ii) pedoturbation processes bringing ancient charcoal to the upper soil layer, blurring the signal of centuries-old Human disturbances, or (iii) the prevalence of other environmental factors on species composition. [less ▲]

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See detailAnalyse à haute résolution spatiale et temporelle des activités humaines à l’Holocène récent dans les forêts humides d’Afrique Centrale
Morin, Julie ULg; Gorel, Anaïs ULg; Biwolé, Achille et al

Poster (2014, November)

Des études paléoécologiques et archéologiques ont démontré que les populations humaines ont de longue date investi les forêts humides d’Afrique Centrale. Les occupations humaines ont toutefois été peu ... [more ▼]

Des études paléoécologiques et archéologiques ont démontré que les populations humaines ont de longue date investi les forêts humides d’Afrique Centrale. Les occupations humaines ont toutefois été peu documentées en raison de difficultés relatives à l’accès au terrain. Nous présentons ici une méthodologie systématique basée sur la quantification et la datation des macrorestes botaniques carbonisés pour définir les activités humaines passées en forêt tropicale africaine. Pour cela, 53 sondages équidistants ont été creusés dans 3 sites du sud-est-du Cameroun. Dans chaque sondage ont été prélevées des quantités fixes de sol par couche de 10 cm. Les macrorestes botaniques carbonisés ont été récoltés par tamisage à l’eau directement sur le site. Les refus de tamis ont été triés (charbons de bois, endocarpes de palmier à huile, graines non identifiées), pesés sur une balance de précision et analysés statistiquement. En outre, 25 échantillons ont été datés par AMS. Les résultats montrent que les activités humaines sont réparties en deux périodes : l’âge du Fer ancien entre 2300 et 1300 BP et l’âge du Fer récent entre 670 BP et l’actuel. En outre, les charbons de bois et les endocarpes de palmier à huile ne représentent pas le même type d’activités. Deux villages âge du Fer ancien datés d’environ 2000 BP ont été identifiés par la présence concomitante d’endocarpes de palmier à huile et de tessons céramiques. Les motifs circulaires imprimés dans la céramique et inédits pour la zone d’étude rappellent les gravures et décors céramiques découverts au Gabon et dans la zone de la Sangha-Likwala-aux-Herbes, datés également de 2000 BP. L’abondance décroissante des charbons dans l’orbe d’influence de ces villages pourrait correspondre à d’anciennes zones agricoles. Les perturbations les plus récentes peuvent, quant à elles, être mises en relation avec la végétation actuelle, en particulier les arbres émergents héliophiles qui dominent la composition floristique et qui sont des recrus post-culturaux. Pour la première fois, une méthodologie quantitative basée sur les restes archéobotaniques a été appliquée en Afrique Centrale. Elle nous a permis de documenter à haute résolution la répartition spatiale et temporelle des activités humaines à l’échelle locale. Ce travail sera poursuivi par une reconstitution paléoenvironnementale à partir de l’identification des macrorestes végétaux. [less ▲]

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See detailLes dispositifs de type "sentier" : état d'avancement et premiers résultats
Doucet, Jean-Louis ULg

Conference (2014, October 20)

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See detailKnowing the past to anticipate the future: soil charcoal as a proxy to model forest evolution
Morin, Julie ULg; Biwolé, Achille; Bourland, Nils et al

Poster (2014, October)

Tropical forests of Central Africa constitute the second most important block of moist forest of the world. However little is known about their past evolution. Indeed, determining the past specific ... [more ▼]

Tropical forests of Central Africa constitute the second most important block of moist forest of the world. However little is known about their past evolution. Indeed, determining the past specific composition of these forests could allow modeling their evolution over time and providing data about their resilience capacity facing global change. To do this, we performed a pedoanthracological analysis in the semi-deciduous forests of southeastern Cameroon. We excavated test pits in 53 plots of botanical inventory along a gradient of vegetation, quantified wood charcoals by layers of 10 cm, identify the species present in charcoals, dated the charcoals by the radiocarbon method, then built up sequences including present forest composition. Results show that repeated fire events occurred across the study area during the last 2500 years. These disturbances are likely human-induced regarding evidence of anthropogenic activities (e.g. potsherds). Nonetheless the past specific composition does not strongly differ from the current one except for the oldest layers related to the major dry climatic event of 2500 BP. We conclude that moist forests have a good resilience capacity regarding moderate disturbances but were and will be deeply impacted by climate change. [less ▲]

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See detailImportance des modèles de distribution de niche potentielle dans la gestion des espèces tropicales exploitées: cas des taxons du genre Guibourtia Benn
Tosso, Dji-ndé Félicien ULg; Daïnou, Kasso ULg; Hambuckers, Alain ULg et al

Poster (2014, September 24)

De la famille des (Fabaceae / Caesalpinioideae) et composé de 13 espèces en Afrique, le genre Guibourtia comporte des taxons à forte valeur culturelle et à forte valeur commerciale. Aujourd'hui, la ... [more ▼]

De la famille des (Fabaceae / Caesalpinioideae) et composé de 13 espèces en Afrique, le genre Guibourtia comporte des taxons à forte valeur culturelle et à forte valeur commerciale. Aujourd'hui, la pression de l'exploitation combinée aux faibles densités de ce genre, fait a priori peser d’importantes menaces sur certaines de ses populations. Un projet de recherche a donc été initié afin de mieux comprendre la structure et la diversité génétique des populations de Guibourtia, en lien avec l'exploitation forestière et les patrons de reproduction spécifiques. Un premier volet de la recherche a consisté à identifier les déterminants climatiques expliquant la distribution des espèces. Nous avons combinée des modèles statiques (Maxent et régression logistique) avec des données du modèle climatique global CNRM CM5, et sur la base de l'occurrence de ces taxons entre 1950 et 2000. Il en ressort que les espèces du genre Guibourtia sont sensibles aux facteurs précipitation (69,2 %) et amplitude thermique (74,3 %). Dans un second temps, il sera utilisé les modèles climatiques des ères géologiques passées afin d'inférer la distribution de l'espèce au cours du Quaternaire, et de faire le lien avec des analyses phylogénétiques et phylogéographiques. Il sera également possible d'évaluer la distribution future de l'espèce tenant compte des modèles d'évolution du climat. Enfin, le projet de recherche s'attèlera particulièrement aux relations phylogénétiques entre espèces morphologiquement similaires en sympatrie ou parapatrie, en caractérisant en détail les flux de gènes entre individus de ces taxons proches, ainsi que leur degré de similarité physiologique. Les résultats de l’étude in fine contribueront à proposer des stratégies de conservation et de gestion durable dans le contexte de l’exploitation forestière d’Afrique centrale et du changement climatique en cours. [less ▲]

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See detailStand structure and species co-occurrence in mixed and monodominant Central African tropical forests
Djuikouo, Marie Noël K.; Peh, Kelvin S.H.; Nguembou et al

in Journal of Tropical Ecology (2014), 30(5), 447-455

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