Exploitation forestière et gestion durable des forêts d’Afrique Centrale

Conference given outside the academic context (2008)

L’avenir du Jardin Botanique National.

Diverse speeche and writing (2008)

Le projet DACEFI : contexte, philosophie et résultats attendus

in Vermeulen, Cédric; Doucet, Jean-Louis (Eds.) Les premières forêts communautaires du Gabon : Récits d'une expérience pilote (2008)

Le Jardin Botanique National de Belgique doit rester l’outil de tous

Article for general public (2007)

The Odd Man Out? Might Climate Explain The Lower Tree Alpha-Diversity Of African Rain Forests Relative To Amazonian Rain Forests?

in Journal of Ecology (2007), 95(5), 1058-1071

1. Comparative analyses of diversity variation among and between regions allow testing of alternative explanatory models and ideas. Here, we explore the relationships between the tree α-diversity of small ... [more ▼]

1. Comparative analyses of diversity variation among and between regions allow testing of alternative explanatory models and ideas. Here, we explore the relationships between the tree α-diversity of small rain forest plots in Africa and in Amazonia and climatic variables, to test the explanatory power of climate and the consistency of relationships between the two continents. 2. Our analysis included 1003 African plots and 512 Amazonian plots. All are located in old-growth primary non-flooded forest under 900 m altitude. Tree α-diversity is estimated using Fisher’s alpha calculated for trees with diameter at breast height ≥ 10 cm. Mean diversity values are lower in Africa by a factor of two. 3. Climate-diversity analyses are based on data aggregated for grid cells of 2.5 × 2.5 km. The highest Fisher’s alpha values are found in Amazonian forests with no climatic analogue in our African data set. When the analysis is restricted to pixels of directly comparable climate, the mean diversity of African forests is still much lower than that in Amazonia. Only in regions of low mean annual rainfall and temperature is mean diversity in African forests comparable with, or superior to, the diversity in Amazonia. 4. The climatic variables best correlated with the tree α-diversity are largely different in the African and Amazonian data, or correlate with African and Amazonian diversity in opposite directions. 5. These differences in the relationship between local/landscape-scale α-diversity and climate variables between the two continents point to the possible significance of an array of factors including: macro-scale climate differences between the two regions, overall size of the respective species pools, past climate variation, other forms of longterm and short-term environmental variation, and edaphics. We speculate that the lower α-diversity of African lowland rain forests reported here may be in part a function of the smaller regional species pool of tree species adapted to warm, wet conditions. 6. Our results point to the importance of controlling for variation in plot size and for gross differences in regional climates when undertaking comparative analyses between regions of how local diversity of forest varies in relation to other putative controlling factors. [less ▲]

Comment concilier exploitation forestière et gestion durable des forêts denses humides ?

Conference given outside the academic context (2007)

Guide pratique pour la mise en place et l’entretien de pépinières villageoises en zone tropicale humide.

Learning material (2007)

Strategies nouvelles et recompositions sociales autour de la faune dans le Bassin du Congo.

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2006), 10(3),

The faunaʼs overexploitation in the Congo basin in general and within logging concessions in particular case still appears as a crucial problematic. Commercial poaching threats not only mammal ... [more ▼]

The faunaʼs overexploitation in the Congo basin in general and within logging concessions in particular case still appears as a crucial problematic. Commercial poaching threats not only mammal biodiversity but also long-term food safety of local populations. Strangely, this situation is generating a new and collective answer from stakeholders having opposite interests. Administrative authorities, international NGOs of conservation, logging companies have found in the context of wood certifi cation a common deal to begin an anti-poaching action on large landscapes. This study analyses interests of each stakeholder and discusses the place given to populations in this social blending around wildlife. [less ▲]

La gestion des populations des essences commerciales exploitées dans l’Est du Cameroun

Conference (2006)

La régénération des espèces forestières vulnérables à l'Est du Cameroun : cas de Milicia excelsa

Conference (2006)

Au Cameroun, le processus de la gestion durable des forêts a conduit une société d'exploitation forestière industrielle à procéder depuis quelques années, en partenariat avec des institutions de recherche ... [more ▼]

Au Cameroun, le processus de la gestion durable des forêts a conduit une société d'exploitation forestière industrielle à procéder depuis quelques années, en partenariat avec des institutions de recherche locales ou internationales, à des études scientifiques d'espèces identifiées comme vulnérable dans ses concessions. A ce titre, la détermination de techniques d'interventions sylvicoles pragmatiques ainsi que l'écologie d'espèces telles que l'iroko, Milicia excelsa sont étudiées afin de comprendre et de remédier au faible niveau de régénération naturelle. Les observations portent d'une part sur les performances de fructification (phénologie, pluie de graine, germination) et de dispersion des semences, et d'autre part, sur la dynamique de populations naturelles de juvéniles. Etant donné qu'une faible performance de régénération peut être due à la consanguinité, elle-même résultant de la raréfaction des populations, il est prévu également une analyse de la diversité génétique locale. Parallèlement, des essais de plantations permettent de juger des effets de différents facteurs abiotiques ou biotiques sur la dynamique des plantules. [less ▲]