6 research outputs found

    Etude analytique de la flore et de la végétation du Parc National de la Ruvubu, Burundi

    Get PDF
    Les études relatives à la flore et à la végétation des aires protégées du Burundi et particulièrement du Parc National de la Ruvubu, la plus grande aire protégée du pays, sont encore fragmentaires. Cette étude se fixe comme objectifs d’individualiser, définir et réaliser une classification syntaxonomique des groupements végétaux de cette aire protégée ainsi que d’évaluer leur structure et diversité. L’étude fournit la liste et la classification des communautés végétales du parc à l’aide de la méthode phytosociologique classique. La richesse spécifique, les indices de diversité de Margalef et de Shannon ainsi que l’équitabilité ont servi à évaluer la diversité et la structure des groupements. Dix groupements variant principalement selon les gradients topographique, pédologique, hydrologique, l’action perturbatrice des feux et le microclimat ont été individualisés. Le statut syntaxonomique des autres unités connues à partir de la littérature a été clarifié. Cinq groupements sont nouveaux: un groupement en savanes (savanes à Hyparrhenia diplandra et Entada abyssinica), deux groupements dans les galeries forestières (galeries forestières à Syzygium cordatum et Aframomum angustifolium, galeries forestières à Syzygium cordatum et Alchornea cordifolia) et deux groupements dans les marais (marais inondés à Cyperus latifolius et Dissotis ruandensis, marais peu inondés à Dissotis brazzae).© 2010 International Formulae Group. All rights reserved.Mots clés: Analyses multivariées, diversité, groupement végétal, phytosociologie

    Diversité et distribution d'abondances des plantes d'un écosystème protégé dans un paysage anthropisé: cas de la Réserve Naturelle Forestière de Bururi, Burundi

    No full text
    Plant Diversity and Abundance Distribution of a Protected Ecosystem in an Anthropogenic Landscape: the Case of the Bururi Natural Forest Reserve of, Burundi. A study on plant species diversity and abundance distribution has been conducted in the Bururi Natural Forest Reserve (BNFR) in Burundi in order to improve species conservation. The BNFR is an ecosystem embedded in an anthropogenic matrix, close to Bururi city and to agricultural lands. It is a forest patch resulting from the fragmentation of a larger forest that once occupied the entire Congo- Nile Crest. This study tested the hypothesis according to which the plant species abundance distribution in conserved forests corresponds to a log normal distribution, indicating that species are regularly distributed in the ecosystem. This distribution model is generally observed in stable ecosystems in which inter-specific competition is considered less important. The observed abundance distribution of the plant species was therefore compared to a log normal, a log series and a broken stick distribution model. Six of the plant species recorded in this study are considered threatened in Burundi. The observed plant species abundance distribution was found similar to the log series model which suggests the impact of disturbance on the abundance distribution despite the status of the BNFR of protected ecosystem in an anthropogenic landscape

    La dynamique spatiale de la forêt située dans la réserve naturelle forestière de Bururi, Burundi

    No full text
    The Forest Spatial Dynamic in the Bururi Forest Nature Reserve, Burundi. The studied forest is a protected area located in Southern Burundi, close to Bururi city and to agricultural villages. The effective protection of this forest started in 1980 but the protected area delimitation occurred in 2000. The forest spatial dynamic is analyzed to assess the effectiveness of this protection status. The study combines six Landsat multispectral satellite images analysis with field observations. Forest area and perimeter analysis highlights its dynamic in two phases: the first one is mainly characterised by deforestation and savannah development around agricultural lands but also by forest regrowth processes between 1986 and 2001. The second phase (2001-2011) of the forest dynamic is characterized by the increase of its surface and perimeter following the transformation of savannah zones. The anthropogenic effect limitation linked to the protected area delimitation, agricultural activities disturbance during socio-political instability period and to the increasing number of forest-rangers, would have influenced the surface and perimeter gain between 2001 and 2011. Local population implication in forest protection could further limit human pressure and promote degraded zones regeneration. Thus, agropastoral practices innovation in neighboring villages of the protected zone could contribute to limit these anthropogenic disturbances
    corecore