Diversité de la flore ligneuse à l’intérieur du Parc National de Waza (Cameroun)

Le Parc National de Waza est une aire protégée de renommée internationale. Il est l’un des plus emblématiques que compte le Cameroun, mais fait face à des pressions anthropiques et d’origine naturelle qui menacent l’intégrité de ses ressources. La présente étude avait pour objectif d’améliorer la connaissance de la flore et de la végétation ligneuse afin de permettre de mieux bâtir les stratégies de gestion de ce parc. Pour y parvenir, un inventaire de la flore ligneuse a été réalisé en 2016, avec la méthode des transects couplée à celle des quadrats de 25 m x 50 m. Le comptage et la mesure des paramètres dendrométriques, ainsi que les observations effectuées à l’intérieur de ces quadrats ont permis d’étudier les différents paramètres qualitatifs et quantitatifs de la ressource ligneuse, dont la richesse spécifique et les indices de diversité. Il en ressort que le parc abrite 38 espèces appartenant à 33 genres répartis dans 19 familles. L’indice de Shannon Weaver est de 2,95 et l’équitabilité de Piélou est de 0,56. Ces indices montrent que l’écosystème reste encore relativement riche, même si les menaces de la dégradation de ses ressources sont perceptibles. Il importe de mettre sur pied les stratégies efficaces de gestion de cette aire protégée et de sa périphérie afin de limiter les menaces auxquelles elle fait face.   English title: Diversity of the woody plants species within the Waza National Park (Cameroon) Waza National Park is an internationally renowned protected area. It is one of the most emblematic in Cameroon, but faces anthropogenic and natural pressures that threaten the integrity of its resources. The purpose of the study was to improve knowledge of the flora and woody vegetation in order to better build management strategies for this park. To achieve this, an inventory of the woody flora was carried out, using the transect method coupled with that of 25 m x 50 m quadrats. The counting and measurement of dendrometric parameters, as well as the observations made inside these quadrats, made it possible to study the various qualitative and quantitative parameters of the woody resource, including specific richness and diversity indices. It appears that the park is home to 38 species belonging to 33 genera distributed in 19 families. The Shannon Weaver index is 2.95 and the Piélou fairness is 0.56. These indices show that the ecosystem is still relatively rich, even if the threats of the degradation of its resources are perceptible. It is important to set up effective management strategies for this protected area and its periphery in order to limit the threats it faces

Disponibilité des produits forestiers non ligneux fondamentaux à la périphérie du Parc national de Lobeke

Non-Timber Forest Products are appropriate to meet the needs of local and indigenous communities surrounding the National Park of Lobéké. In order to better assess their availability, a botanical inventory has been carried out. The methodology use to develop the inventory consist into the establishment of transect in the village of Mambélé. The village is located in the area of the Tri National of Sangha, more precisely in the South-East of Cameroon. In total, 9 transects of 2 km long and 20 m large allow the team to cover an area of 36 ha. Therefore, these transects helped identifying 29 individuals of Irvingia gabonensis, 204 individuals of Ricinodendron heudelotii, 54 individuals of Entandrophragma cylindricum, and 154 individuals of Terminalia superba. In addition, some interesting results are coming out from the calculation of species densities and variances analysis with ANOVA methodology : the availability of each species was linked mainly to two parameters, which include the type of land use area (old secondary forest, secondary forest, swamp forest, young fallow and old fallow) and the distance for harvesting. Therefore, most of identify species are found in secondary forests and old secondary forests. From the analysis, we notice that the diameter class] 20-40 [ is the class where we found most individuals from each species. To conclude, domestication of these Non-Timber Forest Product could be recommended as an alternative option to strengthening the economy and thus contributing to the conservation of biodiversity

Disponibilité des produits forestiers non ligneux fondamentaux à la périphérie du Parc national de Lobeke

Les Produits forestiers non ligneux (PFNL) sont nécessaires à la satisfaction des besoins des communautés locales et autochtones dans la zone périphérique du Parc national de Lobéké. Afin de mieux évaluer leur disponibilité, un inventaire botanique a été réalisé à la suite d’un échantillonnage basé sur la mise en place des transects dans le village de Mambélé. Ce village est situé dans la zone de la Tri nationale de la Sangha (TNS), plus précisément au sud-est du Cameroun. Au total, 9 transects de 2 km de long et 20 m de large ont été parcourus, pour une superficie de 36 ha. Ces transects ont permis de répertorier 29 individus d’Irvingia gabonensis, 204 individus de Ricinodendron heudelotii, 54 individus de Entandrophragma cylindricum, et 154 individus de Terminalia superba. Le calcul des densités de chaque espèce et l’analyse des variances par la méthode d’ANOVA révèlent que la disponibilité de chaque espèce varie selon deux principaux paramètres notamment : le type de milieux (forêt secondaire âgée, forêt secondaire, forêt marécageuse, jeunes jachères, vieilles jachères, champ) et la distance à parcourir pour la récolte. Les espèces identifiées se retrouvent en majeure partie dans les forêts secondaires âgées et dans les forêts secondaires. Il ressort aussi de l’analyse que la classe de diamètre la plus importante où l’on retrouve le plus d’individus de chaque espèce est la classe [20-40[. La domestication de ces PFNL pourrait donc être préconisée comme option alternative pour le renforcement de l’économie locale et contribuer ainsi à la conservation de la biodiversité.Non-Timber Forest Products are appropriate to meet the needs of local and indigenous communities surrounding the National Park of Lobéké. In order to better assess their availability, a botanical inventory has been carried out. The methodology use to develop the inventory consist into the establishment of transect in the village of Mambélé. The village is located in the area of the Tri National of Sangha, more precisely in the South-East of Cameroon. In total, 9 transects of 2 km long and 20 m large allow the team to cover an area of 36 ha. Therefore, these transects helped identifying 29 individuals of Irvingia gabonensis, 204 individuals of Ricinodendron heudelotii, 54 individuals of Entandrophragma cylindricum, and 154 individuals of Terminalia superba. In addition, some interesting results are coming out from the calculation of species densities and variances analysis with ANOVA methodology : the availability of each species was linked mainly to two parameters, which include the type of land use area (old secondary forest, secondary forest, swamp forest, young fallow and old fallow) and the distance for harvesting. Therefore, most of identify species are found in secondary forests and old secondary forests. From the analysis, we notice that the diameter class] 20-40 [ is the class where we found most individuals from each species. To conclude, domestication of these Non-Timber Forest Product could be recommended as an alternative option to strengthening the economy and thus contributing to the conservation of biodiversity

Assessing plant diversity change in logged and unlogged dense semi-deciduous production forest of eastern Cameroon

This study was carried out in the dense semi-deciduous production forest of East Cameroon. The objective of this work of this study was to provide comparative floristic knowledge that can serve as a basis for the planning and sustainable management of ligneous plant resources in Communal Forests before and after logging. Sampling was done in unlogged and logged forest. Data collection was carried out using the linear transects subdivided into 10 plots of 25 m × 20 m (500 m2) with an equidistance of 225 m for the inventory of all trees with dbh ≥10 cm installed measured at 1.3 m above ground level. Nested quadrats 5 m × 5 m, oriented south-west and north-east were set up in each plot for the counting and identification of all individuals with a diameter less than 10 cm. The analysis of inventory data showed that the floristic composition was higher in the unlogged forest. The individuals were more evenly distributed in the logged (Pielou's equitability index = 0.83) than in the unlogged forest. The study of the functional spectra showed that the flora of the two forest types was dominated by Guinean-Congolese species (67.57% in the unlogged forest and 63.07% in the logged forest) and Phanerophytes, particularly Mesophanerophytes. The dominance of sarcochorous species reveals that the main mode of dissemination in this forest is zoochory, particularly endozoochory. The presence of pleochroic species in the logged forest reveals the importance of dissemination by water in the environment. The plants surveyed were divided into five plant assemblages (three for logged forest and two for unlogged forest) based on ecological parameters. The findings of this study suggest that forest management which combines assisted natural regeneration with the natural process of secondary succession facilitates the reconstitution of the vegetation cover and, by extension, the conservation of biodiversity in post-logging forest concessions

Carbon storage potential of cacao agroforestry systems of different age and management intensity

<p>This study was carried out in Traditional and Innovative Cocoa Agroforestry Systems (CAS) of the Central Region of Cameroon. The aim was to assess carbon sequestration potential and tree species richness of each CAS. Sampling was done in 82 plots of 25 × 25 m in Traditional and Innovative CAS of different age classes. In addition to cocoa trees, associated trees with dbh ≥10 cm were inventoried. Aboveground biomass was evaluated using the non-destructive method for cocoa trees and woody plants and destructive method for herbaceous plants, litter and roots. A total of 5843 individuals belonging to 25 families, 35 genera and 39 species were inventoried in these CAS. The most represented species were <i>Elaies guineensis</i> and <i>Carica papaya</i> in Innovative CAS, <i>Citrus sinensis</i> and <i>Dacryodes edulis</i> in Traditional CAS. In the study area, species richness found in all Traditional and Innovative CAS sampled was respectively 38 and 6. Basal area and shade trees density of Innovative CAS were respectively 4.7 m².ha⁻¹, and 21 trees.ha⁻¹ against 38, 13.7 m².ha⁻¹ and 84 trees.ha⁻¹ in Traditional CAS. The total carbon stock of Traditional CAS represented three-times more (138.1 t C.ha⁻¹) that of Innovative CAS (46.9 t C.ha⁻¹). Carbon stock increased significantly with age of Innovative CAS whereas in Traditional CAS, there were no significant differences. Innovative CAS are less preferable as a basic model in the REDD+ process compared to Traditional CAS in carbon storage and biodiversity conservation contexts.</p

Perception and adaptation strategies of forest dwellers to climate variability in the tropical rainforest in eastern Cameroon: The case of the inhabitants of the Belabo-Diang Communal Forest

The design of appropriate adaptation strategies to the impacts of climate change requires a contextual study of local perceptions due to the non-homogeneity of climate in a given agro-ecological area. The research objective of the current study aims to examine the evolution of climate parameters from 1983 to 2019 linked to the perceptions of local populations and appropriate adaptation measures in the Belabo-Diang Communal Forest of Cameroon. The methodological approach includes collecting and analyze climate data from 1983 to 2019; and surveying existing local perceptions and adaptive strategies among 540 households using semi-structured questionnaires. A significant increase in temperature of about 1 °C over 36 years (1983–2019) and a non-significant decrease in precipitation (95.36 mm) over the same period were observed. Local perceptions related to climate change vary according to the sector of activity and are mainly associated with more heat in the dry season (90%), late onset of rains (84%), drought recurrence (82%), less rainfall during the year (80%), and increase in the duration of drought (80%). For 82–100% of households, according to the activity sector, no appropriate adaptation measures to climate change were applied depending on activities. The adaptation measures used by less than 0–20% of respondents, include mainly the abandonment or change of activity, and modification of the agricultural calendar. With the lack of appropriate and adequate adaptation measures by the riparian populations, this study appears necessary to inform policy-makers of the need to develop and implement more appropriate strategies to enable the riparian people living in forest area of Cameroon to better adapt to these effects of climate changes