Bernard-Aloys Nkongmeneck

DENSITY AND NATURAL REGENERATION POTENTIAL OF SELECTED NON-TIMBER FOREST PRODUCTS SPECIES IN THE SEMI-DECIDUOUS RAINFOREST OF SOUTHEASTERN CAMEROON

evariste fongnZoSSie feDoung Higher Teacher’s Training School for Technical Education (ENSET), University of Douala marlene ngAnSoP tounKAm louis ZAPfAcK Department of Plant Biology, Faculty of Science, University of Yaounde 1 Victor Aime KemeuZe Department of Plant Biology, University of Ngaoundere Denis Jean SonWA Center for International Forestry Research (CIFOR) guy merlin nguenAng German Cooperation, GIZ-ProPSFE program, Bertoua Cameroon bernard-Aloys nKongmenecK Department of Plant Biology, Faculty of Science, University of Yaounde 1

Above-ground carbon assessment in the Kom-Mengamé forest conservation complex, South Cameroon: Exploring the potential of managing forests for biodiversity and carbon

Protected areas are important for biodiversity conservation and the maintenance of ecosystem services, including climate regulation through carbon storage. Yet, there is little knowledge of their carbon storage potential. This study assesses the above-ground carbon stock and the congruence between carbon stock and tree diversity in the Kom-Mengame forest conservation complex (KMFCC) in South-Cameroon, based on an inventory of trees with DBH = 10 cm in 1,366 plots (100 × 5 m each) covering 63.8 ha, established in different land use types (terra firma forest, swamp forest and cultivated areas). Above-ground carbon was estimated using generic allometric equation and species-specific wood density derived from wood density databases. Results showed high carbon stock in KMFCC with values ranging from 143.29 ± 124.37 Mg/ha-1 in swamp areas to 240 ± 204.35 Mg/ha-1 in terra firma forests. Mean carbon stock in managed areas differed from that of terra firma forests. Petersianthus macrocarpus showed the greatest carbon stock. The study demonstrates the need for integrated approaches for carbon management in secondary forests where agroforests might be important to maintain biodiversity associated with high carbon storage. These approaches are particularly relevant to the Congo basin region where protected areas are threatened by poor management of their periphery.

Preliminary estimation of carbon stock in a logging concession with a forest management plan in East Cameroon

ABSTRACT Logging operations in Cameroon are based on the extraction of wood from natural forests. In this article, we assessed the carbon stock in a forest management unit (FMU) located in East Cameroon from field inventory to postfelling operations up to sawmill and export terminals. Tree basal area and aboveground biomass were calculated based on trees inventoried in the annual allowable cut. We observed that from an exploitable tree potential of 0.696 trees ha−1 inventoried within a diameter range of 50–110 cm, 0.141 tree ha−1 (i.e., 20% of the inventoried trees) were logged. In other words, out of 6.78 tC ha−1 inventoried, 1.84 tC ha−1 (i.e., 27% was logged), 1.62 tC ha−1 arrived in the log yard and 1.3 tC ha−1 arrived in sawmill, while 0.32 tC ha−1 reached the export terminal. In terms of damages caused on vegetation, 4.45% of all the annual allowance cut (AAC) were affected during logging activities, this represents almost 33,188.07 tons of carbon. These findings show that the implementation of reduced-impact logging (RIL) could reduce these losses throughout the logging steps and help propose a process for the valuation of wood waste in the forest and sawmill. In this context, reducing emissions from deforestation and degradation will be engaged with the right approach.

SPECIES COMPOSITION AND ABUNDANCE OF NON-TIMBER FOREST PRODUCTS AMONG THE DIFFERENT-AGED COCOA AGROFORESTS IN SOUTHEASTERN CAMEROON

the study has been conducted to clarify the species composition and abundance of non-timber forest products (ntfps) of the cocoa agroforests in the gribe village, southeastern cameroon. A total of 40 cocoa-farmed plots were sampled and divided into four age-classes. the number of sampled plots by age class are: (a) 10 plots with 0–10-year-old plot, (b) 10, 10–20-year-old, (c) 10, 20–30-year-old and (d) 10, over 30-year-old. A vegetation survey on these plots recorded a total of 3,879 individual trees. they were classified into 166 species, 131 genera and 45 families. the most diversified families were rubiaceae (including 13 species), Annonaceae (12) Sterculiaceae (10), euphorbiaceae (9), caesalpiniaceae and moraceae (8 for each). the top ten leading dominant species were Musanga cecropioides, Terminalia superba, Ficus mucuso, Celtis mildbraedii, Pterocarpus soyauxii, Triplochiton scleroxylon, Margaritaria discoidea, Markhamia lutea, Trilepisium madagascariense, and Ficus exasperata. the mean values of the Shannon-Wiener diversity index (h’) increased with the age of cocoa plot: 4.8 for the age class of 0–10-year-old, 4.7 for 10–20-year-old, 5.1 for 20–30-year-old and 5.6 for over 30-year-old. An ethnobotanical survey revealed that majority of the recorded species were used either as food (54%), medicine (33%) or for other purposes. We conclude that the cocoa agroforests, maintained by the gribe people, include a high diversity of ntfp species.

Boswellia dalzielii Hutch : état du peuplement et utilisation traditionnelle dans la région de Mbé (Adamaoua-Cameroun)

L’interet sans cesse grandissant porte aux produits forestiers non ligneux (PFNL) au Cameroun a suscite une etude dans la region de Mbe sur la gestion des peuplements de Boswellia dalzielii, une plante medicinale a grande valeur spirituelle. Les observations de terrain montrent que les populations prelevent les ecorces en plaques de forme rectangulaire. La hauteur minimale de collecte des PFNL (1,30 m) n’est pas respectee, mais le volume maximal d’ecorces prelevees (40 482 cm 3) n’est pas susceptible de mettre la ressource en peril. L’absence de jeunes et vieux individus dans le milieu montre que la regeneration et le maintien de cette espece sont problematiques. Des etudes sur la sylviculture de cette espece sont necessaires pour satisfaire les besoins des populations locales car la vulgarisation des connaissances sur l’espece peut l’exposer a une exploitation a grande echelle.

Analyse de la dynamique de déforestation par télédétection couplée aux modèles d’équations structurales: exemple de la forêt néphéliphile du mont Oku (Cameroun)

Résumé Les analyses, synchroniques ou diachroniques, des diversités taxonomique et phytocoenologique en paysages changeants et/ou fortement anthropisés requièrent une analyse de la dynamique d’occupation des sols. Nous présentons ici les apports de la télédétection et des modèles d’équations structurales (MES) à la description compréhensive de la dynamique des paysages. L’objectif de cette étude est de caractériser les changements d’occupation du sol sur le mont Oku (Cameroun) au cours des trente dernières années afin de quantifier la fragmentation de la forêt néphéliphile primaire et de préciser les facteurs favorisant sa régression. Pour cela, nous avons utilisé des images satellitaires Landsat prises entre 1978 et 2007 et modélisé l’influence des facteurs environnementaux (altitude, pente, densité humaine) sur la déforestation avec des MES. Entre 1978 et 2001, la forêt a perdu 62,1% de sa surface, soit 579 ha.an-1 en moyenne, quiont été majoritairement convertis en cultures sous la pression d’un doublement de la densité de population en 18 ans. Une stabilisation apparaît après 2001, liée à l’apparition de nombreux noyaux de forêt secondaire, d’où un couvert forestier en mosaïque, en 2007, composé à 66% de forêts secondaires et 34% de forêts anciennes, celles-ci continuant à régresser et à être dégradées par de nouvelles pratiques, comme le pâturage en forêt. Les conséquences en terme de conservation sont discutées.