Climate Change Vulnerability Assessment in Mangrove-Dependent Communities of Manoka Island, Littoral Region of Cameroon

peer reviewedThis study was conducted on Manoka Island (Littoral Region of Cameroon) with the aim of analyzing climate change vulnerability and local adaptation strategies based on the local community’s perceptions and biophysical evidence. We used household surveys, focus group discussions, field observation, GIS, and remote sensing to collect data on variables of exposure, sensitivity, and adaptive capacity. Historical changes in rainfall and temperature, mangrove cover, and the occurrence of extreme climatic events were used as indicators of exposure. Property losses and income structure were used as indicators of sensitivity, while human, natural, social, financial, and physical assets represented adaptive capacity. 89 households were interviewed in the nine settlements of the island. Results show that Manoka Island is experiencing irregular rainfall patterns (with average annual values deviating from the mean by −1.9 to +1.8 mm) and increasing temperature (with annual values deviating from the mean by −1.2 to +3.12). The dynamics of the coastline between 1975 and 2017 using EPR show average setbacks of more than ±3 m/year, with erosion levels varying depending on the period and location. The number of households perceiving extreme climatic events like seasonal variability, flood, and rain storm was higher. From respondents’ perception, housing and health are the sectors most affected by climate change. The reported high dependence of households on fishing for income, their overall low livelihood diversification, and their poor access to climate information reported by 65% of respondents portray their poor adaptive capacity. Local response initiatives are ineffective and include among others constructing buildings on stilts and using car wheels to counter the advancement of seawater inland. The study concludes that households on Manoka Island are vulnerable to the impacts of climate change. Income diversification, mangrove reforestation, the development of sustainable supply chains for wood fuel, and sustainable fish smoking devices are the main pathways for adaptation planning in this area

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

VEGETATION STRUCTURE AND SPECIES COMPOSITION AT THE NORTHERN PERIPHERY OF THE BOUMBA-BEK NATIONAL PARK, SOUTHEASTERN CAMEROON

Forest conservation outside protected areas is taking center stage in global conservation discourse. This study was conducted to clarify the species composition, vegetation structure and plant diversity at the northern periphery of the Boumba-Bek National Park, whose timber and Non-Timber Forest Products (NTFPs) have been used by the local peoples and logging companies. A total of 16 transects measuring 5 km in length and 5 m in width were delineated. The survey recorded DBH of all tree individuals above 10 cm. The result shows a total number of 17, 583 trees with a density of 439.6 stems/ha (total area = 40 ha). These trees belong to 51 families, 169 genera and 247 species. Shannon-Wiener diversity index (H') ranged from 5.94 to 6.51 and higher diversity was recorded in the Agroforest Zone. The family importance index (FIV) marked highest score for Euphorbiaceae and Combretaceae. The importance index for species (IVI) was higher for Terminalia superba, Musanga cecropioides, Anonidium mannii and Celtis mildbraedii. The height-class distribution of the species shows that the majority of trees belong to the height-class of 5–20 m, which accounts for the average of 87.4% of total stems. The diameter-class distribution of the trees shows an inverse J-shape curve. The study concludes that this forest, despite having undergone disturbance in past years driven by logging and agriculture, is relatively rich and diversified

Importance des forêts secondaires pour la collecte des plantes utiles chez les Badjoué de l'Est Cameroun

Importance of Secondary Forests for the Collect of Useful Plants among Badjoue of the East Cameroon. Secondary forests are important components of many landscapes and livelihoods of the poor populations. Several researchers have investigated issues related to their importance for the forest people of central Africa. Very few studies have however been focused on the level of importance secondary forests and mature forests represent to the local population. The aim of this study was to estimate the use-value of secondary forests for the Badjoue people of East Cameroon. The study was conducted in the Doumo- Pierre village located at the northern periphery of the Dja fauna reserve. To estimate the importance of different vegetation types for the collection of useful plants, we carried out an ethnobonical surveys by making interviews with villagers. Our results show that secondary forests have important use-value for the gathering of the forest products by the forest people. The latter remain however strongly dependent on the mature forest for their livelihood as well. The implication of these results is that national forest conservation and management policies must growingly take into account local people's needs in the process of forest zoning

ANALYSIS BY REMOTE SENSING OF THE VULNERABILITY OF THE MABE MANGROVE RESERVE TO CLIMATE CHANGE, BETWEEN 1986 AND 2014

peer reviewedFace aux changements climatiques et leurs impacts sur le milieu côtier, les écosystèmes de mangrove apparaissent particulièrement vulnérables. La dynamique marine, l’érosion côtière et les pressions anthropiques sont autant de menaces qui pèsent sur ces écosystèmes. Cette étude se propose d’évaluer, à partir de l’analyse diachronique des images satellitaires Landsat et des enquêtes de terrain, la vulnérabilité aux changements climatiques de la réserve de mangrove de Mabe, située à l’embouchure du fleuve Moungo dans la Région administrative du Littoral (Cameroun). La méthodologie utilisée s’appuie sur le traitement et la classification des images Landsat TM et ETM, couplés aux données d’observations et d’enquêtes de terrain. Il en ressort que les mangroves ont enregistré une dégradation totale de 13% en 28 ans, soit une perte annuelle de 0,48%. L’érosion côtière s’est accentuée, induisant une dynamique régressive du trait de côte. Une perte en superficie est donc constatée et estimée à 103 ha (1,03km²). La nécessité de réguler l’installation des pécheurs et la conception des technologies modernes de fumage de poisson s’impose, afin de limiter la consommation en bois de mangrove

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

This study was conducted to determine the population structure and the status of natural regeneration for eight edible and/or commercial wild fruit tree species (Afrostyrax lepidophyllus, Baillonella toxisperma, Irvingia gabonensis, Panda oleosa, Pentaclethra macrophylla, Ricinodendron heudelotii, Scorodophloeus zenkeri and Tetrapleura tetraptera) in semi-deciduous rainforest of southeastern Cameroon. We established 16 transects with 5 km in length and 20 m in width each. Along each transect, all individuals, from seedlings to mature trees, of the eight species were recorded and their diameter at breast height (DBH) was measured. The results show high density values for Afrostyrax lepidophyllus (32.0 ± SD 26.1 stems/ ha), Ricinodendron heudelotii (10.3 ± 18.5 stems/ha), Pentaclethra macrophylla (11.3 ± 8.2 stems/ ha) and Scorodophloeus zenkeri (7.4 ± 12.8 stems/ha). The lowest density was reported for Baillonella toxisperma (0.1 ± 0.1 stems/ha). The investigated species have numerous seedlings, saplings and young trees, except Baillonella toxisperma, Irvingia gabonensis, Panda oleosa and Tetrapleura tetraptera (0.04, 1.05, 0.51 and 0.37 individuals of DBH < 5 cm per ha, respectively). They have relatively low natural regeneration index and are considered of priority for conservation in this forest. The study demonstrates the need to intensify the domestication or assisted natural regeneration of these wild fruit trees in degraded areas and to develop innovative approaches to multiple-use forestry, which could include NTFPs, timber and environmental services