Les gorilles du Parc National de Lobéké (Cameroun): interactions avec les populations locales et implications pour la conservation

La connaissance des interactions entre les populations locales et le gorille est nécessaire pour l’élaboration des stratégies de conservation durable dans une aire protégée. L’insuffisance d’informations de base sur ces interactions a motivé la présente étude autour du Parc National de Lobéké (PNL). Des entretiens et des enquêtes ont été menés auprès des  ménages, des gestionnaires de parc et des associations villageoises dans quatre sites autour du parc. Le résultat des enquêtes indique que le gorille est une source importante de revenus à travers le tourisme, les emplois locaux et des réalisations des opérateurs économiques. Cependant, ces retombées sont disparates selon les sites et restent d’ailleurs négligeables auprès des populations. D’autre part, le gorille génère les conflits, puisqu’il détruit les champs des riverains et est braconné par les populations. Les pertes en cultures sont rapportées par plus de 59% des ménages selon le site et sur près de 30% des superficies cultivées. Ainsi, les stratégies de redistribution des retombées et de résolution des conflits doivent tenir compte des spécificités de chaque site autour du parc. Il est recommandé de sensibiliser les populations à installer leur champ dans un périmètre où elles maîtrisent le contrôle.Mots clés: Gorille, Tri-National de la Sangha, conflit Homme-gorille, gouvernance

Structural diversity and tree density drives variation in the biodiversity-ecosystem function relationship of woodlands and savannas

Positive biodiversity-ecosystem function relationships (BEFRs) have been widely documented, but it is unclear if BEFRs should be expected in disturbance-driven systems. Disturbance may limit competition and niche differentiation, which are frequently posited to underlie BEFRs. We provide the first exploration of the relationship between tree species diversity and biomass, one measure of ecosystem function, across southern African woodlands and savannas, an ecological system rife with disturbance from fire, herbivores and humans. We used >1000 vegetation plots distributed across 10 southern African countries, and structural equation modelling, to determine the relationship between tree species diversity and aboveground woody biomass, accounting for interacting effects of resource availability, disturbance by fire, tree stem density and vegetation type. We found positive effects of tree species diversity on aboveground biomass, operating via increased structural diversity. The observed BEFR was highly dependent on organismal density, with a minimum threshold of c. 180 mature stems ha-1. We found that water availability mainly affects biomass indirectly, via increasing species diversity. The study underlines the close association between tree diversity, ecosystem structure, environment and function in highly disturbed savannas and woodlands. We suggest that tree diversity is an under-appreciated determinant of wooded ecosystem structure and function

Germplasm Acquisition and Distribution by CGIAR Genebanks

The international collections of plant genetic resources for food and agriculture (PGRFA) hosted by 11 CGIAR Centers are important components of the United Nations Food and Agriculture Organization’s global system of conservation and use of PGRFA. They also play an important supportive role in realizing Target 2.5 of the Sustainable Development Goals. This paper analyzes CGIAR genebanks’ trends in acquiring and distributing PGRFA over the last 35 years, with a particular focus on the last decade. The paper highlights a number of factors influencing the Centers’ acquisition of new PGRFA to include in the international collections, including increased capacity to analyze gaps in those collections and precisely target new collecting missions, availability of financial resources, and the state of international and national access and benefit-sharing laws and phytosanitary regulations. Factors contributing to Centers’ distributions of PGRFA included the extent of accession-level information, users’ capacity to identify the materials they want, and policies. The genebanks’ rates of both acquisition and distribution increased over the last decade. The paper ends on a cautionary note concerning the potential of unresolved tensions regarding access and benefit sharing and digital genomic sequence information to undermine international cooperation to conserve and use PGRFA

Home Range and Ranging Behaviour of Bornean Elephant (Elephas maximus borneensis) Females

BACKGROUND: Home range is defined as the extent and location of the area covered annually by a wild animal in its natural habitat. Studies of African and Indian elephants in landscapes of largely open habitats have indicated that the sizes of the home range are determined not only by the food supplies and seasonal changes, but also by numerous other factors including availability of water sources, habitat loss and the existence of man-made barriers. The home range size for the Bornean elephant had never been investigated before. METHODOLOGY/PRINCIPAL FINDINGS: The first satellite tracking program to investigate the movement of wild Bornean elephants in Sabah was initiated in 2005. Five adult female elephants were immobilized and neck collars were fitted with tracking devices. The sizes of their home range and movement patterns were determined using location data gathered from a satellite tracking system and analyzed by using the Minimum Convex Polygon and Harmonic Mean methods. Home range size was estimated to be 250 to 400 km(2) in a non-fragmented forest and 600 km(2) in a fragmented forest. The ranging behavior was influenced by the size of the natural forest habitat and the availability of permanent water sources. The movement pattern was influenced by human disturbance and the need to move from one feeding site to another. CONCLUSIONS/SIGNIFICANCE: Home range and movement rate were influenced by the degree of habitat fragmentation. Once habitat was cleared or converted, the availability of food plants and water sources were reduced, forcing the elephants to travel to adjacent forest areas. Therefore movement rate in fragmented forest was higher than in the non-fragmented forest. Finally, in fragmented habitat human and elephant conflict occurrences were likely to be higher, due to increased movement bringing elephants into contact more often with humans

From trees to money: the contribution of njansang (Ricinodendron heudelotii) products to value chain stakeholders’ financial assets in the South West Region of Cameroon

Njansang -Ricinodendron heudelotii (Baill.) Pierre ex Pax.- is a commonly traded non-timber forest product from Central African humid forests, used as a spice. South West Cameroon was selected as major production area and market where little data exist on the contribution of njansang to stakeholders livelihoods in the value chain. Interviews were used to gather information from 261 harvesters, traders and processing enterprises. From 2013 to 2015, 65.8 tons were harvested, with 13.17 tons traded in markets in the South West Region and in Nigeria for a value of €33,511. The ease of accessing markets makes a significant difference to the quantity harvested and contribution to harvesters’ household income. Average profit for harvesters is higher in regional markets than in local ones. Harvester’s profits were higher than buy’amsell’ams, retailers and exporters. Processors add the most value and earn the highest unit profits. Livelihood dependence upon njansang decreases along the chain, with harvesters more dependent than traders. Seasonality, corruption, storage and processing, influence price. Long-term value chain sustainability could be improved by increasing collaboration between stakeholders, collective action, disseminating knowledge about processing and storage techniques, and promoting domestication and cultivation to enable trade in this largely wild harvested NTFP to continue sustainably

Indigenous African orphan legumes: potential for food and nutrition security in SSA

Open Access Journal; Published online: 25 Apr 2022In Sub-Saharan Africa (SSA), both crop production and the hidden hunger index (HHI, a combination of zinc, iron, and vitamin A deficiency), continue to be worse than the rest of the world. Currently, 31 out of 36 countries of SSA show the highest HHI. At the same time, several studies show climate change as a major constraint to agriculture productivity and a significant threat to SSA food security without significant action regarding adaptation. The food security of SSA is dependent on a few major crops, with many of them providing largely only an energy source in the diet. To address this, crop diversification and climate-resilient crops that have adaptation to climate change can be used and one route toward this is promoting the cultivation of African orphan (neglected or underutilized) crops. These crops, particularly legumes, have the potential to improve food and nutrition security in SSA due to their cultural linkage with the regional food habits of the communities, nutritionally rich food, untapped genetic diversity, and adaptation to harsh climate conditions and poor marginal soils. Despite the wide distribution of orphan legumes across the landscape of SSA, these important crop species are characterized by low yield and decreasing utilization due in part to a lack of improved varieties and a lack of adequate research attention. Genomic-assisted breeding (GAB) can contribute to developing improved varieties that yield more, have improved resilience, and high nutritional value. The availability of large and diverse collections of germplasm is an essential resource for crop improvement. In the Genetic Resources Center of the International Institute of Tropical Agriculture, the collections of orphan legumes, particularly the Bambara groundnut, African yambean, and Kersting’s groundnut, have been characterized and evaluated for their key traits, and new collections are being undertaken to fill gaps and to widen the genetic diversity available to underpin breeding that can be further utilized with GAB tools to develop faster and cost-effective climate-resilient cultivars with a high nutrition value for SSA farmers. However, a greater investment of resources is required for applying modern breeding to orphan legume crops if their full potential is to be realized