Impact potentiel du changement climatique sur les avantages socioculturels et pecuniaires tires de Cochlospermum kunth

écosystémiques fournis par deux espèces du genre Cochlospermum fortement exploitées au Bénin. Cent quatre femmes commerçantes de Cochlospermum ont été interviewées dans trois marches principaux. Les savoirs des femmes de différents groupes sociolinguistiques sur les usages spécifiques du Cochlospermum ainsi que les quantités vendues de poudre de racine de l’espèce et les revenus tirés ont été estimés et comparés au moyen d’indices ethnobotaniques et des marges brutes, sur la base des déclarations des enquêtés. Les probabilités d’occurrence du Cochlospermum ont été générées après modélisation de sa distribution avec l’algorithme MAXENT. Ensuite, les valeurs moyennes actuelles et futures du revenu monétaire et de l’indice d’importance culturelle ont été estimées et liées aux coordonnées géoréférencées des centroïdes des cellules de la grille contenant les probabilités d’occurrence de Cochlospermum, puis projetées sur des cartes. Le nombre moyen d’usages par enquêté était le plus élevé chez les commerçantes Mokolés et près de deux fois plus grand que chez les commerçantes des autres groupes sociolinguistiques (Chi 2 = 62, p < 0,001). Les quantités de poudre de racine de Cochlospermum vendues annuellement par commerçante sont en moyenne similaires sur les marchés considérés soit 31,19 kg. Toutefois, les marges brutes tirées à Angaradébou sont significativement plus élevées que celles de Natitingou. Les deux scénarios de changement climatique entrevoient une augmentation potentielle des avantages pécuniaires tirés de Cochlospermum et un renforcement potentiel de son importance socioculturel. Cochlospermum pourrait alors être une candidate clé à l’autonomisation des femmes dans un contexte de changement climatique.  English title: Climate change and socio-economics of Cochlospermum Abstract This study assessed the potential impact of climate change on ecosystem services provided by the two species of the genus Cochlospermum in Benin. One hundred and four female traders of different sociolinguistic groups were sampled and interviewed. Women’s knowledge of the specific uses of Cochlospermum as well as the quantities of Cochlospermum root powder sold and the income derived were estimated and compared using ethnobotanical index and gross margins, based on the statements of the respondents. The probabilities of occurrence of Cochlospermum were generated after modelling its distribution using MAXENT algorithm. Then, the average values of the current and future monetary income and the index of cultural importance were estimated and linked to the georeferenced coordinates of the centroids of grid cells containing Cochlospermum probabilities of occurrence and then projected on maps. The average number of uses per respondent was highest among Mokolé traders and almost twice as high as among those from other sociolinguistic groups (Chi 2 62, p <0.001). The quantities of Cochlospermum root powder sold annually were on average similar on the markets considered, i.e. 31.19 kg. However, the gross margins drawn at Angaradébou were significantly higher than those at Natitingou. Both used climate change scenarios foresaw a potential increase in the monetary benefits derived from Cochlospermum and a potential enhancement of its socio-cultural importance. Cochlospermum could then be a key candidate for the empowerment of women in a context of climate change. Keyword: wild edible plants; income; Bray Curtis index; Cultural importance index, Maxent, climatic projection

Lantana camara (verbenaceae) : a potential threat to the effectiveness of protected areas to conserve flora and fauna in Benin

Invasive plant species are today among the biggest threats to integrity of many ecosystems including that of the protected areas. Climate change may exacerbate the negative effects of invasive plant species. Here, we used the Maximum Entropy model to project habitat suitability for Lantana camara L., an invasive plant species under current and future climates in the national protected areas network of Benin. The models were run using bioclimatic data and data on soil type. Nineteen percent of the total land in the protected areas network was highly suitable for L. camara under current climate. Highly suitable areas under current and future climates cover about 65 % of the Pendjari Biosphere Reserve, the major wildlife sanctuary in Benin. Other bio-reserves such as W National Park, Lama, Agoua, Dogo-Kétou, Atchérigbé, Mékrou and Kouandé Forest Reserves were also suitable for the species. Presence of L. camara in the protected areas represents a great potential threat to the global food webs being conserved. Based on these results, areas with highly suitable habitats are at high risk of invasion by L. camara, and should be accorded high priority when formulating appropriate management strategies.Keywords: Invasive species ; Climate change ; Habitat suitability ; Protected areas ; West AfricaLantana camara et les aires protegees au BeninLes espèces invasives font de nos jours partie des plus importantes menaces aux quelles font face les écosystèmes y compris les aires protégées. Les changements climatiques peuvent amplifier leurs effets négatifs. Dans la présente étude, nous avons utilisé un algorithme de modélisation de niche écologique, le Maximum Entropy pour analyser la susceptibilité des habitats à être colonisés par Lantana camara L., une plante invasive, sous les conditions climatiques actuelles et futures dans les aires protégées du Bénin. Les modèles ont été établis en utilisant des données bioclimatiques et des données relatives aux types de sol. Dans les conditions climatiques actuelles, 19 % de la superficie totale du réseau des aires protégées est significativement favorable à L. camara. Sous les conditions climatiques actuelles et futures, 65 % de la réserve de biosphère de Pendjari, le plus important sanctuaire de faune sauvage du Bénin, est hautement favorable à l’espèce. D’autres bio-réserves telles que le Parc National W et les reserves forestières de Lama, Agoua, Dogo-Kétou, Atchérigbé, Mékrou et Kouandé ont aussi des habitats favorable à l’espèce. En nous fondant sur ces résultats, les zones favorables sont à haut risque d’invasion par L. camara et  devraient être priorisées lors de la formulation de stratégies préventives appropriées.Mots clés: Espèces envahissantes ; Changements Climatiques ; Habitats favorables ; Aires protégées, Afrique de l’Ouest

Yam bean (Pachyrhizus erosus) tuber processing in Benin: production and evaluation of the quality of yam bean-gari and yam bean-fortified gari

Yam bean (Pachyrhyzus erosus) tubers were processed singly and mixed with cassava into different types of gari (100% yam bean gari, 75% yam bean gari, 50% yam bean gari and 25% yam bean gari) following the traditional gari processing method. Conventional gari from cassava was processed following the same approach and used as control. Physical characteristics, proximate composition and sensory quality of the garis obtained were assessed. Results showed that low and medium (25% and 50%) yam bean fortified gari processing yielded better than 75% and 100% yam bean gari processing. Low and medium yam bean gari were the closest to conventional gari regarding the brown index (18.0 and 18.3 respectively), had good swelling capacity (≥ 3) and had higher relative bulk density (0.57 and 0.53 respectively). The proteins content of the processed yam bean garis increased with increasing incorporation rate of yam bean but, similarly, the crude fibres content increased going beyond the recommended level of 2% maximum. The processed garis were used to cook èba which were submitted to panellists’ appreciation. Panellists scored better low and medium yam bean fortified garis and the resulting èba. Combining the results, the highest suggested incorporation rate was 50% yam bean tubers. © 2013 International Formulae Group. All rights reserved.Keywords: Legume tuber-root crop, quality, physical characteristics, chemical composition, sensory evaluation

West African Cattle Farmers’ Perception of Tick-Borne Diseases

Worldwide, cattle production is struggling to face the negative impacts caused by ticks and Rhipicephalus (Boophilus) microplus is one of the most harmful ticks for livestock. Most of the people in West Africa depend on cattle farming and subsistence agriculture. The presence of ticks on cattle is a major problem faced by smallholder farmers who fight for their livelihood. National and regional tick control programs could assist these rural communities in protecting their livelihoods against ticks and tick-borne diseases, but only if they take into account the targeted herders and their perception on cattle management and tick control. This paper aims to provide a better insight in the socio-economic characteristics of Beninese cattle farmers, and their perception on tick burden, as well as to document common tick control strategies. Different tick species and their seasonality are well understood by cattle herders. For tick control, many still use manual tick removal, especially in the north of the country. The high cost of acaricides, the lack of financial means of African farmers, and of the local stockbreeders in particular, limits the use of acaricides in livestock breeding in Benin. While aiming to increase the meat or milk production of their animals, stockbreeders who can afford it sometimes turn to an abusive use of acaricides, which might in time lead to an increase in tick resistance. This study remains one of the rare studies to report extensively on the perceptions of West African cattle herders

A phylogenetic classification of the world’s tropical forests

Knowledge about the biogeographic affinities of the world’s tropical forests helps to better understand regional differences in forest structure, diversity, composition and dynamics. Such understanding will enable anticipation of region specific responses to global environmental change. Modern phylogenies, in combination with broad coverage of species inventory data, now allow for global biogeographic analyses that take species evolutionary distance into account. Here we present the first classification of the world’s tropical forests based on their phylogenetic similarity. We identify five principal floristic regions and their floristic relationships: (1) Indo-Pacific, (2) Subtropical, (3) African, (4) American, and (5) Dry forests. Our results do not support the traditional Neo- versus Palaeo-tropical forest division, but instead separate the combined American and African forests from their Indo-Pacific counterparts. We also find indications for the existence of a global dry forest region, with representatives in America, Africa, Madagascar and India. Additionally, a northern hemisphere Subtropical forest region was identified with representatives in Asia and America, providing support for a link between Asian and American northern hemisphere forests

Evenness mediates the global relationship between forest productivity and richness

1. Biodiversity is an important component of natural ecosystems, with higher species richness often correlating with an increase in ecosystem productivity. Yet, this relationship varies substantially across environments, typically becoming less pronounced at high levels of species richness. However, species richness alone cannot reflect all important properties of a community, including community evenness, which may mediate the relationship between biodiversity and productivity. If the evenness of a community correlates negatively with richness across forests globally, then a greater number of species may not always increase overall diversity and productivity of the system. Theoretical work and local empirical studies have shown that the effect of evenness on ecosystem functioning may be especially strong at high richness levels, yet the consistency of this remains untested at a global scale. 2. Here, we used a dataset of forests from across the globe, which includes composition, biomass accumulation and net primary productivity, to explore whether productivity correlates with community evenness and richness in a way that evenness appears to buffer the effect of richness. Specifically, we evaluated whether low levels of evenness in speciose communities correlate with the attenuation of the richness–productivity relationship. 3. We found that tree species richness and evenness are negatively correlated across forests globally, with highly speciose forests typically comprising a few dominant and many rare species. Furthermore, we found that the correlation between diversity and productivity changes with evenness: at low richness, uneven communities are more productive, while at high richness, even communities are more productive. 4. Synthesis. Collectively, these results demonstrate that evenness is an integral component of the relationship between biodiversity and productivity, and that the attenuating effect of richness on forest productivity might be partly explained by low evenness in speciose communities. Productivity generally increases with species richness, until reduced evenness limits the overall increases in community diversity. Our research suggests that evenness is a fundamental component of biodiversity–ecosystem function relationships, and is of critical importance for guiding conservation and sustainable ecosystem management decisions

The global biogeography of tree leaf form and habit

Understanding what controls global leaf type variation in trees is crucial for comprehending their role in terrestrial ecosystems, including carbon, water and nutrient dynamics. Yet our understanding of the factors influencing forest leaf types remains incomplete, leaving us uncertain about the global proportions of needle-leaved, broadleaved, evergreen and deciduous trees. To address these gaps, we conducted a global, ground-sourced assessment of forest leaf-type variation by integrating forest inventory data with comprehensive leaf form (broadleaf vs needle-leaf) and habit (evergreen vs deciduous) records. We found that global variation in leaf habit is primarily driven by isothermality and soil characteristics, while leaf form is predominantly driven by temperature. Given these relationships, we estimate that 38% of global tree individuals are needle-leaved evergreen, 29% are broadleaved evergreen, 27% are broadleaved deciduous and 5% are needle-leaved deciduous. The aboveground biomass distribution among these tree types is approximately 21% (126.4 Gt), 54% (335.7 Gt), 22% (136.2 Gt) and 3% (18.7 Gt), respectively. We further project that, depending on future emissions pathways, 17–34% of forested areas will experience climate conditions by the end of the century that currently support a different forest type, highlighting the intensification of climatic stress on existing forests. By quantifying the distribution of tree leaf types and their corresponding biomass, and identifying regions where climate change will exert greatest pressure on current leaf types, our results can help improve predictions of future terrestrial ecosystem functioning and carbon cycling