Diversité végétale de la Forêt Classée de Yaya au Sud-Est de la Côte d’Ivoire

Cette étude a été conduite afin de contribuer à une meilleure connaissance de la diversité floristique ligneuse de la forêt classée de Yaya. Au total, 50 placettes de 200 m2 ont été disposées dans les différents types d’occupation du sol. Dans chacun des rectangles, tous les individus ligneux de diamètre à hauteur de poitrine (DHP) supérieur ou égale à 10 cm ont été identifiés, comptés et mesurés. Ces Relevés de surfaces couplés aux inventaires itinérants ont permis d’inventorier 167 espèces rangées dans 134 genres que se partagent 47 familles. Les familles les plus importantes dans l’ordre étaient : les Fabaceae, les Euphorbiaceae et les Malvaceae. Les Mésophanerophytes et les mégaphanerophytes étaient dominants avec les pourcentages respectifs de 43% et 35%. L’endozochorie était le mode de dissémination le plus rependu avec un taux de 79%. 14% des espèces recensées dans cette forêt étaient des espèces à statut particulier. Les valeurs moyennes des densités et aires basales des différents biotopes n’étaient pas statistiquement différents, qui indiquent une bonne conservation de la forêt. Ces résultats étaient donc suffisants pour justifier sa protection.   English title: Plant diversity of the Yaya Classified Forest in South-eastern Côte d'Ivoire This study was conducted to contribute to a better knowledge of the woody floristic diversity of the Yaya classified forest. A total of 50 plots of 200 m2 were set up in the different land-use types. In each of the rectangles, all woody individuals with a diameter at breast height (DBH) greater than or equal to 10 cm were identified, counted and measured. These area surveys coupled with the roving surveys resulted in 167 species in 134 genera shared by 47 families. The most important families in order were: Fabaceae, Euphorbiaceae and Malvaceae. Mesophanerophytes and megaphanerophytes were dominant with the respective percentages of 43% and 35%. Endozory was the most common mode of spread with a rate of 79%. 14% of the species recorded in this forest were special status species. The mean values of the densities and basal areas of the different biotopes were not statistically different, which indicates a good conservation of the forest. These results were therefore sufficient to justify its protection

Co-limitation towards lower latitudes shapes global forest diversity gradients

The latitudinal diversity gradient (LDG) is one of the most recognized global patterns of species richness exhibited across a wide range of taxa. Numerous hypotheses have been proposed in the past two centuries to explain LDG, but rigorous tests of the drivers of LDGs have been limited by a lack of high-quality global species richness data. Here we produce a high-resolution (0.025° × 0.025°) map of local tree species richness using a global forest inventory database with individual tree information and local biophysical characteristics from ~1.3 million sample plots. We then quantify drivers of local tree species richness patterns across latitudes. Generally, annual mean temperature was a dominant predictor of tree species richness, which is most consistent with the metabolic theory of biodiversity (MTB). However, MTB underestimated LDG in the tropics, where high species richness was also moderated by topographic, soil and anthropogenic factors operating at local scales. Given that local landscape variables operate synergistically with bioclimatic factors in shaping the global LDG pattern, we suggest that MTB be extended to account for co-limitation by subordinate drivers

Socializing One Health: an innovative strategy to investigate social and behavioral risks of emerging viral threats

In an effort to strengthen global capacity to prevent, detect, and control infectious diseases in animals and people, the United States Agency for International Development’s (USAID) Emerging Pandemic Threats (EPT) PREDICT project funded development of regional, national, and local One Health capacities for early disease detection, rapid response, disease control, and risk reduction. From the outset, the EPT approach was inclusive of social science research methods designed to understand the contexts and behaviors of communities living and working at human-animal-environment interfaces considered high-risk for virus emergence. Using qualitative and quantitative approaches, PREDICT behavioral research aimed to identify and assess a range of socio-cultural behaviors that could be influential in zoonotic disease emergence, amplification, and transmission. This broad approach to behavioral risk characterization enabled us to identify and characterize human activities that could be linked to the transmission dynamics of new and emerging viruses. This paper provides a discussion of implementation of a social science approach within a zoonotic surveillance framework. We conducted in-depth ethnographic interviews and focus groups to better understand the individual- and community-level knowledge, attitudes, and practices that potentially put participants at risk for zoonotic disease transmission from the animals they live and work with, across 6 interface domains. When we asked highly-exposed individuals (ie. bushmeat hunters, wildlife or guano farmers) about the risk they perceived in their occupational activities, most did not perceive it to be risky, whether because it was normalized by years (or generations) of doing such an activity, or due to lack of information about potential risks. Integrating the social sciences allows investigations of the specific human activities that are hypothesized to drive disease emergence, amplification, and transmission, in order to better substantiate behavioral disease drivers, along with the social dimensions of infection and transmission dynamics. Understanding these dynamics is critical to achieving health security--the protection from threats to health-- which requires investments in both collective and individual health security. Involving behavioral sciences into zoonotic disease surveillance allowed us to push toward fuller community integration and engagement and toward dialogue and implementation of recommendations for disease prevention and improved health security

Co-limitation towards lower latitudes shapes global forest diversity gradients

The latitudinal diversity gradient (LDG) is one of the most recognized global patterns of species richness exhibited across a wide range of taxa. Numerous hypotheses have been proposed in the past two centuries to explain LDG, but rigorous tests of the drivers of LDGs have been limited by a lack of high-quality global species richness data. Here we produce a high-resolution (0.025° × 0.025°) map of local tree species richness using a global forest inventory database with individual tree information and local biophysical characteristics from ~1.3 million sample plots. We then quantify drivers of local tree species richness patterns across latitudes. Generally, annual mean temperature was a dominant predictor of tree species richness, which is most consistent with the metabolic theory of biodiversity (MTB). However, MTB underestimated LDG in the tropics, where high species richness was also moderated by topographic, soil and anthropogenic factors operating at local scales. Given that local landscape variables operate synergistically with bioclimatic factors in shaping the global LDG pattern, we suggest that MTB be extended to account for co-limitation by subordinate drivers