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Une méta-analyse sur la valeur productive de la biodiversité des cultures
No full textInternational audienceGrowing recognition of biodiversity's role in supporting agricultural productivity has prompted economists and other scholars to quantify the “productive value” of crop biodiversity using observational data from real‐world conditions. We present the first meta‐analysis of that literature, drawing on 158 estimates from 52 observational studies published between 1998 and 2025. Overall, crop biodiversity exhibits a positive and statistically significant effect on agricultural productivity, with an average elasticity of 0.75—meaning a 1% increase in crop biodiversity (proxied by diversity indexes) raises agricultural outcomes by 0.75%. Yet, this average masks considerable heterogeneity across and within studies (standard deviation of 1.23). Complementary meta‐regression analyses attribute much of this heterogeneity to differences in research settings: biodiversity indexes based on species richness yield larger effects than evenness‐based ones, profit‐related outcomes show stronger associations with biodiversity than production‐related ones, and instrumental variable estimates exceed those from other methods. We further detect signs of selective reporting in our sample, with published estimates clustering just above conventional significance thresholds. Adjusting for this bias reduces average effects substantially, though the corrected evidence still points toward a positive—though more modest—productive value of crop biodiversity.La reconnaissance croissante du rôle de la biodiversité dans le soutien à la productivité agricole a incité les économistes et autres chercheurs à quantifier la « valeur productive » de la biodiversité des cultures à l’aide de données d’observation issues de conditions réelles. Nous présentons ici la première méta-analyse de cette littérature, en nous appuyant sur 158 estimations issues de 52 études d’observation publiées entre 1998 et 2025. Dans l'ensemble, la biodiversité des cultures a un effet positif et statistiquement significatif sur la productivité agricole, avec une élasticité moyenne de 0,75 — ce qui signifie qu'une augmentation de 1 % de la biodiversité des cultures (mesurée par des indices de diversité) entraîne une hausse de 0,75 % des résultats agricoles. Cependant, cette moyenne masque une hétérogénéité considérable entre les études et au sein de celles-ci (écart-type de 1,23). Des analyses complémentaires de méta-régression attribuent une grande partie de cette hétérogénéité aux différences dans les contextes de recherche : les indices de biodiversité basés sur la richesse en espèces produisent des effets plus importants que ceux basés sur l’uniformité, les résultats liés aux bénéfices montrent des associations plus fortes avec la biodiversité que ceux liés à la production, et les estimations par variables instrumentales dépassent celles obtenues par d’autres méthodes. Nous détectons en outre des signes de sélection dans notre échantillon, les estimations publiées se situant juste au-dessus des seuils de signification conventionnels. La correction de ce biais réduit considérablement les effets moyens, bien que les résultats corrigés continuent d’indiquer une valeur productive positive — quoique plus modeste — de la biodiversité des cultures
An assessment of European and Atlantic sturgeons’ paleoniches during the Holocene
No full textInternational audienceThe use of species distribution models (SDMs) in paleoecology enhances its contribution to ecology and conservation biology, such as estimating climate change impacts and informing conservation efforts. Acipenser sturio and A. oxyrinchus are closely related sturgeon species currently arranged in two disjunct distributions across the Atlantic Ocean. However, paleogenetic findings highlighted that both species were present in European waters over at least five millennia. Their joint European history during the Holocene period might have been driven by the thermal hypothesis, with A. oxyrinchus being a cooler-water species than A. sturio . Given their current poor state of conservation, quantifying their environmental preferences at a time when the two species were more abundant could help shape future conservation/restoration measures. Paleo-species distribution models were built for each species based on paleoclimate variables and archeozoological remains, most of which were genetically identified at the species level. Response curves for air temperature and precipitation were then applied to estimate relative continental paleohabitat suitability (HSI) in watersheds across four regions (i.e., the Baltic Sea, the Northern Seas, the South European Atlantic shelf, and the Mediterranean Sea) throughout the Holocene. The estimated niches confirmed the thermal sensitivity difference between the two species, with A. oxyrinchus having a narrower thermal range towards colder annual temperatures. Comparing HSI suitability between the two species, the four regions were globally all suitable for A. sturio but not for A. oxyrinchus , which showed much greater variability. Catchments with outlets to the Mediterranean Sea and the South European Atlantic shelf were mainly suitable for A. sturio . In contrast, those with an outlet in the Baltic Sea were slightly more suitable for A. oxyrinchus than for A. sturio . Catchments with outlets to the Northern Seas showed comparable suitability for both species. This superposition in near-past suitable habitats implied that the two species can potentially exist under the same environmental conditions and as such suggested future risks of biotic interactions which should be further acknowledged in potential stocking practices
Governing antibiotic resistance through One Health: Insights from the political and legal landscape in Senegal
No full textInternational audienceAntimicrobial resistance (AMR), especially antibiotic resistance (ABR), could cause up to 10 million deaths per year by 2050. While ABR is a natural phenomenon, it is exacerbated by antibiotic misuse, poor sanitation, insufficient health infrastructure, weak biosecurity, and environmental contamination. The cross-transmission of resistant bacteria between humans, animal and the environment requires a multi-sectoral response inspired by the One Health concept. With the support of international partners and in line with global policies, Senegal has established a national One Health platform and legal measures to combat ABR. Our study proposes to examine the One Health governance capacities for managing ABR in Senegal, and to identify ways of improvement from a One Health perspective. A qualitative approach was adopted, combining the review of 64 legal instruments and 26 semi-structured interviews conducted between January and August 2023 with actors from governmental, private and non-governmental institutions. The analysis focused on governance structure, legal instrument development and implementation, and ABR surveillance programmes. The thematic analysis of the interview contents highlighted factors influencing the One Health governance capacities in Senegal. One Health governance has been institutionalized in Senegal since 2017 with the creation of the national One Health platform housed at the Prime Minister’s Office. However, its effectiveness is limited by weak formalization, inadequate resources, and reliance on external funding. Outdated and poorly enforced legal frameworks hinder ABR management, while rural areas lack sufficient laboratory infrastructure, leading to inappropriate antibiotic use and weak surveillance systems. Power imbalances among stakeholders impede collective action and data-sharing. Despite progress toward international standards, systemic barriers persist. Strengthening the legal framework, improving healthcare infrastructure, and enhancing the One Health platform’s status and funding are critical. Institutionalization must connect global orientations with local realities to avoid inequities. Sustainable ABR management requires inclusive, context-sensitive policies, robust domestic investment, and equitable collaboration among stakeholders across the sectors of human, animal, and environmental health
Detection of Multiple Microorganisms in Ruminant Ticks in Senegal Using High‐Throughput Microfluidic Real‐Time PCR
No full textInternational audienceTicks are major vectors of numerous pathogens affecting both livestock and humans. In Senegal, data on the diversity of tick‐borne pathogens (TBPs) in ruminant‐associated ticks remain limited. In total, 1703 ticks were collected from goats, sheep, and cattle across three ecological zones of Senegal (Sudanian, Sahelian, and Sudano‐Sahelian). Tick species were identified morphologically, and 300 individuals were screened for 36 microorganisms using a high‐throughput microfluidic real‐time PCR system. DNA was successfully extracted and amplified from 289 ticks. The most abundant species were Rhipicephalus evertsi evertsi (32.3%), Hyalomma truncatum (19.6%), R. guilhoni (15.6%), H. rufipes (11.6%), and Amblyomma variegatum (11.0%). Among the screened ticks, 226 (78.9%) were positive for at least one microorganism. True pathogens of veterinary and/or zoonotic importance included Anaplasma ovis (30.8%), Coxiella spp. (23.9%), Rickettsia aeschlimannii (13.1%), Theileria spp. (11.1%), and Ehrlichia canis (4.8%), with sporadic detections of Anaplasma marginale , A. bovis , and Babesia spp. (0.3% each). In addition, non‐pathogenic Francisella ‐like endosymbionts (FLEs) were detected at high prevalence (37.4%) across all ecological zones. The presence of TBPs and/or endosymbionts was significantly associated only with the tick’s host in the multivariable logistic regression model. Ticks collected from goats (OR = 7.82; p = 0.024) and sheep (OR = 7.70; p = 0.015) were significantly more likely to be infected than those collected from cattle (reference group). A total of 96 cases of microorganism co‐occurrence were recorded across different tick species. Co‐infections were more frequent in ticks collected from the Sudano‐Sahelian zone (48.2%) and in those from sheep (32.0%). None of the detected microorganism species showed a significant associated with tick sex. This study represents the first large‐scale molecular survey of TBPs in ruminant‐associated ticks in Senegal, revealing both a high diversity of pathogens and a widespread presence of tick endosymbionts. While endosymbionts, such as FLEs, are not known to be pathogenic, their abundance may influence tick physiology and vector competence. The detection of zoonotic pathogens, such as E. canis and R. aeschlimannii , underscores the need to strengthen tick surveillance and investigate their potential public health implications
One year after the TransMet trial: Transplant oncology at a turning point
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A database of cross-sectional images for testing the biometric traceability of oak (Quercus petraea (Matt.) Liebl. and Quercus robur L.) logs under realistic acquisition conditions
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Transhumance, ressources et décentralisation : le besoin d’articuler les échelles pour sécuriser les systèmes pastoraux au Sénégal
No full textInternational audienceBackground: In Senegal, decentralization has profoundly transformed territorial governance by transferring the management of land and natural resources to local municipalities. In the sylvopastoral zone of Ferlo, a vast Sahelian territory historically dedicated to mobile livestock herding, this reorganization has resulted in administrative fragmentation often disconnected from the sociospatial logics of pastoralism. Aim: This study analyzes the effects of decentralization on the governance of pastoral resources and assesses the relevance of local planning tools, particularly the Land Use and Allocation Plans (POAS) and Pastoral Units (UP), in relation to mobility dynamics. Methods: The research draws on qualitative surveys conducted in nine communes across the Ferlo, the Senegal River Valley, and southeastern Senegal, combining semi-structured interviews, focus groups, and field observations involving herders, local authorities, technical services, and partner organizations. Results: The findings reveal that spatial fragmentation caused by communalization, overlapping customary and institutional frameworks, and weak intercommunal coordination undermine the governance of shared resources and increase herders’ vulnerability. Although POAS and UPs have contributed to structuring local planning, their impact remains limited due to insufficient resources, weak integration of mobility practices, and the predominance of agricultural logics in land allocation decisions. These dynamics have led to growing resource-use conflicts and the gradual marginalization of pastoralism within local policies. Conclusions: The study highlights the need for a multi-level governance framework linking municipalities, intercommunal structures, and the national level, and proposes the establishment of a National Pastoralism Observatory to monitor mobility dynamics, strengthen institutional coordination, and guide public policies toward sustainable, inclusive, and resilient management of Sahelian pastoral territories.Contexto: En el Senegal, la descentralización ha transformado profundamente la gobernanza territorial transfiriendo a los municipios la gestión del territorio y de los recursos naturales. En la zona silvopastoral del Ferlo, amplio territorio saheliano históricamente dedicado a la ganadería móvil, esta reorganización se ha traducido en una parcelación administrativa por lo general desconectada de las lógicas socioespaciales del pastoralismo. Objetivo: Este estudio analiza los efectos de la descentralización en la gobernanza de los recursos pastorales y evalúa la pertinencia de las herramientas de planificación local, especialmente los planes de ocupación y de afectación de los suelos (POAS) y las unidades pastorales (UP), ante las dinámicas de movilidad. Métodos: El enfoque se basa en encuestas cualitativas llevadas a cabo en nueve municipios del Ferlo, del valle del río Senegal y del sudeste del país, combinando entrevistas semidirectivas, grupos de discusión (focus groups) y observaciones de terreno junto a ganaderos, representantes públicos locales, agentes de servicios técnicos y miembros de organizaciones colaboradoras. Resultados: Los resultados revelaron que la fragmentación espacial generada por la comunalización, la superposición de dispositivos tradicionales e institucionales y la falta de coordinación intercomunal, fragilizan la gobernanza de los recursos compartidos y acentúan la vulnerabilidad de los ganaderos. POAS y UP han contribuido a estructurar la planificación local, pero su impacto queda limitado por la insuficiencia de los medios, la poca integración de las prácticas de movilidad y la dominación de las lógicas agrícolas en las decisiones territoriales. Estas dinámicas territoriales se traducen en una multiplicación de los conflictos de uso y una marginalización progresiva del pastoralismo en las políticas locales. Conclusiones: El estudio resalta la necesidad de una gobernanza multiescala que articule municipios, mancomunidades y Estado, y propone la creación de un observatorio nacional del pastoralismo para garantizar el seguimiento de las dinámicas de movilidad, reforzar la coordinación institucional y orientar las políticas públicas a favor de una gestión sostenible, inclusiva y resiliente de los territorios pastorales sahelianos.Contexte : Au Sénégal, la décentralisation a profondément transformé la gouvernance territoriale en transférant aux communes la gestion du foncier et des ressources naturelles. Dans la zone sylvopastorale du Ferlo, vaste territoire sahélien historiquement dédié à l’élevage mobile, cette réorganisation s’est traduite par un morcellement administratif souvent déconnecté des logiques socio-spatiales du pastoralisme. Objectif : Cette étude a analysé les effets de la décentralisation sur la gouvernance des ressources pastorales et a évalué la pertinence des outils de planification locale, notamment les plans d’occupation et d’affectation des sols (POAS) et les unités pastorales (UP), face aux dynamiques de mobilité. Méthodes : L’approche a reposé sur des enquêtes qualitatives menées dans neuf communes du Ferlo, de la vallée du fleuve Sénégal et du sud-est du pays, combinant entretiens semi-directifs, groupes de discussion (focus groups) et observations de terrain auprès d’éleveurs, d’élus locaux, d’agents des services techniques et de membres d’organisations partenaires. Résultats : Les résultats ont révélé que la fragmentation spatiale induite par la communalisation, la superposition de dispositifs coutumiers et institutionnels et le manque de coordination intercommunale fragilisaient la gouvernance des ressources partagées et accentuaient la vulnérabilité des éleveurs. Les POAS et les UP ont contribué à structurer la planification locale, mais leur impact demeure limité par l’insuffisance des moyens, la faible intégration des pratiques de mobilité et la domination des logiques agricoles dans les décisions foncières. Ces dynamiques foncières se traduisent par une multiplication des conflits d’usage et par une marginalisation progressive du pastoralisme dans les politiques locales. Conclusions : L’étude a souligné la nécessité d’une gouvernance multi-échelle articulant communes, intercommunalités et État, et propose la création d’un Observatoire national du pastoralisme pour assurer le suivi des dynamiques de mobilité, renforcer la coordination institutionnelle et orienter les politiques publiques en faveur d’une gestion durable, inclusive et résiliente des territoires pastoraux sahéliens
A regionally based method to identify lithology-specific hydraulic conductivity distributions in shallow aquifers using catchment-scale effective values
No full textInternational audienceWe present a novel method for estimating lithology-specific hydraulic conductivities from catchment-scale effective values, each interpreted as a linear combination of the conductivities of the underlying lithologies. The method particularly applies to discharge-derived estimates of effective conductivity, where river networks integrate the influence of predominantly shallow groundwater flows from adjacent hillslopes. Lithological area fractions are used as weights to formulate an overdetermined linear system, which is solved using a modified method of moments under the assumption of lognormally distributed conductivities to account for spatial variability.The method was validated on synthetic cases and applied to 113 catchments in the Armorican Massif (France). It shows good convergence properties and achieves high predictive accuracy: in 85% of cases, the modeled conductivities fall within a 90% confidence interval of the observed values. Convergence analysis indicates that using five catchments per lithology is sufficient to reach 75% predictive success, with mean and standard deviation parameters estimated within 6% and 30%, respectively. With 80 catchments, prediction accuracy increases to 80%, and parameter estimation errors are reduced to 3% and 15%.The method is computationally efficient and generalizable, offering a powerful tool to explore lithology-specific conductivity datasets at regional scales. It may also be adapted to other variables, such as porosity, where linear averaging applies, enabling broader applications in hydrogeological modeling
Governing by promises. Water scarcity and rural hegemony in Morocco
No full textSource Agritrop Cirad (https://agritrop.cirad.fr/616979/)International audienceOver the last decade, an important field of inquiry has emerged around the notion of promissory legitimation. It focuses less on the fulfillment of collective promises than on their production and reception. This paper aims, first, to foreground its relevance for – critical- policy studies, by highlighting the decisive role that promises can play in the (re)production of hegemony. Second, and more specifically, it seeks to identify some practices of promise adjustment: the everyday strategies by which governing actors adapt, modify and re-assert their promises when their credibility is under stress, in order to reproduce the hegemony of the same groups in society. I explore these practices in the case of an irrigation megaproject in Morocco, where a developmentalist promise is proving insufficient to defuse tensions surrounding future water access. I show that a key adjustment mechanism is to add new promises on top of the first one – in this case, a clientelist promise and a laissez-faire promise. The coexistence of different promises, however, displays the same chronic contradictions as policy in general, with the same attendant limitations in the hegemony it attempts to uphold