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Hydrological variability of large rivers in West Africa: gap-filling with Earth observations and daily rainfall-runoff modelling
No full textInternational audienceIn West Africa, hydrological variability remains poorly understood in many watersheds where observation networks are sparse. After gap-filling gauge data with remote sensing datasets and daily rainfall-runoff modelling, the hydroclimatic variability in upper catchments of the Gambia, KolibaCorubal, KayangaGeba, and Senegal rivers is investigated. CHIRPS rainfall and GLEAM evapotranspiration are used to simulate discharge in 38 sub-basins over 1981-2023 with the GR4J model. Robust performance observed in 34 basins (KGE > 0.5) confirms the effectiveness of the approach even at a daily time step in poorly gauged basins. A dry period (1981-1993), followed by two distinct wet periods (1994-2007, 2008-2023) are identified using standardized precipitation index (SPI), standardized streamflow index (SSI) and the non-parametric Mann-Kendall test. Increased variability in extreme flows and a later peak flood are observed in some basins. Understanding non-stationarity in West African basins is essential to support stakeholders in defining adequate river basin development strategies
Bioéconomie dynamique spatialisée des invasions biologiques : preuve de concept pour la gestion de la jussie en Brière. Métaprogramme BIOSEFAIR. Bilan de projet : 2021 – 2024
No full textBioéconomie dynamique spatialisée des invasions biologiques : preuve de concept pour la gestion de la jussie en Brière Métaprogramme BIOSEFAIRBilan de projet : 2021 -2024 Mai 2025La gestion des espèces exotiques envahissantes (EEE) pose des problèmes complexes relevant d'approches interdisciplinaires couplant écologie et économie. Les outils bioéconomiques d'aide à la décision sont encore peu développés et les modèles existants souffrent notamment d'un manque de réalisme écologique, d'une complexité importante les rendant peu applicables à des cas concrets et d'une relative déconnexion avec les problématiques et besoins rencontrés par les gestionnaires de milieu. En d'autres termes, bien que ces modèles disposent de l'ensemble des ingrédients permettant de définir des outils d'aide à la décision, ils restent principalement tournés vers la sphère académique et formulent des résultats généraux ayant relativement peu d'impact sur le terrain. Afin de combler ces carences, SPABIO s'appuie sur une collaboration transdisciplinaire entre écologues, économistes et gestionnaires des milieux naturels pour (1) développer une nouvelle classe de modèles bio-économiques écologiquement réalistes et directement</div
Etat de conservation du loup en France : mise à jour 2025 de la viabilité démographique de la population sous régime de tirs dérogatoires: Rapport sur saisine inter-ministérielle du 04.12.2024
No full textRapport sur saisine ministérielle du 04.12.2024Ce rapport d'expertise porte sur la viabilité des populations de Loup gris (Canis lupus) en France à l'horizon 2035. Coordonné par l'Office français de la biodiversité (OFB) et le Muséum national d'Histoire naturelle (MNHN) sur saisine interministérielle, il associe une étude prospective des populations à une analyse des impacts des tirs dérogatoires, afin d'évaluer les probabilités d'évolution des effectifs de loups. Les résultats de ces simulations fournissent des informations utiles à la gestion de l'espèce
Une bouse pour les attirer tous : attractivité des déjections pour les bousiers en enclos multi-espèces d'herbivores
No full textInternational audience1. Dung beetles play a decisive part in the degradation of organic matter in grazed ecosystems. The different species can be generalists or specialised in the processing of different resources.2. Our study took place in a safari zoo where numerous herbivore species coexist in large enclosures. All herbivores are fed a similar standard diet. Thus, potential dif- ferences in the attractiveness of their droppings to dung beetles should be only due to specific digestive metabolisms.3. To test the relative attractiveness of these droppings, we conducted a food-choice experiment with 52 pitfall traps baited with different combinations of droppings from herbivore species living in the respective enclosures.4. In total, 411 dung beetles belonging to 16 species were inventoried. The most abundant species was Onthophagus vacca. Equidae droppings were significantly more attractive to dung beetles than Bovinae, Antilopinae or Struthionidae droppings to dung beetles.5. This study suggests that, in western Europe, the local coexistence of different herbi- vores does not facilitate the coexistence of species within dung beetle communities.6. Local dung beetles’ feeding preferences for Equidae droppings, contrasting withprevious studies, might result from pressures of selection induced by the long-term presence of the herbivores in an area otherwise poor in available resources and the isolation of the dung beetle populations from alternative food sources. Dung beetle trophic preferences may therefore depend on the context of the landscape struc- ture and megafaunal history where they occur
Equine milk production in France: challenges and solutions
No full textInternational audienceEquine milk production has been developing in France since the end of the 1990s. Today, more than a hundred producers (around 120) use jenny and mare’s milk, mostly in cosmetics and occasionally in the food market, be- cause of the numerous qualities of the product. This niche sector, poorly structured and federated, includes farms with small herds that rely on an alternative agricultural model. It is often associated with the maintenance of rare breeds and specific local areas, illustrating its impact in the conservation of biological and cultural diversity. In this context, the objective of this research is to better understand the characteristics and organizations of equine milk producers in France, the problems they encounter and the possible solutions to structure this sector. To this end, a qualitative approach was used with around fifty equine milk producers, combining participant observations on farms (for around ten of them) and face-to-face or remote interviews (for all). The comparison in discourses between desired and effective practices highlights coherences and paradoxes that can influence producers’ organi- zation. The description of equine milk producers highlights differences in management methods, production prac- tices and ethical choices. Difficulties come from questions about the refusal of slaughtering, animal wellbeing, characteristics (purebred or not), and sale, product certification, marketing, and economic viability of structures. They are notably caused by a lack of knowledge, available training, and references on the production of equine milk. Finally, by identifying the recurring problems encountered by producers, the research will lay the founda- tions for improving the organization of this production and strengthening collaborations between the different ac- tors of the sector. Moreover, this study paves the way to identify avenues of scientific research that could support the development of this sector under construction
Mathematical Bio-Economics 2.0 for Sustainable Fisheries
No full textInternational audienceReconciling food security, economic development, and biodiversity conservation in the face of global changes is a major challenge. The sustainable uses of marine biodiversity in the context of climate change, invasive species, water pollution, and demographic growth is an example of this bio-economic challenge. There is a need for quantitative methods, models, scenarios, and indicators to support policies addressing this issue. Although bio-economic models for marine resources date back to the 1950s and are still used in fisheries management and policy design, they need major improvements, extensions, and breakthroughs. This paper proposes to design a Mathematical Bio-Economics 2.0 (MBE2) for Sustainable Fisheries to advance the development of bio-economic models and scenarios for the management of fisheries and marine ecosystems confronted with unprecedented global change. These models and scenarios should make both ecological and socioeconomic sense while being well-posed mathematically and numerically. To achieve this, we propose to base the MBE2 framework for Sustainable Fisheries on four research axes regarding the mathematics and modeling of: (i) ecosystem-based fisheries management; (ii) criteria of sustainability; (iii) criteria of resilience; and (iv) governance and strategic interactions. The associated methodology of MBE2 draws mainly on dynamic systems theory, optimal and viable controls of systems, game theory, and stochastic approaches. Our analysis, which is based on these four axes, allows us to identify the main methodological gaps to fill compared to current models for fisheries management. | IntroductionBalancing biodiversity conservation with food security and the preservation of a broader set of ecosystem services (ESs), in a context of ecological transition and climate change, is one of the greatest challenges of the century. The creation and development of the IPBES (International Platform for Biodiversity and Ecosystem Services) at the interface of decision-support and scientific knowledge is in direct line with these concerns.</div
Microclimate, Soil and Plant Dataset From a Mediterranean Urban Canyon With Irrigated Planters
No full textInternational audienceDataset obtained from a fully instrumented experimental urban street canyon, located on a research site in Montpellier (France, Mediterranean climate) and monitored between 21 July 2023 and 31 July 2024. This east–west canyon consists of two parallel concrete walls (height 2.3 m, length 12 m, width 5 m). Three nearly adjacent planters (height 0.9 m, length 2.3 m, width 0.8 m) are aligned along its inner north wall and contain climbing plants of the Lonicera japonica species. Three other nearly adjacent planters (height 0.9 m, length 2.3 m, width 1.1 m) are aligned along its inner south wall and contain shrub plants of the Abelia grandiflora species. Each planter includes 11 sensors to measure soil temperature, water content and matric potential, collecting data every 10 min. Drip irrigation was used and each series of planters received identical irrigation amounts. The irrigation strategy changed several times, to monitor the impacts of irrigation on the overall water balance of the soil–plant–atmosphere system, especially on the local microclimatic variables. A dense network of 102 sensors was installed to monitor wind direction and velocity, air temperature, relative humidity, radiation, grey globe temperature and rainfall at 1.3 m above the ground, which is a standardised measurement height for determining the variables used to quantify thermal comfort indices. This dataset supports (i) understanding thermal, radiative and aerodynamic processes in urban canyons, (ii) detecting irrigation impact on microclimate, (iii) validating CFD‐based microclimate models and (iv) identifying methods to manage urban heatwaves through water resource optimisation. By encompassing a full year of seasonal and climatic variability, this study is the first to evaluate the combined effects of vegetation type and irrigation on urban thermal comfort in a Mediterranean context, providing a significant contribution to urban microclimate research
Understand farmers’decision-making in peanut area allocation and management practices in a Sub-Sahelian region
No full textInternational audiencePeanut is a crucial cash crop across numerous West African countries, especially in Senegal, where small-scale family farms frequently rotate it with millet. Despite significant research on yield enhancement, the drivers behind farmers’ choices have been largely ignored. Recognizing that effective agricultural recommendations must be tailored to the specific context of individual farms, this study aimed for the first time, to understand the decision-making of peanut farmers in a typical rainfed region of the central-western Senegalese peanut basin. We surveyed 46 farmers, gathering data on their resources, perceptions, peanut area allocation, and management practices, as well as socio-economic outcomes. High-peanut farmers, with an average of 28% of their cultivated area allocated to peanut, had more resources than low-peanut farmers, which allocated only 3%. The former enhanced their peanut management by employing farm-saved seeds, hiring labor, and utilizing both manure and synthetic fertilizers. Their average peanut unshelled grain yield (625 kg ha−1) was the highest, although largely under the achievable yield. Their return on investment, which included the value of their own consumption, was also the highest (974%). Medium-peanut farmers presented intermediate characteristics. A widespread high level of self-consumption and investment in watermelon as a new cash crop suggested weak market opportunities for peanut. Low-peanut farmers identified lack of equipment and finance as major constraints, while high-peanut farmers cited lack of finance and quality seeds. All categories recognized peanut’s ecological advantages. These results highlight that limited peanut cultivation and unsustainable practices do not stem from farmers lacking technical knowledge or undervaluing peanut advantages but rather from the socio-economic constraints they face. Solutions for high-peanut farmers may not suit or be adopted by low-peanut farmers. Addressing this disparity requires multi-faceted research and innovations targeting both external and internal farm constraints, shifting from mere inputs provision to co-designing innovations directly with farmers
ECOLOGGING : réseau de Stations Instrumentées Évolutives Modulables et Déplaçable en IoT
No full textInternational audienceCe poster qui est présenté aux J2M 2025, montre le réseau de stations instrumentées IoT low cost développées dans le cadre du projet ECOLOGGING pouvant réaliser des mesures de météorologie, de température et de niveau d'eau, de suivi du sol (en humidité et température) et de Gaz à Effet de Serre.Ces stations ont été déployées sur le territoire français, ainsi qu'en Guyane afin de les tester dans différents écosystèmes et conditions climatiques.Nous présentons également toute la chaîne d'acquisition sécurisée qui utilise un broker MQTTs, Node-Red, une base de données et Grafana.L'émission et la réception des données en 4G est fiable tout comme la récupération des données de l’ensemble des stations qui ont été déployées sur les différents sites, y compris en Guyane
Bioeconomic opportunities in restored tropical forests
No full textSource Agritrop Cirad (https://agritrop.cirad.fr/614555/)International audienceForest restoration faces financial constraints due to land opportunity costs and delayed returns from ecosystem services and timber production. A socially fair bioeconomy of non-timber products from native species is a promising pathway to overcome these challenges. We investigated the bioeconomic potential of native species in the reforested lands of the Brazilian Atlantic Forest. A forest inventory across 46 plots (41 400 m2) in regenerating forests revealed 5181 individuals and 329 species. A review of 603 articles showed 167 species (59%) with bioeconomic potential. Medicinal (58%), cosmetic (12%), and food (5%) uses predominated. Leaves were the most used plant part. Of 2520 patents, we found 78 species patented in 61 countries (8% in Brazil). Only 13% of studies reached the final product stages. The palms (Syagrus romanzoffiana and Euterpe edulis) and the conifer (Araucaria angustifolia) highlight how native species synergistically improve the restoration's supply of resources to the biotech industry