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Articuler environnement et développement au XXIe siècle : les nouveaux défis de l’écodéveloppement
No full textNational audienceLa notion d’écodéveloppement a été promue par Ignacy Sachs dans les années 1970 comme troisième voie entre expansion économique sans limite et renoncement généralisé à la croissance. À l’occasion de son 50ème anniversaire, le CIRED, fondé par Sachs en 1973, a organisé un colloque international à Paris les 30 et 31 mars 2023 sur l’avenir de l’écodéveloppement, et plus largement sur l’articulation environnement-développement au XXIe siècle. Cet article revient sur les principaux enseignements de ce colloque, autour de quatre thèmes : (i) la mise en œuvre des politiques environnementales ; (ii) l’articulation des temporalités de court terme et de long terme ; (iii) la coopération Nord-Sud ; et (iv) la redéfinition des besoins et du bien-être via les notions de capabilité et de sobriété
Changes in chemical fractionation of copper and zinc in soil as a function of incubation moisture content and organic matter amendments
No full textInternational audienceCopper and zinc are essential micronutrients that are potentially toxic when present in excess in soils. Their bioavailability depends on their speciation in soil, but this may vary with environmental conditions. Aeration and hence redox conditions, and organic matter amendments are among the factors likely to cause variation on metal fractionation. We have monitored the chemical fractionation of both native and added copper and zinc in a clay loam top soil during a 5-month laboratory incubation. The effects of aeration (moist soil or flooded) and addition of two organic matter amendments, alfalfa straw or leaf compost, were studied. Metal spike was more labile than legacy metal, and was slowly redistributed over the incubation period. Organic matter caused short-lived flushes of metals, attributed to metal chelation with soluble organic matter. This effect was greater for straw than for more stable compost. There was no evidence that added organic matter increased the capacity of soil organic matter to immobilise metal. Flooding solubilized soil metal (hydr)oxides, releasing legacy Cu and Zn, but with less effect on the capacity to immobilise metal spike. Effects of flooding and organic matter addition were not additive. Both metals appear to be precipitated as sulphides under reducing conditions, and accounted for in the acid soluble phase. Monitoring the dynamics of metal distribution gives a more comprehensive understanding of underlying processes than would a single measurement, and is closer to in campo conditions than slurry microcosms
Using Free Air CO<sub>2</sub> Enrichment data to constrain land surface model projections of the terrestrial carbon cycle
No full textInternational audiencePredicting the responses of terrestrial ecosystem carbon to future global change strongly relies on our ability to model accurately the underlying processes at a global scale. However, terrestrial biosphere models representing the carbon and nitrogen cycles and their interactions remain subject to large uncertainties, partly because of unknown or poorly constrained parameters. Parameter estimation is a powerful tool that can be used to optimise these parameters by confronting the model with observations. In this paper, we identify sensitive model parameters from a recent version of the ORgainzing Carbon and Hydrology in Dynamic Ecosystems (ORCHIDEE) land surface model that includes the nitrogen cycle. These sensitive parameters include ones involved in parameterisations controlling the impact of the nitrogen cycle on the carbon cycle and, in particular, the limitation of photosynthesis due to leaf nitrogen availability. We optimise these ORCHIDEE parameters against carbon flux data collected on sites from the FLUXNET network. However, optimising against present-day observations does not automatically give us confidence in future projections of the model, given that environmental conditions are likely to shift compared to the present day. Manipulation experiments give us a unique look into how the ecosystem may respond to future environmental changes. One such type of manipulation experiment, the Free Air CO2 Enrichment (FACE) experiment, provides a unique opportunity to assess vegetation response to increasing CO2 by providing data under ambient and elevated CO2 conditions. Therefore, to better capture the ecosystem response to increased CO2, we add the data from two FACE sites to our optimisations, in addition to the FLUXNET data. We use data from both CO2 conditions of FACE, which allows us to gain extra confidence in the model simulations using this set of parameters. We find that we are able to improve the magnitude of modelled productivity. Although we are unable to correct the interannual variability fully, we start to simulate possible progressive nitrogen limitation at one of the sites. Using an idealised simulation experiment based on increasing atmospheric CO2 by 1 % yr−1 over 100 years, we find that optimising against only FLUXNET data tends to imply a large fertilisation effect, whereas optimising against FLUXNET and FACE data (with information about nutrient limitation and acclimation of plants) decreases it significantly
Durabilité de l’offre de l’aide alimentaire dans les régions d’Outre-mer : exemple de collaboration INRAE-FFBA
No full textNational audienceLe 28 février au Salon international de l’agriculture, Philippe Mauguin, président-directeur général d’INRAE et Laurence Champier, directrice fédérale de la Fédération française des banques alimentaires (FFBA), ont signé leur première convention de partenariat au service de la lutte contre la précarité alimentaire, qui touche près de 2,6 millions de personnes en France. Cette collaboration, fondée sur l'expertise scientifique d'INRAE et l'engagement social de la FFBA, vise à développer sur les 3 prochaines années des solutions innovantes pour répondre aux besoins des populations les plus vulnérables. Les domaines de travail de ce partenariat incluent notamment :- l'amélioration des connaissances sur les populations en situation de précarité alimentaire ;- l'expérimentation et l'évaluation d'interventions pour répondre à leurs besoins ;- le développement et le partage d'outils pour soutenir les actions de terrain
How to choose a good dissertation topic ? In 10 steps
No full textMasterThese slides summarize the key points from a webinar aimed at guiding Master's students through the process of choosing a dissertation topic. They outline a 10-steps approach that interlaces four critical factors: the student's capabilities and interests, the innovative edge of the research, the supervisor's academic expertise, and the availability of financial resources. They further outline a practical approach to developing the dissertation topic within the larger research article production cycle, and discusses essential timelines for both funded research projects and academic Ph.D. funding opportunities for Master's students
Molecular characterization of cowpea [Vigna unguiculata (L.) Walp.] subspecies with SSR markers
No full textInternational audienceCowpea, Vigna unguiculata, is an important food legume in the tropics and subtropics. However, cowpea is a complex species with more than 10 subspecies that can hybridize and produce intermediate offspring. Partly because of the complex organization of the cowpea gene pool and the lack of adequate markers for these infraspecific units, cowpea breeders are not using the wild part of the cowpea gene pool. Here, we report the molecular characterization of 34 representative accessions with 18 polymorphic simple sequence repeat (SSR) markers from coding regions. Although the SSRs failed to separate the closest groups, i.e., subsp. alba, subsp. tenuis and the perennial groups from subsp. unguiculata, a combination of 11 SSR markers could properly identify the main cowpea subspecies. Regarding the infraspecific phylogeny of cowpea, the SSR markers confirmed the special status of the annual subsp. unguiculata versus the different perennial subspecies. They suggested that subsp. protracta is the oldest subspecies, making the origin of the species in southern Africa likely. All the taxa of hybrid origin, i.e., subsp. alba, subsp. tenuis, subsp. pubescens, and the BWA group of subsp. unguiculata, are in a single clade clearly separated from subsp. unguiculata. Although a limited number of markers were tested, considering that several hundred cowpea SSRs are available, the present work shows that SSR markers can be used for the molecular characterization of cowpea subspecies and can be very helpful for understanding the complex evolutionary history of cowpea
Agriculteurs, citadins et élus locaux : comment transformer une plaine viticole méditerranéenne en un territoire périurbain nourricier ?
No full textInternational audienceFarmers faced with urban sprawl are more or less in tune with city-dwellers’ demands for local food products and services. Our study of the western plain of Montpellier in France, a particularly attractive Mediterranean coastal city, reveals the continuation of a wine-growing agricultural base coexisting with new forms of agriculture. Interviews with farmers, elected representatives and agricultural and urban planners enabled us to identify eight profiles of peri-urban farmers. Faced with the rapid advance of the city, an analysis of their practices and relationships with each other, with city dwellers and with local officials, reveals spatial and social strategies that enable them to integrate into the city and maintain themselves. But there is a gap between these local farming initiatives and an ambitious regional policy aimed at supporting an ecological and food transition. Our analyses can help to facilitate the co-construction of new inclusive local policies that are consistent with the existing agricultural mosaic.Les agriculteurs confrontés à l’étalement urbain sont diversement en phase avec les demandes des citadins en services et produits alimentaires locaux. Notre étude de la plaine Ouest de Montpellier, en France, ville côtière méditerranéenne particulièrement attractive, révèle le maintien d’une base agricole viticole coexistant avec de nouvelles formes d’agriculture. Des entretiens auprès d’agriculteurs, d’élus, de planificateurs agricoles et urbains ont permis d’identifier huit profils d’exploitations agricoles périurbaines. Face à l’avancée rapide de la ville, l’analyse de leurs pratiques et des relations entre elles, avec les citadins et les responsables locaux, révèle des stratégies spatiales et sociales qui leur permettent de s’intégrer à la ville et de se maintenir. Mais il existe un décalage entre ces initiatives agricoles locales et une politique territoriale ambitieuse visant à soutenir une transition écologique etalimentaire. Nos analyses peuvent contribuer à faciliter la co-construction de nouvelles politiques locales inclusives cohérentes avec la mosaïque agricole existante
Early Season Forecasting of Corn Yield at Field Level from Multi-Source Satellite Time Series Data
No full textInternational audienceCrop yield forecasting during an ongoing season is crucial to ensure food security and commodity markets. For this reason, here, a scalable approach to forecast corn yields at the field-level using machine learning and satellite imagery from Sentinel-2 and Landsat missions is proposed. The model, evaluated on 1319 corn fields in the U.S. Corn Belt from 2017 to 2022, integrates biophysical parameters from Sentinel-2, Land Surface Temperature (LST) from Landsat, and agroclimatic data from ERA5 reanalysis dataset. Resampling the time series over thermal time significantly enhances predictive performance. The addition of LST to our model further improves in-season yield forecasting, through its capacity to detect early drought, which is not immediately visible to optical sensors such as the Sentinel-2. Finally, we propose a new two-stage machine learning strategy to mitigate early season partially available data. It consists in extending the current time series on the basis of complete historical data and adapting the model inference according to the crop progress
Environmental disturbances of trophic interactions and their impacts on a multi-host sapronotic pathogen
No full textSapronotic pathogens are constituents of complex trophic networks, such as those that structure aquatic and soil ecosystems. In such habitats, sapronotic pathogens live and reproduce among microbial consortia, and occasionally infect hosts and cause sapronotic disease (sapronosis). Sapronotic pathogens include almost all fungal microparasites and about a third of the bacterial pathogens infecting humans, including for instance non-tuberculous mycobacteria. Even though sapronotic agents are naturally present in the environment, their population dynamics are unknown. Despite growing rates of sapronotic disease incidence among humans and other animals, very few studies have examined sapronotic transmission and dynamics in the context of spatially explicit trophic networks. Patterns of sapronotic pathogen transmission arise from complex interactions, including pathogen natural history, non-host and host environments, and spatial and temporal scales of the system. In order to infer and ultimately predict how environmental disturbances affect trophic interactions and influence sapronotic ecology, we analyzed host and non-host species interacting as prey and as micro- and macropredators within a metacommunity context. Using a set of differential equation models, we assessed responses of environmental load dynamics of a sapronotic disease agent, i.e., a mycobacterial pathogen, within a general framework of environmental disturbance. We show that variation in top-down and horizontal interactions mediated sapronotic pathogen abundance and dynamics in the environment. Our findings indicate that habitat change and trophic interactions within host-pathogen relationships may strongly affect sapronotic pathogen ecology through both synergistic and opposing mechanisms. This work provides for the first time an understanding of environmental disturbance consequences on trophic webs that include major sapronotic pathogens. In addition, the results provide a basis for interpreting the development of epidemics and epizootics in the context of ecosystem modifications, particularly that of agriculture. Further research of this type will provide a better understanding of the complex dynamics of sapronotic pathogens in animals and humans responding to global change
Caring for Groundwater: How Care Can Expand and Transform Groundwater Governance
No full textInternational audienceEfforts to measure and regulate groundwaters and irrigators are notoriously ineffective. The starting point of this article, therefore, is to question the continued faith in techno-managerial solutions to groundwater depletion. We discuss the potential of the conceptual vocabulary of ‘care’ to complement, refresh and expand ways of talking about and doing groundwater governance. Mobilizing a diverse range of examples from places where pressures on aquifers are particularly acute, we do this by exploring what care entails in everyday practices of groundwater use and management. We show that foregrounding care nuances and sometimes challenges stories of users unavoidably depleting aquifers when given the chance and means to do so. Irrigators may display concern about the longer-term sustainability of the aquifers on which their livelihoods depend, even when their own pumping practices are unsustainable. In spite of pressures to intensify and individualize, farmers sometimes do hold on to or creatively develop collective rules to fairly share groundwater and use it sustainably, complementing strategies to make do with what is available with investments inconservation and recharge. Attention to care, moreover, highlights the ongoing processes of tinkering that governing groundwater always entails. The ability to tinker hinges on intimate and often embodied knowledge of a watery place. Accepting the care involved in governing groundwater, our analysis therefore concludes, prompts a re-consideration of what is and who has water expertise, with important implications for the role of ‘outside’ experts. More than a new theory, we propose embracing care as an analytical sensibility, with the study of practices of care serving as one promising way to widen the conceptual and political space for understanding and doing human-groundwater relations