Transformations agricoles et agroalimentaires

À l’heure des robots et du numérique, la terre (habitat, agriculture, paysage, planète) et la nourriture (du corps et de l’âme) sont parmi les préoccupations majeures dans les espaces médiatiques et politiques. Le pétrole et l’abondance qui l’a accompagné nous avaient fait oublier qu’elles sont au fondement des sociétés humaines. La « crise alimentaire » de 2008, qui a secoué plusieurs continents, a rappelé aux gouvernements l’enjeu de la sécurité alimentaire. Après des décennies d’excédents, de baisse du prix des produits agricoles de base, la question de la valeur de la terre et de l’agriculture est de retour. La question de la santé et celle des droits humains prennent une place élargie tant dans les politiques publiques et dans la production de normes alimentaires. Des mouvements sociaux transnationaux s’emparent de la question de l’avenir de l’agriculture et de l’alimentation, et de celle de la « bonne vie ». Pour contribuer à cette réflexion sur l’avenir de la terre et de la nourriture, cet ouvrage étudie la socialisation de l’agriculture, c’est-à-dire sa prise en charge tant par les politiques agricoles (essentiellement nationales) que par l’organisation des marchés dans un cadre national et international. Il le fait en prenant un large recul et mobilise trois temporalités. La première est celle de la planète. La seconde, celle des régimes métaboliques, façons dont l’humanité à différents stades de développement, mobilise matériaux et énergie. La troisième est celle du capitalisme, avec la succession de systèmes hégémoniques (ce qui n’exclue pas de multiples polarités). Cet ouvrage réunit des recherches récentes d’économistes, de sociologues, d’historiens et d’agronomes, de différents pays, recherches qui ont en commun de concerner la place de l’agriculture dans l’évolution des capitalismes

The GEOTRACES Intermediate Data Product 2014

The GEOTRACES Intermediate Data Product 2014 (IDP2014) is the first publicly available data product of the international GEOTRACES programme, and contains data measured and quality controlled before the end of 2013. It consists of two parts: (1) a compilation of digital data for more than 200 trace elements and isotopes (TEIs) as well as classical hydrographic parameters, and (2) the eGEOTRACES Electronic Atlas providing a strongly inter-linked on-line atlas including more than 300 section plots and 90 animated 3D scenes. The IDP2014 covers the Atlantic, Arctic, and Indian oceans, exhibiting highest data density in the Atlantic. The TEI data in the IDP2014 are quality controlled by careful assessment of intercalibration results and multi-laboratory data comparisons at cross-over stations. The digital data are provided in several formats, including ASCII spreadsheet, Excel spreadsheet, netCDF, and Ocean Data View collection. In addition to the actual data values the IDP2014 also contains data quality flags and 1-? data error values where available. Quality flags and error values are useful for data filtering. Metadata about data originators, analytical methods and original publications related to the data are linked to the data in an easily accessible way. The eGEOTRACES Electronic Atlas is the visual representation of the IDP2014 data providing section plots and a new kind of animated 3D scenes. The basin-wide 3D scenes allow for viewing of data from many cruises at the same time, thereby providing quick overviews of large-scale tracer distributions. In addition, the 3D scenes provide geographical and bathymetric context that is crucial for the interpretation and assessment of observed tracer plumes, as well as for making inferences about controlling processes

Seasonal stratification leads to changes within the benthic food web of the Gulf of Lions (northwestern Mediterranean)

Like most continental shelves, the Gulf of Lions in the northwestern Mediterranean Sea provides multiple ecological services and is subject to multiple natural and anthropogenic pressures. In this context, this marine habitat must be described to monitor its evolution and ensure its protection. We used carbon and nitrogen stable isotope analysis to describe the structure of the benthic food web. Two sampling campaigns, corresponding to two contrasting situations in terms of water stratification, were carried out in 2018. One in April when the water column was still well mixed and the annual peak of phytoplankton production had already occurred, the other in September after several months of thermal stratification and low primary productivity. Results revealed that the structure of the food web changed in terms of range, extent and degree of trophic diversity. Between the two sampling dates, isotopic niches of the taxa remained evenly distributed but the niche space shrunk. Temporal changes in stable isotope compositions were greater for active suspension feeders, surface deposit feeders and their direct predators than for other functional groups feeding deep in the sediment or hunting a wider range of prey. The increase in nitrogen isotope ratios of primary consumers is either the result of a fasting effect due to reduced food availability or a change in feeding behavior due to reduced digestibility of primary food sources

Seasonal stratification leads to changes within the benthic food web of the Gulf of Lions (northwestern Mediterranean)

Like most continental shelves, the Gulf of Lions in the northwestern Mediterranean Sea provides multiple ecological services and is subject to multiple natural and anthropogenic pressures. In this context, this marine habitat must be described to monitor its evolution and ensure its protection. We used carbon and nitrogen stable isotope analysis to describe the structure of the benthic food web. Two sampling campaigns, corresponding to two contrasting situations in terms of water stratification, were carried out in 2018. One in April when the water column was still well mixed and the annual peak of phytoplankton production had already occurred, the other in September after several months of thermal stratification and low primary productivity. Results revealed that the structure of the food web changed in terms of range, extent and degree of trophic diversity. Between the two sampling dates, isotopic niches of the taxa remained evenly distributed but the niche space shrunk. Temporal changes in stable isotope compositions were greater for active suspension feeders, surface deposit feeders and their direct predators than for other functional groups feeding deep in the sediment or hunting a wider range of prey. The increase in nitrogen isotope ratios of primary consumers is either the result of a fasting effect due to reduced food availability or a change in feeding behavior due to reduced digestibility of primary food sources

Seasonal stratification leads to changes within the benthic food web of the Gulf of Lions (northwestern Mediterranean) Authors

International audienceDue to its extensive continental shelf, the Gulf of Lion, situated in the northwestern Mediterranean Sea, plays a crucial role in providing ecological services amidst various natural and anthropogenic pressures. Exposed to the impacts of climate change and suitable for marine energy development projects, the conservation of marine biodiversity in this environment raises significant concerns. To detect any potential disturbances in the functioning of the terrigenous mud community on the continental shelf, we conducted stable carbon and nitrogen isotope analyses on suspended particulate organic matter, sediments, and benthic fauna. Since seasonality is a structuring factor for the functioning of such an oligotrophic ecosystem, we conducted two sampling campaigns in 2018 to capture contrasting scenarios of water column stratification-one in April during well-mixed conditions and high phytoplankton production, and another in September at the end of the summer thermal stratification period characterized by low primary productivity. Stable isotope analysis revealed changes in the structure of the benthic food web in response to seasonal stratification of the water column. While isotopic niches of taxa remained evenly distributed, the total niche space contracted between sampling dates, primarily affecting low trophic level consumers. The observed contraction aligns with that reported at the base of the pelagic food web. These results enhance our understanding of the functioning of the continental shelf of the Gulf of Lion. The intense trawling pressure on the study site affected sampling. In this context, this research contributes not only to the knowledge of seasonal trophic variations but also provides a reference state to understand the future of this Mediterranean continental shelf

Seasonal stratification leads to changes within the benthic food web of the Gulf of Lions (northwestern Mediterranean)

Like most continental shelves, the Gulf of Lions in the northwestern Mediterranean Sea provides multiple ecological services and is subject to multiple natural and anthropogenic pressures. In this context, this marine habitat must be described to monitor its evolution and ensure its protection. We used carbon and nitrogen stable isotope analysis to describe the structure of the benthic food web. Two sampling campaigns, corresponding to two contrasting situations in terms of water stratification, were carried out in 2018. One in April when the water column was still well mixed and the annual peak of phytoplankton production had already occurred, the other in September after several months of thermal stratification and low primary productivity. Results revealed that the structure of the food web changed in terms of range, extent and degree of trophic diversity. Between the two sampling dates, isotopic niches of the taxa remained evenly distributed but the niche space shrunk. Temporal changes in stable isotope compositions were greater for active suspension feeders, surface deposit feeders and their direct predators than for other functional groups feeding deep in the sediment or hunting a wider range of prey. The increase in nitrogen isotope ratios of primary consumers is either the result of a fasting effect due to reduced food availability or a change in feeding behavior due to reduced digestibility of primary food sources

Les ressources biologiques

Le dossier thématique propose une lecture transversal des trois formes de vie que constituent le développement d’aires naturelles protégées, les lois de bioéthique et les collections d’échantillons biologiques gérées par des biobanques ou la sélection animale sur critères génotypiques. Ce faisant, il invite à remonter aux enjeux des pratiques associées consistant à distribuer le vivant en domaine de valeur et d’utilité. D’une manière concomitante à leur ascension dans les agendas politiques internationaux, les ressources biologiques occupent aussi une bonne place dans les agendas de recherche en sciences sociales. The thematic dossier proposes a transversal reading of the three forms of life that constitute the development of natural protected areas, bioethics laws and collections of biological samples managed by biobanks or animal selection based on genotypic criteria. In doing so, it invites us to look at the challenges of associated practices that consist in distributing life in areas of value and utility. In a manner concomitant with their rise on international political agendas, biological resources also occupy a good place on social science research agendas. El dossier temático propone una lectura transversal de las tres formas de vida que son el desarrollo de los espacios naturales protegidos, las leyes de bioética y las colecciones de muestras biológicas gestionadas por los biobancos o la selección de animales basada en criterios genotípicos. Al hacerlo, nos invita a mirar los retos de las prácticas asociadas que consisten en distribuir la vida en áreas de valor y utilidad. De forma concomitante a su ascenso en las agendas políticas internacionales, los recursos biológicos también ocupan un buen lugar en las agendas de investigación de las ciencias sociales