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Agricultura francesa: evolução, contexto e cooperativismo
No full textInternational audienceThis communication reviews the evolution of French agriculture since the second half of the 20th century. It addresses the agricultural specializations of different territories in metropolitan France, as well as current issues facing French agriculture. The issue of pesticides, through the example of the "Duplomb Law," is also addressed through the historical mobilization of the population through the widely signed petition. Finally, cooperativism, and in particular Agricultural Equipment Use Cooperatives, is discussed as a potential lever that can help farmers address contemporary economic, environmental, and social challenges.Cette communication fait le point sur l'évolution de l'agriculture française depuis la seconde moitié du XXe siècle. Sont abordées les spécialisations agricoles des différents territoires en métropole, ainsi que les enjeux actuels de l'agriculture française. La question des pesticides à travers le cas de la "Loi Duplomb" est également traitée à travers la mobilisation historique de la population par la pétition signée très largement. Enfin le coopérativisme, et notamment les Coopératives d'Utilisation de Matériel Agricole, est évoqué comme un levier potentiel pouvant aider les exploitants agricoles à faire face aux enjeux à la fois économiques, environnementaux et sociaux contemporains.Este artigo analisa a evolução da agricultura francesa desde a segunda metade do século XX. Aborda as especializações agrícolas de diferentes territórios da França metropolitana, bem como os problemas atuais enfrentados pela agricultura francesa. A questão dos pesticidas, por meio do exemplo da "Lei Duplomb", também é abordada por meio da mobilização histórica da população por meio da petição amplamente assinada. Por fim, o cooperativismo, e em particular as Cooperativas de Uso de Equipamentos Agrícolas, é discutido como uma alavanca potencial que pode ajudar os agricultores a enfrentar os desafios econômicos, ambientais e sociais contemporâneos
Working Group on the Value of Coastal Habitats for Exploited Species: (WGVHES; outputs from 2024 meeting)
No full textThe Working Group on the Value of Coastal Habitats for Exploited Species (WGVHES) aims to support a better understanding of the habitat needs of juvenile fish and shellfish, a key evidence-base for robust fisheries and conservation management. In 2022–2024, the working group focused on evaluating methods used to measure habitat quality in the juvenile life stage, synthesising recommendations for managing Essential Fish Habitat and examining the influence of climate change on juvenile habitat.The group produced a major review article on methods to measure juvenile habitat quality (Ciotti et al. in review). While a large number of studies have measured juvenile habitat quality since 1970, a limited range of methods are being applied. The paper offers recommendations for how to advance insights into the function of juvenile habitats at appropriate scales.Two working documents have been produced by the group towards preparation of papers on effective approaches to management of Essential Fish Habitats. These documents define key lessons learned and explore case studies from across the group’s international experience to advise decision makers on habitat management for exploited species.Another key output of the group is a draft paper informing on management of juvenile habitats facing global change. This considers dynamic shifts in juveniles and their habitats due to climate change and emphasises the need to obtain long-term consistent monitoring data focusing on juveniles, identify life-cycle connection, improve habitat restoration, and support the enhancement of Marine Protected Areas (MPAs) and other measures to increase ecosystem resilience.Overall, the WG’s products demonstrate the challenges and opportunities for understanding habitat needs of exploited coastal species, and implementing effective policy and management in a changing environment. During the next term, the WG will mine the substantial database of juvenile habitat studies to critically evaluate current practice, examine habitat restoration as a tool to support exploited species and publish recommendations for management of Essential Fish Habitat
Unveiling the Hidden Feast: A Model to Translate Molecular Detection Into Predation Rate—Application Example on Biological Control by Generalist Predators in Agricultural Fields
No full textInternational audienceFew processes are as decisive as predation in shaping the structure and dynamics of ecological communities. For most predator species, however, the number of prey items killed by a predator in a day (predation rate) remains impossible to assess because direct observations are scarce or impossible to acquire. For such species, molecular gut content analyses are routinely used to test for the presence of a prey in the predator's gut. Specifically, our model uses a novel mechanistic representation of predation and digestion to integrate field data on prey detection and laboratory data on prey molecular signal decay in the predator's gut. Model fit provides an estimate of the slope and intercept of the digestion curve (molecular signal decay) and an estimate of the predation rate. In a case study targeting 25 carabid beetle species and 5 types of prey in agricultural fields (winter wheat), we use our model to estimate predation rates for each predator–prey pair. Based on predation rate estimates, we introduce a new biocontrol indicator at community scale and explore its potential for advanced agroecological research. We discuss the performance of our model on the basis of the scant information available in the literature and detail its conditions of application to highlight its advantages over existing predation models
Does the C:N ratio suffice to predict carbon and nitrogen mineralization dynamics in an arid agroecosystem soil amended with compost?
No full textInternational audienceAssessing the mineralization dynamics of composts applied to the soil provides knowledge about nutrient release to growing crops. This research aimed to assess carbon (C) and nitrogen (N) mineralization dynamics of two composts with contrasting nutrient content applied to the soil of an arid agroecosystem. Compost C2 was based only on date palm residues and rock phosphate, while compost C4 combined date palm residues with sheep manure and rock phosphate. An unamended soil was used as a control. The addition rate of compost was standardized to 4 g C per kg of dry soil. Treatments were incubated under laboratory conditions of 25 °C and a soil water content of 60% of field capacity for 91 days. C and N mineralization were assessed through periodic measurements of CO2-C emissions and inorganic nitrogen (NH4-N and NO3-N) in soil extracts. Application of compost C2 induced higher C mineralization over the entire incubation period, followed by C4-amended soil and the control. After incubation, the cumulative CO2-C emission of compost-C2- and compost-C4- amended soil was 1561.4 and 1271.1 mg kg−1, respectively, given the high cellulose and low lignin content in compost C2. The total percentages of mineralized C from compost C2 and C4 were 20.6% and 13.3% of the total added organic C, respectively. Applying compost C2 and C4 to the soil resulted in N immobilization of 176.2 and 26.4 mg kg−1, respectively, while unamended soil supplied 76.1 mg kg−1 of net N mineralized during the incubation. Our findings suggest that the C:N ratio alone is insufficient to predict C and N mineralization from composts. Either compost may be applied in crop rotations to maximize benefits for growing crops
Divergent Mechanisms of Internode Elongation in Response to Far-Red in Two Rose Genotypes
No full textInternational audienceThe quality of potted ornamental plants depends on their architecture, which should be compact and branched. Among the techniques for controlling this architecture, LED lighting, by manipulating light quality, offers an effective means of regulating elongation and branching. In rose, the addition of far-red (FR) light stimulated branching but induced excessive stem elongation, i.e., internode elongation. However, some varieties remained insensitive to this effect, demonstrating phenotypic stability. This study investigated the underlying mechanisms of internode elongation in response to FR in two rose cultivars, ‘The Fairy’ (TF) and Knock Out® Radrazz (KO), selected for their respective architectural plasticity and stability to FR. In TF, exposure to FR induced elongation of internodes, driven by cell division, with an increase in gibberellin A4 (GA4) level and a reduction in defense hormones (salicylic acid and jasmonic acid; JA). In contrast, in KO, exposure to FR did not induce internode elongation but caused cell elongation. This effect was accompanied by a reduction in cell number, modulated by hormonal changes (particularly GA4 and JA) and the inhibition of Block of cell proliferation 1, thereby limiting cell division. A deeper understanding of the mechanisms underlying architectural stability might lead to developing strategies to produce compact, branched plants, regardless of environmental conditions
Le concept de services écosystémiques et sa déclinaison au sol : entre promesses et réalités
No full textInternational audienceCe chapitre présente la notion de service écosystémique et retrace la façon dont cette notion a été adaptée aux sols. Il décrit l’internationalisation du concept et son institutionnalisation. Il présente les démarches de classement, de quantification et de cartographie des services écosystémiques, ainsi que leur déclinaison au cas des services écosystémiques fournis par les sols
Les lipides sont des nutriments importants et ne doivent plus être diabolisés, ni chez l'adulte, ni chez l'enfant
No full textFiche Question sur... de l'Encyclopédie de l'Académie d'agriculture de France.Fiche consultable sur le site internet www.academie-agriculture.fr onglet "Publications" puis "Table des matières des documents de l'Encyclopédie"Reproduction autorisée sous réserve d'en citer la provenance Encyclopédie : Question surAfter a very dogmatic but partly understandable period of demonization of lipids, it is appropriate, based on the available data, to counter this perception, which is very likely counterproductive, in adults and especially in children.Après une période très dogmatique mais en partie explicable de diabolisation des lipides, il convient sur la base des données disponibles de contrer cette perception, très vraisemblablement contreproductive, chez l'adulte et surtout chez l'enfant
Impacts sur la santé publique de la dynamique des populations de renards
No full textOpinion and report approved by the Expert Committee Socio-economic analysis in its plenary session on 11 May 2023 and the Expert Committee Animal health and welfare (CES SABA) in its plenary session on 06 June 2023. The French Agency for Food, Environmental and Occupational Health & Safety provides independent scientific opinions and reports. The original version of the ANSES opinion and report in French is available on the website of ANSES at https://www.anses.fr/fr/system/files/SABA2022SA0049Ra.pdf.Suggested citation: ANSES. (2023). Avis et rapport de l'Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail relatif à l'évaluation des impacts sur la santé publique de la dynamique des populations de renards (Saisine 2022-SA-0049). Maisons-Alfort: ANSES, 200 p.International audienceThe Red Fox (Vulpes vulpes) can be hunted as a game species. It may also be listed as a “species likely to cause damage” (ESOD – the acronym in French), for public health reasons among others. Conversely, benefits linked to the presence of foxes are also put forward, such as the predation of rodents carrying zoonotic agents. In this context, ANSES was asked to: (1) list the zoonoses present in France for which foxes play an epidemiological role, (2) identify other public health impacts associated with changes in fox populations, (3) explain the relative importance of the effects of changes in fox populations for humans and/or the environment, (4) analyse the feasibility of a cost‐benefit analysis (CBA) of the prevention and impacts associated with these zoonoses. In France, the fox is a source of zoonotic pathogens, with a major role for Echinococcus multilocularis, a parasite for which the fox is the main source of environmental contamination. However, reducing fox populations does not reduce the risk of transmission of E. multilocularis to humans or domestic animals, and may even have the opposite effect to the one intended. The main levers for action are those relating to exposure to environmental contamination. The fox is part of complex trophic networks, in which its specific role in regulating prey populations is impossible to determine because (i) several predators share the same prey, with a variable role for the fox among the predators, (ii) the dynamics of prey populations is also conditioned by factors other than predation. The relationship between the abundance of rodents and the risk of disease for humans has not been demonstrated either, due to the complexity of the trophic and epidemiological networks, their highly probable variability from one ecosystem to another, and the multiplicity of hosts. As a result, the data currently available does not allow any conclusions to be drawn about the epidemiological role of the fox as a predator of rodents hosting zoonotic agents. Finally, there is no public health justification for culling foxes, particularly for ESOD classification, except in the very specific and localised context of the fight against bovine tuberculosis, for which the selective culling of foxes in and around the livestock buildings of a domestic outbreak has been proposed. In addition, the expertise concluded to the feasibility of a CBA targeted at assessing the burden of alveolar echinococcosis and measures to prevent its transmission. The feasibility study shows the partial nature of a CBA targeting zoonoses, without taking into account other roles played by the fox in the ecosystem
Subsoils, but not toeslopes, store millennia-old PyC in a gently sloping catchment under temperate climate after centuries of fire suppression
No full textInternational audienceAbstract. Pyrogenic carbon (PyC) is the carbonaceous solid residue of incomplete combustion of biomass. It is a continuum of condensed and aromatic molecules. PyC persists for longer in soils relative to non-PyC organic carbon. However, residence time varies depending on the method used to estimate it. The time and spatial scales investigated are not always adapted to the long-residence time and vertical and lateral mobility of PyC in the soil profile and the landscape. In addition, agricultural land-use and shallow slopes are under-represented in the PyC literature. We measured the concentrations and stocks of PyC down to 60 cm along three toposequences in a small agricultural catchment with shallow slopes and homogeneous soil parent material in the west of France. We used two methods (chemo-thermal oxidation – CTO and hydropyrolysis – HyPy) of PyC quantification that cover the intermediate to highly condensed part of the PyC continuum, and also measured the radiocarbon values in both total SOC and the PyC fraction. There was no or little PyC inputs to the catchment in the last 150 years which gave us access to the resultant, long term PyC distribution in the landscape. In particular, we aimed to investigate whether the vertical and horizontal distribution of PyC were similar or differed from SOC and whether they were affected by the gradient of soil evolution along the slope. Topographic position was not the main driver of PyC stocks in this landscape. The stock of PyCCTO averaged 2.5±0.22 t ha-1 across topographic positions and was only slightly larger in a Solimovic Cambisol at the toeslope (3.3±0.26 t ha−1), likely formed following changes in erosion dynamics with land-use. Contrary to previous reports, erosion redistributed already aged PyC without enrichment or depletion. Future studies should assess whether erosion modalities and age and quality of PyC affect its fate during erosion events. PyCHyPy concentrations in the topsoil decreased from upslope (median = 1.6, IQR = 0.22 gC kg−1 soil) to downslope positions (median = 1.10, IQR = 0.40 gC kg−1 soil), which we attribute to PyCHyPy dissolution following the destabilization of mineral associations with iron oxides in the water-table affected portion of the transects. The subsoil (30–60 cm) represented between 37 and 51 % of the PyCCTO stock. PyCHyPy proportion in SOC increased with depth and reached an average of 11±3.3 % at 50–60 cm depth. PyCHyPy had an uncalibrated radiocarbon age of 2520 to 9600 years BP at this depth, significantly older than bulk SOC at the same depth and than PyCHyPy at 0–10 cm. These results confirm the long persistence of PyC in soils and point to a slow advection of PyC towards the soil depth under the pedoclimatic conditions of our study area. Identifying the proportion of PyC produced which is quickly transported away from the watershed and that which remains and is stabilized in soils for millennia after a fire is an important knowledge gap that still needs to be investigated to close the terrestrial PyC budget
Using near-infrared spectroscopy to estimate soil water retention curves with the van Genuchten model
No full textInternational audienceHydraulic properties of unsaturated soils are essential for understanding hydric functioning and solving flow and mass-transfer problems in the vadose zone. One of the best-known models for representing the experimental soil-water retention curve, which describes the matric potential (h) as a function of the water content (0) of a soil horizon, is the van Genuchten (VG) model. It requires four parameters whose values vary by soil type: residual water content (0r), saturated water content (0s), the inverse of the air-entry pressure (alpha) and a shape parameter (n). The main objective of this study was to show the relevance of using near-infrared (NIR) spectroscopy to estimate the parameters of the VG model, based on the relation established between the soil water spectral index (SWSI) and 0 (Soltani et al., 2019a). Based on this approach, the effective saturation of VG equals the effective SWSI. We applied the approach to 25 soil samples collected from topsoil and subsoil horizons in Brittany (western France), which exhibited high variability in texture and soil organic carbon content ranging from 0.07 % to 6.23 %. The results showed that i) the NIR-spectroscopy approach was relevant for estimating hydraulic parameters 0s, alpha and n of the VG model and ii) the parameters obtained from a VG-like equation based on the relation between h and SWSI predicted values of 0 of the soil-water retention curve that were similar to observed values, with a root-mean-square error of 0.031 and 0.045 cm3cm-3 for topsoil and subsoil horizons, respectively. The method was thus more accurate for topsoil horizons