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Towards a Narrative Change? New Archaeobotanical Research on the ‘Green Revolution’ at the Heartlands and Frontiers of al-Andalus
No full textInternational audienceThis study documents the diversity of Andalusi agricultural production and practices in different regions of the Iberian Peninsula between the 11th and the 14th centuries, based on unpublished case studies from the “Landscapes of (Re) Conquest” project and pre-existing published data. At the heart of this research lies the question of agricultural innovations that are widely associated in the scholarly literature with the Arab-Berber expansion across Iberia. The most recent overviews spoke for themselves: none of the crops of the medieval ‘green revolution’ mentioned in the texts (e.g. cotton, sugarcane, spinach, eggplant, etc.) had been discovered (Peña-Chocarro et al. 2019; Ros et al. 2019), and it is only in the last two years that new taxa (e.g. citrus fruits, rice) have begun to appear in Andalusi archaeological contexts in Iberia , on a very occasional basis (Peña-Chocarro and Pérez-Jorda 2023; Peña-Chocarro et al. 2024). These data raise the question of the real expansion of Arab-Berber agriculture in the West, and of the “new plants” and their rhythm of diffusion: was this really a uniformly widespread phenomenon throughout the entire medieval Muslim West? Or was it limited to the landed estates of the urban aristocracy and to the large areas of specialized production (e.g. al-Andalus), well known from written sources? Focusing on Iberia, did the areas at the frontiers of Andalusi territories continue to practice agriculture that was strictly identical to that of the Roman and/or Visigothic periods? Or did they experience similar trends to those in neighbouring Christian territories, i.e. a boom in rye and certain spring crops (e.g. millets, flax, hemp) (Ros et al. 2023)? This innovative research lays the foundations for a new reflection on the persistence and evolution of the production and management of plant resources in the face of the major political, social and economic changes that took place in the Peninsula during the medieval period. They also highlight an otherwise neglected topic in the field of archaeobotany – the contrasting agrarian dynamics of political heartlands and frontiers
Explicit spatial–temporal scenarios of food security in a West-African socio-ecological system under climate change
No full textInternational audienceFood security is a key facet of a sustainable society, while some threats, such as climate change and food riots may unsettle any society. Some aspects of food security such as food production and distribution are inherently spatial, thus requiring spatialized methods to study it. In this study, we introduce Discrete Ecosystem Evolution Rules (DEER), which is a spatial generalization of the EDEN framework developed in environmental sciences. Based on extensive expert knowledge and literature, we developed both spatially implicit and explicit models to assess the impacts of climate change on food security dynamics in a complex West-African social-ecological system (Dano, Burkina Faso). Comparing these two models allowed highlighting the role of spatial structure on food security degradation and recovery over the long term. Results showed that the impacts of climate change on food security were mediated by water availability and soil degradation. The spatial model provided a finer understanding of food security dynamics by highlighting unexpected sequences of events. These insights highlight the relevance of a spatial modeling framework to get a proper understanding of food security and, more generally, of social-ecological dynamics
Deciphering copper and zinc leaching from antifouling paints with different operating modes: flux determination and toxicity evidence
No full textInternational audienceLaboratory experiments were performed using 3 antifouling paints with different operating modes immersed in seawater for 7 days, to estimate copper and zinc fluxes and determine the scale of the related contamination. The toxicity of antifouling paints leachates was also assessed for natural bacterioplanktonic and phytoplanktonic communities. Given the increase in copper and zinc concentrations (4 to 1750-fold enrichment in dissolved Cu and to 7 to 200-fold enrichment in dissolved Zn), a systematic mortality upon phytoplankton was evidenced within 2 days of exposure to leachates produced from 1 hour to 2 days of immersion, whatever the paint. This went oppositely with the environmental risks calculated according to European guidelines, demonstrating an acceptable risk for the environment. Considering that 1 hour of leaching from a 7 cm² painted disk polluted 0.5L of seawater with Cu in our experimental conditions whatever the paint used, we estimated that a painted ship hull of 15 m² can pollute more than 10 m 3 of seawater within the same time. Leachates produced after only 20 minutes even yielded phytoplankton growth inhibition or mortality for insoluble and self-polishing paints, respectively, shortening the time needed for a freshly painted ship hull of 15 m² to pollute 10 m 3 . The bacterioplanktonic community appeared less sensitive than phytoplankton but demonstrated the same hierarchy: the highest toxicity was observed for the insoluble matrix and the lowest toxicity for the soluble one. This study therefore brings added value in terms of biocides flux determination, range of studied paints and concrete toxicity evaluation
How does an exotic invasive insect pest impact island-endemic tree species?
No full textContext: Forests worldwide are increasingly impacted by insect outbreaks, yet the mechanisms linking defoliation to tree mortality remain poorly quantified.Island ecosystems are particularly vulnerable, as endemic species often lack coevolved defences. On Réunion Island, the invasive psyllid Acizzia uncatoides has triggered severe defoliation of the endemic tree Acacia heterophylla.Questions: We ask how insect-driven defoliation influences the survival probability of A. heterophylla. Specifically, we test whether higher defoliation increases mortality risk and whether tree size and habitat modulate this effect.We also aim to quantify mortality risk over time under different combinations 1 of covariates. These questions address both ecological vulnerability and applied management concerns.Methods: We established and monitored eight permanent plots across two major habitats (mountain forest and subalpine vegetation) between 2018 and 2021. All trees were tagged, with repeated measurements of diameter, defoliation, and survival status. We applied a discrete-time Bayesian survival model to estimate survival probabilities. Predictions were generated across gradients of defoliation, tree size, and time, stratified by habitat.Results: Defoliation strongly increased tree mortality. Larger trees exhibited higher mortality risk than smaller ones, even under similar defoliation levels.Habitat also shaped outcomes: mortality rates were higher in the mountain forest than in the subalpine vegetation, after accounting for size and defoliation.Impact: This study provides additional evidence that exotic invasive insectdriven defoliation can rapidly increase mortality in endemic vegetation, highlighting the need for coordinated management and conservation strategies. Its insights can guide practices such as optimising monitoring frequency, refining the timing and scheduling of sanitary thinning, and supporting decisions on releasing a biological control agent.</p
Does substrate diversity affect microbial heat dissipation in soil?
No full textInternational audienceMost studies exploring the relation between the quality of organic substrates and microbial activity have been carried out with individual substrates. However, they have largely overlooked potential effects that might occur when microorganisms simultaneously process a heterogeneous mixture of organic substances. We investigated whether the degree of molecular richness of substrate mixtures had an impact on the overall activity of microbial communities, measured as heat dissipation over a day, in a laboratory incubation experiment. Topsoil samples were taken from a Swedish long-term field trial, established in 1983, in which a crop rotation dominated by spring cereals was either under-sown with perennial ryegrass as a cover crop or was without cover crops. No significant differences in the cumulative heat dissipation between soil with or without cover crops were observed. When all substrate mixtures were evaluated, the substrate richness was not significantly correlated with the overall microbial activity. However, we observed a bell-shaped curve between the total microbial activity and the nominal oxidation state of carbon (C) in the substrate mixtures. In most cases, the measured heat dissipated from soils that received substrate mixtures was significantly higher than the theoretically expected heat dissipation. The latter was based on the weighted sum of heat dissipated of individual substrates. This pattern was more visible in soil without cover crops than in soil with cover crops. The higher-than-expected heat dissipation from substrate mixtures suggests that the response of soil microbial communities to diverse substrates is not simply additive. There are several possible explanations for the observations made: (i) interactions among microbial metabolic pathways, (ii) added substrates may be preferentially used, and (iii) concentration of all the substrates in the mixtures was lower than when added individually, and therefore the metabolic pathways for each substrate was less likely to be saturated. Chemodiversity, the diversity of organic chemical compounds, is often not considered in models evaluating the dynamics of soil organic matter. Our results warrant further investigations into microbial metabolism and the processing of heterogeneous organic substances in order to constrain microbial-and substrate-specific models of soil organic matter
A semi-automated sensitivity-based approach for simplifying marine biogeochemical models for targeted applications: A case study with the Eco3M-MED model
No full textInternational audienceMarine biogeochemical models are being increasingly used to support scenario-based analyses of climate change and ecosystem dynamics. However, their high structural complexity and large parameter space often limit computational efficiency, interpretability, and adaptability in applications requiring the exploration of many scenarios. To address these issues, we propose a Semi-Automated Iterative Simplification (SAIS) approach that integrates local sensitivity analysis with model mechanistic guidance and Kling-Gupta Efficiency (KGE) metrics to evaluate each simplification step. Using the marine biogeochemical model Eco3M-MED as an example, we specified three objectives for model simplification: (1) fidelity of state variables, (2) fidelity of marine ecosystem indicators, and (3) applicability for coupling with higher trophic level models. For each objective, we assessed model sensitivity to parameters and applied the SAIS approach to simplify the model, and obtained three simplified models. KGE-based fidelity evaluations are used to validate each final simplified model against the reference model. The results show that computational time can be reduced by up to approximately 30% without compromising the model's mechanistic foundation. Overall, this method offers a flexible and scalable approach for generating simplified versions of complex biogeochemical models, suitable for applications in regional marine ecosystem assessments, climate scenario explorations, and model coupling frameworks
Characterization of the submarine disposal of a Bayer effluent (Gardanne alumina plant, southern France): V: Evolution of metal and metalloid concentrations in the seawater column of the discharge area (Mediterranean Sea) from 2016 to 2024
No full textInternational audienceThis study examined the evolution of trace metal and metalloid concentrations in the Cassidaigne canyon water column (Mediterranean Sea), at the Gardanne alumina plant discharge area, between 2016 and 2024. Following the 2015 ban on solid waste discharge, the plant progressively switched to the discharge at sea of a regulatory clarified effluent, resulting from filter-presses, CO 2 treatment and biological unit implementations. Several anomalies in element concentrations at discrete depths in the water column above the outfall (station L1) reflected local environmental influences, such as submarine groundwater discharges and lithogenic inputs, including mistral-induced upwelling, remobilizing sediment. From 2016 to 2021, Al concentrations below 200 m depth resulted from the effluent-seawater mixing (the plume) and subsequent metals and metalloids removal and/or release during hydrotalcite particles formation and dissolution. Concretions at the outfall of the effluent (330 m depth) stopped forming after introduction of the CO 2 treatment of the effluent in 2018. Despite occasional biological treatment disruptions leading to increased Al, V, and Cu concentrations at sea in 2020 and 2021, the effluent's chemical footprint remained globally confined in the first hundred meters above the outfall, without broader upper water column impact. Deep Al anomalies at a distant site (station K) in the canyon axis also indicated potential local remobilization from legacy bauxite deposits. Overall, both the plume and the historical residues appeared as localized but distinct sources of contamination. Particular renewed attention emerged from monitoring committees regarding ancient deposits, the spatial extent of which in the canyon far exceeds the chemical footprint of the effluent
Reading the Future of Oil: A Noncausal Approach to Supply News Shocks
No full textThis paper proposes a new strategy to identify oil supply news shocks by combining a Bayesian noncausal structural VAR with a Max-Share approach. The framework jointly resolves the problems of non-fundamentalness and recoverability that undermine standard (proxy) SVAR methods. Exploiting non-Gaussianity in a multivariate Student−t specification, we recover structural shocks from a two sided moving average representation and isolate the expectation driven component of oil supply innovations without external instruments. Applied to global oil market data, the model supports a non fundamental representation and detects anticipatory price and inventory movements consistent with rational expectations storage behavior. The identified shocks explain a substantial fraction of real oil price fluctuations, notably in the late 1970s–1980s and during the 2014–15 collapse, while the COVID-19 episode is predominantly demand driven. Decomposing global supply shows that these shocks are primarily OPEC-driven and generate stagflationary responses in output and inflation, underscoring the central role of expectations in oil market dynamics
Editorial for research topic: Advancing mycorrhizal research for sustainable ecosystem and agricultural practices
No full textInternational audienceMycorrhizal symbiosis, a mutualistic association between plant roots and soil fungi, plays a crucial role in enhancing plant nutrition, stress tolerance, and overall adaptation to environmental conditions (van der Heijden et al., 2015). Despite the long-standing recognition of these benefits, research has primarily focused on understanding the mechanisms underlying the establishment and functioning of these interactions. Recent studies have highlighted the significant role of fungal hyphal networks in soil carbon storage, further emphasizing the ecological importance of mycorrhizal symbioses. However, there remain substantial gaps in our understanding of how these interactions can be optimized for both natural ecosystems and agricultural applications, especially under the increasing pressure of global climate change.The present Research Topic (RT) was initiated in the context of the 7 th French Mycorrhizal Days in Montpellier in May 2024, an international meeting bringing regularly together mycorrhizal research, students and companies from francophone countries (https://jmf7.journees.inrae.fr/). The RT aims to consolidate current research on mycorrhizal symbioses across various levels, from molecular and functional analyses to ecosystem studies and practical applications. The primary objective is to enhance our fundamental knowledge and to facilitate its translation into ecological and sustainable practices for plant growth, soil management, and ecosystem balance. The call for papers attracted several contributions, Mycorrhizal symbiosis is tightly regulated by host plants and fungi and requires major root cell and fungal hyphae reprogramming to form structures enabling nutrient exchange (Choi et al., 2018;Ho-Plágaro and García-Garrido, 2022). Specific molecular players and mechanisms involved in the establishment of arbuscular mycorrhizal (AM) symbioses were investigated in two studies. Strigolactones, phytohormones with dual signalling functions within plant roots and in rhizosphere interactions (Al-Babili and Bouwmeester, 2015), have been demonstrated to impact spore germination and hyphal branching affecting in turn root colonization by AM fungi (Akiyama et al., 2010). Here, Klein et al. analyzed strain-specific impacts of strigolactones using two Rhizophagus irregularis strains and their response regarding germination and pre-symbiotic growth. Observed strain-specific differences may Impact of AM fungi on plant performance was analyzed by Alayafi et al. for two crop plants, sunflower (Helianthus annuus) and pumpkin (Cucurbita pepo), under field conditions for two years. Inoculation with the AM fungus Funneliformis mosseae improved plant nutrient uptake, biomass and specifically oil yield and quality, dependent on possible synergistic effects of intercropping (Reddy et al., 2023). Such field studies, going beyond laboratory work under controlled and limited conditions, underline the importance of beneficial interactions for modern agriculture. In turn, Battie-Laclau et al. reported also that the vineyard's "terroir", understood as a cultivated ecosystem where grapevine interacts with their natural environment, is critical for the composition of the microbiota community. On the other hand, agricultural practices promoting AM fungi in grapevine cultures have been long time neglected as massive fungicide treatments were needed to protect vineyards. Only since recently, with the increasing demand for more natural culture conditions, research is focalizing on promoting AM fungi in vineyards through the use of more organic management practices. Such changes promoting agroecology (Jindo et al., 2022) will induce higher diversity of AM communities and thus determine the future sustainable development of vineyards over next decades. This study showed the dominant effect of geographical effects, AM communities mainly be structured by terroir even before practice, underscoring the necessity for future studies on fungal inoculation in vineyards to consider the specific characteristics of each terroir.Another important topic is the impact and use of beneficial interactions for a better adaptation of plants to challenging environmental conditions and climate change. Mycorrhizal symbioses, among other beneficial associations, are playing a decisive role in improving plant tolerance to abiotic and biotic stress (Usman et al., 2021). Regarding other beneficial interactions, Hassan et al. focalized on plant growth-promoting bacteria (PGPB, Micromonospora sp) and demonstrated their role in mitigating effects on heat stress in wheat by metabolic adaptations enhancing photosynthetic efficiency and antioxidant defence. The importance of AM symbiosis for the bioavailability of essential micronutrients in wheat has been recently highlighted (Nguyen et al., 2025). In a more general context, Lethielleux-Juge reviewed the impact of mycorrhizal symbioses and associated soil microbiomes in ecological restoration. The use of AM fungi, both natives or exotic, have been widely reported in ecosystem restoration (De Moura et al., 2022). AM fungi grow at diverse soil conditions, colonizing most plant species (from herbs to trees), and can evolve together with plants after revegetation. Moreover, the interaction of AM fungi with different ectomycorrhizal fungi, PGPB, rhizobacteria and mycorrhiza-helper bacteria will allow to improve soil attributes and plant adaptation to stress in a complex network of plant-soil-microbiomes with high relevance in ecosystem dynamics.In summary, studies included in this RT are dealing with a broad panel of questions regarding our insight in and application of beneficial mycorrhizal interactions. Further questions concern still better understanding of mycorrhizal networks in natural ecosystems, in soil carbon storage, and under diverse challenging abiotic and biotic environmental conditions.For scientifically based agricultural applications, best practices for managing plant-soil biota on the field-scale will have to include whole microbiome interactions
Stratigraphy of Carbonate‐Bearing Rocks at the Margin of Jezero Crater, Mars: Evidence for Shoreline Processes?
No full textInternational audienceMartian carbonate‐bearing rocks are compelling targets for exploration because they preserve detailed records of past aqueous processes, climate, and habitability. The Margin unit in Jezero crater is a distinct olivine‐ and carbonate‐bearing unit stratigraphically underlying the western fan, lining the inner margin of the western crater rim and has a contested origin. Perseverance spent ∼350 sols investigating the unit as part of its fourth mission campaign, aiming to constrain its origin, alteration history and biosignature preservation potential. This study reports on the lithofacies and stratigraphy of the unit by analyzing Mastcam‐Z mosaics and derived 3D outcrop models, supplemented by long‐distance SuperCam observations and detailed textural analyses from SHERLOC WATSON and ACI images. We find that the Margin unit comprises two distinct subunits. The Eastern Margin Unit (EMU) comprises well‐stratified, low‐angle basinward‐, rimward‐ and subhorizontally inclined medium‐grained sandstones which preserve angular to rounded grains, occasional crossstratification, convex‐up bedding, and erosion surfaces. The Western Margin Unit (WMU) comprises distinctly structureless to decimeter‐scale parallel‐layered rocks which drape the crater rim and are inclined into the crater. The origin of the WMU is uncertain but may be most consistent with a variably carbonated olivine cumulate. The favored depositional model for the EMU is a lacustrine shore zone environment where sediments derived from the adjacent WMU have been locally reworked by wave action along a paleoshoreline at around –2,400 m elevation. These observations suggest that the Margin unit preserves diverse subsurface and surface aqueous environments and further extends the habitability window at Jezero crater