Exploring soil–plant interactions in vineyards using geophysics and hyperspectral imaging
Climate change and evolving land management practices are reshaping soil-plant interactions critical for sustainable viticulture. These interactions are driven by soil texture, hydrogeochemical gradients, and climatic conditions, influencing grapevine traits like nutrient and water content. Integrating innovative methods, this study explores the relationship between soil variability and grapevine characteristics in the Médoc wine region, France. The research combines hyperspectral imaging, electromagnetic induction (EMI), and electrical resistivity tomography (ERT) with traditional soil and leaf sampling. Hyperspectral data, using visible-near infrared (VNIR) wavelengths, reliably estimated leaf traits such as nitrogen and water content, yielding strong predictive relationships (R 2 up to 0.8). These findings suggest VNIR-based indices are cost-effective for monitoring grapevine physiology. Geophysical data revealed significant soil textural gradients, delineating sand, transitional (loam, sandy loam), and clay textural soil classes. Apparent electrical conductivity (ECa) and inverted electrical conductivity (EC) correlated with soil texture and grapevine traits, particularly at depths around 50 cm, aligning with primary root zones. However, interannual variability in correlations emphasised the influence of weather conditions and phenological stages, highlighting the need to align data acquisition with vine growth phases. The integration of hyperspectral imaging and geophysical methods provides a novel framework for linking soil and plant parameters. This interdisciplinary approach enhances the spatial resolution and scalability of vineyard monitoring, offering actionable insights for precision viticulture. Future work should expand datasets and refine predictive models to improve the understanding of soil-plant dynamics under changing environmental conditions. These findings underscore the potential of combining hyperspectral and geophysical data to develop climate-resilient vineyard management strategies, advancing precision agriculture, and sustainable viticulture practices.
(OENO One. vol. 59, 17/10/2025)
LOMA, UB, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LBNL
Trajectoire de la contamination en platine dans les hydrosystèmes français depuis le début du XXe siècle : approche multi-échelles spatio-temporelles
Platine (Pt) est aujourd’hui un élément considéré comme critique pour les technologies en raison de sa rareté et de ses usages récents. Ces nouveaux usages, en particulier dans les pots catalytiques des véhicules thermiques et dans des composés pharmaceutiques administrés lors de chimiothérapies, ont entrainé une augmentation des rejets de Pt dans l’environnement, faisant de lui un contaminant émergent. Toutefois, l’évolution temporelle (ou trajectoire) des concentrations en Pt dans les environnements fluviaux restent encore mal connue nécessitant des approches multi-échelles, tant spatiales que temporelles. Les archives sédimentaires collectées à l’aval des grands fleuves français ont permis d’analyser les trajectoires de Pt depuis le XXe siècle et de définir des niveaux de référence (baseline) dans les sédiments de la Garonne, de la Loire et du Rhône, compris entre 0,6 à 1,6 μg kg-1. Elles ont également révélé des contaminations historiques en Pt dans la Seine (> 10 μg kg-1), liées à des activités industrielles au cours du XXe siècle. À partir des années 2000, les signaux émergents de Pt sont observés dans la Loire et le Rhône tandis que dans la Seine, l’héritage de la contamination historique tend à masquer cette émergence. Les flux estimés montrent que le Rhône exporterait 21 kg an-1 de Pt particulaire contre ~2 kg an-1 pour la Loire et la Seine. Ces archives sédimentaires constituent ainsi des outils essentiels pour caractériser l’évolution de Pt dans des bassins versants contrastés. Pour la Garonne, il n’a pas été possible de trouver un site permettant de prélever une archive sédimentaire couvrant le dernier siècle. L’analyse de sa trajectoire a été possible en couplant dépôts anciens (< 1950) d’une archive sédimentaire et MES, issues d’un réseau d’observation (~30 ans) et sélectionnées pour représenter des conditions de crues. Cette approche a permis de (i) définir une baseline pour quantifier les flux annuels naturels et (ii) identifier des anomalies et estimer des flux anthropiques pouvant être expliqués par des émissions du trafic routier et/ou des traitements anticancéreux pour la plupart des évènements. D’autres anomalies n’ont pu être expliquées suggérant des sources et/ou processus à investiguer. Afin de mieux identifier les sources et les processus de transfert du Pt, une stratégie d’étude a été d’effectuer un changement d’échelle en ciblant une petite rivière urbaine drainant l’agglomération bordelaise (Jalle de Blanquefort) qui avait bénéficié d’un suivi mensuel durant une année et d’un échantillonnage à haute fréquence lors d’un évènement orageux. Cette étude démontre le rôle des conditions météorologiques : en conditions normales, Pt est retrouvé principalement sous forme dissoute, supporté par les rejets de Pt médical par les STEU. En conditions pluvieuses, il est majoritairement sous forme particulaire, issu du ruissellement des routes. Ce type d’évènements intenses (~4h) peut contribuer à un tiers du flux annuel de Pt particulaire démontrant l’importance de surveiller les premières eaux de lessivage (first-flush). En se basant sur les pratiques médicales générales en cancérologies et sur la spatialisation des données d’incidence et de traitement des cancers, une modélisation conceptuelle des émissions de Pt médical (Ptméd) a été réalisée. La répartition des émissions pourrait être non seulement influencée par la densité de population mais également par une classe d’âge (> 60 ans), notamment sur les littoraux et les grandes métropoles. Il est estimé que 67 % du flux national de Ptméd est émis dans les principaux hydrosystèmes, dans lesquels sont rejetés entre 2 et 46 kg an-1 de Ptméd. En première estimation, les hydrosystèmes français auraient exporté, en 2023, 223 kg de Ptméd vers les environnements côtiers. Ce modèle nécessitera des ajustements pour réduire les incertitudes, la spatialisation des données d’incidence, taux d’abattement des STEU, réactivité du Ptméd le long du continuum terre-mer.
(16/10/2025)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Population dynamics of the potentially invasive Asian date mussel, Arcuatula senhousia, in Arcachon Bay, France
Originated from Asia, Arcuatula senhousia has spread globally and is often reported as an invasive species that alters benthic communities and ecosystem functioning. However, very few studies have focused on the population dynamics of this ecosystem-engineering mytilid, partly due to the difficulty in monitoring cohorts of this short-lived, fast-growing species. Through a one-year monthly monitoring of mussel in two distinct locations in Arcachon Bay, France, we observed higher growth performance and P/B ratio at the station closer to the main river mouth, confirming the species preference for brackish, estuarine conditions. Post-recruitment mortality was particularly high, exceeding typical bivalve mortality rates, likely due to the vulnerability of this small species at the sediment surface. Trematode parasites, absent in our samples, were not implicated in mortality. In both locations, the reproductive phenology was similar, with a prolonged spawning season centred in the warmer months. As of 2024, A. senhousia remains a colonizing introduced species in Arcachon Bay with relatively low densities. However, vigilance is necessary, as its population dynamics resemble those observed in the few areas where these data are available and where this species has become invasive.
(Estuarine, Coastal and Shelf Science. vol. 324, n° 0272-7714, pp. 109448, 15/10/2025)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LERAR, COAST, IFREMER, PatriNat, MNHN, IRD, CNRS, OFB - DSUED, OFB
Fate and effects of microplastics, nanoplastics and additives resulting from the degradation of fishing gear during their life cycle. Study in the Bay of Biscay
The fishing industry, which is an essential socio-economic sector, may contribute to marine pollution due to the use of plastic fishing gear (FG). However, scientific studies on how plastic FG contribute to the global oceanic pollution of microplastics (MPs), nanoplastics (NPs) and plastic chemicals were scarce. In this context, used and lost fishing nets (FNs) in the Southeastern Bay of Biscay (SE BOB) were estimated and beached abandoned, lost or otherwise discarded fishing gear (ALDFG) were quantified. Then 6 oil-based FNs (1 made of polyethylene-polypropylene (PE-PP) and 5 made of polyamide (PA)) and 2 partially biobased/biodegradable FNs (polybutylene succinate-polybutylene adipate terephthalate (PBS-PBAT)) were selected to investigate their degradation and toxicity. The degradation of FNs was analyzed through artificial aging. Then, the effects of leachates of FNs were investigated through acute, and subchronic toxicity assays with lethal and sub-lethal endpoints on 4 aquatic species, Aliivibrio fischeri, Tisochrysis lutea, Acartia tonsa and Oryzias latipes. In addition, a comparative study of the toxicity of organic extracts from new FNs and end-of-life (EOL) ones on A. fischeri, RTL-W1 cell line, and O. latipes was conducted. It was estimated through models that the fishing fleet of the SE BoB used 211 tons of FG in 2023 and lost 6 tons of them. In the same period, it was also estimated that 3 tons of ALDFG were beached. Most of the beached FG were mending pieces coming from trawl and bottom seine FG repairs. The artificial aging (AA) of FNs revealed FN-dependent production of MPs and plastic chemicals. Production of these degradation products tended to increase with AA, although not linearly. Three of the seven FNs studied produced a significant number of fragment-shaped MPs after 25 days of AA (1.1x105 MP/g of FN to 6.8x105 MP/g of FN) with a median size of 23.6 μm (min-max: 5 – 430 μm). NPs (< 1 μm) were also identified in the leachates of all FNs. Significant amounts of six trace metals (Cu, Fe, Pb, Zn, Ni, Ag) were quantified in the leachates. Furthermore, we identified 27 organic compounds. Concerning the comparative toxicity of DMSO extracts of new and EOL FNs, the three species studied were affected by most of the products leached from the FNs. The bioluminescence inhibition of A. fischeri was linked to the occurrence of trace metals. Each of the 4 species exposed to leachates of artificially aged FNs experienced varying degrees of effects. The bioluminescence of A. fischeri was significantly impacted by most FNs, but more prominently by the PBS-PBAT ones. The bioluminescence inhibition was mainly related to the release of trace metals. The concentration of microalgae cells (T. lutea) was not significantly affected after 72 h of exposure to FN’s leachates. Most tested FNs significantly disrupted the heart rate and behavior of O. latipes larvae. Alterations in behavior generally increased with FN aging time and were mainly related to the release of organic chemicals. The survival of adult and juvenile copepods was significantly decreased by most of the FNs. The lowest LC50 estimated was found for one PA FN (1.32±1.14 g/L) and one PBS-PBAT FN (1.55±0.82 g/L). Subchronic exposure of copepods caused significant effects on egg production and hatching success. Globally, these results highlighted that FNs contribute to MP (1.48±1.34 to 2.2 MPs/m3 (95% CI: 0-14.8 MP/m3)), NP and plastic chemicals pollution of the oceans. Biobased/biodegradable FNs could offer a solution to better manage EOL FG and to reduce ghost fishing when lost, but their current composition needs to be improved to reduce their toxicity [...]
(08/10/2025)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Aquatic metabolism influences temporal variations of water carbon and atmospheric carbon dioxide fluxes in a temperate salt marsh
Salt marshes are blue carbon (C) ecosystems characterized by intense atmospheric CO2 uptake and C sequestration but also by organic and inorganic C exports through the tide. However, uncertainties about the main biotic factors controlling these vertical and horizontal C fluxes imply studying terrestrial and aquatic metabolisms simultaneously at small timescales (diurnal and tidal) to distinguish their contributions to net ecosystem CO2 exchange (NEE). In a temperate salt marsh, four sampling 24 h cycles were performed to measure all water C biogeochemical parameters (including CO2 partial pressures, pCO2), nutrients, and aquatic metabolism simultaneously to NEE from high tide during marsh immersion (imported coastal waters influenced by the continental shelf) to low tide during marsh emersion (exported channel waters influenced by the marsh drainage). At high tide, water CO2 oversaturation (water pCO2 > air pCO2) due to marsh aquatic heterotrophy and CO2-concentrated water inputs from the coastal end-member induced water–air CO2 emissions during marsh immersion. At low tide, water pCO2 in the channel were also mainly controlled by the marsh aquatic metabolism, inducing a water CO2 oversaturation in winter due to dominant heterotrophy and a water CO2 undersaturation in spring and summer due to dominant autotrophy. In winter, the greatest increases in dissolved inorganic carbon (DIC; from 2354 to 3963 µmol kg−1), total alkalinity (TA; from 2508 to 4016 µmol kg−1) and dissolved inorganic nitrogen (DIN; from 27.7 to 68.4 µM) were measured simultaneously during low tide at night, probably due to intense aerobic/anaerobic microbial respiration of organic matter in channel waters and/or sediments resulting in the greatest water pCO2 increase (from 533 to 1461 ppmv). On the contrary, in spring and summer, large water pCO2 decreases (down to 83 ppmv) and dissolved organic carbon (DOC) increases (up to 1040 µM) from high to low tide could be related to intense autochthonous and allochthonous marsh primary production, including benthic microalgae, phytoplankton and macroalgae. This study suggests that the horizontal exchanges of coastal waters with the salt marsh significantly modify water C dynamics and associated water CO2 sink/source state in the channel due to an intense marsh metabolism (production and respiration). At the daily scale, plant and phytoplankton metabolism rates played a major and a minor role, respectively, in the marsh CO2 sink measured by atmospheric eddy covariance at the ecosystem scale (NEE), even during immersion where emerged plants located on the highest marsh levels can maintain a low CO2 uptake, despite aquatic heterotrophy and associated water–air CO2 emissions.
(Biogeosciences. vol. 22, n° 1726-4170, pp. 5387 - 5411, 08/10/2025)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LERMPL, COAST, IFREMER, LERPC, COAST, IFREMER, DYNECO, IFREMER, UMR MARBEC, IRD, IFREMER, CNRS, UM, BRGM, ISTO, BRGM, INSU - CNRS, UO, CNRS, UMR ISPA, Bordeaux Sciences Agro, INRAE, BOREA, MNHN, IRD, SU, CNRS, UA
Tipping points in ocean and atmosphere circulations
Abstract. Continued anthropogenic pressures on the Earth system hold the potential to disrupt established circulation patterns in the ocean and atmosphere. In this narrative review, we investigate tipping points in these systems by assessing scientific evidence for feedbacks that may drive self-sustained change beyond critical forcing thresholds, drawing on insights from expert elicitation. The literature provides multiple strands of evidence for oceanic tipping points in the Atlantic Meridional Overturning Circulation (AMOC), the North Atlantic subpolar gyre (SPG), and the Antarctic Overturning Circulation, which may collapse under warmer and “fresher” (i.e. less salty) conditions. A slowdown or collapse of these oceanic circulations would have far-reaching consequences for the rest of the climate system and could lead to strong impacts on human societies and the biosphere. Among the atmospheric circulation systems considered, a few lines of evidence suggest the West African monsoon (WAM) as a tipping system. Its abrupt changes in the past have led to vastly different vegetation states of the Sahara (e.g. “green Sahara” states). Despite multiple potential sources of destabilization, evidence about tipping of the monsoon systems over South America and Asia is limited. Although theoretically possible, there is currently little indication for tipping points in tropical clouds or mid-latitude atmospheric circulations. Similarly, tipping towards a more extreme or persistent state of the El Niño–Southern Oscillation (ENSO) is currently not fully supported by models and observations. While the tipping thresholds for many of these systems are uncertain, tipping could have severe socio-environmental consequences. Stabilizing Earth's climate (along with minimizing other environmental pressures, such as aerosol pollution and ecosystem degradation) is critical for reducing the likelihood of reaching tipping points in the ocean–atmosphere system.
(Earth System Dynamics. vol. 16, n° 2190-4979, pp. 1611-1653, 08/10/2025)
PIK, NOC, CAOS, IISc, BCCR, BIO / UiB, UiB, USP, IMAU, KNMI, UNSW, LOCEAN-VARCLIM, LOCEAN, MNHN, IRD, INSU - CNRS, SU, CNRS, IPSL (FR_636), ENS-PSL, UVSQ, CEA, INSU - CNRS, X, CNES, SU, CNRS, UPCité, MOHC, IIASA, LDEO, UQAM, NOCS, LOCEAN-PROTEO, LOCEAN, MNHN, IRD, INSU - CNRS, SU, CNRS, IPSL (FR_636), ENS-PSL, UVSQ, CEA, INSU - CNRS, X, CNES, SU, CNRS, UPCité, CCRC, UNSW, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, IISc
Disentangling Atmospheric and Water Shortage Stresses Is Key to Anticipate Forest Dynamics With Climate Change
Aim: Studies assessing changes in vegetation with climate change have not separated atmospheric and water shortage stresses, although they drive different vegetation patterns in relation to continentality, water balance and bedrock types. We aim to assess how these two stresses will likely impact forest communities. Location: European Alps. Taxon: Angiosperms and Conifers. Methods: We selected from the literature 773 forest plots that were sampled for vegetation composition during the 20th century. We collected at each plot climate variables from databases and calculated several climate indices (including winter rainfall continentality and summer water balance) at two periods (1965–1994 and 1995–2024). We conducted a canonical correspondence analysis (CCA) on the vegetation (understory species) and environmental tables (including eight 1965–1994 climatic variables and bedrock type, exposure, and canopy cover). The significance of differences in climate conditions between the two periods was tested separately for each climate variable and each of the 19 community types identified by a cluster analysis conducted after the CCA. Results: Elevation, continentality and bedrock were the three primary complex environmental variables affecting temperature, atmospheric and water shortage stresses, factors directly driving vegetation composition. Climate change induced an overall decrease in summer water balance and an increase in temperature and continentality. However, a stronger increase in water shortage stress was observed for high elevation sites from northern latitudes with a high summer water balance, while a slight decrease in atmospheric stress was observed for summer-dry continental communities from the southwestern French and Italian Alps. Main Conclusions: Atmospheric and water shortage stresses have specific effects on forest community composition and therefore need to be accounted for when predicting changes in vegetation composition with climate change.
(Journal of Biogeography. vol. 52, n° 0305-0270, 08/10/2025)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LECA, USMB [Université de Savoie] [Université de Chambéry], CNRS, Fédération OSUG, UGA
When invasion is faster than science: the long story of the flatworm who travelled across oceans
Both scientific and policy recommendations on marine non-indigenous species agree on the importance of a rapid detection and identification of species, for a rapid action. But sometimes, detection can just be the beginning of a long investigation, longer than the invasion of the species. In 2020, oyster farmers of the Arcachon Bay (France) noted the presence of a polyclad in cultivated oysters (Magallana gigas). Rapidly, special attention was paid to it because of its potential predatory behavior on bivalves. Because of its absence from public barcode databases until 2023 and from available identification keys, it was described as a new species (Idiostylochus tortuosus) while keeping in mind the high probability to be an introduced non-indigenous species. After several months of investigation, mainly based on molecular markers, the presence of this polyclad in Pacific areas (Australia and Japan)supported this status and finally allowed its identification as Postenterogonia orbicularis described from New-Zealand. Meanwhile, the species took the opportunity to proliferate both in terms of spatial expansion and population densities. This poster aimed to detail the investigation about this traveler polyclad and first results of population dynamic in the Arcachon Bay, acquired during two successive projects, RAPSODI (IFREMER) and VISQUEUX (FEAMPA-OFB).
(07/10/2025)
PatriNat, MNHN, IRD, CNRS, OFB - DSUED, OFB, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CSIC, LERAR, COAST, IFREMER, LERPC, COAST, IFREMER, CAPENA
One decade of monitoring the consequences of different forest management alternatives on ecosystem functioning in young plantations
The global demand for wood biomass is increasing, therefore it is necessary to develop forest management alternatives that can, simultaneously, produce large amounts of biomass and maintain ecosystem functions and services in a sustainable way. However, assessing the consequences of silviculture is challenging, as forest ecosystems function slowly over long periods of time. Therefore, in this study, an experimental platform was set up to monitor the long-term effects of several forest management alternatives (FMA) on ecosystem functioning in a pine forest in a temperate region characterised by oligotrophic conditions. In practice, we monitored three contrasting FMA over a decade: (i) wood biomass production (WBP), designed using an approach of very intense forestry (high stand density; seed lot of pines selected to growth fast), (ii) combined objective management (COM; low stand density), aimed at improving pine growth by alleviating any competition by spontaneous vegetation, and (iii) nutrient management (NuM; medium stand density), designed to improve tree nutrition using N-fixers in the stand furrows. Overall, although FMA showed contrasting stand growth and structures, they had modest effects on forest biogeochemistry over a decade of monitoring: FMA showed similar trends regarding atmospheric deposition, soil solution chemistry and water table-ditch chemistry. The main difference observed was a more important role of dissolved organic matter in NuM biogeochemical functioning. Conversely to their effects on biogeochemistry, the FMA appeared to influence the biophysical properties of stands. The WBP management (with high stand density) was shown to be shadier, cooler and wetter than the other FMA. This trend was fairly clear during the summer periods although differences were observed all year-long. An important result regarding biophysical effects was that, in addition to being observed in the topsoil layers, they were also evident in deeper soil layers and in the water table. All in all, our results indicated that contrasting FMA have tended to influence the ecosystem functioning, in particular its biophysical component, but showed no early sign of unsustainable biogeochemical functioning. Nonetheless, this latter result should be confirmed in the long-term through further monitoring.
(06/10/2025)
UMR ISPA, Bordeaux Sciences Agro, INRAE, UEFP, INRAE, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Investigation of the combined influence of salinity and particle concentration on the adsorption of anionic and zwitterionic PFAS onto estuarine sediment using the RSM modelling approach
Salinity (S) and suspended particulate matter (SPM) are key factors influencing the sorption of micropollutants in estuaries, due to strong gradients in these ecosystems.
We initially investigated the adsorption kinetics of 11 anionic and zwitterionic PFAS onto estuarine sediment under one S/SPM combination in laboratory-controlled conditions, as well as their adsorption isotherms under two S/SPM combinations. We also determined their distribution coefficients (Kd) across 35 S/SPM combinations covering estuarine conditions. The adsorption kinetics of PFAS could be described by a pseudo-second-order model (equilibrium time <24h). Sorption isotherms were fitted by both linear and Freundlich models; the linear sorption range was in the range 0.12-1.31 nM and Kd varied between 0.6 and 55271 L/kg. Based on response surface modelling, both S and SPM were significant factors, i.e. Kd was positively related to S (salting-out effect), while it was negatively related to SPM concentration (third-phase effect). SPM had a stronger effect than S for short-chain carboxylates, whereas S was the dominant factor for most other compounds. We also provide, for the first time, evidence of a significant negative interaction between these two factors. This study provides a new perspective to model the fate of PFAS at the land-sea interface.
(03/10/2025)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS