Hydroclimate change in subtropical South Africa during the mid-Piacenzian Warm Period
The mid-Piacenzian Warm Period (mPWP, 3.264–3.025 Ma) of the Pliocene epoch has been proposed as an analog for future climate scenarios. Disagreement between the paleoenvironmental reconstruction and model simulations of the climate in subtropical regions for this period suggests that more investigation of the subtropical climate variability of the mPWP is needed. This study presents pollen, microcharcoal and benthic foraminifera oxygen isotope records generated from marine sediment cores of International Ocean Discovery Program (IODP) Exp. 361 Site U1479 from the Cape Basin offshore of South Africa for the period between 3.337 and 2.875 Ma. With an average sample resolution of 3 ka, this record represents the highest-resolution record of mPWP vegetation change from the region. Our results indicate that the vegetation during the mPWP was dominated by fynbos (species-rich heathy vegetation in the Cape Floristic Region) with variable proportions of Ericaceae. Moreover, the development of the Afrotemperate forest (tall, multilayered indigenous forests in South Africa) reflects shifts in the amounts of precipitation between winter and summer in the year-round rainfall zone. The vegetation variation is probably influenced by the latitudinal insolation gradient in response to precession forcing. Several glacials depicted by the benthic foraminifera oxygen isotope record were characterized by lower percentage values of Restionaceae, higher percentage values of ericoid fynbos and Afrotemperate forest. These events correspond well with cooler SE Atlantic sea surface temperatures driven by interactions of both atmospheric and oceanographic processes. The cooler sea surface temperatures attributed to Antarctic ice sheet expansion, reduced Agulhas leakage (heat and salt transfer from the Indian Ocean to the Atlantic Ocean) and/or intensified southern Benguela upwelling, resulted in less precipitation in the winter rainfall zone of South Africa.
(Quaternary Science Reviews. vol. 249, n° 0277-3791, pp. 106643, 02/09/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Acute Toxicity of Sodium Chloride, Nitrates, Ortho-Phosphates, Cadmium, Arsenic and Aluminum for Juveniles of the Freshwater Pearl Mussel: Margaritifera Margaritifera (L.1758)
The freshwater pearl mussel (FWPM) Margaritifera margaritifera (L.1758) is critically endangered in Europe and ecotoxicological studies on the species are scares. Here, 96 h acute toxicity tests were conducted at 16 °C with sodium chloride (NaCl), nitrates (NO3−), ortho-phosphates (PO43−), cadmium (Cd), aluminum (Al) and arsenic (As) on 13- to 28-month-old post-parasitic juveniles. The experimental protocol was developed according to conditions described in a standard guide and was modified in order to assess toxicity thresholds for the Dronne River. Results showed that juveniles were tolerant to concentrations of Al, Cd, As, PO43−, NO3− and NaCl, largely higher than those found in the Dronne river, since 96 h EC50s (effective concentrations) were >954 µg/L for Al; >110 µg/L for Cd; >127 µg/L for As; >5.01 mg/L for PO43−; between 1000 and 1500 mg/L for NO3− and were 1.19 and 1.33 g/L for NaCl. Moreover, the use of a substrate in experiments was found not to affect juvenile responses and younger juveniles seemed more sensitive than older individuals. This study thus provides new data about the tolerance of FWPM to environmental pollution and suggests that pollutant concentrations in the river are significantly lower than levels affecting them.
(Environments. vol. 7, n° 2076-3298, pp. 48, 02/09/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
AquaVIT Quand les plantes aquatiques invasives transcendent les frontières : approche pluridisciplinaire des relations entre espèces, milieux et gestionnaires
Le projet de recherche AquaVIT vise à accompagner l’évolution des modalités de gestion des grands lacs aquitains, confrontés à des enjeux environnementaux liés à la colonisation par les plantes aquatiques invasives. Ces plantes exotiques à caractère envahissant peuvent occuper une place importante au sein des écosystèmes lacustres et, par la même occasion, entraver de nombreux usages des lacs, notamment la pratique d’activités de loisirs. En Nouvelle-Aquitaine, ces macrophytes invasifs font l’objet d’une attention de la part des gestionnaires, élus et scientifiques depuis maintenant plus de trente ans. Néanmoins, un certain nombre d’interrogations demeurent. Les plantes présentent encore des dynamiques de colonisation importantes dans de nombreux plans d’eau et les opérations de gestion visant à les réguler sont menées localement. Le projet de recherche AquaVIT s’intéresse particulièrement aux questions suivantes : - Les plantes invasives constituent-elles un élément perturbateur du bon fonctionnement écologique lacustre ? - Comment "faire avec" les plantes au quotidien ? - Comment "faire ensemble" ? Le projet AquaVIT affiche une ambition pluridisciplinaire forte, qui associe, dès sa conception, les sciences humaines et sociales d’une part, et les sciences biogéochimiques et écologiques d’autre part. Ce projet propose une alternative à la vision quantitative et mesurable, strictement centrée sur la plante (i.e distribution et biomasse des plantes), vers une approche plus qualitative, orientée sur les relations entre la plante et son environnement, celui-ci étant considéré d’un point de vue écosystémique et social. Appropriée par chacune des disciplines, cette posture a donné lieu à des approches empiriques diverses et spécifiques. Dans le projet AquaVIT ont été déployées, entre autres, des enquêtes (qualitatives et quantitatives) auprès des acteurs, des études sociohistoriques basées sur des analyses de documents, mais aussi des prélèvements et mesures biologiques et physico-chimiques in situ, ainsi que des expérimentations en laboratoire. Le croisement de ces regards et de ces méthodes constitue une des richesses du projet. Les résultats obtenus invitent à s’éloigner d’une représentation univoque des conséquences potentielles de la présence d’herbiers denses de plantes aquatiques invasives, tout comme à contextualiser la problématique socio-environnementale de leur gestion. Ceci peut être illustré par le fait que les processus écologiques et biogéochimiques à l’œuvre dans les herbiers sont étroitement liés aux conditions hydrodynamiques locales, ou encore que les représentations et les attitudes à leur sujet dépendent pour partie des usages et des pratiques de terrain. Dans certaines conditions, une telle « contextualisation » de la problématique a favorisé l’émergence d’innovations organisationnelles, se traduisant, par exemple, par des dispositifs à caractère participatif. En dépit des motivations et des intentions à s’engager, dont témoignent les usagers des plans d’eau, les soutiens (humains, techniques et financiers) des pouvoirs publics, restent essentiels. Sur un plan spatial, ces innovations peinent toutefois à dépasser l’échelle des sites, de sorte que la mise en relation entre plusieurs secteurs, que l’on est parfois en mesure d’attendre compte tenu de la dynamique des plantes et des processus, repose encore très largement sur les réseaux sociotechniques des gestionnaires traditionnels des milieux, et peu sur les utilisateurs finaux.
(pp. 125 p., 02/09/2026)
UR EABX, INRAE, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UR ETBX, INRAE
Measuring Air Pollutant Concentrations and Fluxes
Estimating agriculture’s contribution to air pollution and global warming is needed to understand and limit its impacts on the environment and climate. It is equally important to estimate the capacity of agricultural practices to mitigate these emissions and to characterize atmospheric deposition and the impacts of air pollutants on agroecosystems. This chapter presents methods for measuring air pollutant concentrations, their fluxes at the soil-vegetation-atmosphere interface, and emissions from livestock facilities. Methods for measuring air concentrations are described with a focus on compounds emitted from or impacting agriculture (including forests): ammonia, nitrogen oxides, pesticides, volatile organic compounds including methane, abiotic and biotic particles, and ozone. The main methods for measuring emission and deposition fluxes of air pollutants between terrestrial surfaces, especially agroecosystems, and the atmosphere are described with a specific focus on the eddy covariance method as well as on emissions from livestock buildings. Then the general principles of source apportionment methods for estimating emissions spatial variability are presented. To address the questions on atmospheric chemistry, the methods used for measuring the reactivity of atmospheric compounds are presented. Finally, an insight is given on the developments of measurement methodologies to address new compounds and improve the sensors’ sensitivity and response time as well as provide estimates of spatial variability of concentrations and fluxes at larger scales.
(pp. 119-157, 02/09/2026)
ECOSYS, INRAE, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, LISA (UMR_7583), INSU - CNRS, UPEC UP12, CNRS, UPCité, LATMOS, UVSQ, INSU - CNRS, SU, CNRS, PhLAM, CNRS, IRCELYON, UCBL, INC-CNRS, CNRS, SAS, INRAE, Institut Agro, IGE, IRD, INSU - CNRS, CNRS, Fédération OSUG, UGA, Grenoble INP, UGA, ICARE, UO, CNRS, INSIS - CNRS, ICPEES, UNISTRA, INC-CNRS, CNRS, MNGE, UNISTRA, Université de Haute-Alsace (UHA), INSERM, INC-CNRS, CNRS, PC2A, CNRS, LCE, AMU, INC-CNRS, CNRS, IMT Lille Douai, IMT, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
SESAM mode-locked Tm:LuYO 3 ceramic laser generating 54-fs pulses at 2048 nm
(Applied optics. vol. 59, n° 1559-128X, pp. 10493, 02/09/2026)
JSNU, HNU, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CIMAP - UMR 6252, UNICAEN, NU, IRAMIS, CEA, ENSICAEN, NU, CNRS, IRMA, UNICAEN, NU, ENSICAEN, NU, CEA, UNIROUEN, NU, INSA Rouen Normandie, INSA, NU, CNRS
Study of the dissolved organic matter (DOM) of the Auzon cut-off meander (Allier River, France) by spectral and photoreactivity approaches
Wetlands are recognized for the importance of their hydrological function and biodiversity, and there is now a consensus to protect and restore them as well as to complete the knowledge on their functioning. Here, we studied the dissolved organic matter (DOM) of a wetland composed of the Auzon cutoff meander, the Allier River, the alluvial fluvial flow, and watershed aquifer. Water was sampled at different locations, in spring, summer, and autumn. For each sample, DOM was characterized for its chemical and optical properties and its photooxidant capacity through its ability to generate DOM triplet excited states (3 DOM*) and singlet oxygen upon simulated solar light exposure. UV-visible and fluorescence indices revealed that DOM was mainly microbial-derived whatever the sampling sites with spatial and temporal variations in terms of aromaticity (5.5-22%), specific UV absorbance at 254 nm (0.28-2.82 L m −1 mgC −1), ratio of the absorbance at 254 and 365 nm (4.6-10.8), fluorescence index (1.35-166), and biological index (0.812-2.25). All the samples generated 3 DOM* and singlet oxygen, rates of formation of which showed parallel variations. Using principal component analysis (PCA), we found positive correlations between the sensitizing properties of DOM samples and parameters associated to the abundance of low molecular weight and low absorbing chromophores. Moreover, the parameter variation across the wetland reinforced the hydrological movements observed in a previous study, suggesting that these parameters could be used as water connection tracers.
(Environmental Science and Pollution Research. vol. 27, n° 0944-1344, pp. 26385-26394, 02/09/2026)
ICCF, SIGMA Clermont, INC-CNRS, UCA [2017-2020], CNRS, GEOLAB, UBP, IR SHS UNILIM, UNILIM, UCA [2017-2020], CNRS, UCA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Lidar Observations of the Swash Zone of a Low-Tide Terraced Tropical Beach under Variable Wave Conditions: The Nha Trang (Vietnam) COASTVAR Experiment
(Journal of Marine Science and Engineering, n° 2077-1312, 02/09/2026)
LEGOS, IRD, UT3, Comue de Toulouse, INSU - CNRS, CNES, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LGO, UBS, IFREMER, UBO EPE, CNRS, LEESA, UB, CNRS, HCMUT, VNU-HCM, LGL-TPE, ENS de Lyon, UCBL, INSU - CNRS, UJM, UJM EPE, CNRS
The sediment-fill of Pago Pago Bay (Tutuila Island, American Samoa): New insights on the sediment record of past tsunamis
Extensive bathymetric and two-dimensional seismic surveys have been carried out and cores collected in Pago Pago Bay (Tutuila, American Samoa) in order to describe and gain a better understanding of the sediment fill of the bay, which was affected by the 2009 South Pacific Tsunami. Eight sedimentary units were identified over the volcanic bedrock. The basal transgressive unit displays retrograding onlaps towards the shore, whereas the overlying seven aggradational layers alternate between four draping units and three pinching out seaward units. 'Core to seismic' correlation reveals that draping units are composed of homogeneous silts, while pinching out units are dominated by very coarse coral fragments showing fresh cuts, mixed with Halimeda plates. The basal unit is attributed to transgressive sedimentation in response to flooding of the bay after the last glacial maximum, followed by the upper aggrada-tional units corresponding to highstand sedimentation. The changeovers in these upper units indicate an alternation between low-energy silt units and high-energy coral debris units interpreted as tsunami-induced deposits. The 14 C dating reveals that high-energy sedimentation units can last up to approximately 2000 years while low-energy sedimentation units can last up to approximately 1000 years. This alternation, deposited during the last high-stand, may be explained by cycles of tectonic activity and quiescence of the Tonga Trench subduction, which is the main source of tsunamigenic earthquakes impacting the Samoan archipelago. In the uppermost silt unit, only the geochemical signature of the terrestrial input of the 2009 SPT backwash deposits was detected between 7 cm and 9 cm depth. Hence, Pago Pago Bay offers a unique sediment record of Holocene bay-fill under the impact of past tsunamis intermittently during the last 7000 years.
(Sedimentology, n° 0037-0746, 02/09/2026)
LIENSs, INSU - CNRS, ULR, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UNSW
Des concrétions fuligineuses en contextes archéologiques : quel potentiel informatif ?
Les spéléothèmes (concrétions carbonatées de grottes) sont des archives naturelles qui se caractérisent par leur capacité à enregistrer les environnements passés ainsi que par leur haute résolution temporelle, en particulier lorsqu’ils sont laminés annuellement. Leur potentiel d’étude ne se limite pas qu’aux recherches sur les reconstitutions paléo-climatiques. Les concrétions peuvent par exemple piéger des particules anthropiques comme de la suie, et ces concrétions fuligineuses ont un fort potentiel informatif en archéologie. Dans cet article, nous présenterons les potentiels d’application archéologique de l’analyse fuliginochronologique à travers plusieurs cas, dans des contextes temporels différents. Les cas les plus récents (en Belgique, en France et en Slovénie), pour lesquels nous disposons parfois d’informations historiques et textuelles autorisant un contrôle des faits archéologiques enregistrés, permettront de valider le potentiel d’archive micro-chronologique des spéléothèmes dans le cadre d’une étude fuliginochronologique. Ensuite, nous étendrons l’utilisation de cette méthode à un site paléolithique français afin de mettre en lumière le potentiel informatif de cette approche en préhistoire.
(Géomorphologie : relief, processus, environnement. vol. 26, n° 1266-5304, pp. 241-254, 02/09/2026)
UP1 UFR03, UP1, ArScAn, UP1, UP8, UPN, MCC, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LAMPEA, AMU, CNRS, MC, TRACES, EHESS, UT2J, Comue de Toulouse, MCC, Inrap, CNRS
Estrogenic activity of surface waters using zebrafish- and human-based in vitro assays : The Danube as a case-study
Most in vitro reporter gene assays used to assess estrogenic contamination are based on human estrogen receptor α (hERα) activation. However, fish bioassays can have distinct response to estrogenic chemicals and mixtures, questioning the relevance of human-based bioassays for assessing risk to this species. In this study, zebrafish liver cells stably expressing zebrafish ERβ2 (ZELHβ2) and human breast cancer cells expressing hERα (MELN) were used to quantify the estrogenic activity of 25 surface water samples of the Danube River, for which chemicals have been previously quantified. Most samples had a low estrogenic activity below 0.1 ng/L 17β-estradiol-equivalents that was more often detected by MELN cells, while ZELHβ2 response tend to be lower than predicted based on the chemicals identified. Nevertheless, both bioassays quantified well a higher estrogenic activity at two sites, which was confirmed in vivo using a transgenic zebrafish assay. The results are discussed considering the effect-based trigger values proposed for water quality monitoring.
(Environmental Toxicology and Pharmacology. vol. 78, n° 1382-6689, pp. art. 103401, 02/09/2026)
SEBIO, INERIS, URCA, ULH, NU, URCA, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, INERIS, LPTC, UB, CNRS, UFZ, RWTH Aachen