Résumé
La plate-forme Biochem-Env, implantée sur le centre INRAE de Versailles-Grignon, se prépare pour une première campagne terrain, programmée au printemps 2021, à bord de son tout nouveau Lab-Mobile. Nous étions conviés le 3 février dernier - aux côtés de ses partenaires, fournisseurs et chercheurs - à l’inauguration de cet équipement unique en France, spécialement aménagé et équipé pour la collecte, la préparation et la caractérisation biochimique d’échantillons environnementaux.
Auteurs, date et publication :
Auteurs S. Denis
Publication : La Gazette du Laboratoire
Date : 2020
Issue : 265
Catégorie(s)
#BiochemEnv #INRAERésumé
Two well-dated ca Holocene-long sedimentary sequences from deepest parts of Lake Bourget provide new insights onto the evolution of erosion patterns at a regional scale in NW European Alps. The combination of high resolution geochemistry e XRF core scanning, calibrated by 150 punctual measurements e and isotope geochemistry ( Nd) of the terrigenous fraction permitted the reconstruction not only of the intensity, but also the type (physical erosion vs. chemical weathering) and the location (Prealpine massifs vs. High Crystalline massifs) of dominant erosion processes. Those data point the persistency of weak erosion fluxes from 9600 to 5500 cal. BP due both to a dry climate and the growing sheltering effect of soils that rapidly progressed between 9600 and 8000 cal. BP. Soils then reached a steady state before being destabilised around 4400 cal. BP, probably in response to human impact. The human impact then reached a sufficient intensity to change erosion patterns at a regional scale, but did not result in a significant increase of the regional terrigenous flux. The following enhancement of erosion processes occurred around 2700 cal. BP. It was first paced by changing climatic conditions, but probably reinforced by human impact during Late Iron Age e Antiquity period. Over the long-term trend, the Lake Bourget record pinpoints an evolution of paleohydrological conditions in the Alps dominated by dry conditions from 9500 to 4400 cal. BP and a subsequent drift toward wetter conditions that culminated during the so-called Little Ice Age (ca 1350e1900 AD). In such a context the current dry conditions in European Alps appear out-of-trend. At high resolution, 17 periods of enhanced hydrological activity highlight the rapid climatic changes that are typical of the Holocene.
Auteurs, date et publication :
Auteurs Fabien Arnaud , Sidonie Révillon , Maxime Debret , Marie Revel , Emmanuel Chapron , Jérémy Jacob , Charline Giguet-Covex , Jérôme Poulenard , Michel Magny
Publication : Quaternary Science Reviews
Date : 2025
Volume : 51
Pages : 81-92
Catégorie(s)
#INRAE #OLARésumé
On the basis of sedimentological analysis of two cores taken at Chatillon, Lake Le Bourget (northern French Pre-Alps), and well dated by radiocarbon dates in addition to tree ring dates obtained from an archaeological layer, this paper presents a high-resolution lake-level record for the period 4500–3500 cal. a BP. The collected data provide evidence of a complex palaeohydrological (climatic) oscillation spanning the ca. 4300–3850 cal. BP time interval, with major lake-level maxima at ca. 4200 and 4050–3850 cal. a BP separated by a lowering episode around 4100 cal. a BP. The lake-level highstands observed at Chatillon between 4300 and 3850 cal. BP appear to be synchronous with (i) a major flooding period recorded in deep cores from the large lakes Le Bourget and Bodensee, and (ii) glacier advance and tree line decline in the Alps. Such wetter and cooler climatic conditions in west-central Europe around 4000 cal. a BP may have been a nonlinear response to decrease and seasonal changes in insolation. They may also provide a possible explanation for the general abandonment of prehistoric lake dwellings north of the Alps between 4360 and 3750 cal. a BP. Copyright # 2012 John Wiley & Sons, Ltd.
Auteurs, date et publication :
Auteurs Michel Magny , Fabien Arnaud , Yves Billaud , André Marguet
Publication : Journal of Quaternary Science
Date : 2025
Volume : 27
Issue : 5
Pages : 494-502
Catégorie(s)
#INRAE #OLARésumé
Soil microbial communities are major drivers of cycling of soil nutrients that sustain plant growth and productivity. Yet, a holistic understanding of the impact of land-use intensification on the soil microbiome is still poorly understood. Here, we used a field experiment to investigate the long-term consequences of changes in land-use intensity based on cropping frequency (continuous cropping, alternating cropping with a temporary grassland, perennial grassland) on bacterial, protist and fungal communities as well as on their co-occurrence networks.
Auteurs, date et publication :
Auteurs Sana Romdhane , Aymé Spor , Samiran Banerjee , Marie-Christine Breuil , David Bru , Abad Chabbi , Sara Hallin , Marcel G. A. van der Heijden , Aurélien Saghai , Laurent Philippot
Publication : Environmental Microbiome
Date : 2022
Volume : 17
Issue : 1
Pages : 1
Catégorie(s)
#ACBB #ACBB Lusignan #ANR-Citation #INRAERésumé
In a context of global change, soil has been identified as a potential carbon (C) sink, depending on land-use strategies. To detect the trends in carbon stocks after the implementation of new agricultural practices, early indicators, which can highlight changes in short timescales, are required. This study proposes the combined use of stable isotope probing and chemometrics applied to solid-state 13C nuclear magnetic resonance (NMR) spectra to unveil the dynamics of the storage and mineralization of soil carbon (C) pools. We focused on light organic matter fractions isolated by density fractionation of soil water stable aggregates because they respond faster to changes in land use than the total soil organic matter (SOM). Samples were collected from an agricultural field experiment with grassland, continuous maize cropping, and ley grassland under temperate climate conditions. Our results indicated contrasting aggregate dynamics depending on land-use systems. Under our experimental conditions, grassland returns larger amounts of C as belowground inputs than maize cropping, evidencing a different distribution of light C fractions between aggregate classes. Coarse aboveground inputs from maize contributed mostly to larger macroaggregates. Land-use changes with the introduction of ley grassland provoked a decoupling of the storage and/or degradation processes after the grassland phase. The newly derived maize inputs were barely degraded during the first 3 years of maize cropping, whereas grassland-derived material was depleted. As a whole, results suggest large microbial proliferation as shown by 13C NMR under permanent grassland, then reduced within the first years after the land-use conversion, and finally restored. The study highlighted a fractal structure of the soil, determining a scattered spatial distribution of the cycles of storage and degradation of soil organic matter related to detritusphere dynamics. As a consequence, vegetal inputs from a new land use are creating new detritusphere microenvironments that may be disconnected from the dynamics of C cycle of the previous land use. The formation of those different and unconnected microenvironments may explain the observed legacy effect of the previous land use, since each microenvironment type contributes separately to the overall soil C cycle. The effects of the new land use on the soil C cycle are delayed until the different detritusphere microenvironments remain unconnected, and the ones from the previous land use represent the predominant microenvironment type. Increasing knowledge of the soil C dynamics at a fine scale will be helpful in refining the prediction models and land-use policies.
Auteurs, date et publication :
Auteurs Marco Panettieri , Denis Courtier-Murias , Cornelia Rumpel , Marie-France Dignac , Gonzalo Almendros , Abad Chabbi
Publication : SOIL
Date : 2020
Volume : 6
Issue : 2
Pages : 435-451
Catégorie(s)
#ACBB #ACBB Lusignan #ANR-Citation #INRAERésumé
Abstract
Diadromous fish have exhibited a dramatic decline since the end of the 20th century. The allis shad (
Alosa alosa
) population in the Gironde‐Garonne‐Dordogne (GGD) system, once considered as a reference in Europe, remains low despite a fishing ban in 2008. One hypothesis to explain this decline is that the downstream migration and growth dynamics of young stages have changed due to environmental modifications in the rivers and estuary. We retrospectively analysed juvenile growth and migration patterns using otoliths from adults caught in the GGD system 30 years apart during their spawning migration, in 1987 and 2016. We coupled otolith daily growth increments and laser ablation inductively‐coupled plasma mass spectrometry measurements of Sr:Ca, Ba:Ca, and Mn:Ca ratios along the longest growth axis from hatching to an age of 100 days (i.e., during the juvenile stage). A back‐calculation allowed us to estimate the size of juveniles at the entrance into the brackish estuary. Based on the geochemistry data, we distinguished four different zones that juveniles encountered during their downstream migration: freshwater, fluvial estuary, brackish estuary, and lower estuary. We identified three migration patterns during the first 100 days of their life: (a) Individuals that reached the lower estuary zone, (b) individuals that reached the brackish estuary zone, and (c) individuals that reached the fluvial estuary zone. On average, juveniles from the 1987 subsample stayed slightly longer in freshwater than juveniles from the 2016 subsample. In addition, juveniles from the 2016 subsample entered the brackish estuary at a smaller size. This result suggests that juveniles from the 2016 subsample might have encountered more difficult conditions during their downstream migration, which we attribute to a longer exposure to the turbid maximum zone. This assumption is supported by the microchemical analyses of the otoliths, which suggests based on wider Mn:Ca peaks that juveniles in 2010s experienced a longer period of physiological stress during their downstream migration than juveniles in 1980s. Finally, juveniles from the 2016 subsample took longer than 100 days to exit the lower estuary than we would have expected from previous studies. Adding a new marker (i.e., Ba:Ca) helped us refine the interpretation of the downstream migration for each individual.
Auteurs, date et publication :
Auteurs Elodie Boussinet , David José Nachón , Aldo Sottolichio , Aude Lochet , Stefan Stoll , Gilles Bareille , Helene Tabouret , Christophe Pécheyran , Marie‐Laure Acolas , Françoise Daverat
Publication : Journal of Fish Biology
Date : 2025
Volume : 104
Issue : 4
Pages : 1054-1066
Catégorie(s)
#INRAE #XPOAuteurs, date et publication :
Auteurs Elke I. Zimmer , T. Jager , V. Ducrot , L. Lagadic , S. A. L. M. Kooijman
Publication : Ecotoxicology
Date : 2012
Volume : 21
Issue : 8
Pages : 2195-2204
Catégorie(s)
#INRAE #PEARLAuteurs, date et publication :
Auteurs D. Azam , L. beaulaton , F. Marchand , P. Marhin
Date : 2025
Catégorie(s)
#INRAE #PEARLAuteurs, date et publication :
Auteurs Gaétan Pottier , Frédéric Marchand
Date : 2018
Catégorie(s)
#INRAE #PEARLRésumé
La pêche à l'électricité est une méthode largement utilisée pour les échantillonnages piscicoles en cours d’eau (suivis annuels des populations et des communautés de poissons, approche de types indice poisson rivière ou indicateurs mono spécifiques saumon, anguille, truite). Cependant l’évolution des matériels, de leurs caractéristiques et des réglages possibles ainsi que la formation des personnels utilisant cette technique nécessitent que soient décrits les principaux facteurs influençant la qualité de ces échantillonnages.
Cet ouvrage synthétise l’ensemble des paramètres à connaître et à prendre en compte pour réaliser ou exploiter des pêches scientifiques à l’électricité. Il rappelle les notions de base en électricité, les différentes formes de courant, le gradient de tension ou le rapport cyclique. La réaction des poissons faces à ces types de courant électrique est décrite ainsi que l’impact du réglage des appareils sur leur intégrité. Les différents facteurs qui influent sur l’efficacité de la pêche à l'électricité, qu’ils soient biotiques (espèce, tailles…) ou abiotiques (fréquence du courant ou caractéristiques du cours d’eau comme la largeur, la profondeur, la conductivité…), sont récapitulés.
Sur la base de ces éléments, cet ouvrage fournit des conseils pour la mise en œuvre d’une pêche à l’électricité: la configuration du matériel, le choix du type de courant et les réglages, afin de concilier le meilleur rapport entre l’efficacité de capture et le respect du bien-être des poissons. Il propose également des méthodes pour mesurer certains paramètres tels que le gradient de tension.
Les différentes techniques (à pied ou en bateau) sont ensuite revues et quelques éléments de prévention sont rappelés.
Enfin, des fiches techniques sur des méthodes standardisées de pêches scientifiques à l’électricité (indices d’abondance anguille, saumon, truite ou d’inventaire du peuplement piscicole) sont proposées.
Auteurs, date et publication :
Auteurs Gaétan Pottier , Didier Azam , Laurent Beaulaton , Thibault Vigneron , Jacques Rives , Frédéric Marchand , Caroline Pénil
Date : 2022