Résumé
There is currently an intense debate about the potential for additional organic carbon storage in soil, the strategies by which it may be accomplished and what the actual benefits might be for agriculture and the climate. Controversy forms an essential part of the scientific process, but on the topic of soil carbon storage, it may confuse the agricultural community and the general public and may delay actions to fight climate change. In an attempt to shed light on this topic, the originality of this article lies in its intention to provide a balanced description of contradictory scientific opinions on soil carbon storage and to examine how the scientific community can support decision-making despite the controversy. In the first part, we review and attempt to reconcile conflicting views on the mechanisms controlling organic carbon dynamics in soil. We discuss the divergent opinions about chemical recalcitrance, the microbial or plant origin of persistent soil organic matter, the contribution of particulate organic matter to additional organic carbon storage in soil, and the spatial and energetic inaccessibility of soil organic matter to decomposers. In the second part, we examine the advantages and limitations of big data management and modeling, which are essential tools to link the latest scientific theories with the actions taken by stakeholders. Finally, we show how the analysis and discussion of controversies can guide scientists in supporting stakeholders for the design of (i) appropriate trade-offs for biomass use in agriculture and forestry and (ii) climate-smart management practices, keeping in mind their still unresolved effects on soil carbon storage.
Auteurs, date et publication :
Auteurs Delphine Derrien , Pierre Barré , Isabelle Basile-Doelsch , Lauric Cécillon , Abad Chabbi , Alexandra Crème , Sébastien Fontaine , Ludovic Henneron , Noémie Janot , Gwenaëlle Lashermes , Katell Quénéa , Frédéric Rees , Marie-France Dignac
Publication : Agronomy for Sustainable Development
Date : 2023
Volume : 43
Issue : 1
Pages : 21
Catégorie(s)
#ACBB #ACBB Lusignan #INRAERésumé
Soil microbial biodiversity provides many useful services in cities. However, the ecology of microbial communities in urban soils remains poorly documented, and studies are required to better predict the impact of urban land use. We characterized microbial communities (archea/bacteria and fungi) in urban soils in Dijon (Burgundy, France). Three main land uses were considered – public leisure, traffic, and urban agriculture – sub-categorized in sub-land uses according to urban indexes and management practices. Microbial biomass and diversity were determined by quantifying and high-throughput sequencing of soil DNA. Variation partitioning analysis was used to rank soil physicochemical characteristics and land uses according to their relative contribution to the variation of soil microbial communities. Urban soils in Dijon harbored high levels of microbial biomass and diversity that varied according to land uses. Microbial biomass was 1.8 times higher in public leisure and traffic sites than in urban agriculture sites. Fungal richness increased by 25 % in urban agriculture soils, and bacterial richness was lower (by 20 %) in public leisure soils. Partitioning models explained 25.7 %, 46.2 % and 75.6 % of the variance of fungal richness, bacterial richness and microbial biomass, respectively. The organic carbon content and the C/N ratio were the best predictors of microbial biomass, whereas soil bacterial diversity was mainly explained by soil texture and land use. Neither metal trace elements nor polycyclic aromatic hydrocarbons contents explained variations of microbial communities, probably due to their very low concentration in the soils. The microbial composition results highlighted that leisure sites represented a stabilized habitat favoring specialized microbial groups and microbial plant symbionts, as opposed to urban agriculture sites that stimulated opportunistic populations able to face the impact of agricultural practices. Altogether, our results provide evidence that there is scope for urban planners to drive soil microbial diversity through sustainable urban land use and associated management practices.
Auteurs, date et publication :
Auteurs Amélie Christel , Samuel Dequiedt , Nicolas Chemidlin-Prevost-Bouré , Florian Mercier , Julie Tripied , Gwendoline Comment , Christophe Djemiel , Lionel Bargeot , Eric Matagne , Agnès Fougeron , Jean-Bertrand Mina Passi , Lionel Ranjard , Pierre-Alain Maron
Publication : Science of The Total Environment
Date : 2023
Pages : 163455
Catégorie(s)
#Genosol #INRAERésumé
Synchronic variations in abundance in populations of the same species are common phenomena encountered in various environments, including lakes, and different taxa of freshwater fishes. This phenomenon can be caused by similar environmental conditions across physically separated populations. In the context of the ongoing climate change, it is essential to test this hypothesis, identify the factors driving the synchrony and elucidate the mechanisms, in the attempt to improve fisheries management. This study investigates synchronic variations in European whitefish (Coregonus spp.) populations in five peri-alpine lakes. The hypothesis suggests that shared biotic or abiotic factors contribute to similar trends in whitefish landings. Environmental and seasonal variables impacting the early life stages of the species were analyzed, and the Euclidean distances between the multivariate time series were calculated to identify similarities or dissimilarities in lake environmental parameters. We found that regional winter and spring temperatures were consistent across the lakes, but these factors did not fully account for variations in landings statistics. Wind intensity, water level and zooplankton abundance showed lake-specific patterns that could better explain local conditions and dynamics. Linear models did not reveal a coherent correlation with a common environmental variable across all lakes. However, distinct relationships were found in four of the lakes, with local factors significantly contributing to abundance variations. The spring abundance of Daphnia spp., a primary food source for whitefish larvae, was the main factor correlated with fish landing trends in Lake Geneva and Lake Bourget. Higher availability of Daphnia spp. may decrease intraspecific competition and density-dependent mortality. In Lake Neuchâtel, winter water temperature was negatively correlated with fish abundance proxies, suggesting that warmer winters may compromise reproduction success. Lake Annecy saw an increase in whitefish landings following a substantial reduction in fishing efforts during the late 2000s. A significant negative correlation was found between whitefish landings and fishing efforts. No relationship was found for Lake Aiguebelette, maybe due to a lack of zooplankton data. In conclusion, the observed synchrony in the European whitefish population is likely driven by a combination of interacting environmental and anthropogenic factors rather than a single common variable. Further research and a more detailed dataset are needed to better understand these complex relationships.
Cover image: Whitefish (courtesy of Rémi Masson)
Auteurs, date et publication :
Auteurs Fabien Bourinet , Orlane Anneville , Hilaire Drouineau , Chloé Goulon , Jean Guillard , Alexandre Richard
Publication : Journal of Limnology
Date : 2023
Volume : 82
Catégorie(s)
#INRAE #OLARésumé
Forests provide essential ecosystem services such as wood production and soil carbon storage, which can be influenced by forest management. Fertilisation and understory removal are common practices set up in managed forests to reduce tree mortality and relieve trees from their main limitations, but their effects on belowground functioning and soil carbon storage are still unclear. In this study, we investigated the effects of phosphorus fertilisation, understory removal and their interaction on the carbon stored in the ecosystem and soil enzyme activities in two contrasting moorlands in south-western France (dry and wet moorlands) planted with maritime pines (Pinus pinaster Ait.). In the wet moorland, we found that fertilisation and understory removal had a positive effect on tree biomass, but they did not affect soil carbon stocks nor carbon-related enzyme activities. In the dry moorland, understory removal had a significant positive effect on tree biomass and a strong negative effect on topsoil organic carbon stocks and carbon-related enzyme activities. Overall, understory removal did not affect total carbon stocks at the ecosystem scale due to compensatory effects between carbon pools, i.e. the increase in carbon stored in the aboveground biomass was cancelled by a decrease in carbon stored in the soil. These results highlight the importance of adapting forest practices depending on the environmental context and carbon sequestration objectives.
Auteurs, date et publication :
Auteurs Lucie Bon , Laurent Augusto , Jonathan Gaudry , Mark R. Bakker , Catherine Lambrot , Sylvie Milin , Pierre Trichet , Nicolas Fanin
Publication : European Journal of Forest Research
Date : 2023
Volume : 142
Issue : 4
Pages : 723-737
Catégorie(s)
#FORET Xylosylve #INRAERésumé
Dans le cadre du programme Investissements d’avenir « Infrastructures nationales de biologie et santé» relatif à l’action « Santé et Biotechnologies » lancé en 2011 par le Commissariat Général à l’Investissement (CGI), le Ministère de l’Enseignement Supérieur et de la Recherche et I ’Agence Nationale de la Recherche (ANR), le CNRS, l’INRA et l’UJF se sont associés pour déposer un projet intitulé « Analyse et Expérimentation sur les Ecosystèmes – Service (AnaEE-S) » devenu par la suite AnaEE France. La présente charte a pour objet de définir les modalités d’accès au service qui est proposé par l’Infrastructure AnaEE France et fixer les droits et obligations des utilisateurs.
Auteurs, date et publication :
Auteurs Marion Bousquet , Christine Schrive , André Chanzy , Jean-François Le Galliard , Christian Pichot , Jacques Roy , Thierry Caquet , Serge Aubert , Laurent Saint-André , Franck Delbart , Didier Azam , Cécile Callou , Berndt Zeller , Jean Clobert
Date : 2023
Catégorie(s)
#CNRS #Coordination AnaEE #INRAERésumé
Nitrogen fertilization is a key agronomic lever for high crop productivity, but also an important source of N2O emission, a potent greenhouse gas. Process-based agroecosystem simulation models are popular tools for managing the timing and amount of fertilization, and help reduce N2O emissions. However, accurate simulation of N2O emissions at field scale is still a challenge due to the spatial and temporal variability of the soil conditions. In this study, we investigated the sources of structural uncertainty in predicting N2O emissions under a wide range of pedo-climatic conditions using a representative field data set. We implemented the same nitrification/denitrification/N2O emission formalism in three different agroecosystem models and analyzed how the inter-model variability of variables involved in nitrification and denitrification processes, affected the simulated N2O emissions. We characterized the dispersion of the key variables (water-filled pore space, NO3− and NH4+ concentration, and soil temperature) between models and we evaluated the effect of variable uncertainty on N2O emissions uncertainty using a sensitivity analysis. We also analyzed model errors over a wide range of soil-climate conditions to identify the most challenging conditions for simulation, which require further model improvement. Our results highlighted that the simulation of the timing and amplitude of the NO3− and NH4+ peaks was highly variable between agroecosystem models, with an important impact on N2O emission. These peaks occurred mainly after fertilization or incorporation of crop residues, and the different representations of fertilization and mineralization between the models had a major effect on the simulation of N2O emissions. Our analysis also emphasized that wet acidic soils with high denitrification potential are more challenging for models to simulate.
Auteurs, date et publication :
Auteurs Sibylle Dueri , Joël Léonard , Florent Chlebowski , Pablo Rosso , Michael Berg-Mohnicke , Claas Nendel , Fiona Ehrhardt , Pierre Martre
Publication : Agricultural and Forest Meteorology
Date : 2023
Volume : 340
Pages : 109619
Catégorie(s)
#ACBB #ACBB Mons #ANR-Citation #INRAERésumé
Soils are one of the major reservoirs of biological diversity on our planet because they host a huge richness of microorganisms. The fungal:bacterial (F:B) ratio targets two major functional groups of organisms in soils and can improve our understanding of their importance and efficiency for soil functioning. To better decipher the variability of this ratio and rank the environmental parameters involved, we used the French Soil Quality Monitoring Network (RMQS)-one of the most extensive and a priori-free soil sampling surveys, based on a systematic 16 km x 16 km grid and including more than 2,100 samples. F:B ratios, measured by quantitative PCR targeting the 18S and 16S rDNA genes, turned out to be heterogenously distributed and spatially structured in geographical patterns across France. These distribution patterns differed from bacterial or fungal densities taken separately, supporting the hypothesis that the F:B ratio is not the mere addition of each density but rather results from the complex interactions of the two functional groups. The F:B ratios were mainly influenced by soil characteristics and land management. Among soil characteristics, the pH and, to a lesser extent, the organic carbon content and the carbon:nitrogen (C:N) ratio were the main drivers. These results improved our understanding of soil microbial communities, and from an operational point of view, they suggested that the F:B ratio should be a useful new bioindicator of soil status. The resulting dataset can be considered as a first step toward building up a robust repository essential to any bioindicator and aimed at guiding and helping decision making.
Auteurs, date et publication :
Auteurs Christophe Djemiel , Samuel Dequiedt , Arthur Bailly , Julie Tripied , Melanie Lelievre , Walid Horrigue , Claudy Jolivet , Antonio Bispo , Nicolas Saby , Matthieu Vale , Pierre-Alain Maron , Lionel Ranjard , Sebastien Terrat
Publication : MSPHERE
Date : 2023
Catégorie(s)
#ANR-Citation #Genosol #INRAEAuteurs, date et publication :
Auteurs Budiman Minasny , Alex B. McBratney , Dominique Arrouays , Abad Chabbi , Damien J. Field , Peter M. Kopittke , Cristine L. S. Morgan , José Padarian , Cornelia Rumpel
Publication : Environmental Science & Technology
Date : 2023
Volume : 57
Issue : 48
Pages : 19094-19098
Catégorie(s)
#ACBB #ACBB Lusignan #INRAERésumé
Theoretical studies on oceans and large lakes have shown that submesoscale instabilities in frontal zones tend to reduce horizontal density gradients and enhance vertical density gradients, thereby re-stratifying the Surface Mixed Layer (SML). Submesoscale filament dynamics are primarily studied using numerical models and remote sensing imagery. However, in large lakes, this concept remains without substantial field validation, mainly due to the difficulty in conducting the necessary high-resolution water column measurements. Using a procedure we recently developed to predict the time and location of mesoscale and submesoscale features generated by strong wind fields, this work presents direct field evidence demonstrating the role of submesoscale cold filaments in re-stratifying the SML under weakly stratified conditions in a large lake (Lake Geneva). The dynamics of the observed filaments were further investigated with a high-resolution three-dimensional (3D) numerical model and Lagrangian particle-tracking. The numerical model accurately captured the formation of these filaments. The enhancement of thermal stratification strength,
N
2
, reached
O
(10
-5
) s
-2
in areas adjacent to cold filaments under atmospheric cooling and heating conditions. In the pelagic zone (offshore), strong vertical velocities of
O
(100 m d
-1
) were associated with secondary circulation that rapidly transports and accumulates passive particles in the thermocline and hypolimnion layers, as confirmed by Acoustic Doppler Current Profiler (ADCP) backscattering intensity data. The field observations indicate that under weak stratification, Dissolved Oxygen (DO) variability reaches 0.5 mg l
-1
near cold filaments. This documentation of strong vertical motions associated with submesoscale filaments is expected to contribute to the understanding of the vertical exchange of heat, contaminants and oxygen between the atmosphere and the pelagic zone of large lakes, as well as in oceans where carrying out such field measurements is very challenging.
Auteurs, date et publication :
Auteurs Seyed Mahmood Hamze-Ziabari , Mehrshad Foroughan , Ulrich Lemmin , Rafael Sebastian Reiss , David Andrew Barry
Publication : Frontiers in Marine Science
Date : 2023
Volume : 10
Pages : 1200178
Catégorie(s)
#INRAE #OLAAuteurs, date et publication :
Auteurs Raia Silvia Massad , Florence Lafouge , Yang Liu , Raluca Ciuraru , Xavier Leroux , Benjamin Loubet
Date : 2025