Auteurs, date et publication :
Auteurs Yannick Bayona , Marc Roucaute , Kevin Cailleaud , Laurent Lagadic , Anne Bassères , Thierry Caquet
Publication : Ecotoxicology
Date : 2015
Volume : 24
Issue : 9
Pages : 1976-1995
Catégorie(s)
#INRAE #PEARLRésumé
Springtails (Collembola) are the most abundant arthropods in terrestrial ecosystems and, are considered as key indicators of organic matter turnover and soil functioning. Mixture of tree species are often regarded as a mean to improve tree growth, soil fertility and biodiversity.
Auteurs, date et publication :
Auteurs N. Korboulewsky , C. Heiniger , S. De Danieli , J.J. Brun
Publication : Forest Ecology and Management
Date : 2025
Volume : 482
Pages : 118876
Catégorie(s)
#FORET OPTMix #INRAEAuteurs, date et publication :
Auteurs Yu-Chun Kao , Mark W. Rogers , David B. Bunnell , Ian G. Cowx , Song S. Qian , Orlane Anneville , T. Douglas Beard , Alexander Brinker , J. Robert Britton , René Chura-Cruz , Natasha J. Gownaris , James R. Jackson , Külli Kangur , Jeppe Kolding , Anatoly A. Lukin , Abigail J. Lynch , Norman Mercado-Silva , Rodrigo Moncayo-Estrada , Friday J. Njaya , Ilia Ostrovsky
Publication : Nature Communications
Date : 2025
Volume : 11
Issue : 1
Pages : 2526
Catégorie(s)
#INRAE #OLAAuteurs, date et publication :
Auteurs Katja Klumpp , Juliette M G Bloor , Per Ambus , Jean-François Soussana
Publication : Plant Soil
Date : 2025
Volume : 343
Pages : 97-107
Catégorie(s)
#ACBB #ACBB Theix #INRAERésumé
Forest practices are rapidly becoming mechanised in France, resulting in unknown consequences for the current and long-term functioning and functions of ecosystems. Degradation of forest soil porosity cannot be remediated artificially, and restoration via natural processes is slow and not likely to include deep soil layers, where tree roots take up large amounts of water and nutrients. In 2007 and 2008, two experimental sites were set up in the Lorraine Plateau (France). The soils are Ruptic Luvisols and are classified as highly sensitive to compaction. We observed multiple parameters and studied weakly bound soil solutions, which are known to react to changes in ecosystem functioning. We hypothesised that (i) soil solution chemistry is a relevant indicator to assess soil changes after compaction and dynamics of soil recovery in the decade following compaction, (ii) restoration is greater at the more fertile site and (iii) soil pH is a relevant parameter to explain the behaviour of soil solutions. Our results showed that soil solution concentrations changed drastically after compaction and that restoration was more effective in the less fertile soil than in the more fertile one. Finally, a soil pH threshold of 4.5 was relevant for explaining the behaviour of nitrate, which is particularly useful for monitoring solution geochem istry in these acidic soils. Liming at the less fertile site increased the pH to more than 4.5, which changed the behaviour of nitrate and reinforced the utility of this threshold for explaining soil biogeochemical functioning. Soil solution is a relevant indicator of current soil functioning after compaction; however, this study demon strated that additional information is required to understand its meaning accurately. This study highlights that long-term observation is needed to identify the consequences of soil compaction on long-living ecosystems.
Auteurs, date et publication :
Auteurs J. Ranger , P. Bonnaud , P. Santenoise , B. Zeller , G. Nourrisson , M. Pelletier , D. Gelhaye , A. Legout
Publication : Forest Ecology and Management
Date : 2025
Volume : 499
Pages : 119538
Catégorie(s)
#ANR-Citation #FORET Azerailles-Clermont #INRAE #M-POETERésumé
Organic matter decline and compaction are two major processes of soil degradation. Organic amendment is a current practice to compensate the loss of organic matter, which could in addition contribute to increase soil aggregate stability and limit compaction. Therefore, the objective of this work was to study the effect of multiple physico-chemical stresses, organic amendment (compost of sewage sludge and green waste) addition and soil compaction, on the fate and impact (measured through the urease enzyme activity) of isoproturon. Compost addition and compaction did not significantly affect the fate and impact of isoproturon. The lack of effect of compost can be due to the delay between soil sampling and soil amendment. Compaction had no effect probably because the porosity reduction does not affect the habitable pore space accessible to degrading microorganisms. Nevertheless, isoproturon significantly increased the urease enzyme activity in compacted and not compacted unamended soils contrary to the amended ones. It seems that the organic amendment could act as a buffer with regards to the impact of isoproturon. The results obtained in this work suggest that, in general, the fate and impact of isoproturon in soils will not change following compaction and/or organic amendment addition, neither the corresponding risks for the environment.
Auteurs, date et publication :
Auteurs Laure Mamy , Christian Mougin , Pierre Benoit , Sabine Houot , Agathe Brault , Nathalie Cheviron , Ghislaine Delarue , Valérie Dumeny , Laure Vieublé-Gonod
Publication : Environments
Date : 2020
Volume : 7
Issue : 10
Pages : 79
Catégorie(s)
#BiochemEnv #INRAE #PRO #PRO QualiAgroRésumé
In acidic soils, the fixation of Al in the interlayer spaces of 2:1 clay minerals and the subsequent formation of hydroxyl interlayer minerals (HIMs) are known to reduce soil fertility. The resulting crystal structure of HIMs consist of complex mixed-layer minerals (MLMs) with contrasting relative proportions of expandable, hydroxy-interlayers (HI) and illite layers. The present study aims to experimentally assess the influence of particle size on the formation of such complex HIMs for vermiculite saturated with potassium (K). Based on chemical and structural data, this study reports the dissolution and Al-interlayer occupancy of three size fractions (0.1-0.2, 1-2 and 10-20 mu m) of K-vermiculite, which were obtained at pH = 3 by using stirred flow-through reactors. The Al-interlayer occupancies were ordered 0.1-0.2 mu m < 10-20 mu m < 1-2 mu m even though the dissolution rate (in mol(vermiculite) g(-1) s(-1)) increases with decreasing particle size. For fine particles (0.1-0.2 mu m), a rapid but low Al-interlayer occupancy during the transitory state and a null rate in the steady-state were evidenced and interpreted as indicating (i) a rapid but limited K+ interlayer exchange during the first step of the overall reactions and (ii) a stoichiometric dissolution of the crystal (TOT layer + interlayer) in the steady-state. By contrast, although the stoichiometric dissolution of the TOT layer is reached in the steady-state for the coarsest fractions (10-20 and 1-2 lm), the Al-interlayer occupancies continue to evolve due to the exchange of interlayer K+, which continues to progress for a longer duration. The mechanism of auto-aluminization is interpreted in the present study as multiple processes that involve (i) the dissolution of the mineral under acidic conditions, (ii) the interlayer diffusion of initial interlayer cations and their exchange with those from the aqueous phase and (iii) the fixation of interlayer aluminum. Competition between the kinetics of ion-exchange reactions and that of mineral dissolution is responsible for the above Al-interlayer occupancy order among the particle sizes (i.e., 0.1-0.2 mu m < 10-20 mu m < 1-2 mu m). Moreover, this mechanism may be the cause of complex mineralogical structures such as mixed-layer minerals, which are commonly found in the clay-size fraction of acidic soils. (C) 2016 Elsevier Ltd. All rights reserved.
Auteurs, date et publication :
Auteurs Jean-Christophe Viennet , Fabien Hubert , Emmanuel Tertre , Eric Ferrage , Valentin Robin , Liva Dzene , Carine Cochet , Marie-Pierre Turpault
Publication : Geochimica Et Cosmochimica Acta
Date : 2016
Volume : 180
Pages : 164-176
Catégorie(s)
#FORET Breuil #INRAEAuteurs, date et publication :
Auteurs Lais Gonzaga Gomez , Benjamin Loubet , Florence Lafouge , Raluca Ciuraru , Sandy Bsaibes , Julien Kammer , Pauline Buysse , Brigitte Durand , Jean-Christophe Gueudet , Olivier Fanucci , Olivier Zurfluh , Céline Decuq , François Truong , Valérie Gros , Christophe Boissard
Publication : Atmospheric Environment
Date : 2025
Volume : 266
Pages : 118665
Catégorie(s)
#INRAE #PT-RMSRésumé
This study generated new insight into the effect of bedrock grain sizes on pedogenesis under identical topographic and climatic environment. The physico-chemical and mineralogical properties of two adjacent Typic Dystrochrepts (USDA, 1999) respectively developed from fine and coarse textured granites were compared. This research study was performed in the Morvan Mountains (France). Analysis of the two underlying bedrocks revealed similar chemical and mineralogical properties, with the crystal grain size being the only parameter which differed. In these soils, bedrock played the key role in the particle size fraction distribution, the main factor controlling water retention in the soils. Weathering reactions of clay minerals were more marked in the fine textured granite soil. In this soil, both clay mineral swelling and mica transformation into expansible phyllosilicates were greater compared to the coarse textured granite soil. In the clay fraction of the fine textured granite soil, there were smaller amounts of low crystallised Fe and Al minerals, with higher carbon content in the topsoil, as compared to the coarse granite soil. The exchangeable cation analysis of the fine textured granite soil revealed a higher proportion of base saturation and a smaller proportion of Al-tit than in coarse textured granite soil which could be explained by preferential leaching of Al cations. The decrease in exchangeable Al, the higher swelling of the smectitic layer and the smaller proportion of Fe and Al-oxy-hydroxides could be explained by the complexing acid conditions, which increased mineral weathering and Al leaching. The higher water retention increased the time of contact between minerals and the soil solution, and the higher carbon content in the topsoil could have enhanced the complexing acid conditions. (C) 2015 Elsevier B.V. All rights reserved.
Auteurs, date et publication :
Auteurs L. Mareschal , M. P. Turpault , J. Ranger
Publication : Geoderma
Date : 2015
Volume : 249
Pages : 12-20
Catégorie(s)
#FORET Breuil #INRAERésumé
Background: Over the last 30 years, extensive studies have revealed the crucial roles played by microbes in aquatic ecosystems. It has been shown that bacteria, viruses and protozoan grazers are dominant in terms of abundance and biomass. The frequent interactions between these microbiological compartments are responsible for strong trophic links from dissolved organic matter to higher trophic levels, via heterotrophic bacteria, which form the basis for the important biogeochemical roles of microbial food webs in aquatic ecosystems. To gain a better understanding of the interactions between bacteria, viruses and flagellates in lacustrine ecosystems, we investigated the effect of protistan bacterivory on bacterial abundance, production and structure [determined by 16S rRNA PCR-DGGE], and viral abundance and activity of two lakes of contrasting trophic status. Four experiments were conducted in the oligotrophic Lake Annecy and the mesotrophic Lake Bourget over two seasons (early spring vs. summer) using a fractionation approach. In situ dark vs. light incubations were performed to consider the effects of the different treatments in the presence and absence of phototrophic activity.
Results: The presence of grazers (i.e. < 5-μm small eukaryotes) affected viral production positively in all experiments, and the stimulation of viral production (compared to the treatment with no eukaryotic predators) was more variable between lakes than between seasons, with the highest value having been recorded in the mesotrophic lake (+30%). Viral lysis and grazing activities acted additively to sustain high bacterial production in all experiments. Nevertheless, the stimulation of bacterial production was more variable between seasons than between lakes, with the highest values obtained in summer (+33.5% and +37.5% in Lakes Bourget and Annecy, respectively). The presence of both predators (nanoflagellates and viruses) did not seem to have a clear influence upon bacterial community structure according to the four experiments.
Conclusions: Our results highlight the importance of a synergistic effect, i.e. the positive influence of grazers on viral activities in sustaining (directly and indirectly) bacterial production and affecting composition, in both oligotrophic and mesotrophic lakes.
Auteurs, date et publication :
Auteurs Lyria Berdjeb , Thomas Pollet , Isabelle Domaizon , Stéphan Jacquet
Publication : BMC Microbiology
Date : 2025
Volume : 11
Issue : 1
Pages : 88