Résumé
Agricultural practices should modify the diversity of soil microbes. However, the precise relationships between soil properties and microbial diversity are poorly known. Here, we study the effect of agricultural management on soil microbial diversity and C turnover in tropical grassland of north-eastern Laos. Three years after native grassland conversion into agricultural land, we compared soils from five land use management systems: one till versus two no-till rotational cropping systems, one no-till improved pasture and the natural grassland. Soils were incubated in microcosms during 64 days at optimum temperature and humidity. Bacterial and fungal diversity were evaluated by metagenomic 454-pyrosequencing of 16S and 18SrRNA genes, respectively. Changes in soil respiration patterns were evaluated by monitoring 12C- and 13C-CO2 release after soil amendment with 13C-labelled wheat residues. Results show that residue mineralization increased with bacterial richness and diversity in the tilled treatment 7 days after soil amendment. Native soil organic C mineralization and priming effect increased with fungal richness and diversity in improved pasture and natural grassland. No-till cropping systems represented intermediate situations between tillage and pasture systems. Our findings evidence the potential of controlling soil microbial diversity by agricultural practices to improve soil biological properties. We suggest the promotion of no-till systems as a fair compromise between the need for agriculture intensification and soil ecological processes preservation.
Auteurs, date et publication :
Auteurs Pascal Lienhard , Sébastien Terrat , Olivier Mathieu , Jean Levêque , Nicolas Chemidlin Prévost-Bouré , Virginie Nowak , Tiffanie Régnier , Céline Faivre , Sengphanh Sayphoummie , Khamkéo Panyasiri , Florent Tivet , Lionel Ranjard , Pierre-Alain Maron
Publication : Environmental Chemistry Letters
Date : 2013
Volume : 11
Issue : 4
Pages : 391-398
Catégorie(s)
#Genosol #INRAERésumé
absent
Auteurs, date et publication :
Auteurs Francois Lafolie , Isabelle Cousin , Pierre-Alain Marron , Alain Mollier , Valérie Pot , Nicolas Moitrier , Nathalie Moitrier , Cédric Nouguier
Publication : Revue Forestière Française
Date : 2025
Pages : np
Catégorie(s)
#INRAE #VirtualSoilAuteurs, date et publication :
Auteurs Annette Bérard , Christophe Mazzia , Valérie Sappin-Didier , Line Capowiez , Yvan Capowiez
Publication : Ecological Indicators
Date : 2025
Volume : 40
Pages : 27-33
Catégorie(s)
#INRAE #PROAuteurs, date et publication :
Auteurs Yannick Bayona
Date : 2025
Catégorie(s)
#INRAE #PEARLAuteurs, date et publication :
Auteurs E. Vaudour , J.M. Gilliot , L. Bel , L. Bréchet , D. Hadjar , J. Hamiache , Y. Lemonnier
Publication : International Journal of Applied Earth Observation and Geoinformation
Date : 2025
Volume : 26
Pages : 217-234
Catégorie(s)
#INRAE #PRO #PRO QualiAgroRésumé
An in situ study was performed to investigate the role of zooplankton as a vector of microcystins (MCs) from Planktothrix rubescens filaments to fish during a metalimnic bloom of P. rubescens in Lake Hallwil (Switzerland). The concentrations of MCs in P. rubescens and various zooplanktonic taxa (filter-feeders and predators) were assessed in different water strata (epi-, meta- and hypolimnion) using replicated sampling over a 24-hour survey. The presence of P. rubescens in the gut content of various zooplanktonic taxa (Daphnia, Bosmina and Chaoborus) was verified by targeting the cyanobacterial nucleic acids (DNA). These results highlighted that cyanobacterial cells constitute a part of food resource for herbivorous zooplanktonic taxa during metalimnic bloom periods. Furthermore, presence of MCs in Chaoborus larvae highlighted the trophic transfer of MCs between herbivorous zooplankton and their invertebrate predators. Our results suggest that zooplanktonic herbivores by diel vertical migration (DVM) act as vectors of MCs by encapsulating grazed cyanobacteria. As a consequence, they largely contribute to the contamination of zooplanktonic predators, and in fine of zooplanktivorous whitefish. Indeed, we estimated the relative contribution of three preys of the whitefish (i.e. Daphnia, Bosmina and Chaoborus) to diet contamination. We showed that Chaoborus and Daphnia were the highest contributor as MC vectors in the whitefish diet (74.6 and 20.5% of MC-LR equivalent concentrations, respectively).
Auteurs, date et publication :
Auteurs Benoît Sotton , Jean Guillard , Orlane Anneville , Marjorie Maréchal , Olga Savichtcheva , Isabelle Domaizon
Publication : Science of The Total Environment
Date : 2025
Volume : 466-467
Pages : 152-163
Catégorie(s)
#INRAE #OLAAuteurs, date et publication :
Auteurs Priault Pierrick , Thomas Anaïs , Ndiaye Abdoulaye , Piutti Séverine , Dallé Erwin , Marron Nicolas
Date : 2025
Catégorie(s)
#FORET AgroTCR #INRAERésumé
Double-stranded DNA viruses infecting eukaryotic algae (e.g., phycodnaviruses) and cyanobacteria (e.g., cyanophages) are now recognized as widespread and ubiquitous in aquatic environments. However, both the diversity and functional roles of these viruses in fresh waters are still poorly understood. We conducted a yearlong study in 2011 of the community structure of planktonic virus groups in the upper lit layer of two important freshwater natural ecosystems in France, Lake Annecy (oligotrophic) and Lake Bourget (oligo-mesotrophic). Using PCR-DGGE to target a number of different structural and functional signature genes, i.e.,g20, g23, psbA, polB, and mcp, the phytoplankton viruses were shown to display temporal and spatial variability. There were marked seasonal changes in community structure for all viral groups in Lake Bourget, but only for T4-like myoviruses and psbA-containing cyanophages in Lake Annecy. The multivariate statistical analyses revealed that (1) various environmental factors can directly or indirectly explain the community structure observed for each phytoplankton viral group, and (2) temporal patterns of T4like myovirus community structure were similar between the two lakes. In general, our results (1) suggest that the observed algal virus patterns were associated with significant shifts in phytoplankton biomass and/or structure, which in turn were shaped by the abiotic environment, and (2) support the Bank model proposed by Breitbart and Rohwer (Trends Microbiol 13:278–284, 2005). This study provides new evidence that freshwater lakes contain a significant diversity of algal viruses, and that the distribution of these viruses strongly mirrors that of their hosts.
Auteurs, date et publication :
Auteurs X. Zhong , F. Rimet , S. Jacquet
Publication : Ecological Research
Date : 2025
Volume : 29
Issue : 2
Pages : 271-287
Catégorie(s)
#INRAE #OLAAuteurs, date et publication :
Auteurs Floriane Larras , Bernard Montuelle , Frédéric Rimet , Nathalie Chèvre , Agnès Bouchez
Publication : Ecotoxicology
Date : 2025
Volume : 23
Issue : 6
Pages : 1109-1123
Catégorie(s)
#INRAE #OLAAuteurs, date et publication :
Auteurs Vincent Berthon , Benjamin Alric , Frédéric Rimet , Marie-Elodie Perga
Publication : Freshwater Biology
Date : 2025
Volume : 59
Issue : 8
Pages : 1755-1767