Les phénols de la lignine et le 13C, traceurs de l'origine des matières organiques du sol

Abstract In spodosols of Gascony (France), conversion of maritime pine stands into maize cropping leads to an incorporation of maize organic matter, which changed the isotopic (δ13C) and phenolic signature in A and L horizons of soil. Hydrolysis of phenol lignin in forests and cultivated soils showed the predominance of vanillic units under forest and the early but moderate incorporation of cinnamic acids. Incorporation of syringic units appeared higher, related to a large maize production of stable syringic phenols. Syringic units represented a long-term marker of maize inputs in soils, whereas vanillic units revealed the degradation of forest organic matter.

Diversité des communautés microbiennes telluriques à l'échelle du territoire national

Communication orale - résumé Session 5 : sols, biodiversité, écologie fontionnelleCommunication orale - résumé Session 5 : sols, biodiversité, écologie fontionnelle; absent

Caractérisation et dynamique du carbone organique du sol

Rapport final des recherches engagées dans le cadre du GIP ECOFOR "Fonctionnement de l'écosystème forestier landais"*INRA Orléans, Documentation de centre, Ardon 45166 Olivet Diffusion du document : INRA Orléans, Documentation de centre, Ardon 45166 Olivet; National audience

Observatoire de la qualité des sols. Rapport sur les travaux 1995-1998

*INRA Orléans, Documentation de centre, Ardon 45166 Olivet Diffusion du document : INRA Orléans, Documentation de centre, Ardon 45166 Olivet; National audience

Biogeographical patterns of soil molecular microbial biomass as influenced by soil characteristics and management

Aim The spatial organization of soil microbial communities on large scales and the identification of environmental factors structuring their distribution have been little investigated. The overall objective of this study was to determine the spatial patterning of microbial biomass in soils over a wide extent and to rank the environmental filters most influencing this distribution.

Bacterial social networks across the French National territory

EA SPE BIOME GENOSOL UB Agrosup EA SPE BIOME GENOSOL UB AgrosupEASPEBIOMEGENOSOL UB Agrosup; New generation sequencing evidenced that soil houses a huge microbial biodiversity. Based on these observations, it is now possible to better describe the spatial distribution of soil microbial communities, to study the ecological processes involved (environmental selection, dispersal limitations), and to compute the data to define the ecological attributes of soil microbial taxa. These huge datasets also offer the opportunity to study how soil microbial populations are interrelated. With this study, we revealed the first soil bacterial "social" network across French national territory based on 2,20…

Procedures and protocol for soil biodiversity monitoring : ‘RMQS-Biodiv', a french pilot area experience.

PosterFR2116Poster

Clear-cutting effects on soil organic matter content and quality in a temperate maritime pine forest a spatial and temporal assessment

International audience

Validation and application of a PCR primer set to quantify fungal communities in the soil environment by real-time quantitative PCR

Fungi constitute an important group in soil biological diversity and functioning. However, characterization and knowledge of fungal communities is hampered because few primer sets are available to quantify fungal abundance by real-time quantitative PCR (real-time Q-PCR). The aim in this study was to quantify fungal abundance in soils by incorporating, into a real-time Q-PCR using the SYBRGreen (R) method, a primer set already used to study the genetic structure of soil fungal communities. To satisfy the real-time Q-PCR requirements to enhance the accuracy and reproducibility of the detection technique, this study focused on the 18S rRNA gene conserved regions. These regions are little affec…

Connaître les sols français pour mieux les gérer

National audience

Organic carbon dynamics in soil particle-size separates of sandy Spodosols when forest is cleared for maize cropping

Summary In southwest France, much of the forest lands on sandy Spodosols has been converted to continuous maize cropping in the last few decades. To evaluate the impacts of such change on the content and properties of the soil organic matter, we compared the amount of organic carbon and 13C natural abundance in soil and particle-size separates at three locations, selected on the basis of different contents of 0–50 μm particles (clay + silt). After three decades of cultivation, the amount of carbon from the forest pools (Cf) decreased by about 60%, attributable mainly to easily degradable material in sand-sized fractions (−70%). However, a recalcitrant residue remained in soil at a constant …

Bacterial "social" network in french soils : a Metagenomics insight

EA SPE BIOME GENOSOL UB Agrosup EA SPE BIOME GENOSOL UB AgrosupEASPEBIOMEGENOSOL UB Agrosup; New generation sequencing evidenced that soil houses a huge microbial biodiversity. Based on these observations, it is now possible to better describe the spatial distribution of soil microbial communities, to study the ecological processes lying behind (environmental selection, dispersal limitations), and to mine the data to define the ecological attributes of soil microbial taxa. These huge datasets also offer the opportunity to study how soil microbial populations are interrelated. The objective of this study was to design the first bacterial "social" network in french soils to characterize how b…

Le projet ECOMIC-RMQS ou comment faire de la microbiogéographie à l'échelle de la France

Innovative tools to diagnose the impact of land use practices on soil microbial communities

International audience; Preservation and sustainable use of soil biological communities represent major challenges in the current agroecological context. Indeed, most of soil ecosystem services results from biological functions particularly driven by taxonomic and functional assemblages of microbiological communities (i.e. nutrient cycling, soil aggregation, depollution, etc.). Consequently, soil microbial communities are logical candidates as effective indicators of soil quality and sustainability. But, good biological indicators must be associated with references that encompass an operating range of measured values that allow performing the desired diagnosis. Even if numerous studies have…

Biogeography of soil microbial communities: a review and a description of the ongoing french national initiative

International audience; Microbial biogeography is the study of the distribution of microbial diversity on large scales of space and time. This science aims at understanding biodiversity regulation and its link with ecosystem biological functioning, goods and services such as maintenance of productivity, of soil and atmospheric quality, and of soil health. Although the initial concept dates from the early 20th century (Beijerinck (1913) De infusies en de ontdekking der backterien, in: Jaarboek van de Knoniklijke Akademie van Wetenschappen, Muller, Amsterdam), only recently have an increasing number of studies have investigated the biogeographical patterns of soil microbial diversity. A such …

Relevance of different soil fauna and microflora groups in the monitoring of soil biodiversity: RMQS-Biodiv, a French pilot area experience.

PosterFR2116Poster

Is soil an island for bacteria ? Contribution of the soil bacterial taxa area relationship unsing new generation sequencing

EA SPE BIOME GENOSOL; International audience

Conclusion générale

Effets des techniques culturales sans labour (TCSL) sur le stockage de carbone dans le sol

Water-extractable organic matter linked to soil physico-chemistry and microbiology at the regional scale

10 pages; International audience; A better understanding of the links between dissolved organic matter and biogeochemical processes in soil could help in evaluating global soil dynamics. To assess the effects of land cover and parental material on soil biogeochemistry, we studied 120 soil samples collected from various ecosystems in Burgundy, France. The potential solubility and aromaticity of dissolved organic matter was characterised by pressurised hot-water extraction of organic carbon (PH-WEOC). Soil physico-chemical characteristics (pH, texture, soil carbon and nitrogen) were measured, as was the δ13C signature both in soils and in PH-WEOC. We also determined bacterial and fungal abund…

Soil biodiversity monitoring in Europe : ongoing activities and challenges

International audience; The increasing interest in soil biodiversity and its protection includes both the biodiversity conservation issues and the mostly unknown economic and ecological values of services provided by soil biodiversity. Inventory and monitoring are necessary tools for the achievement of an adequate level of knowledge regarding soil biodiversity status and for the detection of biodiversity hot spots as well as areas where current levels of biodiversity are under threat of decline. In this paper the main tools and methodological approaches for soil biodiversity measurement are presented. Technical aspects related to the inventory and monitoring activities at a large spatial sc…

Organic carbon dynamics in soil particle-size separates of sandy spodosols when forest is cleared for maize cropping

21 ref.; International audience

Le RMQS au service de l'écologie microbienne des sols français

International audience; L'écologie microbienne des sols a longtemps été reconnue comme souffrant d'un certain manque de généricité car les études ont souvent été menées à l'échelle de parcelles voire de petits territoires et avec peu de sites investigués. Il en résulte un manque de connaissances sur les processus de distribution des populations et de la régulation de la diversité microbienne à grande échelle face à des modifications environnementales dues aux usages des terres ou au changement climatique. Dans les années 2000, le RMQS, avec 2 240 sites échantillonnés sur toute la France, a représenté une opportunité unique pour étudier les micro-organismes du sol sur de grandes échelles spa…

Mapping, understanding and predicting soil microbial diversity across France

International audience; Microorganisms are extremely abundant and diverse in soils. Their huge diversity is central in soil functioning regarding the diversity of functions it supports (mineralization, detoxification, stability of soil…) and is more and more studied, especially in a context of increasing pressure on soil resources. Conversely to macroorganisms whose distribution on a wide scale has been studied for over a century, spatial scaling and determinism distribution of soil microorganisms on nationwide scale still needs to be documented, notably to decipher the environmental filters shaping these communities. communities were investigated at the scale of France to characterize thei…

Predictive models of abundance and diversity of soil microbial communities

International audience

Soil bacterial interaction networks on a wide scale

EA BIOME INRA AGROSUP UB; International audience

Mapping field-scale spatial patterns of size and activity of the denitrifier community

International audience; There is ample evidence that microbial processes can exhibit large variations in activity on a field scale. However, very little is known about the spatial distribution of the microbial communities mediating these processes. Here we used geostatistical modelling to explore spatial patterns of size and activity of the denitrifying community, a functional guild involved in N-cycling, in a grassland field subjected to different cattle grazing regimes. We observed a non-random distribution pattern of the size of the denitrifier community estimated by quantification of the denitrification genes copy numbers with a macro-scale spatial dependence (6–16 m) and mapped the dis…

Impacts des TCSL sur les gaz à effet de serre

Mapping spatial patterns of denitrifiers for bridging community ecology and microbial processes along environmental gradients

International audience; While there is ample evidence that microbial processes can exhibit large variations at a field scale, very little is known about the spatial distribution of the communities mediating these processes. The objective of this study was to explore spatial patterns of size and activity of the denitrifying community, a functional guild involved in N-cycling, in a grassland field subjected to different cattle grazing regimes. We used geostatistical modeling to map the distribution of size and activity of the denitrifier community in the pasture. Size of the denitrifier community was estimated by PCR quantification of the denitrification gene copy numbers while its activity w…

Comparaison de l'arisa et du séquençage haut débit pour l'étude des processus de diversification des communautés microbiennes du sol

EA SPE EcolDur GenoSol; National audience

Biogeographical patterns of soil bacterial communities.

International audience; This study provides the first maps of variations in bacterial community structure on a broad scale based on genotyping of DNA extracts from 593 soils from four different regions of France (North, Brittany, South-East and Landes). Soils were obtained from the soil library of RMQS (Réseau de Mesures de la Qualité des Sols = French soil quality monitoring network). The relevance of a biogeographic approach for studying bacterial communities was demonstrated by the great variability in community structure and specific geographical patterns within and between the four regions. The data indicated that the distribution of bacterial community composition might be more relate…

Influence du type de sol et du mode d’occupation des sols sur la quantité d’ADN extraite et la densité des communautés bactériennes indigènes

National audience

Determinants of the distribution of nitrogen-cycling microbial communities at the landscape-scale

Little information is available regarding the landscape-scale distribution of microbial communities and its environmental determinants. However, a landscape perspective is needed to understand the relative importance of local and regional factors and land management for the microbial communities. In this manuscript, we investigated the distribution of functional microbial communities involved in N-cycling and of the total bacterial and crenarchaeal communities over 107 sites using a grid with a 16 km lag distance within Burgundy, a 31 500 km2 region in France. After quantifying the abundances of the total bacterial, crenarchaeal, nitrate-reducing, denitrifying and ammonia-oxidizing communit…

Mapping field-scale spatial distribution patterns of size and activity of the denitrifier community

International audience

Measurement, Reporting and Verification (MRV) of soil carbon

Measurement, Reporting and Verification (MRV) of soil carbon. International Scientific Conference Our under Common Climate Future Change

Distribution et déterminisme de la diversité des communautés de champignons telluriques à l'échelle de trois régions françaises

aeres : C-ACTN; National audience; no abstract

Spatial patterns of bacterial taxa in nature reflect ecological traits of deep branches of the 16S rRNA bacterial tree

International audience; Whether bacteria display spatial patterns of distribution and at which level of taxonomic organization such patterns can be observed are central questions in microbial ecology. Here we investigated how the total and relative abundances of eight bacterial taxa at the phylum or class level were spatially distributed in a pasture by using quantitative PCR and geostatistical modelling. The distributions of the relative abundance of most taxa varied by a factor of 2.5–6.5 and displayed strong spatial patterns at the field scale. These spatial patterns were taxon-specific and correlated to soil properties, which indicates that members of a bacterial clade defined at high t…

A review of the world's soil museums and exhibitions

The soil science community needs to communicate about soils and the use of soil information to various audiences, especially to the general public and public authorities. In this global review article, we synthesis information pertaining to museums solely dedicated to soils or which contain a permanent exhibition on soils. We identified 38 soil museums specifically dedicated to soils, 34 permanent soil exhibitions, and 32 collections about soils that are accessible by appointment. We evaluate the growth of the number of museums since the early 1900s, their geographical distribution, their contents, and their attendance. The number of museums has been continuously growing since the early 190…

Le potentiel de stockage de carbone du semis direct en comparaison d'autres techniques culturales

International audience

Contrasting Spatial Patterns and Ecological Attributes of Soil Bacterial Taxa across French National Territory

EA SPE BIOME GENOSOL UB UB Agrosup EA SPE BIOME GENOSOL UB UB AgrosupEASPEBIOMEGENOSOLUB UB Agrosup; Even though recent studies have clarified the influence of environmental filters on bacterial community diversity, those constraining bacterial populations variations remain unclear. In consequence, our ability to understand the ecological attributes of soil bacteria and to predict microbial community response to environmental stress is therefore limited. Here, we characterized the bacterial community composition and the various bacterial taxonomic groups constituting the community across the French country, by using a 16x16 km systematic grid representing 1825 sites to precisely decipher th…

Carbohydrate dynamics in particle-size fractions of sandy spodosols following forest conversion to maize cropping

International audience; In southwest France, much of the forested land on sandy spodosols has been converted to continuous maize cropping in the last few decades. To evaluate the impacts of this change on soil organic matter properties, we compared total organic C and neutral and amino sugars content in whole soil and particle size separates of two forested, and five related sites that had been either clear-cut for 12 and 18 mo, or cultivated to maize for 4-22yr. Soil carbohydrates accounted for 4-7% of the total organic C across all sites. Soil organic C contents of clear-cut and cultivated sites were only 57-79% of the average value measured in forested sites. Accordingly, carbohydrate co…

Biogeographical patterns of soil bacterial diversity at the scale of France

EA SPE BIOME GENOSOLEASPEBIOMEGENOSOL; Biogeographical patterns of soil bacterial diversity at the scale of France. 16. International Symposium on Microbial Ecology - ISME16

Ecomic - RMQs : Cartographie de la diversité microbienne des sols à l'échelle de la France

aeres : C-AFF; National audience; no abstract

Mapping spatial patterns of denitrifiers for bridging community ecology and microbial processes along environmental gradients

While there is ample evidence that microbial processes can exhibit large variations at a field scale, very little is known about the spatial distribution of the communities mediating these processes. The objective of this study was to explore spatial patterns of size and activity of the denitrifying community, a functional guild involved in N-cycling, in a grassland field subjected to different cattle grazing regimes. We used geostatistical modeling to map the distribution of size and activity of the denitrifier community in the pasture. Size of the denitrifier community was estimated by PCR quantification of the denitrification gene copy numbers while its activity was estimated by measurin…

How build up soil bacterial co-occurrence networks from wide spatial scalesampling?

National audience; Although land use drives soil bacterial diversity and community structure, littleinformation about the bacterial interaction networks is available. Here, we investigatedbacterial co-occurrence networks in soils under different types of land use (forests, grasslands,crops and vineyards) by sampling 1798 sites in the French Soil Quality Monitoring Networkcovering all of France. An increase in bacterial richness was observed from forests tovineyards, whereas network complexity respectively decreased from 16,430 links to 2,046.However, the ratio of positive to negative links within the bacterial networks ranged from 2.9 inforests to 5.5 in vineyards. Networks structure was ce…

Monitoring microbial diversity in European soils: ongoing projects and challenges

SPEEcolDurGenoSolCT3communication orale invitée, résumé et slides; According to the Convention of Biological Diversity (Rio de Janeiro, 1992), biodiversity is the variation in life from genes to species, communities, ecosystems, and landscapes. Soils represent a huge reservoir of biodiversity which varies in terms of taxonomic richness, relative abundance and distribution according to soil types, climatic conditions, vegetation and land uses. The key functions supporting ecosystem services as identified in the Millennium Ecosystem Assessment (MEA, 2005) largely depend upon organisms that inhabit the soil. Thus, the design and implementation of a sustainable soil management strategy requires…