Résumé
Agriculture is the main source of terrestrial emissions of N2O, a potent greenhouse gas and the main cause of ozone layer depletion. The reduction of N2O into N2 by microorganisms carrying the nitrous oxide reductase gene (nosZ) is the only biological process known to eliminate this greenhouse gas. Recent studies showed that a previously unknown clade of N2O-reducers was related to the capacity of the soil to act as an N2O sink, opening the way for new strategies to mitigate emissions. Here, we investigated whether the agricultural practices could differently influence the two N2O reducer clades with consequences for denitrification end-products. The abundance of N2O-reducers and producers was quantified by real-time PCR, and the diversity of both nosZ clades was determined by 454 pyrosequencing. Potential N2O production and potential denitrification activity were used to calculate the denitrification gaseous end-product ratio. Overall, the results showed limited differences between management practices but there were significant differences between cropping systems in both the abundance and structure of the nosZII community, as well as in the [rN2O/r(N2O+N2)] ratio. More limited differences were observed in the nosZI community, suggesting that the newly identified nosZII clade is more sensitive than nosZI to environmental changes. Potential denitrification activity and potential N2O production were explained mainly by the soil properties while the diversity of the nosZII clade on its own explained 26% of the denitrification end-product ratio, which highlights the importance of understanding the ecology of this newly identified clade of N2O reducers for mitigation strategies.
Auteurs, date et publication :
Auteurs Luiz Domeignoz-Horta1 , Aymé Spor , David Bru , Marie-Christine Breuil , Florian Bizouard , Joel Leonard , Laurent Philippot
Publication : Frontiers in Microbiology
Date : 2025
Volume : 6
Catégorie(s)
#ACBB #ACBB Mons #INRAEAuteurs, date et publication :
Auteurs C Rumpel , A Crème , PT Ngo , G Velásquez , ML Mora , A Chabbi
Publication : Journal of soil science and plant nutrition
Date : 2025
Volume : 15
Issue : 2
Pages : 353–371
Catégorie(s)
#ACBB #ACBB Lusignan #INRAEAuteurs, date et publication :
Auteurs Pottier G. , Texier Q. , L. Beaulaton , F. Marchand , D. Azam , Vigneron T.
Date : 2025
Pages : 19
Catégorie(s)
#INRAE #PEARLRésumé
Understanding how plants are constructed—i.e., how key size dimensions and the amount of mass invested in different tissues varies among individuals—is essential for modeling plant growth, carbon stocks, and energy fluxes in the terrestrial biosphere. Allocation patterns can differ through ontogeny, but also among coexisting species and among species adapted to different environments. While a variety of models dealing with biomass allocation exist, we lack a synthetic understanding of the underlying processes. This is partly due to the lack of suitable data sets for validating and parameterizing models. To that end, we present the Biomass And Allometry Database (BAAD) for woody plants. The
BAAD contains 259 634 measurements collected in 176 different studies, from 21 084 individuals across 678 species. Most of these data come from existing publications. However, raw data were rarely made public at the time of publication. Thus, the BAAD contains data from different studies, transformed into standard units and variable names. The transformations were achieved using a common workflow for all raw data files. Other features that distinguish the BAAD are: (i) measurements were for individual plants rather than stand averages; (ii) individuals spanning a range of sizes were measured; (iii) plants from 0.01– 100 m in height were included; and (iv) biomass was estimated directly, i.e., not indirectly via allometric equations (except in very large trees where biomass was estimated from detailed sub-sampling). We included both wild and artificially grown plants. The data set contains the following size metrics: total leaf area; area of stem cross-section including sapwood, heartwood, and bark; height of plant and crown base, crown area, and surface area; and the dry mass of leaf, stem, branches, sapwood, heartwood, bark, coarse roots, and fine root tissues. We also report other properties of individuals (age, leaf size, leaf mass per area, wood density, nitrogen content of leaves and wood), as well as information about the growing environment (location, light, experimental treatment, vegetation type) where available. It is our hope that making these data available will improve our ability to understand plant growth, ecosystem dynamics, and carbon cycling in the world’s vegetation
Auteurs, date et publication :
Auteurs D.-S. Falster , R.-A. DUURSMA , MASAE I-I , D.-R. BARNECHE , R.-G. FITZJOHN , A. VA ˚ RHAMMAR , M. AIBA , M. ANDO , N.-I. ANTEN , M.-J. ASPINWALL , J.-L. BALTZER , C. BARALOTO , M. BATTAGLIA , J.-J. BATTLES , B. BOND-LAMBERTY , M. VAN BREUGEL , J. CAMAC , Y. CLAVEAU , L. COLL , M. DANNOURA
Publication : Ecology
Date : 2025
Volume : 96
Issue : 5
Pages : 1445
Catégorie(s)
#CIRAD #FORET Itatinga #INRAEAuteurs, date et publication :
Auteurs L. Beaumelle , F. Gimbert , M. Hedde , A. Guérin , I. Lamy
Publication : Science of The Total Environment
Date : 2025
Volume : 520
Pages : 136-145
Catégorie(s)
#INRAE #PRO #PRO Colmar #PRO QualiAgroRésumé
Mixing species has been proposed as a forest management option to mitigate the effects of the increase in summer drought episodes predicted by climate change models in temperate zones. Studying how the relationship between tree rings and summer drought episodes is modified by species mixture is of primary importance in this context. Based on a dendroclimatology study, we (i) qualified and quantified the relationship between ring width (RW) or mean ring density (MRD) and soil water deficit (SWD) in a ring-porous species, Quercus petraea, and a coniferous species, Pinus sylvestris, and (ii) determined if the relationships between tree ring characteristics and SWD are modified in mixtures. We found interspecific differences in RW patterns depending on the seasonality of the drought periods: RW in Q. petraea responded mainly to SWD from May to July, and RW in P. sylvestris to SWD from May to September. The ring-width of both species was strongly reduced by SWD; however, inter-specific differences in response to SWD seasonality triggered RW variations of opposite directions between the two species, for several years. In contrast, MRD for both species was dependent on the SWD from June to July. MRD in Q. petraea increased slightly with SWD whereas MRD in P. sylvestris decreased strongly with SWD. The relationship between RW and SWD was not modified in mixtures compared to pure stands. We found that the effect of SWD on MRD was stronger in mixtures. The impact of SWD on species may be worsened in mixtures, but mixture of species with different growth sensitivities to the seasonality of the drought periods and to the drought intensity might help to buffer the effects of climatic fluctuations on the overall mixed stands productivity compared to pure stands.
Auteurs, date et publication :
Auteurs Maude Toïgo , Patrick Vallet , Valène Tuilleras , François Lebourgeois , Philippe Rozenberg , Sandrine Perret , Benoit Courbaud , Thomas Perot
Publication : Forest Ecology and Management
Date : 2025
Pages : 10
Catégorie(s)
#FORET OPTMix #INRAERésumé
Microviridae is a subset of single-stranded DNA (ssDNA) viruses infecting bacteria. This group of phages has been previously observed to be very abundant (representing >90% of the total known viral metagenomic sequences) in Lake Bourget. However, this observation was made only during one period (in summer) and from a single sample collected at a single depth (near surface). This result suggests the importance of these viruses, poorly examined thus far, especially in fresh waters. In this study, performed on the two largest natural lakes in France (e.g. Lakes Annecy and Bourget), Microviridae structure was determined each month throughout the year (2011) using PCR-DGGE, with primers that target the major-capsid-protein-encoding gene VP1; cloning/sequencing was used to investigate their diversity. Our results confirm that Microviridae are diverse in peri-alpine lakes and are mainly represented by gokushoviruses. We also found for the first time ssDNA viruses belonging to Alpavirinae, another subfamily within Microviridae recently proposed by Krupovic and Forterre (2011), generally prophages infecting members of the Phylum Bacteroidetes. Our data also support highly variable community composition and dynamics of individual components whose patterns were different between lakes, suggesting distinct host communities and/or abiotic influences between the two ecosystems. We point out that most of the major observed ssDNA Microviridae viruses display boom-bust patterns (with a sharp increase/decline) in their dynamics, with high relative abundances, suggesting brutal control of hosts and rapid regulation of the host community structure.
Auteurs, date et publication :
Auteurs Xu Zhong , Baptiste Guidoni , Louis Jacas , Stéphan Jacquet
Publication : Research in Microbiology
Date : 2025
Volume : 166
Issue : 8
Pages : 644-654
Catégorie(s)
#INRAE #OLAAuteurs, date et publication :
Auteurs Mylène Hugoni , Isabelle Domaizon , Najwa Taib , Corinne Biderre-Petit , Hélène Agogué , Pierre E. Galand , Didier Debroas , Isabelle Mary
Publication : Environmental Microbiology Reports
Date : 2025
Volume : 7
Issue : 2
Pages : 321-329
Catégorie(s)
#INRAE #OLARésumé
Meteoric 10Be, due to its high affinity with soil and sediment particles, is widely used in geomorphologic and environmental studies attempting to evaluate the soil production/denudation rates or soil ages up to 107 years. However, the evolution of the 10Be distribution as a function of depth is poorly known in soils as revealed by recent reviews (Graly et al., 2010; Willenbring and von Blanckenburg, 2010). In this study, 10Be concentrations in the bulk and the 0–2 μm (lutum) granulometric fraction of samples along Luvisols profiles developed from loess in Northern France have been measured. The bulk 10Be concentrations are significantly higher in one of the three sites, likely reflecting differences in the inherited 10Be concentrations of the loess parent material as well as in the accumulation rates of the later. However, the bulk 10Be concentrations along all profiles are significantly correlated with the lutum (0–2 μm fraction) content, the maximum 10Be concentrations being evidenced in the Bt-horizon. Dominant adsorption of 10Be to the lutum has been furthermore corroborated by the mass-balance calculations with as much as 79.8 ± 9.0% of 10Be being associated with the lutum. Contrary to the bulk 10Be concentrations, the lutum 10Be concentrations showed several maxima coinciding with shifts in the coarse to fine silt ratio. This was interpreted as a change in the loess deposit dynamic. Finally, using numerical modeling approach based on the advection-diffusion equation, an average downward migration of 10Be by clay translocation was estimated. It ranges from 0.01 to 0.08 cm yr−1. Inherited 10Be in the loess parent material represented from 64 to 71% of the total 10Be content in the simulated soils. Vertical 10Be distributions and their maximum concentrations in the Bt-horizon thus mainly result from redistribution of the inherited 10Be by clay translocation and bioturbation.
Auteurs, date et publication :
Auteurs M. Jagercikova , S. Cornu , D. Bourlès , P. Antoine , M. Mayor , V. Guillou
Publication : Quaternary Geochronology
Date : 2015
Volume : 27
Pages : 11-21
Catégorie(s)
#ACBB #ACBB Mons #INRAE #PROAuteurs, date et publication :
Auteurs Jean-Marc Roussel , Jean-Marc Paillisson , Anne Tréguier , Eric Petit , Marc Cadotte
Publication : Journal of Applied Ecology
Date : 2015
Volume : 52
Issue : 4
Pages : 823-826