Résumé
Abstract
Grassland management effects on soil organic carbon storage under future climate are unknown. Here we examine the impact of ley grassland durations in crop rotations on soil organic carbon in temperate climate from 2005 to 2100, considering two IPCC scenarios, RCP4.5 and RCP8.5, with and without atmospheric CO
2
enhancements. We used the DailyDayCent model and a long-term experiment to show that ley grasslands increase soil organic carbon storage by approximately 10 Mg ha
−1
over 96 years compared with continuous cropping. Surprisingly, extending ley duration from 3 to 6 years does not enhance soil organic carbon. Furthermore, in comparison with non-renewed grasslands, those renewed every three years demonstrated a notable increase in soil organic carbon storage, by 0.3 Mg ha
−1
yr
−1
. We concluded that management of ploughing and renewal intervals is crucial for maximizing soil organic carbon stocks, through balancing biomass carbon inputs during regrowth and carbon losses through soil respiration.
Auteurs, date et publication :
Auteurs Teng Hu , Sparkle L. Malone , Cornelia Rumpel , Abad Chabbi
Publication : Communications Earth & Environment
Date : 2024
Volume : 5
Issue : 1
Pages : 38
Catégorie(s)
#ACBB #ACBB Lusignan #ANR-Citation #INRAEAuteurs, date et publication :
Auteurs M. Christina , Le Maire G , P. Battie-Laclau , Nouvellon Y , Bouillet J-P , Jourdan C , de Moraes Gonçalves J-L-M , J.-P. Laclau
Publication : Global Change Biology
Date : 2025
Volume : 21
Pages : 2022-2039
Catégorie(s)
#CIRAD #FORET Itatinga #INRAEAuteurs, date et publication :
Auteurs Robert I. Griffiths , Bruce C. Thomson , Pierre Plassart , Hyun S. Gweon , Dorothy Stone , Rachael E. Creamer , Philippe Lemanceau , Mark J. Bailey
Publication : Applied Soil Ecology
Date : 2025
Volume : 97
Pages : 61-68
Catégorie(s)
#Genosol #INRAERésumé
Local tree density may vary in young Eucalyptus plantations under the effects of environmental conditions or inadequate management, and these variations need to be mapped over large areas as they have a significant impact on the final biomass harvested. High spatial resolution optical satellite images have the potential to provide crucial information on tree density at an affordable cost for forest management. Here, we test the capacity of this promising technique to map the local density of young and small Eucalyptus trees in a large plantation in Brazil. We use three Worldview panchromatic images acquired at a 50 cm resolution on different dates corresponding to trees aged 6, 9 and 13 months and define an overall accuracy index to evaluate the quality of the detection results. The best agreement between the local densities obtained by visual detection and by marked point process modeling was found at 9 months, with only small omission and commission errors and a stable 4% underestimation of the number of trees across the density gradient. We validated the capability of the MPP approach to detect trees aged 9 months by making a comparison with local densities recorded on 112 plots of similar to 590 m(2) and ranging between 1360 and 1700 trees per hectare. We obtained a good correlation (r(2) = 0.88) with a root mean square error of 31 trees/ha. We generalized detection by computing a consistent map over the whole plantation. Our results showed that local tree density was not uniformly distributed even in a well-controlled intensively-managed Eucalyptus plantation and therefore needed to be monitored and mapped. Use of the marked point process approach is then discussed with respect to stand characteristics (canopy closure), acquisition dates and recommendations for algorithm parameterization. (c) 2012 Elsevier B.V. All rights reserved.
Auteurs, date et publication :
Auteurs J. Zhou , C. Proisy , X. Descombes , G. Le Maire , Y. Nouvellon , J.-L. Stape , G. Viennois , J. Zerubia , P. Couteron
Publication : Forest Ecology and Management
Date : 2013
Volume : 301
Pages : 129-141
Catégorie(s)
#CIRAD #FORET Itatinga #INRAERésumé
Short-rotation plantations are extending worldwide due to the increased demand for pulp and wood. Reliable estimations of recent expansion of short-rotation plantation areas and associated land use changes are a prerequisite to assess their environmental impact on regional carbon and water cycles, and on climate. A binary classification methodology using MODerate resolution Imaging Spectroradiometer (MODIS) 16-day 250 m NDVI time series was developed and applied to classify Eucalyptus plantations across Brazil. The identification of Eucalyptus plantations specific patterns in the timeserieswas based on the calculation ofmatching functions between theNDVI time series and a ~2 years long reference time series. Among the seven tested matching functions, the bounding envelope
was the most successful. This method was robust to residual noise on the NDVI time series, and a threshold coefficient for the binary classification was adjusted using an omission-commission criteria.With this method, it was possible to detect any presence of Eucalyptus between 2003 and 2009 at monthly time-steps, including the periods of bare soils between two rotations that are typically 6–7 years long. The dates of first afforestation, of clear-cut at the end of a rotation, and of re-planting at the beginning of a new rotation were retrieved from the NDVI time series with a precision of ~66 days. The final almost continuous tri-dimensional map (space and time) was validated with three different datasets, from local to regional data. All three datasets gave similarly high global accuracy statistics, but a global underestimation of Eucalyptus areas compared to large scales census was observed. Discrepancies and way to improve the Eucalyptus area estimates were discussed in this study. The developed methodology could be applied to other short-rotation tree plantations.
Auteurs, date et publication :
Auteurs G. Le Maire , S. Dupuy , Y. Nouvellon , R. Araujo Loos , R. Hakamada
Publication : Remote Sensing of Environment
Date : 2025
Volume : 152
Pages : 136-149
Catégorie(s)
#CIRAD #FORET Itatinga #INRAERésumé
Organic waste products (OWP) application to crop lands makes possible nutrients recycling. However, it can result in long-term accumulation of trace elements (TE) in soils. The present study aimed at (i) assessing the impact of regular applications of urban composts and manure on the TE contents of topsoils and crops in a long-term field experiment, (ii) comparing the TE mass balances with the stock variations of TE in soils, and (iii) proposing a prospective evaluation of this practice, based on estimated soil safe threshold values and simulations of soil TE accumulation for 100 years. In the long-term field experiment, physicochemical properties and TE contents (Cd, Cr, Cu, Hg, Ni, Pb and Zn) have been measured in OWP, soils, plants and leaching waters for the period 1998–2015, and used for mass balance calculations and long-term simulations of TE accumulations. The composts of green wastes and sludge (GWS) and of municipal solid waste (MSW) were the OWP with the largest TE contents, while the farmyard manure tended to have the lowest. Repeated application of OWP led to significant accumulation of Zn and Cu in the topsoil layer (not for Cr, Cd, Hg, Ni, Pb), especially with GWS, without overpassing calculated protective threshold values. No effect of repeated application of OWP has been observed on TE contents in grains (wheat, maize, barley). The positive mass balance has been dominated by the input flux of TE through OWP and resulted in the observed increases of soil stocks for Cu and Zn. Prospective simulation of soil content evolution until 2100 showed that soil content reached 0.4 mg Cd kg−1 soil (GWS, MSW), 38 mg Cu kg−1 soil (GWS) and 109 mg Zn kg−1 soil (GWS), which remained lower than protective threshold values.
Auteurs, date et publication :
Auteurs Aurélia Marcelline Michaud , Philippe Cambier , Valérie Sappin-Didier , Valentin Deltreil , Vincent Mercier , Jean-Noël Rampon , Sabine Houot
Publication : Environmental Science and Pollution Research
Date : 2025
Volume : 27
Issue : 5
Pages : 5367-5386
Catégorie(s)
#INRAE #PRO #PRO QualiAgroRésumé
A mass budget of polychlorinated biphenyls (PCBs) was constructed for two altitude lakes located in the French Alps to (i) quantify inward and outward PCB flux over the entire year of 2012, (ii) hierarchize the dominant pathways of PCB transfers, and (iii) evaluate to what extent these pathways vary between both lakes. The annual PCB inputs were similar, and the glacial runoff and sediment-to-water exchange were negligible sources of PCBs to the water column relative to atmospheric deposition. The annual inputs were primarily introduced by snow deposition and transferred into the lakes during the few weeks of spring thaw. While the dominant deposition pathways were similar, the main processes by which the water column lost pollutants differed between the two lakes. Despite these differences, the mass budget revealed that PCB inputs exceeded outputs for both studied lakes and that the lakes acted as atmospheric PCB sinks for the surrounding mountain environment. The differences in the PCB distribution between the key compartments (sediment and water column) are most likely due to differences in the lacustrine internal processes.
Auteurs, date et publication :
Auteurs Yann-Michel Nellier , Marie-Elodie Perga , Nathalie Cottin , Philippe Fanget , Emmanuel Malet , Emmanuel Naffrechoux
Publication : Science of The Total Environment
Date : 2025
Volume : 511
Pages : 203-213
Catégorie(s)
#INRAE #OLARésumé
In this work, by comparing genomes of closely related individuals of Streptomyces isolated at a spatial microscale (millimeters or centimeters), we investigated the extent and impact of horizontal gene transfer in the diversification of a natural Streptomyces population. We show that despite these conspecific strains sharing a recent common ancestor, all harbored significantly different gene contents, implying massive and rapid gene flux. The accessory genome of the strains was distributed across insertion/deletion events (indels) ranging from one to several hundreds of genes. Indels were preferentially located in the arms of the linear chromosomes (ca. 12 Mb) and appeared to form recombination hot spots. Some of them harbored biosynthetic gene clusters (BGCs) whose products confer an inhibitory capacity and may constitute public goods that can favor the cohesiveness of the bacterial population. Moreover, a significant proportion of these variable genes were either plasmid borne or harbored signatures of actinomycete integrative and conjugative elements (AICEs). We propose that conjugation is the main driver for the indel flux and diversity in Streptomyces populations.
IMPORTANCE Horizontal gene transfer is a rapid and efficient way to diversify bacterial gene pools. Currently, little is known about this gene flux within natural soil populations. Using comparative genomics of Streptomyces strains belonging to the same species and isolated at microscale, we reveal frequent transfer of a significant fraction of the pangenome. We show that it occurs at a time scale enabling the population to diversify and to cope with its changing environment, notably, through the production of public goods.
Auteurs, date et publication :
Auteurs Abdoul-Razak Tidjani , Jean-Noël Lorenzi , Maxime Toussaint , Erwin van Dijk , Delphine Naquin , Olivier Lespinet , Cyril Bontemps , Pierre Leblond
Publication : mBio
Date : 2019
Volume : 10
Issue : 5
Catégorie(s)
#FORET Montiers #INRAERésumé
Although numerous studies have demonstrated the key role of bacterial diversity in soil functions and ecosystem services, little is known about the variations and determinants of such diversity on a nationwide scale. The overall objectives of this study were i) to describe the bacterial taxonomic richness variations across France, ii) to identify the ecological processes (i.e. selection by the environment and dispersal limitation) influencing this distribution, and iii) to develop a statistical predictive model of soil bacterial richness. We used the French Soil Quality Monitoring Network (RMQS), which covers all of France with 2,173 sites. The soil bacterial richness (i. e. OTU number) was determined by pyrosequencing 16S rRNA genes and related to the soil characteristics, climatic conditions, geomorphology, land use and space. Mapping of bacterial richness revealed a heterogeneous spatial distribution, structured into patches of about 111km, where the main drivers were the soil physico-chemical properties (18% of explained variance), the spatial descriptors (5.25%, 1.89% and 1.02% for the fine, medium and coarse scales, respectively), and the land use (1.4%). Based on these drivers, a predictive model was developed, which allows a good prediction of the bacterial richness (R-adj(2) of 0.56) and provides a reference value for a given pedoclimatic condition.
Auteurs, date et publication :
Auteurs Sebastien Terrat , Walid Horrigue , Samuel Dequietd , Nicolas P. A. Saby , Melanie Lelievre , Virginie Nowak , Julie Tripied , Tiffanie Regnier , Claudy Jolivet , Dominique Arrouays , Patrick Wincker , Corinne Cruaud , Battle Karimi , Antonio Bispo , Pierre Alain Maron , Nicolas Chemidlin Prevost-Boure , Lionel Ranjard
Publication : PloS One
Date : 2017
Volume : 12
Issue : 10
Catégorie(s)
#ANR-Citation #Genosol #INRAEAuteurs, date et publication :
Auteurs CM Armas-Herrera , M-F Dignac , C Rumpel , CD Arbelo , A Chabbi
Publication : European Journal of Soil Science
Date : 2025
Volume : 67
Issue : 4
Pages : 360–373