Etude isotopique et spatialisation du carbone dans l'agglomération dijonnaise

Changement d’usage réglementaire du sol. Comment sélectionner les zones à préserver ?

Agrosup SPE EA EcolDur CT4 EJ3; National audience

δ pattern of dissolved inorganic carbon in a small granitic catchment: the Strengbach case study (Vosges mountains, France)

Abstract The transfers and origins of dissolved inorganic carbon (DIC) were studied for a year in a soil–spring–stream system in the Strengbach catchment, Vosges mountains, France. This 80 ha experimental research basin is located on the eastern side of the mountains, at an altitude ranging from 883 to 1146 m.a.s.l. and is mainly covered by spruce (80%). Brown acid and podzolic soils developed on a granitic basement, and, as a result, the DIC originates solely from CO2 generated by oxidation of soil organic matter. The ( δ 13 C DIC ) in catchment waters is highly variable, from about −22‰ in the springs and piezometers to about −12‰ in the stream at the outlet of the catchment. In the sprin…

13C differentiation of dissolved organic carbon pool during carbon mineralization in soil from a native deciduous forest and a coniferous plantation

International audience

Evolution du bilan hydrique à l'échelle de bassins versants en contexte de changement climatique - Mise place d’une méthodologie.

6 pages; International audience

Différenciation isotopique (13C) du carbone organique dissous (COD) au cours de la dégradation des matières organiques dans les sols forestiers : influence de la végétation

National audience

ISLSCP II global river fluxes of carbon and sediments to the oceans.

International audience

Hydrologie, Changement Climatique, Adaptation, Ressource en Eau en Bourgogne : rapport final du projet HYCCARE Bourgogne

HYCCARE Bourgogne est un projet de recherche-action dont l’objectif est de mettre à disposition des décideurs locaux des outils qui leur permettront de mieux prendre en compte le risque lié aux impacts du changement climatique sur la ressource en eau.

13C differentiation of the dissolved organic carbon pool during carbon mineralization in soil from a native deciduous forest and a coniferous plantation

International audience

Contribution of a new dynamic climate regionalization protocol for estimating the water balance of Douglas-fir forests

Quantifying the regionalized impacts of climate change on forests is a major ecologicaland socio-economic issue. The decline of Douglas-fir (Pseudotsuga menziesii) has been observed forabout 20 years and should be accelered. Recent work shows that regionalized estimation of waterbalance under forest canopy is hampered by the ability of regional climate models to correctlysimulate precipitation amount and seasonal cycle. Here we evaluate the ability of a new climateregionalization protocol to simulate a realistic precipitation regime required for the calculation offorest soil water balance.

Impact of trace metals from past mining on the aquatic ecosystem: a multi-proxy approach in the Morvan (France).

10 pages; International audience; This study seeks to determine to what extent trace metals resulting from past mining activities are transferred to the aquatic ecosystem, and whether such trace metals still exert deleterious effects on biota. Concentrations of Cd, Cu, Pb and Zn were measured in streambed sediments, transplanted bryophytes and wild brown trout. This study was conducted at two scales: (i) the entire Morvan Regional Nature Park and (ii) three small watersheds selected for their degree of contamination, based on the presence or absence of past mining sites. The overall quality of streambed sediments was assessed using Sediment Quality Indices (SQIs). According to these standar…

13C composition of dissolved organic carbon in upland forested catchments of the Morvan Mountains (France): Influence of coniferous and deciduous vegetation.

10 pages; International audience; One of the main environmental changes caused by human activities is that of land use. These changes influence the quantity and quality of the dissolved organic matter (DOM) fluxes through the vegetation–soil–stream system. The aim of this work is to evaluate the influence of the substitution of native deciduous forests by well managed coniferous forests on dissolved organic carbon (DOC) fluxes and their associated carbon isotopic composition (d13CDOC). DOC fluxes and d13CDOC were monitored for 2 years in the streams of four similar upland forested catchments in the Morvan Mountains (France). Mean annual DOC concentrations and fluxes were 2–4 times lower in …

Hydrological response to an abrupt shift in surface air temperature over France in 1987/88.

10 pages; International audience; During the last few decades, Europe has seen a faster increase of observed temperature than that simulated by models. The air temperature over Western Europe showed an abrupt shift at the end of the 1980s, still insufficiently documented. The aim of this study is to assess the characteristics of this shift and its potential impacts on the hydrological cycle over France. Such an assessment is essential for a better understanding of past and future climatic changes and their impact on water resources.A subset of 119 temperature, 122 rainfall, and 30 hydrometric stations was studied, over the entire French metropolitan territory. Several change-point detection…

Potientalities of a hydroclimatic modelling chain at the basin scale of Burgundy.

Storage and release of fossil organic carbon related to weathering of sedimentary rocks

International audience; The biogeochemical carbon cycle, which plays an undeniable role in global climate change, is defined both by the size of carbon reservoirs (such as the atmosphere, biomass, soil and bedrock) and the exchange between them of various mineral and organic carbon forms. Among these carbon forms, fossil organic carbon (FOC) (i.e., the ancient organic matter stored in sedimentary rocks) is widely observed in modern environments but is not included in the supergene carbon budget. Using a digitized map of the world and an existing model of CO2 consumption associated with rock weathering, we establish the global distribution of FOC stored in the first meter of sedimentary rock…

Evaluation de la réserve en eau à l'échelle des pédopaysages de Bourgogne

National audience; Cette étude a pour objet de définir la sensibilité de la ressource en eau sur les sols bourguignons au regard des changements climatiques de demain, et de zoner les secteurs pouvant être impactés par la sécheresse ou des ruissellements excessifs à l'échelle des unités de paysage. A partir du référentiel pédologique de Bourgogne aux 1/250000ème la Réserve Utile des sols est déterminée selon des fonctions de pédotransfert à partir de la texture, du taux de matière organique, du taux d'éléments grossiers et de l'épaisseur des strates des différentes unités typologiques de sol. La spatialisation de cette réserve à l'échelle régionale s'effectue sur la base des Unités Cartogra…

Isotopic Differentiation (13C) of Dissolved Organic Carbon and CO2 During Organic Matter Degradation in Forest Soils: Influence of Vegetation

International audience

A comparison of extraction procedures for water-extractable organic matter in soils

The characteristics of dissolved organic matter (DOM) in soils are often determined through laboratory experiments. Many different protocols can be used to extract organic matter from soil. In this study, we used five air-dried soils to compare three extraction methods for water-extractable organic matter (WEOM) as follows: (i) pressurised hot-water-extractable organic carbon (PH-WEOC), a percolation at high pressure and temperature; (ii) water-extractable organic carbon (WEOC), a 1-hour end-over shaking; and (iii) leaching-extractable organic carbon (LEOC), a leaching of soil columns at ambient conditions. We quantified the extraction yield of organic carbon; the quality of WEOM was charac…

Assessment and mapping the sensitive areas to desertification in an insular Sahelian mountain region Case study of the Ribeira Seca Watershed, Santiago Island, Cabo Verde.

10 pages; International audience; This paper presents the assessment and mapping of the Ribeira Seca catchment, an insular Sahelian mountain region sensitive to desertification, located on the island of Santiago, Cabo Verde. Desertification is a threat to the global environment, representing a serious ecological problem in Cabo Verde. To successfully combat desertification, an evaluation of desertification consequences is required and the building of cartography of the sensitivity for arid and semi-arid ecosystems is required as a first step. The MEDALUS model was the basis for this study in which six quality indicators were used: climate, soil, vegetation, land management, erosion and soci…

Évolution du bilan hydrique à l'échelle de bassins versants en contexte de changement climatique – mise place d’une méthodologie

Assessment of hydric balance at the catchment scale, under climate change scenario Face to climate change, public policies must implement adaptation strategies. This implies that the effects of climate change are plainly identified on territories. However, in the current state, data and knowledge at the local level are limited or not available to decision makers. This work proposes to well characterize the local impacts of climate change and to develop synergies between researchers and territorial actors to prepare the public decision.

Impact du changement climatique sur l’évolution de la ressource en eau en Bourgogne, France (1980-2100) - Analyse des paramètres hydroclimatiques simulés à haute résolution par un modèle climatique régional (WRF)

Impact of climate change on water resource evolution in Burgundy, France (1980-2011) – Analysis of hydro-climatic parameters simulated at high resolution by a regional climate model (WRF) The regional climatic model ARW / WRF is used to make a dynamic downscaling of climate (driven by ERA-Interim) at a high spatial resolution (3 km2) over Burgundy, at daily time scale over the period 1980-2011. Climatic simulations were analyzed and compared with meteorological data, in order to validate them with the aim of their use by hydro(geo)logic models. The hydro-climatic parameters necessary as climatic inputs of these models, in particular precipitation and evapotranspiration, reproduce correctly …

Sensitivity of water quality of three contrasted north-eastern French watersheds to climate change (2006-2100) using SWAT model

International audience; The SWAT model has been chosen to assess climate change impacts on water quality of three subbassins ofnorth-eastern France: located on headwaters of three major rivers of France (Loire, Seine and Rhône riversrespectively). These watersheds have a size less than 3000km² and present different hydrogeological andgeological characteristics. Land-use as well as their agricultural practices being also diversified, the threewatersheds studied constitute a relevant experimentation area. The goal of this study is to assess local vulnerability of surface water quality (sediments, nutrients,dissolved oxygen loads) to climate change (2006-2100) following the Representative Conc…

Effect of temperature on soil microbial structure and fractionation during C mineralisation

International audience; Microbial carbon mineralization in soils leads to the production of different gaseous or dissolved components that have environmental impacts. Our study deals with the influence of soil temperature on the production of gaseous and dissolved carbon components during carbon mineralization in forest soils in France. After an incubation of soil samples for 42 days at 4 different temperatures, we determined both size and 13C isotopic signature of dissolved organic carbon and CO2 pools. We also characterised the soil microbial community structure (PLFA profiles). While temperature clearly increases the CO2 production, a low decrease of the dissolved organic carbon pool was…