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[Departement_IRSTEA]Eaux [TR1_IRSTEA]GEUSI [ADD1_IRSTEA]Gestion intégrée de la ressource et des infrastructures; International audience; Space-borne instruments can measure river water surface elevation, slope and width. Remote sensing of river discharge in ungauged basins is far more challenging, however. This work investigates the estimation of river discharge from simulated observations of the forthcoming Surface Water and Ocean Topography (SWOT) satellite mission using a variant of the classical variational data assimilation method "4D-Var". The variational assimilation scheme simultaneously estimates discharge, river bathymetry and bed roughness in the context of a 1.5D full Saint Venant hydraulic model. Algorithms and procedures are developed to apply the method to fully ungauged basins. The method was tested on the Po and Sacramento Rivers. The SWOT hydrology simulator was used to produce synthetic SWOT observations at each overpass time by simulating the interaction of SWOT radar measurements with the river water surface and nearby land surface topography at a scale of approximately 1 m, thus accounting for layover, thermal noise and other effects. SWOT data products were synthesized by vectorizing the simulated radar returns, leading to height and width estimates at 200 m increments along the river centerlines. The ingestion of simulated SWOT data generally led to local improvements on prior bathymetry and roughness estimates which allowed the prediction of river discharge at the overpass times with relative root-mean-squared errors of 12.1% and 11.2% for the Po and Sacramento rivers respectively. Nevertheless, equifinality issues that arise from the simultaneous estimation of bed elevation and roughness may prevent their use for different applications, other than discharge estimation through the presented framework.

Policies to mitigate climate change and biodiversity loss often assume that protecting carbon-rich forests provides co-benefits in terms of biodiversity, due to the spatial congruence of carbon stocks and biodiversity at biogeographic scales. However, it remains unclear whether this holds at the scales relevant for management, with particularly large knowledge gaps for temperate forests and for taxa other than trees. We built a comprehensive dataset of Central European temperate forest structure and multi-taxonomic diversity (beetles, birds, bryophytes, fungi, lichens, and plants) across 352 plots. We used Boosted Regression Trees to assess the relationship between above-ground live carbon stocks and (a) taxon-specific richness, (b) a unified multidiversity index. We used Threshold Indicator Taxa ANalysis to explore individual species' responses to changing above-ground carbon stocks and to detect change-points in species composition along the carbon-stock gradient. Our results reveal an overall weak and highly variable relationship between richness and carbon stock at the stand scale, both for individual taxonomic groups and for multidiversity. Similarly, the proportion of win-win and trade-off species (i.e. species favored or disadvantaged by increasing carbon stock, respectively) varied substantially across taxa. Win-win species gradually replaced trade-off species with increasing carbon, without clear thresholds along the above-ground carbon gradient, suggesting that community-level surrogates (e.g. richness) might fail to detect critical changes in biodiversity. Collectively, our analyses highlight that leveraging co-benefits between carbon and biodiversity in temperate forest may require stand-scale management that prioritizes either biodiversity or carbon-in order to maximize co-benefits at broader scales. Importantly, this contrasts with tropical forests, where climate [...], Pre-review Version 2018, 07\23 + Supplementary information 43 Pages, 5 figures + 9 supplementary Figures

International audience; The exploration of the patterns and the mechanisms that shape organisms distribution along large latitudinal gradients is among the most debated topics in ecology and biogeography due to its implications for conservation in the face of global change. In Europe, beech forests cover a vast surface area, from the southern part of Scandinavia to the mountains of south Italy, providing relatively homogeneous habitat conditions along this latitudinal gradient. This should be reflected by a high similarity in taxonomical composition of its forest biota. However, this hypothesis could be contradicted by the fact that the large-scale distribution of organisms may be hampered by their dispersal capability. This could determine differences in organism spread patterns across European beech forests that should be reflected by a pattern of distance decay of compositional similarity whose magnitude should depend on the dispersal traits of the organisms. To test this hypothesis we assembled a multi-taxon database, including both organisms that are best suited for long-range dispersal (i.e. birds, bryophytes, lichens, fungi) and organisms that are usually less effective in long range dispersal (i.e. beetles and plants). This database consists of 354 plots clustered in 20 forest areas distributed from northern France to southern Italy. Preliminary results reveal a pattern of distance decay of compositional similarity for all organism groups. However, its magnitude reflects the dispersal ability of the organisms, being stronger for those that are less suited for long range dispersal. Only for lichens, results are not consistent with our expectations showing a high rate of compositional dissimilarity over a relatively short distance (i.e. 500 Km). This may reflect their strong sensitivity to local microclimatic conditions. More refined results are expected by an extra close-to-trait analysis considering more in detail the dispersal capability of the single species within each taxonomical group.

International audience; Understanding how forest biodiversity and carbon stocks can be simultaneously maintained or enhanced is crucial for the development of effective forest management strategies and policies aimed at halting biodiversity loss under climate and land use change. Many existing policies and strategies assume that forests hosting high carbon stocks provide co-benefits in terms of high biodiversity. While this relationship has been demonstrated in tropical forests, it has not been rigorously assessed in temperate forests, and further research is needed to understand how carbon stock and biodiversity covary, and whether non-linearities, community thresholds and variability across taxa exist. We built a comprehensive biodiversity dataset including six taxonomical groups (beetles, birds, bryophytes, fungi, lichens, and vascular plants) distributed over 352 plots representing three forest types, in 22 distinct study areas across three European countries (France, Hungary and Italy). We used Boosted Regression Trees and Threshold Indicator Taxa ANalysis (TITAN) to address three questions: (1) is there a positive relationship between overall multi-taxa diversity (multidiversity) and aboveground carbon stocks in European temperate forests? (2) Are there nonlinearities or thresholds (e.g. synchronous change-points in species composition) along the carbon stock gradient we considered, and are they consistent across taxonomical groups and forest types? (3) How do individual species respond to increasing aboveground carbon and how does the proportion of species with positive (win-win species) or negative (trade-off species) relationships vary across taxonomical groups? We found neither higher multidiversity, nor a consistently higher number of species across the six taxonomical groups in forests storing higher aboveground carbon. We found evidence for synchronous change-points in community composition along the carbon gradient, although these were neither consistent, nor equally abrupt across taxonomical groups and forest types. For all taxonomical groups except lichens, trade-off species markedly decreased at carbon stocks between 80 and 110 Mg/ha, roughly corresponding to the canopy closure phase of the forest stand development. The turnover between trade-off and win-win species was gradual along the carbon gradient, and the proportion of these two groups of species varied across taxonomical groups, and forest types. Maximizing forest carbon storage may not benefit all facets of biodiversity at the same time, although it may enhance some specific taxa and functional groups. Explicitly distinguishing between win-win and trade-off species, and considering taxon-specific community change-points along the carbon gradient could provide a conceptual basis for forest managers to operatively reconcile biodiversity conservation and carbon stock retention.

International audience; Aim: Biodiversity monitoring and conservation are extremely complex, and surrogate taxa may represent proxies to test methods and solutions. However, cross-taxon correlations in species diversity (i.e., cross-taxon congruence) may vary widely with spatial scale. Our goal is to assess how cross-taxon congruence varies with spatial scale in European temperate forests. We expect that congruence in species diversity increases when shifting from fine to coarse spatial scales, with differences between species richness and composition, and across pairs of taxonomic groups. Location: European temperate forests. Time period: Present. Major taxa studied: Vascular plants, bryophytes, birds, epiphytic lichens, saproxylic beetles and wood-inhabiting fungi. Methods: We used field data (354 plots across 23 sites) encompassing Italy, France and Hungary, with species information for six taxonomic groups. We accounted separately for spatial grain (the size of elementary sampling unit) and extent (the geographical area included in the survey) and evaluated the relationships within all the possible pairs of taxa. Results: Although no pair of taxa had its species richness consistently correlated across scales, we found no changes in the direction of correlations when analysing species composition. However, when increasing grain and extent, we did find a general increase in the magnitude of correlations in species composition and partial changes in significance, with plants having the highest number of significant correlations. Main conclusions: Species richness congruence among taxa is strongly scale dependent owing to differences in the relative contribution of large- and small-scale processes across taxa. Cross-taxon congruence in species composition is scale dependent only for its magnitude, because life-history traits of individual species make responses to environmental factors similar across scales. Forest monitoring should consider multi-taxon sampling and limit the use of surrogates at specific spatial scales, especially for species richness. Sampling plant species composition in scattered plots across different sites may effectively summarize the whole community composition.

International audience; Scale dependency is one of the main factors causing the variability of correlations among species diversity parameters. Recent syntheses demonstrated how both extent (the geographical area comprised by the survey or total sample) and grain (the scale of each sampling unit) have a significant effect on cross-taxon congruency. These results, however, do not represent a definitive framework to understand this variation across spatial scales, since this was only indirectly analyzed, by comparing the results of different studies. Our goal is to assess if and how cross-taxon congruency vary across different spatial scales in European temperate forests. Our general hypothesis is that cross-taxon congruency in species richness and composition in European temperate forests increases together with the scale of analysis. We account separately for differences in spatial grain and extent, and evaluate the relationships between all the possible pairs of taxonomic groups. We use a comprehensive set of field data encompassing Italy, France and Hungary (Fig. 1), and including species diversity information for six taxonomic groups: vascular plants, bryophytes, birds, epiphytic lichens, saproxylic beetles, and wood-inhabiting fungi. We calculated effect sizes for species richness and community composition correlation at three different spatial scales of grain and extent: (i) plot grain - site extent, (ii) plot grain - continental extent, and (iii) site grain - continental extent. No pair of taxa had their species richness consistently correlated (either positively or negatively) in all three combinations of grain and extent analyzed (Fig. 2). However, birds and bryophytes, and fungi and lichens had the highest correlation of species richness when sampled at a plot-level grain and site extent. When analyzing congruent patterns of species composition, plants resulted as the best surrogates for other taxa, even across different spatial scales (Fig. 3). We demonstrate that diversity congruency relationships among taxa in European temperate forest are for the most part, scale-dependent. Our results support that increasing database extent and sampling grain masks local patterns of congruency and highlights those due to common response to broad environmental and biogeographic factors that covary across the European continent. We suggest the results presented in this study to be taken into serious consideration when developing indicators of sustainable forest management for the conservation of forest biodiversity.

International audience; Managing forests sustainably is important to preserve biodiversity and the services it underpins, above all climate change mitigation through the storage of carbon in woody biomass. Biodiversity conservation and carbon storage strictly depend on forest structure, and many scientists advocate for a higher degree of structural complexity in order to increase the provision of these ecosystem services. However, a thorough understanding of the trade-offs and synergies between forest biodiversity, structure and function is still lacking especially due to the scattered and inadequate information on the distribution of forest biodiversity, whose sampling and monitoring are particularly complex and costly. By establishing a network of scientists who collected data in European deciduous forests, we were able to create a dataset including information on forest structure and six taxonomic groups (vascular plants, lichens, bryophytes, fungi, beetles and birds) for more than 350 sampling units across France, Hungary and Italy. We used these data to test the following hypotheses: i) a higher degree of forest structural heterogeneity results in higher levels of multi-taxon biodiversity; ii) forest stands containing a high amount of carbon stored in tree aboveground biomass re also those hosting a high degree of multi-taxon biodiversity.

International audience; We investigate the long memory properties of 224 european rivers spanning more than 50 years of daily flow data. For this purpose, we identify two periods of interest; High Flow Seasons (HFS) as 3-month periods receiving the maximum occurrences of peaks-over-threshold flows and Dry Months (DM) as 1-month periods with the minimum average flow.

International audience; A warming climate is expected to have an impact on the magnitude and timing of river floods; however, no consistent large-scale climate change signal in observed flood magnitudes has been identified so far. We analyzed the timing of river floods in Europe over the past five decades, using a pan-European database from 4262 observational hydrometric stations, and found clear patterns of change in flood timing. Warmer temperatures have led to earlier spring snowmelt floods throughout northeastern Europe; delayed winter storms associated with polar warming have led to later winter floods around the North Sea and some sectors of the Mediterranean coast; and earlier soil moisture maxima have led to earlier winter floods in western Europe. Our results highlight the existence of a clear climate signal in flood observations at the continental scale.

Farm management information systems centered around the farm manager in open-field crop production.Prevailing differences between academic and commercial farm management information systems.Grouping of farm management information systems based on cluster analysis. Farm Management Information Systems (FMIS) in agriculture have evolved from simple farm recordkeeping into sophisticated and complex systems to support production management. The purpose of current FMIS is to meet the increased demands to reduce production costs, comply with agricultural standards, and maintain high product quality and safety. This paper presents current advancements in the functionality of academic and commercial FMIS. The study focuses on open-field crop production and centeres on farm managers as the primary users and decision makers. Core system architectures and application domains, adoption and profitability, and FMIS solutions for precision agriculture as the most information-intensive application area were analyzed. Our review of commercial solutions involved the analysis of 141 international software packages, categorized into 11 functions. Cluster analysis was used to group current commercial FMIS as well as examine possible avenues for further development. Academic FMIS involved more sophisticated systems covering compliance to standards applications, automated data capture as well as interoperability between different software packages. Conversely, commercial FMIS applications targeted everyday farm office tasks related to budgeting and finance, such as recordkeeping, machinery management, and documentation, with emerging trends showing new functions related to traceability, quality assurance and sales.

The Office of Hydrologic Development (OHD) of the U.S. National Oceanic and Atmospheric Administration's (NOAA) National Weather Service (NWS) conducted the two phases of the Distributed Model Intercomparison Project (DMIP) as cost-effective studies to guide the transition to spatially distributed hydrologic modeling for operational forecasting at NWS River Forecast Centers (RFCs). Phase 2 of the Distributed Model lntercomparison Project (DMIP 2) was formulated primarily as a mechanism to help guide the U.S. NWS as it expands its use of spatially distributed watershed models for operational river, flash flood, and water resources forecasting. The overall purpose of DMIP 2 was to test many distributed models forced by high quality operational data with a view towards meeting NWS operational forecasting needs. At the same time, DMIP 2 was formulated as an experiment that could be leveraged by the broader scientific community as a platform for the testing, evaluation, and improvement of distributed models. DMIP 2 contained experiments in two regions: in the DMIP 1 Oklahoma basins, and second, in two basins in the Sierra Nevada Mountains in the western USA. This paper presents the overview and results of the DMIP 2 experiments conducted for the two Sierra Nevada basins. Simulations from five independent groups from France, Italy, Spain and the USA were analyzed. Experiments included comparison of lumped and distributed model streamflow simulations generated with uncalibrated and calibrated parameters, and simulations of snow water equivalent (SWE) at interior locations. As in other phases of DMIP, the participant simulations were evaluated against observed hourly streamflow and SWE data and compared with simulations provided by the NWS operational lumped model. A wide range of statistical measures are used to evaluate model performance on a run-period and event basis. Differences between uncalibrated and calibrated model simulations are assessed. Results indicate that in the two study basins, no single model performed best,in all cases. In addition, no distributed model was able to consistently outperform the lumped Model benchmark. However, one or more distributed models were able to outperform the lumped model benchmark in many of the analyses. Several calibrated distributed models achieved higher correlation and lower bias than the calibrated lumped benchmark in the calibration, validation, and combined periods. Evaluating a number of specific precipitation-runoff events, one calibrated distributed model was able to perform at a level equal to or better than the calibrated lumped model benchmark in terms of event-averaged peak and runoff volume error. However, three distributed models were able to provide improved peak timing compared to the lumped benchmark. Taken together, calibrated distributed models provided specific improvements over the lumped benchmark in 24% of the model-basin pairs for peak flow, 12% of the model-basin pairs for event runoff volume, and 41% of the model-basin pairs for peak timing. Model calibration improved the performance statistics of nearly all models (lumped and distributed). Analysis of several precipitation/runoff events indicates that distributed models may more accurately model the dynamics of the rain/snow line (and resulting hydrologic conditions) compared to the lumped benchmark model. Analysis of SWE simulations shows that better results were achieved at higher elevation observation sites. Although the performance of distributed models was mixed compared to the lumped benchmark, all calibrated models performed well compared to results in the DMIP 2 Oklahoma basins in terms of run period correlation and %Bias, and event-averaged peak and runoff error. This finding is noteworthy considering that these Sierra Nevada basins have complications such as orographically-enhanced precipitation, snow accumulation and melt, rain on snow events, and highly variable topography. Looking at these findings and those from the previous DMIP experiments, it is clear that at this point in their evolution, distributed models have the potential to provide valuable information on specific flood events that could complement lumped model simulations. Published by Elsevier B.V.

The project CARE-W presented in this paper deals with the public water supply networks and their problems of ageing such as structural failures, hydraulic insufficiencies, leakage, deteriorating water quality and increasing maintenance cost that impact on an urban environment. The ultimate goal of the project is to develop a suite of tools, which provide the most cost-efficient system of maintenance and repair of water distribution networks, with the aim to guarantee a security of water supply that meets social, health, economic and environmental requirements. The paper comprises a description of the project work-packages, which include: - A control panel of Performance Indicators (PI) for rehabilitation.- description of technical and statistical tools assessing and forecasting some of the PI.- A procedure to define the best choice for annual rehabilitation programming.- A procedure to define the best strategy of planning rehabilitation investments (at long term, 10 to 20 years).- A software, combining the above products with a common database, tested and evaluated by several test cities. CARE-W is aimed to utilities for water supply systems, operating companies, local authorities, financial institutions and national regulators. It is supported by the European Commission under the fifth framework programme.

A research program was set up with European Institutes to compare the testing methods employed by these laboratories to measure characteristic parameters of the air assisted orchard sprayers. The parameters studied in the frame of this program are : the air flow rate, the air velocity and the liquid distribution. The study showed off the differences and explained if these differences come from the measuring devices or the testing methods., Un programme de recherche a été mis sur pied en collaboration avec les instituts européens pour comparer les méthodes d'essai utilisées par ces laboratoires afin de mesurer les paramètres caractéristiques des pulvérisateurs pneumatiques utilisés dans les vergers. Les paramètres étudiés dans le cadre de ce programme sont : le débit d'air, la vitesse de l'air et la répartition du liquide. L'étude a permis de mettre en évidence certaines différences et d'expliquer si ces différences étaient dues aux appareils de mesure ou aux méthodes d'essai.