Das Projekt "Steady-State Dilution and Mixing-Controlled Reactions in Three-Dimensional Heterogeneous Porous" wird vom Umweltbundesamt gefördert und von Eberhard Karls Universität Tübingen, Zentrum für Angewandte Geowissenschaften (ZAG), Arbeitsgruppe Hydrogeology durchgeführt. Understanding transport of contaminants is fundamental for the management of groundwater re-sources and the implementation of remedial strategies. In particular, mixing processes in saturated porous media play a pivotal role in determining the fate and transport of chemicals released in the subsurface. In fact, many abiotic and biological reactions in contaminated aquifers are limited by the availability of reaction partners. Under steady-state flow and transport conditions, dissolved reactants come into contact only through transverse mixing. In homogeneous porous media, transverse mixing is determined by diffusion and pore-scale dispersion, while in heterogeneous formations these local mixing processes are enhanced. Recent studies investigated the enhancement of transverse mixing due to the presence of heterogeneities in two-dimensional systems. Here, mixing enhancement can solely be attributed to flow focusing within high-permeability inclusions. In the proposed work, we will investigate mixing processes in three dimensions using high-resolution laboratory bench-scale experiments and advanced modeling techniques. The objective of the proposed research is to quantitatively assess how 3-D heterogeneity and anisotropy of hydraulic conductivity affect mixing processes via (i) flow focusing and de-focusing, (ii) increase of the plume surface, (iii) twisting and intertwining of streamlines and (iv) compound-specific diffusive/dispersive properties of the solute species undergoing transport. The results of the experimental and modeling investigation will allow us to identify effective large-scale parameters useful for a correct description of conservative and reactive mixing at field scales allowing to explain discrepancies between field observations, bench-scale experiments and current stochastic theory.
Das Projekt "Plant-soil interactions in changing rice cropping systems and their influence on C and N dynamics" wird vom Umweltbundesamt gefördert und von Universität Bonn, Institut für Nutzpflanzenwissenschaften und Ressourcenschutz - Pflanzenernährung (Prof. Werner) durchgeführt. Plant-soil interactions drive the input, cycling and losses of C and N in soil. This subproject aims at elucidating the input and fate of C in the soil-plant systems and its effect of N retention in soil under different paddy management (continuous vs. alternating with maize cropping). In particular we will investigate (i) how much of the assimilate C is released by the plants into the rhizosphere soil, and how this rhizodeposition is affected by N supply, soil density and crop variety during plant development, (ii) how the exudation of C and N responds to land use change, (iii) how C released into the rhizosphere affects the turnover of soil C and utilization of fertilizer N, and (iv) to what degree leaching contributes to the loss of C and N from the rooted surface soil. To answer these questions, we will combine the use of isotopic 13C and 15N labeling in laboratory and field experiments with a sophisticated characterization of root exudates, root border cells, and compound-specific isotope tracing in the residues of bacteria and fungi in rhizosphere, bulk soil as well as within different dissolved organic and inorganic carbon species in soil leachates. In this way and in collaboration with SP 2, 5, 6, and 7 of this research unit, our project links the cycling of C and N in paddy soils to one of its most prominent drivers, the release of organic compounds by roots.
Das Projekt "Barley dwarfs acting big in agronomy. Identification of genes and characterization of proteins involved in dwarfism, lodging resistance and crop yield" wird vom Umweltbundesamt gefördert und von Deutsche Forschungsgemeinschaft durchgeführt. Barley (Hordeum vulgare) is an important cereal grain which serves as major animal fodder crop as well as basis for malt beverages or staple food. Currently barley is ranked fourth in terms of quantity of cereal crops produced worldwide. In times of a constantly growing world population in conjunction with an unforeseeable climate change and groundwater depletion, the accumulation of knowledge concerning cereal growth and rate of yield gain is important. The Nordic Genetic Resource Center holds a major collection of barley mutants produced by irradiation or chemical treatment. One phenotypic group of barley varieties are dwarf mutants (erectoides, brachytic, semidwarf, uzu). They are characterized by a compact spike and high rate of yield while the straw is short and stiff, enhancing the lodging resistance of the plant. Obviously they are of applied interest, but they are also of scientific interest as virtually nothing is known about the genes behind the development of plant dwarfism. The aim of this project is to identify and isolate the genes carrying the mutations by using state of the art techniques for gene cloning at the Carlsberg Laboratory. The identified genes will be connected with the mutant phenotype to reveal the gene function in general. One or two genes will be overexpressed and the resulting recombinant proteins will be biochemically and structurally characterized. The insights how the mutation effects the protein will display the protein function in particular. Identified genes and their mutant alleles will be tested in the barley breeding program of the Carlsberg brewery.
Das Projekt "Sub project: Spherule layers in the 2011 ICDP drilling in the Barberton Mountain Land: Early impact record on Earth" wird vom Umweltbundesamt gefördert und von Museum für Naturkunde - Leibniz-Institut für Evolutions- und Biodiversitätsforschung durchgeführt. The 2011 ICDP drilling 'Barberton Mountain Land' drilled relatively unweathered rare late Archean volcanic and sedimentary rocks including the oldest known impact ejecta layers on Earth. The chemical signature (high Iridium concentrations, Chromium isotopic ratios) of some of these up to tens of cm thick Archean spherule layers advocate that these ejecta deposits formed dominantly from extraterrestrial material. The ejecta layers contain millimeter sized spherules that are larger and form thicker layers compared to any impact ejecta layer known from Phanerozoic sediments, including the global ejecta layer of the Chicxulub impact catering event that terminated the Mesozoic era of Earths history. We propose to conduct 1) bulk chemical analyses of major and trace elements, 2) petrographic, micro-chemical and mineralogical characterization of the impact ejecta layers, and 3) LA-ICP-MS elemental mapping of platinum group element (PGE) distributions. This aims at 1) characterization of the ejecta layers, 2) identification of the phases hosting the extraterrestrial PGE signature, 3) discrimination of the primary geological evidence of the impact event from those characteristics that resulted from syn- and post-sedimentary alteration. We want to exploit the geological evidence for extracting key information regarding size, type and frequency of projectiles impacting the Archean Earth.
Das Projekt "Description of the Nature of the Accidental Misuse of Chemicals and chemical products (DeNaMiC)" wird vom Umweltbundesamt gefördert und von Bundesinstitut für Risikobewertung durchgeführt. The overall objective of this project is to provide an overview of the nature and extent of injury from chemicals and chemical products in the European region and detail information on the circumstances of how these exposures occur. The outcomes of this research will improve understanding of accidental poisoning and exposure to chemicals in household consumer products. The aim is to identify what data are available to characterise the nature and extent of injury from chemicals in household consumer chemicals and chemical products within Europe, and to find out what conclusions can be drawn from these data sources. It also aims to explore the feasibility of extracting information from poison centres databases for the same purpose, both retrospectively and prospectively. It is envisaged that the project findings will be used to evaluate and improve risk assessment and risk management measures to reduce the incidence and severity of poisoning exposures. To address the specific objectives of the project the work has been divided into five subcomponents as outlined below. 1. Undertake a literature review of published statistical data on the nature and frequency of incidents and events related to accidental exposures to household chemical products to provide an overview of what information is currently available1. 2. Review the data collected by two poisons centres on the circumstances of exposure to consumer chemical products by undertaking a retrospective analysis of enquiries made to two key European poisons centres over a three year period. 3. Evaluate the information collected through the retrospective study to determine how useful these data are for risk assessment purposes and to what extent such data can be collected on a European-wide basis. 4. Undertake a review of risk management measures currently used to reduce risk of poisoning from chemical consumer products. This will include an assessment of the alerting mechanisms used by poisons centres and lessons learned from toxicovigilance activities (e.g. monitoring toxicity of commercial products or identifying products causing significant morbidity or mortality). 5. Design and execute a prospective feasibility study to investigate in more detail the circumstances of exposure to a defined set of consumer chemical poisoning incidents. The design of the study will take into account the results and recommendations of the other subcomponents. The study will involve four poisons centres (Lille, London, Göttingen and Prague) and will be conducted over a six month period. Selected cases reported during this time will be analysed to assess the effectiveness of controls and barriers. This will include information on the circumstances of exposure and severity of poisoning and an assessment of possible preventative measures.
Das Projekt "Recrystallization regimes in an ice sheet - Towards a microstructure-based law of ice" wird vom Umweltbundesamt gefördert und von Universität Heidelberg, Interdisziplinäres Zentrum für Wissenschaftliches Rechnen durchgeführt. A detailed understanding of the dynamics of polar ice sheets is essential for an accurate climate reconstruction and for the prediction of sea-level fluctuations. Today, the required simulations of ice movement are based on general, empirical material properties of ice. A more accurate description of these properties has to be extracted from the ice micro-structure over the entire ice sheet. This project will provide the necessary data-set for a quantitative parameterization of the entire grain boundary network based on microscopic image sequence analysis. Owning to the complexity and scope of the image data, specific and efficient methods of digital image processing (DIP) have to be developed and verified. Initially, the DIP methodology will be applied to the entire length of the East Antarctic EDML ice core, where the main emphasis will be the data reduction with regard to geometric parameters of grains and the evolution of grain boundaries. One goal is to document the extend to which the depth profiles of these micro-structural parameters are coupled with profiles of tracers and climate proxies in ice cores. The variability of subgrain boundaries with regard to the change of dislocation density represents a first indications of the depth dependence of ice viscosity and thus the rate of deformation. In this project, we will perform a semi-quantitative analysis of this aspect of micro-structural influence on ice dynamics.
Das Projekt "Characterization of manure and manure derived dissolved organic matter and its influence on the transport of antibiotics in soil" wird vom Umweltbundesamt gefördert und von Universität Trier, Fach Bodenkunde durchgeführt. Antibiotika gelangen mit kontaminierter Gülle in Böden. Vorliegende Studien deuten an, dass Gülle und v.a. güllebürtige gelöste organische Substanzen (DOM) den Transport und die Sorption von Antibiotika in Böden beeinflussen. Der Kenntnisstand zur Zusammensetzung von Gülle - über den Nährstoffstatus hinaus - ist jedoch gering. Daher zielt das Projekt auf die Charakterisierung des Einflusses von Gülle und güllebürtigen DOM auf die Mobilität von Antibiotika in Böden. Spezifische Ziele sind die Bestimmung 1) der relevanten physikochemischen Eigenschaften und Variabilität von Gülle und güllebürtigen DOM durch physikalische, chemische und analytische Methoden; 2) der residualen Antibiotikabelastung von Feld-Gülle; 3) der Wirkung von Gülle und güllebürtigen DOM auf die Retention von Antibiotika in Boden-Säulen. Dazu werden die Fraktionierung und Analyse von Gülle, güllebürtigen DOM, Bodeneluaten und & 8209;segmenten, um die chemischen Mechanismen des güllebeeinflussten Transportes zu ermitteln, sowie physikalische Modellierungen der Transportprozesse kombiniert. 4) Der Einfluss der physikochemischen Eigenschaften der Sorbate auf die Retention im Boden wird anhand fünf ausgewählter Sulfonamid-Antibiotika als Modell-Substanzen untersucht.
Das Projekt "SP 2.1 Design, modeling and evaluation of improved cropping strategies and multi-level interactions in mixed cropping systems in the North China Plain" wird vom Umweltbundesamt gefördert und von Universität Hohenheim, Institut für Kulturpflanzenwissenschaften (340), Fachgebiet Allgemeiner Pflanzenbau (340a) durchgeführt. In China, the productivity of arable land needs to be further increased. However, with N-fertilizer rates being extremely high already and due to a shortage of irrigation water, further yield increases are not possible by increasing the amount of these input factors. Strategies to reduce or avoid negative environmental effects including water saving while maintaining high yields have to be developed. Yield increases, may be possible by appropriately adjusting cropping systems, either by design (e.g. intercropping as a mixed cropping system), crop sequence and rotation, or improved input factor efficiency. The main objective of this subproject will be to design, model and evaluate improved cropping strategies and multi-level interactions in mixed cropping systems. Based on a process-oriented modeling approach, the project will emphasize on the evaluation of cropping system prototypes including different crops (spring maize, summer maize, wheat, peanut), different designs (intercropping, mixed cropping), different crop sequences and rotations (e.g. spring maize monoculture versus double cropping winter wheat-summer maize) and different input factor levels of water and nitrogen for different regions and agro-climatic conditions in the North China Plain. By doing so, the project aims at exploring the possibilities and at creating new methodologies for improving the cropping systems in the North China Plain. Within the modeling approach competitive relationships between crop species regarding yield, solar radiation, water and nitrogen will be analyzed and modeled. The project will design the necessary methods and basic approaches for the description of the relevant indicator parameters and transfer these into a thorough modeling approach.
Das Projekt "SP 2.2 QTL analysis and optimization of breeding schemes for improved nitrogen-use efficiency of maize and wheat for sustainable cropping systems in the North China Plain" wird vom Umweltbundesamt gefördert und von Universität Hohenheim, Institut für Pflanzenzüchtung, Saatgutforschung und Populationsgenetik (350), Fachgebiet Angewandte Genetik und Pflanzenzüchtung (350a) durchgeführt. In China, agriculture needs to be intensified by increasing the productivity per unit land. However, the possibility to improve yield by further increasing the amounts of input is very limited due to already very high input amounts of fertilizers and irrigation water in the present cropping system. Hence, the development and characterization of improved varieties, especially with regard to traits of utmost importance for sustainable resource use, such as nitrogen- (NUE) and water-use efficiency (WUE), is crucial for a sustainable agriculture in the North China Plain. The decision about the requirement of one common or two separate breeding programs for developing varieties adapted to low and high N fertilization strongly depends on an appropriate estimation of the correlation between yield at different fertilization levels. Therefore, maize and wheat varieties are evaluated in multiple locations in the North China Plain. Adopting novel breeding approaches based on doubled haploids (DH) can speed up the process of developing new varieties substantially and rapidly provides suitable cultivars for new cropping systems. Therefore, optimum breeding strategies for maize breeding are modeled and simulated to optimize alternative breeding schemes with respect to the optimum allocation of test resources using different optimization criteria. Modeling of production systems and material flows is a powerful tool to increase sustainable resource use by identifying cropping systems, which combine reduced inputs with high yields. However, an appropriate model requires knowledge about the genetics of crop growth and yield and its interaction with environmental factors. Therefore, maize and wheat populations developed by the Chinese partners in the first project phase are phenotyped in multi-location field trials and genotyped with molecular markers to map quantitative trait loci (QTL) for NUE.
Das Projekt "Spatiotemporal dynamics of biogenic Si pools in initial soils and their relevance for desilication" wird vom Umweltbundesamt gefördert und von Leibniz-Zentrum für Agrarlandschaftsforschung (ZALF) e.V., Institut für Bodenlandschaftsforschung durchgeführt. The project has the objective to clarify the interactions between dynamics of biogenic Si pools and desilication rates in transient soil systems. This will be the first attempt ever to quantify sizes and turnover dynamics of both phytogenic and zoogenic Si pools in soils at the same time, together with the controls acting on them. Starting with a characterization of soils initial state at catchment scale we will analyze the annual SiO2 production of the vegetation as a function of (i) spatial distribution of plant available Si in soils as well as (ii) dynamics of invading Si accumulators. To do so we will employ modern remote sensing techniques (UAV). After four vegetation periods, changes in soils phytogenic Si pool will be compared to cumulative SiO2 production of Si accumulators by mass balance calculations. Using plot scale manipulation experiments we will elucidate the influence of an increasing phytogenic Si pool on desilication rates. At four sites annual Si exports via soil solution will be determined under pure stands of both, Si accumulator and non-accumulator plants. Plant SiO2 will be subjected to dissolution experiments to yield mechanistic information necessary for the development of algorithms to model observed desilication rates. The dynamics of the zoogenic Si pool (testate amoebae) in soil will be quantified as a function of plant pattern dynamics at catchment scale. For the first time, the attempt will be made to quantify the zoogenic Si pool size by analyzing living and dead amoebae with Energy-dispersive X-Ray Spectroscopy combined with Scanning Electron Microscopy (SEM-EDX). The factors controlling testate amoebae densities will be identified in plot and lab experiments. We will test the presumed carbon, water / nutrient and Si limitation on amoebal growth at plot scale using a completely randomized block design. The influence of silica supply on testate amoebae (idiosome growth) will be clarified in lab experiments under controlled conditions (clonal cultures).
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