In forest ecosystems ectomycorrhizal fungi are responsible for the mobilization of mineral nutrients from soil organic matter (SOM) resulting in a marked increase in productivity of their symbiotic host plants. In return the fungi obtain a significant amount of photosynthetic products from these plants, allowing the formation of an extensive hyphal system. These hyphae constitute a major part of soil biomass and, ultimately, a major source for SOM formation. While plant-fungal nutrient exchange has been analyzed extensively, this proposal is focused on the fungal contribution to SOM formation and on the processes leading to the acquisition of nutrients by the fungi. These two processes will be studied separately and in a quantitative way using isotopic labeling in soil bioreactors. Analysis of the fate of 13C labeled fungal material (Laccaria bicolor) in soil bioreactors will tell how fast and to what extent the various fractions of hyphal biomass are transformed into non-living SOM. As potential molecular or structural markers for SOM formation from fungal hyphae we will analyze characteristic remnants of fungal hyphae in SOM using scanning electron microscopy, DNAfragments using a PCR approach for the fungal rRNA internal transcribed spacerregions and biochemical markers like fatty acids and ergosterol. The impact of ectomycorrhizal mycelia supported by Pinus sylvestris plantlets on 13C- and 15N-labeled SOM and on microbial biomass will be analyzed in separate soil bioreactor experiments.
The formation of biogeochemical interfaces in soils is controlled, among other factors, by the type of particle surfaces present and the assemblage of organic matter and mineral particles. Therefore, the formation and maturation of interfaces is studied with artificial soils which are produced in long-term biogeochemical laboratory incubation experiments (3, 6, 12, 18 months. Clay minerals, iron oxides and charcoal are used as major model components controlling the formation of interfaces because they exhibit high surface area and microporosity. Soil interface characteristics have been analyzed by several groups involved in the priority program for formation of organo-mineral interfaces, sorptive and thermal interface properties, microbial community structure and function. Already after 6 months of incubation, the artificial soils exhibited different properties in relation to their composition. A unique dataset evolves on the development and the dynamics of interfaces in soil in the different projects contributing to this experiment. An integrated analysis based on a conceptual model and multivariate statistics will help to understand overall processes leading to the biogeochemical properties of interfaces in soil, that are the basis for their functions in ecosystems. Therefore, we propose to establish an integrative project for the evaluation of data obtained and for publication of synergistic work, which will bring the results to a higher level of understanding.
Magnetic properties of ferrimagnetic minerals depend on their crystal lattice, anisotropy, chemical composition and grain size. The latter parameter is strongly controlled by microstructures, which are significant for the interpretation of the magnetic properties of shocked magnetic minerals. Fracturing and lattice defects are the main causes for magnetic domain size reduction and generate an increase in coercivity and the suppression of magnetic transitions (e.g. 34 K transition in pyrrhotite, Verwey transition in magnetite).Especially for an adequate investigation of shock-induced modifications in ferromagnetic minerals, a combination of microstructural and magnetic measurements is therefore essential.This project focusses on two significant aspects of extreme conditions - the consequence of shock waves on natural material on Earth and on the magnetic mineralogy of exotic magnetic minerals in iron meteorites. In order to obtain general correlations between deformation structures and magnetic properties, the specific magnetic properties and carriers as well as microstructures of samples from two impact structures in marine targets (Lockne and Chesapeake Bay) will be compared with shocked magnetite ore and magnetite-bearing target lithologies from outside the crater (Lockne) as well as from undeformed megablocks within the crater (Chesapeake Bay). We will test the hypothesis if shock-related microstructures and associated magnetic properties can significantly be overprinted by postshock hydrothermal alteration. We especially want to focus on the Verwey transition (TV) as lower TVs are described for shocked impact lithologies. Hence, the main focus of this study lies on magneto-mineralogical investigations which combine low- and high-temperature magnetic susceptibility and saturation isothermal remanent magnetization with mineralogical and microstructural investigations. The same methods will then be used for the investigation of iron meteorites, whose magnetic properties are often controled by exotic magnetic minerals like cohenite, schreibersite and daubreelite in addition to the metal phases. Magnetic transition temperatures of those phases are poorly documented in relation to their chemical composition as well as to their crystallographic and microstructural configuration. For a general understanding of shock-related magnetization processes in extraterrestrial and terrestrial material, however, it is crucial to obtain a general correlation between the initial 'unshocked' state and the subsequent shock- and alteration-related overprints.
Der Datensatz enthält Informationen zu Nutzung und Oberflächenmaterial der einzelnen Flächen im Straßenraum der Bezirks- und Hauptverkehrsstraßen. Zusätzlich sind verschiedene im Straßenraum befindliche Linien- und Punktobjekte enthalten. Zu den Linienobjekten gehören: Hochbord, Tiefbord, Geländer, Mauer, Rinne und Zaun. Zu den Punktobjekten gehören: Pflanzkübel, Lampe, Hängelampe, Mast für Hängelampe, Poller/Pfosten/Wegesperre, Fußgängerleitsystem, Verkehrsampel, Bügel, Fahrradbügel, Findling, Bank, Tisch, Kunst im öffentlichen Raum/Skulptur, Brunnen. In der Regel sind im Datensatz alle Objekte im Bereich des Tiefbauvermögens der FHH enthalten. Flächen im Zuständigkeitsbereich der Autobahn GmbH und des Hafens sind nicht enthalten. Flächen, die eindeutig zum städtischen Straßenraum gehören, aus verschiedenen Gründen aktuell aber rechtlich nicht dem Tiefbauvermögen zugerechnet werden, sind ebenfalls enthalten und werden mit dem Attribut "Fremdeigentum" gekennzeichnet. Enthaltene Attribute: Bezirksnummer, Bezirk, Stadtteilnummer, Stadtteil, Straßenname, Straßentyp, Kategorie, Nutzungsnummer, Nutzung, Inhaltsnummer, Inhalt (Oberflächenmaterial), Ebenennummer, Ebene (Lage regulär auf Straßenebene oder darüber bzw. darunter), Fremdeigentum, Quelle, Bemerkung, Fläche (in m^2), Objekt-ID und Stand der Erfassung. Die Ersterfassung der Feinkartierung Straßen erfolgte auf Grundlage einer Luftbilddigitalisierung in den einzelnen Bezirken zwischen 2013 und 2021. Die Pflege der Daten erfolgt seit 2022 kontinuierlich anhand von Planunterlagen, Luft- und Befahrungsbildern durch den Landesbetrieb Geoinformation und Vermessung im Auftrag der Behörde für Verkehr und Mobilitätswende. Die Aktualität der jeweiligen Fortführung des Objektes ist den Attributen zu entnehmen. Die Datengrundlage weist jedoch einen älteren Stand auf, als der Tag der Fortführung. Auch Baustellen aus den Vorjahren werden u.U. erst in späteren Jahrgängen umgewandelt, sodass anhand des Datensatzes keine Analyse möglich ist, wie viele Flächenänderungen in einem Jahr im Straßenraum erfolgt sind. Insbesondere die Punkt- und Linienobjekte erheben keinen Anspruch auf Vollständigkeit, da sie z.T. bereits bei der Ersterfassung nicht vollständig erfasst wurden und Aufstell- und Abbauprozesse der datenpflegenden Stelle in der Regel nicht gemeldet werden. Es kann keine Gewähr für die Richtigkeit aller Daten übernommen werden. Aufgrund der Aktualität des Datensatzes kann keine rechtssichere bzw. tagesaktuelle Aussage getroffen werden. Sollten Sie Anmerkungen zum Datensatz haben oder Korrekturen melden wollen, schicken Sie diese bitte an fachdatenmanagement@gv.hamburg.de. Der Datensatz enthält Informationen zu Nutzung und Oberflächenmaterial der einzelnen Objekte im Straßenraum der Bezirks- und Hauptverkehrsstraßen. In der Regel sind im Datensatz alle Objekte im Bereich des Tiefbauvermögens der FHH enthalten. Flächen im Zuständigkeitsbereich der Autobahn GmbH und des Hafens sind nicht enthalten. Flächen, die eindeutig zum städtischen Straßenraum gehören, aus verschiedenen Gründen aktuell aber rechtlich nicht dem Tiefbauvermögen zugerechnet werden, sind ebenfalls enthalten und werden mit dem Attribut "Fremdeigentum" gekennzeichnet. Enthaltene Attribute: Bezirksnummer, Bezirk, Stadtteilnummer, Stadtteil, Straßenname, Straßentyp, Kategorie, Nutzungsnummer, Nutzung, Inhaltsnummer, Inhalt (Oberflächenmaterial), Ebenennummer, Ebene (Lage regulär auf Straßenebene oder darüber bzw. darunter), Fremdeigentum, Quelle, Bemerkung, Fläche (in m^2), Objekt-ID und Stand der Erfassung. Die Ersterfassung der Feinkartierung Straßen erfolgte auf Grundlage einer Luftbilddigitalisierung in den einzelnen Bezirken zwischen 2013 und 2021. Die Pflege der Daten erfolgt seit 2022 kontinuierlich anhand von Planunterlagen, Luft- und Befahrungsbildern durch den Landesbetrieb Geoinformation und Vermessung im Auftrag der Behörde für Verkehr und Mobilitätswende. Die Aktualität des jeweiligen Objektes ist den Attributen zu entnehmen. Es kann keine Gewähr für die Richtigkeit aller Daten übernommen werden. Aufgrund der Aktualität des Datensatzes kann keine rechtssichere bzw. tagesaktuelle Aussage getroffen werden.
Chromium (Cr) is introduced into the environment by several anthropogenic activities. A striking ex-ample is the area around Kanpur in the Indian state of Uttar Pradesh, where large amounts of Cr-containing wastes have been recently illegally deposited. Hexavalent Cr, a highly toxic and mobile contaminant, is present in significant amounts in these wastes, severely affecting the quality of sur-roundings soils, sediments, and ground waters. The first major goal of this study is to clarify the solid phase speciation of Cr in these wastes and to examine its leaching behavior. X-ray diffraction and synchrotron-based X-ray absorption spectroscopy techniques will be employed for quantitative solid phase speciation of Cr. Its leaching behavior will be studied in column experiments performed at un-saturated moisture conditions with flow interruptions simulating monsoon rain events. Combined with geochemical modeling, the results will allow the evaluation of the leaching potential and release kinetics of Cr from the waste materials. The second major goal is to investigate the spatial distribution, speciation, and solubility of Cr in the rooting zone of chromate-contaminated soils surrounding the landfills, and to study the suitability of biochar as novel soil amendment for mitigating the deleterious effects of chromate pollution. Detailed field samplings and laboratory soil incubation studies will be carried out with two agricultural soils and biochar from the Kanpur region.
The aim of P2 within the Research Unit 'The Forgotten Part of Carbon Cycling: Organic Matter Storage and Turnover in Subsoils (SUBSOM)' is to contribute to the understanding of the different sources and stabilization processes of subsoil organic matter. This will be achieved by the analysis of the soil organic matter composition in topsoil versus subsoil by 13C NMR spectroscopy in bulk soils as well as organo-mineral associations. This will be done on a number of soil profiles differing in parent material and mineralogy and therefore also in the relevance of organo-mineral associations for subsoil C stabilization. In addition, a specific sampling approach will allow to differentiate three zones associated with the dominating effect of (1) leaching of DOC (the 'bulk soil' between trees), (2) root litter decomposition (the 'root-affected zone'), and (3) direct rhizodeposition of root exudates (the 'rhizosphere' sensu strictu). The contribution of above-ground versus below-ground litter is differentiated by the analysis of cutin and suberin biomarkers. Organic matter derived from microbial sources will be identified by the microbial signature of polysaccharides in the subsoil through the analysis of neutral sugars and amino sugars. Organo-mineral associations will be further characterized by N2-BET analyses to delineate the coverage of the mineral phase with organic matter. With these analyses and our specific analytical expertise at the submicron scale (nanoSIMS) we will participate in selected joint experiments of the research unit.
Biogeochemical interfaces shape microbial community function in soil. On the other hand microbial communities influence the properties of biogeochemical interfaces. Despite the importance of this interplay, basic understanding of the role of biogeochemical interfaces for microbial performance is still missing. We postulate that biogeochemical interfaces in soil are important for the formation of functional consortia of microorganisms, which are able to shape their own microenvironment and therefore influence the properties of interfaces in soil. Furthermore biogeochemical interfaces act as genetic memory of soils, as they can store DNA from dead microbes and protect it from degradation. We propose that for the formation of functional biogeochemical interfaces microbial dispersal (e.g. along fungal networks) in response to quality and quantity of bioavailable carbon and/or water availability plays a major role, as the development of functional guilds of microbes requires energy and depends on the redox state of the habitat.To address these questions, hexadecane degradation will be studied in differently developed artificial and natural soils. To answer the question on the role of carbon quantity and quality, experiments will be performed with and without litter material at different water contents of the soil. Experiments will be performed with intact soil columns as well as soil samples where the developed interface structure has been artificially destroyed. Molecular analysis of hexadecane degrading microbial communties will be done in vitro as well as in situ. The corresponding toolbox has been successfully developed in the first phase of the priority program including methods for genome, transcriptome and proteome analysis.
Previous studies indicated that the development and biogeochemistry of paddy soils relates to the parent material, thus the original soil paddies derive from. The proposed research focuses on redox-mediated changes in mineral composition and mineral-associated organic matter (OM) during paddy transformation of different soils. We plan to subject soil samples to a series of redox cycles, in order to mimic paddy soil formation and development. Soils with strongly different properties and mineral composition as well as at different states of paddy transformation; ranging from unchanged soils to fully developed paddy soils, are to be included. We hypothesize that dissolved organic matter is one key driver in redox-mediated transformations, serving as an electron donator as well as interacting with dissolved metals and minerals. The extent of effects shall depend on the parent soil's original mineral assemblage and organic matter and their mutual interactions. The experimental paddy soil transformation will tracked by analyses of soil solutions, of the (re-)distribution of carbon (by addition of 13C-labelled rice straw), of indicative biomolecules (sugars, amino sugars, fatty acids, lignin) and of minerals (including the redox state of Fe). For analyses of organic matter as well as of mineral characteristics we plan to utilize EXAFS and XPS, for Fe-bearing minerals also Mößbauer spectroscopy. This approach of experimental pedology seems appropriate to give insight into the major factors during paddy soil formation and development.
The nature of the microbial communities inhabiting the deeper soil horizons is largely unknown. It is also not clear why subsurface microorganisms do not make faster use of organic compounds under field conditions. The answer could be provided by a reciprocal soil transfer experiment studying the response of transferred soils to fluctuations in microclimate, organic inputs, and soil biota. The subproject P9 will be responsible for the establishment of reciprocal transfer experiments offering a strong link between subgroups interested in organic matter quality, transport of organic substances, as well as functions of the soil microbial community. A single, high molecular weight substrate (13C labelled cellulose) will be applied at two different levels in the pre-experiment to understand the dose-dependent reaction of soil microorganisms in transferred surface and sub-soils. Uniformly 13C labelled beech roots - representing complex substrates - will be used for the main reciprocal soil transfer experiment. We hypothesize that transferring soil cores between subsoil and surface soil as well as addition of labelled cellulose or roots will allow us to evaluate the relative impact of surface/subsurface habitat conditions and resource availability on abundance, function, and diversity of the soil microbial community. The second objective of the subproject is to understand whether minerals buried within different soil compartments (topsoil vs. subsoil) in the field contribute to creation of hot spots of microbial abundance and activity within a period of two to five years. We hypothesize that soil microorganisms colonize organo-mineral complexes depending on their nutritional composition and substrate availability. The existence of micro-habitat specific microbial communities could be important for short term carbon storage (1 to 6 years). The third objective is to understand the biogeography and function of soil microorganisms in different subsoils. Parent material as well as mineral composition might control niche differentiation during soil development. Depending on size and interconnectedness of niches, colonization and survival of soil microbial communities might be different in soils derived from loess, sand, terra fusca, or sandstone. From the methodological point of view, our specific interest is to place community composition into context with soil microbial functions in subsoils. Our subgroup will be responsible for determining the abundance, diversity, und function of soil microorganisms (13C microbial biomass, 13C PLFA, enzyme activities, DNA extraction followed by quantitative PCR). Quantitative PCR will be used to estimate total abundances of bacteria, archaea and fungi as well as abundances of specific groups of bacteria at high taxonomic levels. We will apply taxa specific bacterial primers because classes or phyla might be differentiated into ecological categories on the basis of their life strategies.
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