Beach sand deposits are widespread in the area around Sandefjord, at the western coast of the Oslofjord, southern Norway. The age of the deposits continuously increases with elevation, as the area has been subject to steady glacio-isostatic uplift throughout the Holocene. Existing local sea level curves provide age control related to elevation. Thus, the area offers excellent conditions to test hypotheses on soil formation and OSL dating. A chronosequence covering the last 10 000 years will be established. A preliminary study showed that soil formation leads to Podzols within 4300 - 6600 years. Micromorphological analyses suggest that clay illuviation takes place before and below podzolisation. It is hypothesised that clay translocation goes on contemporarily with podzolisation, but at greater soil depth, where the chemical conditions are suitable. This hypothesis will be proved by more detailed micromorphological investigation and chemical analyses. The factors controlling soil forming processes and their rates, will be determined by analyzing elemental composition, primary minerals and clay mineralogy. Preliminary OSL dating tests suggest that the beach sand deposits are OSL dateable despite the high latitude. This hypothesis will be checked by comparing OSL datings to ages derived from the 14C-based sea level curves.
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.
Water, carbon and nitrogen are key elements in all ecosystem turnover processes and they are related to a variety of environmental problems, including eutrophication, greenhouse gas emissions or carbon sequestration. An in-depth knowledge of the interaction of water, carbon and nitrogen on the landscape scale is required to improve land use and management while at the same time mitigating environmental impact. This is even more important under the light of future climate and land use changes.In the frame of the proposal 'Uncertainty of predicted hydro-biogeochemical fluxes and trace gas emissions on the landscape scale under climate and land use change' we advocate the development of fully coupled, process-oriented models that explicitly simulate the dynamic interaction of water, carbon and nitrogen turnover processes on the landscape scale. We will use the Catchment Modelling Framework CMF, a modular toolbox to implement and test hypothesis of hydrologic behaviour and couple this to the biogeochemical LandscapeDNDC model, a process-based dynamic model for the simulation of greenhouse gas emissions from soils and their associated turnover processes.Due to the intrinsic complexity of the models in use, the predictive uncertainty of the coupled models is unknown. This predictive (global) uncertainty is composed of stochastic and structural components. Stochastic uncertainty results from errors in parameter estimation, poorly known initial states of the model, mismatching boundary conditions or inaccuracies in model input and validation data. Structural uncertainty is related to the flawed or simplified description of natural processes in a model.The objective of this proposal is therefore to quantify the global uncertainty of the coupled hydro-biogeochemical models and investigate the uncertainty chain from parameter uncertainty over forcing data uncertainty up the structural model uncertainty be setting up different combinations of CMF and LandscapeDNDC. A comprehensive work program has been developed structured in 4 work packages, that consist of (1) model set up, calibration and uncertainty assessment on site scale followed by (2) an application and uncertainty assessment of the coupled model structures on regional scale, (3) global change scenario analyses and finally (4) evaluating model results in an ensemble fashion.Last but not least, a further motivation of this proposal is to provide project results in a manner that they support planning and decision taking under uncertainty, as this proposal is part of the package proposal on 'Methodologies for dealing with uncertainties in landscape planning and related modelling'.
The project DIGSTER - Map and Go (Digital Based Terrain Mapping) aims at the technical aspects of digital terrrain mapping. For many questions in administration, planning and expertise terrrain mappings are indispensable. The whole process starting with the data acquisition in the field and ending with map products will be digitally performed by the system. Therefore, a platform appropriate for the use in the field (PDA) is combined with technologies from the disciplines of satellite navigation, remote sensing, communication, and mobile geoinformation systems. For DIGSTER a lot of practical applications already exist in connection with policies and directives on the national and also European level.
Especially during the last decades, the natural forests of Ethiopia have been heavily disturbed by human activities. Some forests have been totally cleared and converted into fields for agricultural use, other suffered from different influences, such as heavy grazing and selective logging. The ongoing research in the Shashemane-Munessa-study area (Gu 406/8-1,2) showed clearly that, in spite of interdiction and control, forests continue to be cleared and degraded. However, it is not yet sufficiently known, how and why these processes are still going on. Growing population pressure and economic constraints for the people living in and around the forests contribute to the actual situation but allow no final answers to the complex situation. Concerning a sustainable management of the forests there is to no solid basis for recommendations from the socioeconomic and socio-cultural view. Therefore, a comprehensive analysis of the traditional needs and forms of forest use, including all forest products, is necessary. The objective of this project is, to achieve this basis by carrying out intensive field observations, the consultation of aerial photographs, satellite imagery and above all semi-structured interviews with the population in the study area in order to contribute to the recommendations for a sustainable use of the Munessa Shasemane forests.
Arsenic-contaminated ground- and drinking water is a global environmental problem with about 1-2Prozent of the world's population being affected. The upper drinking water limit for arsenic (10 Micro g/l) recommended by the WHO is often exceeded, even in industrial nations in Europe and the USA. Chronic intake of arsenic causes severe health problems like skin diseases (e.g. blackfoot disease) and cancer. In addition to drinking water, seafood and rice are the main reservoirs for arsenic uptake. Arsenic is oftentimes of geogenic origin and in the environment it is mainly bound to iron(III) minerals. Iron(III)-reducing bacteria are able to dissolve these iron minerals and therefore release the arsenic to the environment. In turn, iron(II)-oxidizing bacteria have the potential to co-precipitate or sorb arsenic during iron(II)- oxidation at neutral pH followed by iron(III) mineral precipitation. This process may reduce arsenic concentrations in the environment drastically, lowering the potential risk for humans dramatically.The main goal of this study therefore is to quantify, identify and isolate anaerobic and aerobic Fe(II)-oxidizing microorganisms in arsenic-containing paddy soil. The co-precipitation and thus removal of arsenic by iron mineral producing bacteria will be determined in batch and microcosm experiments. Finally the influence of rhizosphere redox status on microbial Fe oxidation and arsenic uptake into rice plants will be evaluated in microcosm experiments. The long-term goal of this research is to better understand arsenic-co-precipitation and thus arsenic-immobilization by iron(II)-oxidizing bacteria in rice paddy soil. Potentially these results can lead to an improvement of living conditions in affected countries, e.g. in China or Bangladesh.
Farm structures are often characterized by regional heterogeneity, agglomeration effects, sub-optimal farm sizes and income disparities. The main objective of this study is to analyze whether this is a result of path dependent structural change, what the determinants of path dependence are, and how it may be overcome. The focus is on the German dairy sector which has been highly regulated and subsidized in the past and faces severe structural deficits. The future of this sector in the process of an ongoing liberalization will be analyzed by applying theoretical concepts of path dependence and path breaking. In these regards, key issues are the actual situation, technological and market trends as well as agricultural policies. The methodology will be based on a participative use of the agent-based model AgriPoliS and participatory laboratory experiments. On the one hand, AgriPoliS will be tested as a tool for stakeholder oriented analysis of mechanisms, trends and policy effects. This part aims to analyze whether and how path dependence of structural change can be overcome on a sector level. In a second part, AgriPoliS will be extended such that human players (farmers, students) can take over the role of agents in the model. This part aims to compare human agents with computer agents in order to overcome single farm path dependence.
Community forestry has not met the great public expectations on a significant contribution to sustainable forestry yet. Recent research in the management and policy of community forestry describes a complex process of multi level social choice which determines the outcomes. Our hypothesis is that the key factors determining the outcomes of community forestry are the interests and power of the external stake holders. This hypothesis will be tested in a comparative quantitative and qualitative analysis. In seven countries comprising developed and developing countries 84 cases will be used for comparison. The comparative analysis will be carried out by one PhD student financed by the project. He will do the field work in close cooperation with PhD students who are already conducting their PhD analysis the different countries. The comparative analysis is aimed to explore key drivers of community forestry which are not yet identified in literature.
Electrical conductivity is a key parameter in models of magnetic field generation in planetary interiors through magneto-hydrodynamic convection. Measurements of this key material parameter of liquid metals is not possible to date by experiments at relevant conditions, and dynamo models rely on extrapolations from low pressure/temperature experiments, or more recently on ab-initio calculations combining molecular dynamics and linear response calculations, using the Kubo-Greenwood formulation of transport coefficients. Such calculations have been performed for Fe, Fe-alloys, H, He and H-He mixtures to cover the interior of terrestrial and giant gas planets. These simulations are computationally expensive, and an efficient accurate scheme to determine electrical conductivities is desirable. Here we propose a model that can, at much lower computational costs, provide this information. It is based on Ziman theory of electrical conductivity that uses information on the liquid structure, combined with an internally consistent model of potentials for the electron-electron, electron-atom, and atom-atom interactions. In the proposal we formulate the theory and expand it to multi-component systems. We point out that fitting the liquid structure factor is the critical component in the process, and devise strategies on how this can be done efficiently. Fitting the structure factor in a thermodynamically consistent way and having a transferable electron-atom potential we can then relatively cheaply predict the electrical conductivity for a wide range of conditions. Only limited molecular dynamics simulations to obtain the structure factors are required.In the proposed project we will test and advance this model for liquid aluminum, a free-electron like metal, that we have studied with the Kubo-Greenwood method previously. We will then be able to predict the conductivities of Fe, Fe-light elements and H, He, as well as the H-He system that are relevant to the planetary interiors of terrestrial and giant gas planets, respectively.
Soil organic matter (SOM) controls large part of the processes occurring at biogeochemical interfaces in soil and may contribute to sequestration of organic chemicals. Our central hypothesis is that sequestration of organic chemicals is driven by physicochemical SOM matrix aging. The underlying processes are the formation and disruption of intermolecular bridges of water molecules (WAMB) and of multivalent cations (CAB) between individual SOM segments or between SOM and minerals in close interaction with hydration and dehydration mechanisms. Understanding the role of these mediated interactions will shed new light on the processes controlling functioning and dynamics of biogeochemical interfaces (BGI). We will assess mobility of SOM structural elements and sorbed organic chemicals via advanced solid state NMR techniques and desorption kinetics and combine these with 1H-NMR-Relaxometry and advanced methods of thermal analysis including DSC, TGADSC- MS and AFM-nanothermal analysis. Via controlled heating/cooling cycles, moistening/drying cycles and targeted modification of SOM, reconstruction of our model hypotheses by computational chemistry (collaboration Gerzabek) and participation at two larger joint experiments within the SPP, we will establish the relation between SOM sequestration potential, SOM structural characteristics, hydration-dehydration mechanisms, biological activity and biogechemical functioning. This will link processes operative on the molecular scale to phenomena on higher scales.
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