Das Projekt "Water yield response to changes in land-use and climate in a semihumid/-arid transition region (Jinghe basin, Northwest China)" wird vom Umweltbundesamt gefördert und von Technische Universität Dresden, Institut für Bodenkunde und Standortslehre durchgeführt. The effort of vegetation restoration in recent decades has been effective for soil erosion control, but accompanied by a drastic reduction of water yield in the main tributaries of the Yellow River. This has led to an emerging debate notably about forest development. Increased temperature and decreased precipitation may also have contributed to water yield reduction. An essential key for developing an integrated land-use and water management approach is to understand and separate the hydrological response to changes in land use and climate. In this study on multiple scales ranging from single tree to watershed, water balance components, vegetation structure dynamics, and soil hydraulic properties will be investigated and continuously monitored on selected plots with vegetation typical to the region. Our research will be carried out in the semihumid/-arid transition region of Jinghe which is an important tributary of the Yellow River. We follow a nested approach on scales of plots and watersheds along a upstream/downstream situation in a representative subbasin. On the basis of our measurements, the process-oriented model BROOK90 will be implemented for predicting the water yield response to changes in climate and vegetation depending on relief and soil conditions. The results obtained from plot studies will be used to parameterize the distributed model SWIM. In a next step, SWIM will be fitted to the catchment discharge and to assess the effect of different land use and vegetation management on water yield. This assessment will provide a solid foundation for how much of the catchment area can be changed by vegetation restoration through forest management to maintain a certain level of water supply security that will ensure a more sustainable regional development.
Das Projekt "Culture experiments on the environmental controls of trace metal ratios (Mg/Ca, B/Ca, U/Ca) recorded in calcareous tests of bipolar deep-sea benthic foraminifera" wird vom Umweltbundesamt gefördert und von Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung durchgeführt. The Polar eans are our most important climate amplifiers: First, the production of polar deep waters drives the Global Thermohaline Conveyer Belt, and thus, climate. Second, the Antarctic deep water during glacial time was, disputably still is, the largest marine sink of atmospheric CO2. Employment of effective and fossilisable proxies on changes in the physical and geochemical properties is essential to assess glacial-interglacial variabilities, modern and future changes in bipolar deep-waters. In this respect, analyses on trace metal (Mg/Ca, U/Ca, B/Ca) ratios recorded in tests of foraminifers to estimate calcification temperatures, alkalinity, carbonate ion saturation, and pH are common methods. However, for the Arctic and Southern Ocean deep-sea benthic foraminifera calibration curves constrained by either core-top samples or culture experiments are lacking. Newly developed high-pressure aquaria have recently facilitated the first efficient cultivation (producing offspring) of our most trusted palaeodeep-water recorders Fontbotia wuellerstorfi and Uvigerina peregrina. In different experimental set-ups the same facilities will be used to cultivate these foraminifera and associated species at different temperatures and in waters with different carbonate chemistries to establish the first species-specific trace metal calibration curves for both Polar Oceans. Core top analyses on more than 150 core sites from both oceans will verify the experimental results.
Das Projekt "Glufosinat: Metabolismus in transgenen und nicht-transgenen Pflanzengeweben sowie Schicksal im Boden" wird vom Umweltbundesamt gefördert und von RWTH Aachen University, Institut für Umweltforschung, Biologie V, Lehrstuhl für Umweltbiologie und -chemodynamik durchgeführt. Glufosinat (oder Phosphinotricin) ist ein vergleichsweise modernes Herbizid, das seit etwa 25 Jahren in Gebrauch ist. Bei der Verbindung handelt es sich um eine Aminosäure; üblicherweise bezeichnet man das DL-Racemat als Glufosinat, das L-Enantiomer als Phosphinothricin. Die Verbindung ist Teilstruktur eines von den Pilzen Streptomyces viridochromogenes und Streptomyces hygroscopicus produzierten natürlichen Antibiotikums (Tripeptid: L-Alanin-L-Alanin-L-Phosphinothricin). Neben seiner antibakteriellen Wirkung zeigt Glufosinat eine nicht-selektive herbizide Wirkung. Der antibakterielle und herbizide Effekt geht nur vom L-Enantiomer aus; das D-Enantiomer ist inaktiv. Sowohl Glufosinat (Racemat) als auch das Tripeptid (Bialaphos oder Bilanaphos; mit L-Enantiomer) werden als Herbizide vermarktet. Die herbizide Wirkung von Phosphinothricin beruht auf einer Inhibition der Glutaminsynthetase. Glufosinat weist günstige ökotoxikologische Eigenschaften auf, z.B. bezüglich Versickerung, Abbau sowie Toxizität gegenüber Tier und Mensch. Auf Grund dieser Eigenschaften ist Glufosinat ein geeigneter Kandidat zur Herstellung gentechnisch modifizierter Herbizid-resistenter Pflanzen, um Glufosinat auch selektiv - im Nachauflauf - einsetzen zu können. Dazu wurden verschiedene Spezies, wie z.B. die Zuckerrübe, mit dem bar-Gen aus Streptomyces hygroscopicus transformiert. Das bar-Gen codiert für eine Phosphinothricin-N-acetyltransferase, die Phosphinothricin zum nicht herbizid-wirksamen, stabilen N-Acetylderivat umsetzt. Bei entsprechend hoher Expression des bar-Gens resultiert eine Glufosinat-resistente Pflanze. Ein Ziel unseres Forschungsvorhabens war es, den Metabolismus von Glufosinat und der einzelnen Enantiomere (L- und D-Phyosphinothricin) in transgenen und nicht transgenen Pflanzenzellkulturen zu untersuchen. Die transgenen Kulturen, die von der Zuckerrübe (Beta vulgaris) stammten, waren mit dem bar-Gen transformiert, exprimierten demnach die Phosphinothricin-N-acetyltransferase. Sie wurden aus entsprechenden Sprosskulturen initiiert. Daneben wurden nicht-transgene Kulturen von Zuckerrübe, Karotte (Daucus carota), Fingerhut (Digitalis purpurea) und Stechapfel (Datura stramonium) untersucht. In einer zweiten Versuchsserie wurden abgetrennte Sprosse und Blätter von 20 Wildpflanzen auf den Metabolismus von Glufosinat untersucht. Es sollte überprüft werden, ob qualitative und quantitative Unterschiede im Umsatz des Herbizids im Pflanzenreich vorkommen und möglicherweise eine natürliche (teilweise) Resistenz gegenüber Glufosinat existiert. Schließlich wurde das Schicksal des Herbizids im Boden (Abbau, Versickerung) nach Aufbringung des Wirksstoffs in einer handelsüblichen Formulierung auf ein bewachsenes Versuchsfeld im Freiland untersucht.
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 "Sub project: Imaging Induced Seismicity at the KTB" wird vom Umweltbundesamt gefördert und von Universität Hamburg, Zentrum für Meeres- und Klimaforschung, Institut für Geophysik durchgeführt. The observation of naturally or artificially generated acoustic emissions (i.e., small earthquakes) by seismic networks is a powerful tool to image transport processes in the earth. During the injection experiments at the KTB a large number of events were observed. The precise spatio-temporal characterization of the seismic events is of utmost importance since all following interpretations (e.g., transport properties) rely entirely on this result. The localization of the events depends on the model used for the localization. The anisotropy of the KTB rocks is a well known feature but was not considered for the localization. Previous studies demonstrate that this leads to severe errors in the location of events. In this study we will first determine the anisotropic elastic features from the comprehensive KTB VSP data sets using 3-D anisotropic tomography for P- and S-waves. This step is essential for the localization. The obtained tomographic anisotropic 3-D model will then be used for the localization of the acoustic emissions of the 2000 and 2004 injection experiments. A newly developed technology based on reversed modelling or time reversed acoustic mirrors will be used to image the events. This techniques does not require picking of events and increases the detection level of the network owing to the stacking character of the method and allows to locate arrivals not visible in the individual seismograms of the network.
Das Projekt "Sub project: Hydrochemical and hydraulic properties of the continental upper crust at the KTB site" wird vom Umweltbundesamt gefördert und von Regierungspräsidium Freiburg, Abteilung 9 - Landesamt für Geologie, Rohstoffe und Bergbau durchgeführt. A constant rate pumping test of one year duration is planed to be carried out in the 4.0 km deep pilot hole of KTB. Watertable fluctuations in the pilot borehole and in the 9.1 km deep main borehole will be monitored as well. A wealth of data (pumping rate, watertable/ pressure, temperature, salinity/electrical conductivity, water samples,....) will become available, some even online. The first objective of the proposed project is to determine the flow system (type of aquifer model). From this deduced hydraulic model follow the hydraulic characteristics (such as: transmissivity, storage coefficient, fracture lengt/ width/aperture, permeability of fractures and matrix,....) describing the properties of the crystalline basement rocks in vicinity of the KTB pilot- and main hole. The length of the expect test radius is some 1000 m. The proposed project intends also to determine the degree of the hydraulic connection between the two holes (having a depth difference of 5.1 km). Additional information, such as water analyses, will be needed in interpreting the hydraulic data. A second major objective is the modelling of water-rock interaction (WRI) processes using the chemical data of KTB fluids. In particular the time series of chemical data will be used to model the kinetic and time dependent processes. We expect as well to see some breakthroughs of 'fresh, clean' crystalline basement water and another breakthrough resulting from fluid stored in the main hole and its surrounding.
Das Projekt "Sub project: What ends an Interglacial? Feedbacks between tropical rainfall, Atlantic climate and ice sheets during the Last Interglacial (EndLIG)" wird vom Umweltbundesamt gefördert und von Universität Bremen, Fachbereich 5 Geowissenschaften, Fachgebiet Geosystem Modellierung durchgeführt. When and how the present interglacial will end remains an open question. With a relatively wellknown climate, the Last Interglacial (LIG) and following glacial inception can shed some light on the climate mechanisms leading to the establishment of a new ice age. Two key questions arise from the chain of climate events known to end the LIG: (1) Did the interglacial North Atlantic warmth, prolonged by an active thermohaline circulation (THC), favor or delay the growth of northern ice sheets? (2) Did reorganizations in South American moisture contribute to prolong the North Atlantic warmth by maintaining a salty North Atlantic and active THC at the end of the LIG, as suggested by tropical moisture feedbacks observed during glacial times? To address these questions, we propose here to combine new paleoclimate reconstructions with climate model experiments. First, we will reconstruct the detailed evolution of the South American rainbelt during the last glacial inception, by applying complementary proxies on a transect of marine sediment cores. Second, we will assess the impact of tropical hydrologic changes on tropical Atlantic sea surface salinities (SSS) and the Atlantic THC, by comparing tropical Atlantic SSS and deep-water properties with model sensitivity experiments where we will vary the tropical freshwater forcing. Finally, we will perform a transient climate/ice-sheet model run for the last glacial inception, and a sensitivity study, in which different ocean heat fluxes will be imposed to investigate the effect of prolonged North Atlantic warmth on ice sheet growth.
Das Projekt "Tagung 'Welterbe und nachhaltige Entwicklung' an der INA Vilm" wird vom Umweltbundesamt gefördert und von Bundesamt für Naturschutz durchgeführt. Vom 16. - 20. Oktober 2017 hat an der INA die Tagung 'World Heritage and Climate Change - Towards an Update of the Policy Document on the Impacts of Climate Change on World Heritage Properties' stattgefunden. Mitveranstalter waren IUCN, das UNESCO-Welterbezentrum, sowie die beiden anderen Beratungsorganisationen der Welterbekonvention, ICOMOS und ICCROM. Zielsetzung des Workshops war es, zur Umsetzung der Entscheidungen des Welterbekomitees von 2016 und 2017 beizutragen, welche eine Überarbeitung des 'Policy Documents on the Impacts of Climate Change on World Heritage Properties' fordert. In den Prozessen der Welterbekonvention wird das Thema 'Sustainable Development' mittelfristig eine wichtige Rolle spielen. Der Klimawandel ist ein zentrales Element der 'Policy for the Integration of a Sustainable Development Perspective into the Processes of the World Heritage Convention'. Damit stand der Workshop in direktem Zusammenhang mit dem bereits 2016 durchgeführten Workshop zum Thema 'World Heritage and Sustainable Development'. Die Veranstaltung war mit 20 internationalen Expertinnen und Experten aus 15 verschiedenen Ländern sehr gut besucht. Es ist gelungen Expertinnen und Experten aus allen globalen Regionen, dem Natur- und Kulturerbesektor, sowie Vertreter der Mitveranstalter zusammen zu bringen. Die Ergebnisse des Workshops lassen sich wie folgt zusammenfassen: - Die TeilnehmerInnen stellten fest, dass Klimawandel sich in den vergangenen Jahren zu einem der Haupteinflussfaktoren auf Welterbestätten entwickelt hat. - Die aktuelle Policy, 2007 verabschiedet, benötigt eine umfassende Überarbeitung, da sie sich ausschließlich mit dem Management von Klimawandelfolgen in Welterbstätten befasst und übergeordnete Fragen zum Zusammenhang zwischen Welterbe und Klimawandel und neue Entwicklungen im internationalen Klimaschutz nicht behandelt. - Im Workshop wurden Empfehlungen im Hinblick auf diese Überarbeitung entwickelt, die sich mit den Inhalten der zukünftigen 'Policy', dem Ansatz für die Umsetzung der neuen Policy und dem weiteren Prozess zur Erarbeitung dieser befassen. Die wichtigsten Ergebnisse des Workshops wurden in einem Bericht zusammengefasst und werden direkt in den weiteren Prozess zur Überarbeitung des Dokumentes einfließen, welcher vom UNESCO-Welterbezentrum und den Beratungsorganisationen gesteuert wird. Dieser Bericht wurde vom Welterbezentrum bereits auf dessen Webseite veröffentlicht.
Das Projekt "INI 1128575 STP-2: Fate of Plant Residues in Soil Organic Matter Pools under Contrast Land Use as Evaluated by Two Tracer Techniques" wird vom Umweltbundesamt gefördert und von Universität Bayreuth, Fachgruppe Geowissenschaften, Bayreuther Zentrum für Ökologie und Umweltforschung (BayCEER), Lehrstuhl für Agrarökosystemforschung durchgeführt. Soil C sequestration through changes in land use and management is one of the important strategies to mitigate the global greenhouse effect. Plant residue is the primary source of C formation and sequestration in soil. The relative contribution of residues depends upon composition and decomposability of litter which is a function of lad use and management. The present project is conceived with objective to evaluate the fate of plant residue in soil C influenced by different land-use management practices. Ultimate aim to sketch policy for appropriate management practices, which would facilitate enrichment of C stock in soils for maintaining soil health and fertility as well as mitigation of global warming by C sequestration. Management practices like intensity of tilling and no tillage have a definite effect on SOC stock; it would be considered as pertinent management practice for residue derived C-turnover. To fulfil the objective as stated, representative soil samples will be collected under various land covers/uses and management practices and analysed for important physico chemical properties e.g. pH, CEC, clay content, bulk density, soil water storage, and soil porosity are the important soil physical parameters which influences C load in soil. Different pools of C viz. total SOC (Ctot), Water stable aggregates, labile fractions of oxidisable organic carbon etc. will be studied to know the C stock and its distribution in soil. Impact of added plant residue on C sequestration and C dynamics of plant residues decomposition in contrast land use will be analyzed and quantified by using 14C labelled plant residues as well as 13C natural abundance and allow for differentiation between residues-derived carbon and native SOC. Labeled microbial biomass C and mineralizable C, acetone exactable reside, 14C and d13C in CO2 and in SOM pool will be measured that may provide precise estimates of residues decomposition rates and contribution in soil organic C. Microbial biomass carbon (Cmic) and mineralizable carbon (Cmin) measured as early indicators of future trends in total SOM as it provides a good measure of labile organic matter because it directly reflects recent soil organic matter turnover. Data on biomass productivity will also be collected from those sites. Results would help us to know the relative efficiency of different land use managements for organic C enrichment or depletion in soils.
Das Projekt "D5: Functional soil landscape modelling in the Andean mountain forest zone: impact of land use and natural disturbances" wird vom Umweltbundesamt gefördert und von Universität Bayreuth, Bayreuther Zentrum für Ökologie und Umweltforschung (BayCEER), Abteilung für Bodenphysik durchgeführt. Spatial patterns of soil types and related hydrological, mechanical, chemical and biological properties considerably affect ecosystem behaviour and functioning on the local as well as on the landscape scale. In the tropical montane forests of Southern Ecuador landslides are assumed to have significant impact on pedogenesis, pedodiversity, landscape evolution and biodiversity. Consequently, soil landscape modelling needs to take into account the main governing factors of landslide dynamics like topography, soil hydrology, and vegetation development. Based on comprehensive datasets from previous funding periods and ongoing research our project aims at functional soil landscape modeling with special focus on pedodiversity and landslide risk assesment. Results will further be used for disturbance analyses, and hydrological modelling on the local, catchment and landscape scale in close cooperation with other working groups. Soil landscape modelling will be conducted using advanced statistical models like classifcication and regression trees (CART) and artificial neuronal networks (ANN). Hydrological modeling is conducted using GIS segmentation algorithms together with process based 2D- and 3D- hillslope and catchment models. Special attention will be directed to spatial heterogeneity and parameter uncertainty. A total of 8 existing monitoring plots provide us with throughfall, matric potential, water content and discharge data of subcatchments for model calibrations. Occurrence and relevance of preferential flow can be assessed with the help of dye tracer image analyses from previous funding periods.
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