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Forschergruppe (FOR) 1806: The Forgotten Part of Carbon Cycling: Organic Matter Storage and Turnover in Subsoils (SUBSOM)

Das Projekt "Forschergruppe (FOR) 1806: The Forgotten Part of Carbon Cycling: Organic Matter Storage and Turnover in Subsoils (SUBSOM)" wird vom Umweltbundesamt gefördert und von Universität Bochum, Geographisches Institut, Arbeitsgruppe Bodenkunde und Bodenökologie durchgeführt. We are currently facing the urgent need to improve our understanding of carbon cycling in subsoils, because the organic carbon pool below 30 cm depth is considerably larger than that in the topsoil and a substantial part of the subsoil C pool appears to be much less recalcitrant than expected over the last decades. Therefore, small changes in environmental conditions could change not only carbon cycling in topsoils, but also in subsoils. While organic matter stabilization mechanisms and factors controlling its turnover are well understood in topsoils, the underlying mechanisms are not valid in subsoils due to depth dependent differences regarding (1) amounts and composition of C-pools and C-inputs, (2) aeration, moisture and temperature regimes, (3) relevance of specific soil organic carbon (SOC) stabilisation mechanisms and (4) spatial heterogeneity of physico-chemical and biological parameters. Due to very low C concentrations and high spatio-temporal variability of properties and processes, the investigation of subsoil phenomena and processes poses major methodological, instrumental and analytical challenges. This project will face these challenges with a transdisciplinary team of soil scientists applying innovative approaches and considering the magnitude, chemical and isotopic composition and 14C-content of all relevant C-flux components and C-fractions. Taking also the spatial and temporal variability into account, will allow us to understand the four-dimensional changes of C-cycling in this environment. The nine closely interlinked subprojects coordinated by the central project will combine field C-flux measurements with detailed analyses of subsoil properties and in-situ experiments at a central field site on a sandy soil near Hannover. The field measurements are supplemented by laboratory studies for the determination of factors controlling C stabilization and C turnover. Ultimately, the results generated by the subprojects and the data synthesized in the coordinating project will greatly enhance our knowledge and conceptual understanding of the processes and controlling factors of subsoil carbon turnover as a prerequisite for numerical modelling of C-dynamics in subsoils.

The effect of elevated atmospheric CO2 concentration on gross nitrogen dynamics, plant N-uptake and microbial community dynamics in a permanent grassland

Das Projekt "The effect of elevated atmospheric CO2 concentration on gross nitrogen dynamics, plant N-uptake and microbial community dynamics in a permanent grassland" wird vom Umweltbundesamt gefördert und von Universität Gießen, Institut für Pflanzenökologie (Botanik II) durchgeführt. To predict ecosystem reactions to elevated atmospheric CO2 (eCO2) it is essential to understandthe interactions between plant carbon input, microbial community composition and activity and associated nutrient dynamics. Long-term observations (greater than 13 years) within the Giessen Free Air Carbon dioxide Enrichment (Giessen FACE) study on permanent grassland showed next to an enhanced biomass production an unexpected strong positive feedback effect on ecosystem respiration and nitrous oxide (N2O) production. The overall goal of this study is to understand the long-term effects of eCO2 and carbon input on microbial community composition and activity as well as the associated nitrogen dynamics, N2O production and plant N uptake in the Giessen FACE study on permanent grassland. A combination of 13CO2 pulse labelling with 15N tracing of 15NH4+ and 15NO3- will be carried out in situ. Different fractions of soil organic matter (recalcitrant, labile SOM) and the various mineral N pools in the soil (NH4+, NO3-, NO2-), gross N transformation rates, pool size dependent N2O and N2 emissions as well as N species dependent plant N uptake rates and the origin of the CO2 respiration will be quantified. Microbial analyses will include exploring changes in the composition of microbial communities involved in the turnover of NH4+, NO3-, N2O and N2, i.e. ammonia oxidizing, denitrifying, and microbial communities involved in dissimilatory nitrate reduction to ammonia (DNRA). Stable Isotope Probing (SIP) and mRNA based analyses will be employed to comparably evaluate the long-term effects of eCO2 on the structure and abundance of these communities, while transcripts of these genes will be used to target the fractions of the communities which actively contribute to N transformations.

Natural variation of flowering time due to cis-regulatory evolution of FLOWERING LOCUS T and its orthologs and paralogs in Brassica napus

Das Projekt "Natural variation of flowering time due to cis-regulatory evolution of FLOWERING LOCUS T and its orthologs and paralogs in Brassica napus" wird vom Umweltbundesamt gefördert und von Max-Planck-Institut für Pflanzenzüchtungsforschung, Abteilung Entwicklungsbiologie der Pflanzen durchgeführt. In many plant species, FLOWERING LOCUS T and related proteins are the mobile signal that communicates information on photoperiod from the leaves to the shoots, where the transition to flowering is realized. FT expression is tightly controlled at the transcriptional level so that it is restricted to leaves, occurs only in appropriate photoperiods, and integrates ambient temperature and developmental cues, as well as information on biotic and abiotic stress. We previously established that FT transcription in the model plant Arabidopsis thaliana requires proximal promoter cis-elements and a distal enhancer, both evolutionary conserved among Brassicacea species. In addition, FT transcription is blocked prior vernalization in biannual accessions and vernalization-dependency of FT is controlled through a CArG-box located in the first intron that binds the transcriptional repressor FLOWERING LOCUS C (FLC). Chromatin-mediated repression by the Polycomb Group (PcG) pathway is required for photoperiod-dependent FT regulation and participates in FT expression level modulation in response to other cues.In this project, I propose to explore the available sequence data from the 1001 genome project in Arabidopsis to evaluate how often changes in regulatory cis-elements at FT have occurred and how these translate into an adaptive value. Allele-specific FT expression pattern will be measured in F1 hybrids of different accessions in response to varying environmental conditions. FT alleles that show cis-regulatory variation will be further analyzed to pinpoint the causal regulatory changes and study their effect in more detail. The allotetrapolyploid species Brassica napus is a hybrid of two Brassiceae species belonging to the A- and C-type genome, which are in turn mesopolyploid due to a genome triplication that occurred ca. 10x106 years ago. We will determine allele-specific expression of FT paralogs from both genomes of a collection of B. napus accessions. The plants will be grown in the field in changing environmental conditions to maximize the chance to detect expression variation of the paralogs. We will compare the contribution of the founder genomes to the regulation of flowering time and asses variation in this contribution. A particular focus will be to study the impact of chromatin-mediated repression on allele selection in B. napus.

Biological Regulation of Subsoil C-cycling under Field Conditions

Das Projekt "Biological Regulation of Subsoil C-cycling under Field Conditions" wird vom Umweltbundesamt gefördert und von Universität Hohenheim, Institut für Bodenkunde und Standortslehre, Fachgebiet Bodenbiologie durchgeführt. 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.

A meta-analysis of global insecticide concentrations in agricultural surface waters

Das Projekt "A meta-analysis of global insecticide concentrations in agricultural surface waters" wird vom Umweltbundesamt gefördert und von Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, Institut für Umweltwissenschaften durchgeführt. Although global pesticide use increases steadily, our field-data based knowledge regarding exposure of non-target ecosystems is very restricted. Consequently, this meta-analysis will for the first time evaluate the worldwide available peer-reviewed information on agricultural insecticide concentrations in surface water or sediment and test the following two hypotheses: I) Insecticide concentrations in the field largely exceed regulatory threshold levels and II) Additional factors important for threshold level exceedances can be quantified using retrospective meta-analysis. A feasibility study using a restricted dataset (n = 377) suggested the significance of the expected results, i.e. an threshold level exceedance rate of more than 50Prozent of the detected concentrations. Subsequent to a comprehensive database search in the peer-reviewed literature of the past 60 years, analysis of covariance with the relevant threshold level exceedance as the continuous dependent variable (about 10,000 cases) will be performed and the impact of significant predictor variables will be quantified. Parameters not yet considered in pesticide exposure assessment will be included as independent variables, such as compound class, environmental regulatory quality, and sampling design. The simultaneous presence of several insecticide compounds as a well as their metabolites will also be considered in the evaluation. The present approach may provide an innovative and integrated view on the potential environmental side effects of global high-intensity agriculture and in particular of pesticides use.

DFG Trilateral collaboration Deutschland-Israel-Palestine: Wastewater from Olive Oil Mills in Israel and Palestine: Interactions with Soil, Organic Contaminants and Mechanisms of Incorporation into Soil

Das Projekt "DFG Trilateral collaboration Deutschland-Israel-Palestine: Wastewater from Olive Oil Mills in Israel and Palestine: Interactions with Soil, Organic Contaminants and Mechanisms of Incorporation into Soil" wird vom Umweltbundesamt gefördert und von Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, Institut für Umweltwissenschaften durchgeführt. Due to the often practised uncontrolled disposal into the environment, olive oil production wastewater (OPWW) is presently a serious environmental problem in Palestine and Israel. The objectives of this interdisciplinary trilateral research project are (i) to understand the mechanisms of influence of the olive oil production wastewater on soil wettability, water storage, interaction with organic agrochemicals and pollutants; (ii) monitor short-term and long-term effects of OPWW land application in model laboratory and field experiments; (iii) identify the components responsible for unwanted changes in soil properties and (iv) analyse the mechanisms of association of OPWW OM with soil, the interplay between climatic conditions, pH, presence of multivalent cations and the resulting effects of land application. Laboratory incubation experiments, field experiments and new experiments to study heat-induced water repellency will be conducted to identify responsible OPWW compounds and mechanisms of interaction. Samples from field experiments and laboratory experiments are investigated using 3D excitation-emission fluorescence spectroscopy, thermogravimetry-differential thermal analysis-mass spectrometry (TGA-DSC-MS), LC-MS and GC-MS analyses. We will combine thermal decomposition profiles from OPWW and OPWW-treated soils in dependence of the incubation status using TGA-DSC-MS, contact angle measurements, sorption isotherms and the newly developed time dependent sessile drop method (TISED). The resulting process understanding will open a perspective for OPWW wastewater reuse in small-scale and family-scale olive oil production busi-nesses in the Mediterranean area and will further help to comprehend the until now not fully un-ravelled effects of wastewater irrigation on soil water repellency.

Between Path Dependence and Path Creation: The Impact of Farmers' Behavior and Policies on Structural Change in Agriculture

Das Projekt "Between Path Dependence and Path Creation: The Impact of Farmers' Behavior and Policies on Structural Change in Agriculture" wird vom Umweltbundesamt gefördert und von Leibniz-Institut für Agrarentwicklung in Mittel- und Osteuropa durchgeführt. 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-mediated mechanisms to stabilize pollination of agricultural production highly dependent on shrinking honey bee populations under global change

Das Projekt "Community-mediated mechanisms to stabilize pollination of agricultural production highly dependent on shrinking honey bee populations under global change" wird vom Umweltbundesamt gefördert und von Universität Lüneburg, Institut für Ökologie (IE), Professur für Tierökologie durchgeführt. Almond in California represents an agroecosystem pollinated solely by a single species, the European honey bee, a species that is becoming increasingly difficult and expensive to manage due to substantial, unpredictable mortality. Therefore, sustainable and high output production require a more integrated approach that diversifies sources of pollination. For this purpose, detailed data of our understanding how diversity can stabilize pollination are required. The project will identify alternative wild pollinator species and collect high quality data contributing to our understanding of how diversity (pollen and insects) can bolster honey bee pollination during stable and unstable climatic conditions. The research will be carried out on almond orchards in Northern California known to be either pollinator species rich (up to 30 species) or depauperate (honey bees only). The replicated extremes in pollinator diversity represent a unique opportunity to study the effects of diversity on pollination in real agroecosystems combined with laboratory and glasshouse experiments. The overall goal is to provide basic research that is essential for our general understanding of how insect diversity can affect high-quality pollination under land use and climate change.

Fragmentation of the international forest regime complex: multi-dimensional descriptions, explanations, steering consequences and polital options; The production and utilisation of forest regime fragmentation by bureaucratic politics

Das Projekt "Fragmentation of the international forest regime complex: multi-dimensional descriptions, explanations, steering consequences and polital options; The production and utilisation of forest regime fragmentation by bureaucratic politics" wird vom Umweltbundesamt gefördert und von Georg-August-Universität Göttingen, Burckhardt-Institut, Professur für Forst- und Naturschutzpolitik und Forstgeschichte durchgeführt. This project aims at analysing the influence of competing national and international bureaucracies on the fragmentation of the international forest regime complex (IFRC). Its objectives are: - describing the political dimension of fragmentation of the IFRC programme- explaining the political dimension of fragmentation based on the model of bureaucratic politics- analysing the steering consequences resulting from fragmentation - trans-disciplinary design of solutions for coping with political aspects of fragmentationBuilding on the bureaucratic politics approach these objectives will be pursued by testing the linking hypothesis: Interest and influence of the bureaucracies cause a fragmented programme of the IFRC. This programme supports the goal of profitable timber production but keeps the decision about biodiversity and CO2 sequestration open hindering the effective steering by the IFRC. The project develops an analytical framework consisting of the following independent variables: competing national and competing international bureaucracies, elected politicians, national and international non-state actors and media discourses. The fragmentation of the political programme of the IFRC is the overall dependent variable. This project will analyse the influence of bureaucracies and their coalitions on fragmentation at the international level as well as in national case studies in Sweden, Poland and Germany. The other independent variables will be covered by sub-projects 2, 3 and 4. The findings will be linked to the other political and to the economic and technic-ecological sub projects in order to contribute to the multi-disciplinary description and explanation of fragmentation and its steering consequences.

Teilprojekt: Kalibrierung und Dekonvolution von Bohrlochseismogrammen zur Optimierung von seismischen Gefährdungsanalysen und Bestimmung von Erdbeben-Quellparameter am Beispiel von Wellenformendaten aus dem ICDP-GONAF-Projekt

Das Projekt "Teilprojekt: Kalibrierung und Dekonvolution von Bohrlochseismogrammen zur Optimierung von seismischen Gefährdungsanalysen und Bestimmung von Erdbeben-Quellparameter am Beispiel von Wellenformendaten aus dem ICDP-GONAF-Projekt" wird vom Umweltbundesamt gefördert und von Helmholtz-Zentrum Potsdam Deutsches GeoForschungsZentrum durchgeführt. In den zurückliegenden 1.5 Jahren des Projektes konzentrierten sich die Arbeiten auf das erste bereits fertiggestellte vertikale Seismometer-Array des ICDP-GONAF-Observatoriums auf der Tuzla Halbinsel im Südosten Istanbuls. Aufgrund des verbesserten Signal-Rausch-Verhältnisses an den Bohrlochseismometern im Vergleich zu den Oberflächenstationen war es möglich, deutlich mehr M kleiner als 0 Mikrobeben zu detektieren. Diese Messdaten stellten die Grundlage für die bereits durchgeführten seismologischen Studien dar. In der hier beantragten Verlängerung werden wir unsere Erdbebendatenbank für das östliche Marmarameer fortlaufend erweitern, indem wir die im Sommer 2014 fertig gestellten Seismometer-Arrays auf der Armutlu-Halbinsel in die Detektionsalgorithmen integrieren, sowie dann auch weitere vier GONAF-Bohrlocharrays, deren Fertigstellung bis Frühjahr 2015 geplant ist. Es wurden verschiedene Methoden zur Bestimmung oberflächennaher Eigenschaften des Tuzla-Standortes, wie z.B. seismische Geschwindigkeiten und Dämpfung, angewendet und angepasst. Dieselben Methoden werden auf die neuen GONAF-Stationen übertragen, um zu verifizieren, ob die Beobachtungen in Tuzla standortspezifisch, oder auch für andere geologische Formationen repräsentativ sind. Die dann erstmals durchgeführte vergleichende Analyse unterschiedlicher Standorte in der Region wird neue Einblicke geben, um die Auswerteverfahren für die Korrektur von Standort-Effekten weiterzuentwickeln. Dies ist z.B. für eine genaue Abschätzung von Erdbeben-Quellparametern essentiell. Darüber hinaus planen wir, Processing-Methoden des Vertical-Seismic Profiling einzusetzen, um die Zweige der Nordanatolischen Verwerfungszone unterhalb des östlichen Marmarameeres abzubilden (passive fault-zone imaging). Dabei wird die lokale Seismizität genutzt, die in kleiner als 20 km Epizentralentfernung von den GONAF-Stationen in Tiefen von 5 bis 20 km auftritt und an den verschiedenen Tiefenstockwerken der GONAF-Arrays registriert wird. Schließlich werden Wellenformen-Registrierungen von erstmals in 300m Tiefe eingesetzten 3-Komponenten 1Hz MARK Seismometern ausgewertet, unter Anderem um verstärkt S-Wellen-Eigenschaften der Region zu untersuchen.

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