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This project focuses on the long-term stability (or otherwise) of vegetation, based on a series of multi-proxy records in southern South America. We will build a network of sites suitable for high-resolution reconstructions of changes in vegetation since the Last Glacial Maximum, and use these to test a null hypothesis that changes in vegetation over the past 14,000 years are driven by internal dynamics rather than external forcing factors. The extent to which the null hypothesis can be falsified will reveal the degree to which we can expect to be able to predict how vegetation is affected by external events, including future climate change. The southern fringes of the South American landmass provide a rare opportunity to examine the development of moorland vegetation with sparse tree cover in a wet, cool temperate climate of the Southern Hemisphere. We present a record of changes in vegetation over the past 17,000 years, from a lake in extreme southern Chile (Isla Santa Inés, Magallanes region, 53°38.97S; 72°25.24W; Fontana, Bennett 2012: The Holocene), where human influence on vegetation is negligible. The western archipelago of Tierra del Fuego remained treeless for most of the Lateglacial period. Nothofagus may have survived the last glacial maximum at the eastern edge of the Magellan glaciers from where it spread southwestwards and established in the region at around 10,500 cal. yr BP. Nothofagus antarctica was likely the earlier colonizing tree in the western islands, followed shortly after by Nothofagus betuloides. At 9000 cal. yr BP moorland communities expanded at the expense of Nothofagus woodland. Simultaneously, Nothofagus species shifted to dominance of the evergreen Nothofagus betuloides and the Magellanic rain forest established in the region. Rapid and drastic vegetation changes occurred at 5200 cal. yr BP, after the Mt Burney MB2 eruption, including the expansion and establishment of Pilgerodendron uviferum and the development of mixed Nothofagus-Pilgerodendron-Drimys woodland. Scattered populations of Nothofagus, as they occur today in westernmost Tierra del Fuego may be a good analogue for Nothofagus populations during the Lateglacial in eastern sites. Climate, dispersal barriers and/or fire disturbance may have played a role controlling the postglacial spread of Nothofagus. Climate change during the Lateglacial and early Holocene was a prerequisite for the expansion of Nothofagus populations and may have controlled it at many sites in Tierra del Fuego. The delayed arrival at the site, with respect to the Holocene warming, may be due to dispersal barriers and/or fire disturbance at eastern sites, reducing the size of the source populations. The retreat of Nothofagus woodland after 9000 cal. yr BP may be due to competitive interactions with bog communities. Volcanic disturbance had a positive influence on the expansion of Pilgerodendron uviferum and facilitated the development of mixed Nothofagus-Pilgerodendron-Drimys woodland.
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.
Flowering time (FTi) genes play a key role as regulators of complex gene expression networks, and the influence of these networks on other complex systems means that FTi gene expression triggers a cascade of regulatory effects with a broad global effect on plant development. Hence, allelic and expression differences in FTi genes can play a central role in phenotypic variation throughput the plant lifecycle. A prime example for this is found in Brassica napus, a phenotypically and genetically diverse species with enormous variation in vernalisation requirement and flowering traits. The species includes oilseed rape (canola), one of the most important oilseed crops worldwide. Previously we have identified QTL clusters related to plant development, seed yield and heterosis in winter oilseed rape that seem to be conserved in diverse genetic backgrounds. We suspect that these QTL are controlled by global regulatory genes that influence numerous traits at different developmental stages. Interestingly, many of the QTL clusters for yield and biomass heterosis appear to correspond to the positions of meta-QTL for FTi in spring-type and/or winter-type B. napus. Based on the hypothesis that diversity in FTi genes has a key influence on plant development and yield, the aim of this study is a detailed analysis of DNA sequence variation in regulatory FTi genes in B. napus, combined with an investigation of associations between FTi gene haplotypes, developmental traits, yield components and seed yield.
Forests play a relevant role in mitigation of climate change. A major issue, however, is the scientifically well founded, transparent and verifyable monitoring of achievements in forest carbon sequestration through reduction of deforestation and forest degradation, and through fostering sustainable forest management. Monitoring is particularly difficult in diverse and inaccessible humid tropical forest areas. The proposed research will contribute to the improvement of forest carbon monitoring under the challenging conditions of humid tropical forests. Sample based field observations and model based biomass predictions will be linked to area-wide satellite remote sensing imagery (RapidEye) and to strip samples of LiDAR imagery. Techniques of linking these data sources will be further developed and analysed with respect to (1) precision of carbon estimation and (2) accuracy of carbon regionalization. The proposed project implies research on methodological improvements of both sample based forest inventories (resampling techniques for biomass, imputation of non-response) and remote sensing application to forest monitoring (regionalization, sample based application of LiDAR data). At the core of this research is the analysis of the error variance components that each data source brings into the system. Such error analysis will allow identifying optimal resource allocation for the efficient improvement of forest carbon monitoring systems.
The dataset is composed of Neo HySpex (VNIR/SWIR) hyperspectral imagery acquired during airplane overflights on June 6th, 2015 covering the Omongwa Pan located in the South-West Kalahari, Namibia. The dataset includes three cloud-free flight lines with 408 spectral bands ranging from VNIR to SWIR wavelength regions (0.4-2.5 µm). The dataset also includes Level 2A EnMAP-like imagery simulated using the end-to-end Simulation tool (EeteS). The overall goal of the campaign was to acquire imagery over the Omongwa Pan and use the spectral reflectance for the analyses of surface sediments, specifically the mineralogical composition of exposed surface evaporites / salts on the airborne and spaceborne scale. The data are highly novel and can be used to test estimation of surface sediment properties in a highly saline and dynamic environment.
This report analyses the taxation of energy use in 41 countries, covering 80% of global energy use. It appears at a juncture when many countries struggle to sustain orreconnect with economic growth and face formidable fiscal consolidation challenges. At the same time, concerns over the very highhuman costs of air pollution are mounting and the urgency of acting to limit greenhouse gases isnow abundantly clear.Energy use is an important source of greenhouse gas emissions and of air pollution. It also is acritical input into production and consumption in modern economies. If deployed effectively, taxes onenergy use are a powerful tool to balance the benefits and costs of energy use. Energy use taxes canalso play a useful role in fiscal consolidation. What this report tells us, however, is that with currentpolicies energy taxes fail to live up to their potential.Taxes on energy use influence the price and use of energy. Ideally, end-user energy prices wouldreflect their environmental impacts to ensure that resources are used most productively and that thenegative side-effects of energy use are contained. Taxes can help to achieve this, while also providingincentives to seek alternative, cleaner technologies.To employ energy taxes more effectively, it is necessary to understand the signals they providein respect of energy use. This report systematically analyses the structure and level of energy taxesacross 41 countries: the OECD countries and seven selected partner economies (Argentina, Brazil,China, India, Indonesia, Russia and South Africa). Effective tax rates, expressed per unit of carbonand per unit of energy, are situated within the energy market structures and other pricing policies ineach country, allowing the price signals they send to be better understood.Our analysis highlights vastly different levels of energy use and taxation among these41 countries, but also some common patterns. Transport energy is typically taxed at higher ratesthan other forms of energy use whereas fuels for heating and process use or electricity generationare more likely to be untaxed or taxed at lower rates. Fuels used for similar purposes are often taxeddifferently, with low rates applying to some of the fuels most harmful for human health and theenvironment. Tax rates on coal are particularly low.The picture is not, however, entirely bleak. The awareness about the need to curb negative sideeffectsof energy use is rising on governments political agendas, with many, including the selectedpartner economies, reconsidering price signals and taxes on harmful forms of energy use andinvesting in renewable sources of energy. This report can serve as a reference for policy makers andanalysts to identify reform options to ensure that energy taxes are best adapted to their economic,social and environmental goals - that is, to develop better tax policies for better lives.
Dissolved organic matter (DOM), ubiquitous in natural waters, can both accelerate and inhibit the transformation of organic contaminants under the action of sunlight. In this project we relate the inhibition effect of DOM to its antioxidant capacity. Background Triplet-induced oxidation of several organic contaminants is likely to play a significant role for their fate in the aquatic environment. DOM carries not only photosensitizer moieties, able to form excited triplet states with oxidizing character, but also moieties that may be considered as antioxidants. Thus, DOM can act as a light-activated oxidant as well as a reductant. In a preceding project, we employed model aromatic ketones as the photosensitizers to disentangle this dual chemical nature and study the possible inhibition of triplet-induced oxidation. We could show that DOM is able to inhibit (or, in other words; slow down the rate of) triplet-induced oxidation of several organic contaminants, but especially those containing aniline functionalities. Various phenolic compounds, used as model antioxidants to mimic the corresponding moieties of DOM, were also shown to inhibit triplet-induced oxidation. The basic hypothesis, still valid at the present state of knowledge, is that oxidation intermediates of the target contaminant interact with model antioxidants or antioxidant moieties of the DOM, leading to reduction of the oxidation intermediates with consequent regeneration of the parent compound. However, the reason why certain contaminants undergo inhibition while others don't is still open. Objectives and methods We now intend to improve our understanding of the mechanisms that govern triplet-induced oxidation of contaminants and its inhibition by DOM. The two main objectives and the corresponding experimental methods are: 1. Detection, by nanosecond laser flash photolysis, of the oxidation intermediates of a few selected aniline derivatives and investigation of their decay kinetics in the presence of DOM and model antioxidants. 2. Study of the relationships between extent of inhibition of triplet-induced oxidation and electron donating capacity of different types of DOM to narrow down the suite of possible antioxidant moieties in DOM responsible for the observed inhibition of oxidation. Electrochemical measurements and selective oxidation of DOM by various chemical oxidants (ozone, chlorine, chlorine dioxide) will be used as additional experimental tools. Significance The results are anticipated to provide quantitative methods to assess the photoinduced degradation of a wide class of organic contaminants containing aniline moieties, including sulfonamide antibiotics, in natural waters.
Flavonoids (including flavones, flavonols, catechins, isoflavones, coumestans and anthocyanins) as well as biogenetically related phenylpropanoids of plant origin (e.g. stilbenes or lignans) represent important non-nutritive secondary ingredients of vegetables and fruits. Based on epidemiological studies as well as on numerous in vitro and in vivo experiments flavonoids and other polyphenolic plant constituents are suggested to play a major role in the prevention of important chronic diseases such as cancer that affect large numbers of the human population. This protective action of dietary flavonoids and of related compounds is believed to be mainly due to their anti-oxidative activity involving scavenging of cytotoxic oxygen radicals and to inhibition of specific cancer related targets such as protein kinases and matrix metalloproteinases. For the so called 'phytoestrogens' (isoflavones, coumestans and lignans) another mode of action has been demonstrated: they bind to estrogen receptors and are able to inhibit estrogen-dependent tumor growth. Due to the described importance of flavonoids in the prevention of chronic diseases like cancer a detailed analysis of important modern and traditional Chinese vegetables with regard to their major phenolic constituents will be carried out using modern analytical methods. In addition to the elucidation of individual profiles of plant polyphenolics present in Chinese vegetables special attention will be given to the natural qualitative and quantitative variability of polyphenolic compounds as influenced by environmental factors as well as to their anti-proliferative effects against human cancer cells.
In der Pedosphere stellen Humin/Ton-Assoziate ein wichtiges Kompartiment im Hinblick auf die Immobilisierung und Umweltstabilität von Xenobiotika einschließlich ihrer Metabolite dar. Dieses Projekt soll weiterführende Erkenntnisse zu den Wechselwirkungen in diesen Systemen erbringen, wobei ein spezieller Augenmerk auf die orts/raumaufgelösten und die struktur-chemischen Aspekte der Humin/Ton-Assoziate liegen soll, da für diese Parameter ein wesentlicher Beitrag zu den Sorptions- und Bindungsverhältnissen immobilisierter Xenobiotika einschließlich ihrer reaktiven Metabolite erwartet wird. Im Rahmen dieses Projektes soll das biogeochemische und umweltdynamische Verhalten von MCPA und Nonylphenol einschließlich ihrer Metabolite im Hinblick auf die Bildung, die Freisetzung und die Biodegradation von kovalent immobilisierten Rückständen in natürlichen und modelhaften Humin/Ton-Assoziaten untersucht werden. Dazu sollen 13C- und 14C-markierte Verbindungen synthetisiert und zwei ausgesuchten Böden (orthic Luvisol und Cambisol) sowie künstlich hergestellten Humin/Ton-Assoziaten zugesetzt werden. Die natürlichen und synthetischen Assoziate sollen durch FTIR, NMR, spektrophotometrische und mikroskopische Methoden charakterisiert werden. Die gebildeten kovalent immobilisierten xeniobiotischen Rückstände sollen parallel durch invasive und nicht-invasive analytische Methoden qualitativ und quantitativ erfasst werden. Eine Zuordnung der immobilisierten Verbindungen zu verschiedenen Fraktionen innerhalb der Assoziate soll durch sequentielle Extraktionen und Anreicherungsverfahren und nachfolgende Chemolyse sowie GPC und radioanalytische Verfahren erreicht werden. Dabei sollen durch diese invasive Methoden retrospektiv Hinweise auf die Einbindungsmechanismen erhalten werden. Nicht-invasive Methoden (hier im Besonderen NMR-Spektroskopie) erlauben dagegen eine Erfassung der Bindungsverhältnisse in situ. Desweiteren sollen die Freisetzung und die Abbauprozesse der immobilisierten Rückstände sowie der bakterielle Beitrag und der Einfluss von biologischen oberflächenaktiven Stoffen (z.B. Rhamnolipiden) auf diese Prozesse an den experimentellen Ansätzen untersucht werden.
1. Vorhabenziel: Die Untersuchung von mikrobiellen Gemeinschaften in Salzpfannen im südwestlichen Afrika über die Zeit birgt das Potential, wertvolle Informationen über die mit den Mikroorganismen assoziierten Klima- und Umweltbedingungen der Vergangenheit zu erhalten. In der GeoArchives II Phase wollen wir neue mikrobiologische Ansätze und Methoden anwenden, um die Änderungen der mikrobiellen Gemeinschaften mit der Zeit zu dokumentieren (Kultivierungsexperimente von Schlüsselorganismen, externe DNA als Schlüssel zur Vergangenheit), die gewonnenen Daten mit biogeochemischen Methoden (mikrobielle Biomarker) zu validieren und Klimainformationen aus den Daten abzuleiten. Außerdem wollen wir die Wechselwirkung von Mikroorganismen mit Gesteinsoberflächen im Zuge von bodenbildenden Verwitterungsprozessen in der Region untersuchen. Weiterhin sollen mit Hilfe geochronologischer Datierungsansätze relevante Landschaftsformen (Salzpfannen, Hänge, Schwemmfächer und Terrassen) in ihrer Genese datiert werden, um aktuelle Fragen nach den Auswirkungen des Klima- und Nutzungswandels auf die heutigen Landschaftsökosysteme zu beantworten. 2. Arbeitsplanung: Im Projekt sollen zwei Probenahmen durchgeführt werden. Die Salzpfannen werden Ende 2016 Gegenstand der ersten Kampagne sein. Die Salzpfannenproben sollen für die Kultivierungsexperimente und die Studien zur extrazellularen DNA verwendet werden. In der zweiten Kampagne soll im Frühjahr 2017 im Tsauchab-Tal Material für die Untersuchung der Verwitterungsprozesse gewonnen werden. Des Weiteren sollen Altersdatierung von Hangsedimenten, Schwemmfächern, Flussterrassen und Talbodenverschüttungen vorgenommen werden, um die Stabilität und das Potenzial dieser Flächen für die Landnutzung unter dem Einfluss des Klimawandels zu bewerten.
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