In bog ecosystems, vegetation controls key processes such as the retention of carbon, water and nutrients. In northern hemispherical bogs, a shift from Sphagnum- to vascular plant-dominated vegetation is often traced back to Climate Change and increased anthropogenic nitrogen deposition and coincides with substantially reduced capacities in carbon, water and nutrient retention. In southern Patagonia, bogs dominated by Sphagnum and vascular plants coexist since millennia under similar environmental settings. Thus, South Patagonian bogs may serve as ideal examples for the long-term effect of vascular plant invasion on carbon, water and nutrient balances of bog ecosystems. The contemporary balances of carbon and water of both a bog dominated by Sphagnum and vascular plants are determined by CO2- H2O and CH4 flux measurements and an estimation of lateral water losses as well as losses via dissolved organic and inorganic carbon compounds. The high time resolution of simultaneous eddy covariance measurements of CO2 and H2O in both bog types and the strong interaction between climatic variables and the physiology of bog plants allow for direct comparisons of carbon and water fluxes during cold, warm, dry, wet, cloudy or sunny periods. By the combination with leaf-scale measurements of gas exchange and fluorescence, plant-physiological controls of photosynthesis and transpiration can be identified. Long-term peat accumulation rates will be determined by carbon density and age-depth profiles including a characterization of peat humification characteristics. A reciprocal transplantation experiment with incorporated shading, liming and labeled N addition treatments is conducted to explore driving factors affecting competition between Sphagnum and vascular plants as well as the interactions between CO2-, CH4-, and water fluxes and decisive plant functional traits affecting key processes for carbon sequestration and nutrient cycling. Decomposition rates and driving below ground processes are analyzed with a litter bag field experiment and an incubation experiment in the laboratory.
Recent progress in the operation of CO2 gas ion sources for accelerator mass spectrometer (AMS) 14C analysis on microgram-size samples opens a wide range of new applications in dating studies, e.g. for environmental and archeological applications. This proposal aims at implementing a gas ion source at the AMS system MICADAS at the Klaus-Tschira Laboratory of the Curt-Engelhorn-Zentrum für Archäometrie (CEZA) in Mannheim and to use this new capability for cutting-edge applications in environmental studies, namely the dating of small amounts of organic carbon contained in glacier ice and of specific organic compounds in ground water. Cold glaciers hold unique records on past climate and atmospheric composition. Mid-latitude ice cores furthermore enable reconstructions of recent ice chemistry changes, but cannot be dated by stratigraphic methods. For such ice bodies, only radiometric dating based on 14C analysis of organic matter contained in the ice matrix presently offers a reasonable dating potential in the late Holocene and beyond. The challenge of this approach lies in the very restricted availability of this matter, but the ability to analyse microgram samples of organic carbon from ice via a gas ion source should now enable reliable 14C dating of ice. Ground water constitutes an important water resource worldwide, especially in semi-arid regions, and in addition constitutes a useful climate archive. Dating of ground water by 14C in the dissolved inorganic carbon (DIC) is standard but problematic due to the complex carbonate geochemistry. Dating of ground water based on dissolved organic carbon (DOC) has been attempted with mixed success, but now the new analytical developments enable compound-specific 14C analyses of the various DOC components, offering the chance to identify compounds suitable for dating. This project is based on the extensive experience of the collaborating scientists in 14C analytics and applications as well as in the use of glacier ice and ground water as archives, including the development and application of 14C dating methods for these systems. It will establish 14C-measurements at the MICADAS AMS of the CEZA via a gas ion source on a routine base to analyse CO2-samples in the range of 5 to 40 microgram C at a precision down to 0,5 Prozent. By improving existing sample preparation techniques for glacier ice samples, reliable 14C values of the particulate and dissolved organic fractions from small (some 100 g) ice samples shall be obtained. This capability will be applied to constrain ages of cold, sedimentary glaciers as well as of small scale, cold Alpine congelation ice bodies. The project will further develop and test the tools required for micro-scale, compound-specific radiocarbon dating of ground water via its organic fraction. For this purpose, ground water samples from the Upper Rhine Graben area will be analysed, where extensive isotopic data, including DIC 14C values, are available for comparison.
Die Modellerweiterung betrifft sowohl die Bilanzierungsgrenzen als auch die Detaillierungstiefe. Mit der Modellerweiterung einhergehend soll explizit auch die Datengrundlage, insbesondere für Kälteanwendungen und Einspeisezeitreihen für fluktuierende erneuerbare Energien, verbessert werden. Die Datengrundlage zur Gebäudeklimatisierung wird durch eine empirische Erhebung und sozialwissenschaftliche Auswertung aktualisiert. In einer auf die Kopplung des Strom-, Wärme- und Kältesektors zugeschnittenen Szenarienanalyse werden die sektorübergreifenden Effekte, wie z.B. Brennstoffmix, CO2-Emissionen und EE-Anteile in den verschiedenen Sektoren, berechnet. Basierend auf diesen quantitativen Ergebnissen und einer vorangegangenen Analyse der Rahmenbedingungen werden Handlungsempfehlungen für die Weiterentwicklung von Rahmenbedingungen für sektorübergreifende Flexibilität, der marktorientierten EE-Integration sowie die Entwicklung im Bereich der Infrastruktur für Wärme- und Kälteanwendungen hinsichtlich Klimaschutz und EE-Integration abgeleitet. Das Projekt gliedert sich in 4 inhaltliche Arbeitspakete (AP), wobei jedes Arbeitspaket aus mehreren Arbeitsschritten (AS) besteht. Während die Arbeitspakete 1 bis 3 den Wärmesektor (AP 1), den Sektor Klimatisierung (AP 2) sowie die Ableitung von Windstrom- und PV-Zeitreihen (AP 3) zum Inhalt haben, wird in AP 4 das bestehende Strommarktmodell PowerFlex zu einem sektorübergreifenden Strommarktmodell PowerFlex-Heat&Cold weiterentwickelt und im Rahmen einer Szenarienanalyse angewendet. AP 1 und AP 2 schaffen dabei die methodische und datentechnische Grundlage für die gekoppelte Modellierung des Strom-Wärme-Kälte-Sektors und liefern einen zentralen Dateninput für die Szenarienanalyse in AP 4. Die in AP 3 abgeleiteten Wind- und PV-Zeitreihen spiegeln aufgrund der Fluktuation des dargebotsabhängigen Stromangebots näherungsweise auch den Bedarf an Flexibilität wider. Die Arbeiten für Projektleitung und Koordination sind AP 5 zugeordnet.
The species Beta vulgaris includes annual, biennial, and perennial accessions. Annual beets germinate, bolt, and flower within one season. Biennial beets such as sugar beets need prolonged exposure to cold temperatures to acquire floral competence. After seed production, annual and biennial beets senesce and die. By contrast, perennial beets live several years and repeat flower onset each year or bolt earliest in the third season. We hypothesize that there is at least one common flowering time gene which is responsible for bolting induction in annual, biennial, and perennial beets and that the different regulation of this gene (these genes) distinguishes between annual and perennial growth. Allelic variants of this gene (genes) may also be responsible for bolting failure in non-bolting Beta plants. Using genome-wide transcriptome and quantitative real-time PCR analyses, we will identify floral transition genes that induce bolting and floral competence in beets with different phenology. In order to detect loci that are responsible for perennial growth, a QTL analysis will be performed using Beta populations segregating for annual and iteroparous perennial growth. Subsequently, candidate genes determined by the transcriptome analysis will be mapped and tested for co-localization with detected QTLs to identify the common bolting inducing gene as well as genes responsible for longevity and repeated flowering. Additionally, we will clone genes that are responsible for bolting failure in perennials by a bulked segregant sequencing approach using a Beta population that segregate for biennial and non-bolting perennial plants. The identification of bolting control and bolting failure genes will allow to control the timeing of flowering and to create a genetic tool for targeted manipulation of bolting and flowering time in sugar beet.
Dieses Projekt verfolgt das Ziel neue, optimierte Partikelsysteme für die additive Fertigung in der Flüssigphase zu erzeugen. Für die Herstellung der Ausgangsstoffe werden zwei alternative Prozessrouten untersucht. Über die Nassmahlung sowie die Schmelzemulgierung mit jeweils integrierter Oberflächenfunktionalisierung werden Partikelsysteme zwischen etwa 2 und 50 Mykrometer mit optimalen Fließ- und Packungseigenschaften hergestellt und damit die Voraussetzungen geschaffen, die verarbeitbaren Partikelgrößen in der additiven Fertigung deutlich abzusenken. Im ersten Projektteil werden Polymermaterialien unterhalb ihrer Glastemperatur in einer Rührwerkskugelmühle zerkleinert. Die Verwendung von Alkoholen erlaubt ein Kaltmahlen im Temperaturbereich bis herunter zu minus 80 Grad C. Beim Schmelzemulgierverfahren wird der Polymerausgangsstoff in einem flüssigen Medium, in dem er schlecht löslich ist, geschmolzen. Die Schmelze wird infolge hoher Scher- und Dehnbeanspruchung unter Zusatz entsprechender Hilfsstoffe zur Tropfenstabilisierung emulgiert. Nach Abkühlung der Emulsion, Erstarren des Polymers und Abtrennung der flüssigen Phase stehen pulverförmige Ausgangswerkstoffe zur Verfügung. Besonderer Vorteil der Schmelzemulgierung ist es, dass sphärische Partikeln hergestellt werden können. Die erzeugten Partikelgrößenverteilungen hängen in beiden Herstellungsverfahren von der Beanspruchungsintensität und von der Verweilzeitverteilung des Produktes ab. In beiden Fällen geht es darum optimal auf die additive Fertigung hin zugeschnittene Partikelgrößenverteilungen zu erzeugen. Erfolgt die Stabilisierung und Oberflächenfunktionalisierung über Nanopartikel, die an der Oberfläche der festen oder flüssigen Polymerpartikel angelagert werden, können zusätzlich die Haftkräfte durch Steuerung der Oberflächenrauheit maßgeblich reduziert werden und damit optimale Fließeigenschaften eingestellt werden. Beide Prozesse werden im Hinblick auf die nötige massespezifische Zerkleinerungsenergie, um die bestimmte Produktpartikelgrößenverteilung zu erhalten, optimiert.
The main objectives of this study are the evaluation and quantification of the inorganic and organic mercury (methylmercury) levels in water, fish and fish-eating predators tissues, especially in the Giant Otter (Pteronura brasiliensis), of distinct areas of the Tambopata National Reserve (TNR) in the region Madre de Dios (Mother of God) region - Peru, which presents high levels of mercury contamination as a consequence of small-scale gold mining activities. An evaluation of how the South Interoceanic Highway, built only 25 km away from the legal limits of the TNR, could influence the increment of mining activities in the surroundings of the study area, and further threatening the living conditions of the aforementioned species, will also be performed. The techniques proposed for the chemical analysis of the sample are cold vapor atomic absorption spectrometry (CVAAS) and inductively coupled plasma optical emission spectrometry (ICP-OES), for total mercury determination; and inductively coupled plasma mass spectrometry (ICP-MS) and gas chromatography with electron capture detection (GC-ECD), for organic mercury determination (methylmercury).
Responding to the twin crises of global warming and biodiversity loss requires a deep understanding of how climate affects the processes that generate and destroy biodiversity, primarily through its effects on the ecology and distribution of species. Recent improvements in our ability to reconstruct the history of biodiversity through timed phylogenies, estimate changes in genetic diversity, and predict the potential distribution of selected species with ecological niche models (ENMs) now allow us to infer the evolution of ecological preferences and distributional ranges at different temporal scales. Our two case studies focus on alpine/arctic regions, because they are among those most endangered by global warming. The first study will use, for the first time, a combination of ENM and phylogeny to test the model of hybrid, polyploid speciation by secondary contact in arctic/alpine plants. We selected Primula sect. Aleuritia (simply Aleuritia, from here on), because our previous phylogenetic work provided clear hypotheses for the parental origins of polyploids, yet the distributions of the inferred progenitors do not currently overlap. Did the ranges of the proposed parents overlap at the time of allopolyploid origins, as predicted by the secondary contact model? To answer this question, we will produce a high-resolution, dated phylogeny of Aleuritia, optimize the ecological preferences of the hypothesized progenitors onto the dated phylogeny, and project their past distributional ranges onto the fine-resolution climatic scenarios recently developed for the Pleistocene. In the second case study, we will try to explain how small populations persisted on summits in the past and how they are affected by current and future climate change. Here we selected Saxifraga florulenta, a rare, endemic species of the Maritime Alps, because hypotheses of its phylogenetic relationships are available from our previous work, it occurs exclusively above 2000 m, and has very narrow ecological requirements. Consequently, if current trends of global warming continue, the strict ecological adaptation of S. florulenta to siliceous substrates at the highest altitudes of the Maritime Alps may represent a serious extinction risk. We will investigate whether the phylogeographic history, genetic diversity, climatic niche and dispersal mode of S. florulenta can explain its long persistence in the Maritime Alps, a hot spot of biodiversity, and predict its future survival or extinction on mountain tops. We will use a combination of genetic analysis and niche modeling to reconstruct changes in the niche, geographic distribution, and genetic diversity of this cold-adapted species.
Warm conveyor belts (WCBs) are coherent airstreams that typically develop along cold fronts associated with extratropical cyclones. These airstreams originate in the moist subtropical marine boundary layer and ascend within 1-2 days to the upper troposphere whilst moving more than 2000 km towards the pole. They occur most frequently during winter in the western North Pacific and North Atlantic where they are responsible for the major part of precipitation. The key role of WCBs for the dynamics of the synoptic and large-scale atmospheric flow stems from their profound impact upon the tropospheric distribution of potential vorticity (PV). The coherent ascent of WCBs leads to the diabatic production of a positive PV anomaly in the lower troposphere and of a negative PV anomaly in upper-level ridges just below the tropopause. When interacting with the extratropical waveguide, these negative PV anomalies can exert a profound impact upon the downstream flow evolution. Hence a WCB can be the trigger for the amplification and breaking of an upper-level Rossby wave, which is particularly relevant in situations where Rossby wave breaking events act as precursors of high-impact weather systems (e.g., heavy precipitation in the western Mediterranean, Saharan dust storms, cold air outbreaks). Recent studies indicate that errors in medium-range numerical weather predictions might be related to the inaccurate representation of WCBs and their effect on upper-level PV. In order to advance the basic understanding of these complex, non-linear and highly important dynamical processes, this project will (i) investigate the parameters and processes that determine the intensity of a WCB, its associated PV evolution and downstream effects, (ii) assess the errors in global models' analyses and forecasts associated with the different stages of a WCB life cycle, (iii) quantify the climatological frequency of the triggering and intensification of upper-level Rossby waves by WCBs, and (iv) provide clear guidance for investigating the dynamics of WCBs within the framework of THORPEX field experiments. In three subprojects, complementary techniques will be applied in order to reach these objectives, including idealized simulations of moist baroclinic waves, real case sensitivity experiments, diagnostic investigations based upon (re-)analysis and forecast data, and a feature-based verification of WCBs in global models using independent observational datasets. In this way this project will contribute to an improved basic understanding of the dynamical effects of WCBs on the downstream evolution of upper-level Rossby waves and (high-impact) surface weather events.
Snow avalanches are a major natural hazard in mountainous areas throughout the world. Avalanche forecasting, which aims at warning the public on the current and near future avalanche risk, relies on weather observations and forecasts as well as snow cover instability observations. Snow slab avalanches, which represent the vast majority of destructive avalanches,start with a failure in a buried weak snowpack layer. Such weak layers often form at or near the snow surface. Avalanche forecasters and researchers alike are therefore extremely interested in snow properties at the snow surface as well as within the snow cover. Traditional manual snowpack observations, which are still widely uised, are too time consuming and subjective to provide accurate measurements of the properties of the snow cover. Numerical models and modern measuring techniques, specifically the SnowMicroPenetrometer (SMP), have therefore been developed to improve avalanche forecasting. The SMP is a portable measuring device which records high resolution penetration resistance data of the snow stratigraphy. However, due to the difficult interpretation of the data, especially in relation to avalanche formation, thus far these modern technologies are not widely used to improve avalanche forecasting. This is in part because the physical processes leading to the formation of weak snowpack layers are not yet fully understood nor is the relation between SMP penetration resistance data and the physical properties of snow. The aim of the proposal is therefore to increase the knowledge on the formation of weak snowpack layers and to develop a signal processing method to automatically identify and characterize layers within SMP signals. This will be done by developing experimental procedures to study the physical processes governing the formation of near surface weak snowpack layers in the cold laboratory. Several experiments with different controlled boundary conditions will be performed, the changes of the physical properties of the snow will be tracked and the limiting conditions for layer reproduction will be identified. In parallel, systematic measurements on homogeneous as well as layered snow samples with the SMP will be performed in the cold laboratory. This will help relating SMP penetration resistance data to physical parameters of snow and lead to the development of a signal processing method to automatically identify and characterize layers within SMP signals. Additionally, field data will be collected to validate the automatic layer identification method.
Global climate change in cryogenic regions has dominated the research agenda recently, as investigators seek ways of identifying the hazards to infrastructure in cold regions to establish distinct uncertainties through a risk based consideration of sensitivity and consequences and thereby mitigate the risk of permafrost degradation. The latest IPCC report states that temperature increased at the top of the permafrost layer in the Arctic by up to 3 C since the 1980s. The permafrost base has been thawing at rates of up to 0.04 m/yr, permafrost degradation is causing changes in land surface characteristics and drainage systems and snow cover has decreased in most regions. This has been greatest at lower elevations, e.g. in Switzerland. Melting massive ice or degrading permafrost is becoming increasingly susceptible to causing initiation of slope instabilities and debris flows, having caused the 1997 Val Pola debris flows in the Italian Alps. Recent instabilities in the Vallée du Du Durnand in Valais and the Bérard Rock Glacier in France, both in 2006, emphasise the growing concern. Clear risks were also identified in Turtmanntal, Val d'Anniviers and Mattertal, where some rock glacier features indicated formation of crevasses and depressions at critical positions in the landform and increased risk of failure through the body of the mountain permafrost. Knowledge of the evolving thermal state and internal structure, as well as the response of permafrost soils to a gradual warming cycle, is necessary. This project focuses on the variations of geotechnical response of Alpine permafrost with time and temperature. The time effects are important, since a rock glacier will flow or creep downhill. Landforms have changed in the smaller rock glaciers in the West Alps, where these are particularly sensitive to warming scenarios. Clearly this may lead to instability. The specific goals are: o to investigate artificially frozen soils in the laboratory to understand the relative influences of stresses, soil-ice content, particle size and shape, strain rate and temperature on the strength and stiffness, particularly within the thawing zone, o to obtain equivalent strength and stiffness data from stored (and future) cored samples of Alpine Permafrost and to compare with those from artificial frozen soil, o to establish relationships between key parameters for both artificial and real mountain permafrost, o to test an existing constitutive law to represent the thermo-hydro-mechanical behaviour of Alpine permafrost, o to obtain relevant parameters for future input to the constitutive model and subsequent numerical analysis of the test data.
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