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Found 121 results.

Demonstration of a sustainable CHP concept using residues from olive oil production (OLIVEPOWER)

Das Projekt "Demonstration of a sustainable CHP concept using residues from olive oil production (OLIVEPOWER)" wird vom Umweltbundesamt gefördert und von New Energy Biomasse Hellas GmbH durchgeführt. Objective: The project focuses on the demonstration of an innovative and sustainable CHP concept using residues from olive oil production (olive wastes) as fuel. A first plant based on the new concept will be realised in Greece. The main objective of the project is to demonstrate a closed cycle concept able to reduce landfill problems and emissions and to promote the use of renewable electricity production in Southern Europe. The project will be based on an approach integrating the whole chain (fuel logistics and preparation, energy production, by-product utilisation). An optimised fuel logistic concept will guarantee for a secured fuel supply over the whole year. The fuel will not only be dewatered and dried but also a marketable by-product will be produced. By this means a better fuel quality can be achieved and solid wastes as well as waste- water can be omitted. The development and design of the combustion unit focuses on a technology tailored to the special characteristics of the olive waste.

Soil N dynamics as affected by different land use in Western and Southern China

Das Projekt "Soil N dynamics as affected by different land use in Western and Southern China" wird vom Umweltbundesamt gefördert und von Technische Universität Dresden, Institut für Bodenkunde und Standortslehre durchgeführt. The aim of the research project is to quantify the stocks and turnover of soil nitrogen in Western and Southern China as dependent from soil structure and land use. Key soil characteristics are determined at representative sites with regional specific land use and degradation status. The investigations will follow a land use gradient of natural forests, arable and pasture soils, the latter ones considering different degradation and rehabilitation status. The actual and potential soil nitrogen turnover will be horizon-wise quantified and related to soil structure and land use impacts. Beside mineral nitrogen, also preliminary organic N compounds using physical and chemical extraction will be detected. Parameters for the investigations are, beside total C and N stocks and distribution, gross and net N mineralization, nitrification, microbial biomass C and N and microbial respiration and indicators for soil N turnover like active N pools and light fraction of organic matter. In the last phase the structure of the soil microbial microbial community will be determined and related to indicators of nitrogen status and efficiency. The research activities will be carried out in close co-operation with the Institute for Soil and Water Conservation/ Yangling University at loess soils and the Nanjing Institute for Soil Science/ Chinese Academy for Science in Nanjing at red soil sites.

Water use characteristics of bamboo (South China)

Das Projekt "Water use characteristics of bamboo (South China)" wird vom Umweltbundesamt gefördert und von Universität Göttingen, Burckhardt-Institut, Abteilung Waldbau und Waldökologie der Tropen durchgeführt. Bamboos (Poaceae) are widespread in tropical and subtropical forests. Particularly in Asia, bamboos are cultivated by smallholders and increasingly in large plantations. In contrast to trees, reliable assessments of water use characteristics for bamboo are very scarce. Recently we tested a set of methods for assessing bamboo water use and obtained first results. Objectives of the proposed project are (1) to further test and develop the methods, (2) to compare the water use of different bamboo species, (3) to analyze the water use to bamboo size relationship across species, and (4) to assess effects of bamboo culm density on the stand-level transpiration. The study shall be conducted in South China where bamboos are very abundant. It is planned to work in a common garden (method testing), a botanical garden (species comparison, water use to size relationship), and on-farm (effects of culm density). Method testing will include a variety of approaches (thermal dissipation probes, stem heat balance, deuterium tracing and gravimetry), whereas subsequent steps will be based on thermal methods. The results may contribute to an improved understanding of bamboo water use characteristics and a more appropriate management of bamboo with respect to water resources.

Pasture rehabilitation on, and management of degraded areas in the Andes of South Ecuador

Das Projekt "Pasture rehabilitation on, and management of degraded areas in the Andes of South Ecuador" wird vom Umweltbundesamt gefördert und von Universität Bayreuth, Fachgruppe Biologie, Bayreuther Zentrum für Ökologie und Umweltforschung (BayCEER), Lehrstuhl für Pflanzenphysiologie durchgeführt. Project abstract: This knowledge transfer project will be centered in the San Francisco valley in the South Ecuadorian Andes. However, the problem of abandoning pastures because of heavy infestation by weeds, in particular by bracken fern (Pteridium spec.), is a general issue in the tropical Andes. Pastures which have been abandoned for that reason amount meanwhile to 11Prozent of the area of the San Francisco valley. Infestation by bracken fern and shrubs is a consequence of the traditional use of fire for clearing of the natural forest and pasture management. Growth of both, bracken and woody weeds, is fostered by recurrent burning. In a 2-phase experiment on a heavily bracken-infested slope at c. 2000 m altitude, substantial control of the weed and subsequent pasture rehabilitation could be achieved. In the planned project, this procedure shall be scaled-up to farm level and the altitudinal range of repasturisation shall be extended from 1000 m to 2400 m altitude. To that end local farmers will put respective parts of their land to the projects disposal and public authorities will provide man-power. There are several challenges to be met: (i) Long-term bracken infestation has depleted the soils from nutrients, in particular P and N. Therefore targeted fertilization is needed for profitable grass productivity. (ii) Since bracken can never be completely eradicated, its regrowth must be suppressed by trampling, i.e. frequent grazing. A sustainable grazing management has to be developed which corresponds to soil fertility. (iii) The dominating pasture grass is the C4-type grass Setaria sphacelata. It is growing well in a warm climate but its competitive strength in the harsher climate above 2000 m is low. Bracken as a C3-type plant is less dependent on the temperature. To this adds that it occurs in 2 species in the area, one of which is an upland type. Thus the climate gradient over the elevational transect will influence the competitive strength of both competitors. Therefore the suitability of the traditional monoculture of this grass species for pasture rehabilitation shall be tested in the context of a comprehensive pasture management experiment which the farmers will be involved. (iv) A special problem is the high oxalate concentration in the growing parts of the Setaria leaves which can cause calcaemia in cattle. In a pot experiment which will be run in collaboration with a research team of the UTPL, feeding quality and toxicity of a monotonous diet of Setaria will be tested. Beside the experimental areas, demonstration sites will be installed where regular training workshops will be organized to encourage the farmers to apply the developed rehabilitation and management strategy to their own farms.

Transports and variability-driving mechanisms in Flemish Pass at the western boundary of the subpolar North Atlantic (FLEPVAR)

Das Projekt "Transports and variability-driving mechanisms in Flemish Pass at the western boundary of the subpolar North Atlantic (FLEPVAR)" wird vom Umweltbundesamt gefördert und von Universität Hamburg, Fachbereich Geowissenschaften, Institut für Meereskunde durchgeführt. Labrador Sea Water (LSW) formed in the Labrador Sea constitutes the lightest contribution to North Atlantic Deep Water (NADW), a conglomerate of water masses that form the cold return flow of the Atlantic meridional overturning circulation (MOC). Climate variability can be modulated by changes in the MOC strength; such changes are thought to be linked to variations in LSW formation. The Deep Western Boundary Current (DWBC) is the main southward pathway for newly formed LSW. Topographic obstacles at the southern exit of the Labrador Sea split the DWBC into an upper branch carrying LSW through Flemish Pass (1200m sill depth) and a branch carrying all NADW components along the continental slope around Flemish Cap. Up to now, transports through Flemish Pass and their contribution to the MOC are still uncertain, the importance of the pass for the export of LSW and its associated variability are yet unknown. In this project the transports through Flemish Pass will be quantified, and mechanisms driving and governing the variability of the flow will be investigated. The project focuses on the following questions: What is the magnitude of transports for waters passing through Flemish Pass and their associated variability? Which processes drive the variability? What is the relevance of the deep water export through Flemish Pass for the MOC, especially when compared to the DWBC export? Are both deep water export pathways (through Flemish Pass or around Flemish Cap) coupled? What processes govern the inflow of deep water into Flemish Pass? To answers these questions, ship-based measurements and time series from moored instruments in the Flemish Pass will be analyzed in conjunction with output from two state-of-the-art Ocean models run at high-resolution.

Upwelling in the Atlantic sector of the Southern Ocean

Das Projekt "Upwelling in the Atlantic sector of the Southern Ocean" wird vom Umweltbundesamt gefördert und von Universität Bremen, Institut für Umweltphysik, Abteilung Ozeanographie durchgeführt. Upwelling is an important process in setting the characteristic of the mixed layer. Upwelling also provides a pathway for gases, nutrients, and other compounds from the ocean's interior into the mixed layer and ultimately into the atmosphere. Since the upwelling velocities are small, they cannot be measured directly. Recently, Rhein et al. (2010) exploited the helium isotope disequilibria found in the equatorial eastern Atlantic to infer upwelling speeds, upwelling rates, and vertical heat fluxes between the mixed layer and the ocean's interior. The disequilibrium in the mixed layer is caused by upwelling of 3He-enriched water from the interior. The surplus 3He is introduced into the deep ocean by hydrothermal activities.A first survey of historical Helium isotope data in the Antarctic Circumpolar Current (ACC) and the Weddell Sea showed, that the mixed layer is also enriched with 3He, which in summer months is supplied by upwelling of water from below the mixed layer. Although the first estimates of upwelling velocities from the historical data set look promising, the present Helium data lack a sufficient resolution in the upper 200-300m to determine the horizontal and vertical He gradients, necessary for the compilation of the upwelling velocity and of the contribution of diapycnal mixing. Here we propose to take the historical He data, and a new dedicated He data sets to be taken in November 2010 - February 2011 during the POLARSTERN cruise ANT 27/2 and January- February 2012 during POLARSTERN cruise ANT28/3 to calculate upwelling speeds and -rates in the Weddell Sea and the ACC, as well as heat fluxes between the interior and the mixed layer.This proposal is part of the Cluster ' Eddies and Upwelling: Major Factors in the Carbon Budget ofthe Southern Ocean'

Einfluss von Dürre auf das Waldsterben in Europa und Westkanada (Water03 - IDDEC)

Das Projekt "Einfluss von Dürre auf das Waldsterben in Europa und Westkanada (Water03 - IDDEC)" wird vom Umweltbundesamt gefördert und von Technische Universität München, Wissenschaftszentrum Weihenstephan für Ernährung, Landnutzung und Umwelt, Fachgebiet für Ökoklimatologie durchgeführt. While many forests and woodlands may be at increasing risk of climate-induced dieback, significant knowledge gaps remain in our understanding of the causes of climate-induced tree mortality. Recent publications underscore the critical importance of understanding the mechanisms that trigger plant mortality (Adams et al., 2009), particularly regarding features and traits that could be used as physiological indicators of tree death (McDowell et al., 2008). Alterations in wood formation and structure often occur prior to visual symptoms of crown decline. Thus, physiological, morphological, and anatomical traits related to xylem ('water-conducting pipes') may provide early-warning signals of drought-induced dieback. A better mechanistic understanding of drought-induced forest dieback would improve our ability to predict tree mortality and future changes in forest composition and coverage. The project aims at studying how drought episodes promote dieback via changes in xylem structure. Different genotypes of aspen (parkland region and the southern boundary of the boreal forest in western Canada), oak (Southern Europe) and pine (experiment) will be studied along gradients of moisture availability. Xylem-related traits that will be measured include ring-width, number of missing rings, quantitative wood anatomical structures (diameter and frequency of vessels/ tracheids, inter-vessel pit structure) as well as cavitation resistance, hydraulic conductivity, and water potentials.

Water consumption and carbon capture by trees of an evergreen and a dry forest in the Andes of South Ecuador as functional indicators of slow environmental changes

Das Projekt "Water consumption and carbon capture by trees of an evergreen and a dry forest in the Andes of South Ecuador as functional indicators of slow environmental changes" wird vom Umweltbundesamt gefördert und von Universität Bayreuth, Fachgruppe Biologie, Bayreuther Zentrum für Ökologie und Umweltforschung (BayCEER), Lehrstuhl für Pflanzenphysiologie durchgeführt. This transfer project contributes to the development of a multifactorial indicator prototype for global change effects. It uses water and carbon relations of trees as primary functional indicators of subtle environmental changes which cannot be directly observed. Acquisition of carbon by a tree and its concomitant water loss by transpiration is coupled as water use efficiency (WUE), which as a parameter integrating two ecophysiological processes should display a high sensitivity to ambiental conditions. The project is based on a new model allowing computation of the entire crown. Parameterization of the model is by data of leaf gas exchange, total water loss, and structural data of the crown. Total water consumption will be determined either by stem flow monitoring or by the D2O injection method. Net carbon gain by the entire crown can be calculated from a crown-specific WUE. The described measurements will be supplemented by data on stem growth, phenology (longevity of leaves and foliage dynamics), long-term water relations (13C discrimination data) and tree hydrology (natural abundance of deuterium). To extend the indicator from the single tree scale to a wider area, project C5 will collaborate with project C6 which will investigate WUE using multispectral satellite and airborne data. For calibration transfer functions to remotely sensed data must be developed. Since Eddie covariance analysis cannot be used, project C6 will measure atmospheric dynamics of heat and water vapour above the canopy of an assemblage of such trees by scintillometry. These measurements shall be calibrated by C5. Of all trees on the study plots total transpiration will be measured and correlated with simultaneously recorded scintillometer data. Thus projects C5 and C6 will use the same plots and trees. Using the calibrated scintillometer data, project C6 will up-scale the functional indicator WUE to the landscape level. Because of their general applicability, functional indicators like WUE are especially useful for modelling approaches.

Identification of the processes leading to ikaite formation in polar sea ice

Das Projekt "Identification of the processes leading to ikaite formation in polar sea ice" wird vom Umweltbundesamt gefördert und von Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung durchgeführt. Die Entscheidung die Versuche zur Ikait Bildung in Polarem Meereis nicht in Eistankversuchen, sondern in Laborversuchen mit einer geringeren Komplexität durchzuführen, hat zu vielen grundlegenden neuen Erkenntnissen geführt. Zum einen konnten wir zeigen, dass die vielfach publizierte Aussage, dass das vorhanden sein von Phosphat eine Grundvoraussetzung für die Ikait Bildung in Polarem Meereis ist, nicht zutrifft. Vielmehr haben wir gezeigt, dass die Ikait Fällung einen wichtigen Einfluss auf die Nährstoffdynamik im Meereissystem haben könnte. Wir konnten wir zeigen, dass unter Meereis Bedingungen Ikait das einzig zu erwartende Kalzium Karbonat Polymorph ist. In einem nächsten Schritt, sind nun die hier gewonnenen Erkenntnisse aus 'Eisfreien' Experimenten um den Parameter 'Eis' zu erweitern um herauszufinden, welche Bedingungen genau zu den Kristallen in der Form und Größe führen wie sie in natürlichen Systemen zu beobachten sind. Als eine der wichtigsten Erkenntnisse erachten wir jedoch die Ergebnisse zur Phosphat Anreicherung durch die Ikait Bildung. Bei zukünftigen Expeditionen wird nun zu untersuchen sein inwieweit die bisher beobachtete Phosphatanreicherung mit dem Vorhandensein von Ikait Kristallen korreliert.

Investigation of reactive halogen species in a smog chamber and in the field

Das Projekt "Investigation of reactive halogen species in a smog chamber and in the field" wird vom Umweltbundesamt gefördert und von Universität Heidelberg, Institut für Umweltphysik durchgeführt. The objective of the proposed activities as part of the DFG research group HaloProc is the investigation of Reactive Halogen (RH) chemistry in the atmosphere by Differential Optical Absorption Spectroscopy. The importance of RH includes the destruction of ozone, change in the chemical balance, increased deposition of toxic compounds (like mercury) and potential indirect effects on global climate. In our laboratory experiments we observed events of 'Bromine Explosion' (auto catalytic release of reactive bromine from salt surfaces - key to ozone destruction) that were strongly dependent on pH and humidity. Our measurements from field campaigns in Namibia/Botsuana, Southern Russia and Mauritania during HaloProc1 showed 1 to 2 orders of magnitude lower BrO and IO levels than expected based on previous observations at salt flats. Environmental conditions might have strong influence, which would be consistent with the smog chamber studies. One of the main questions of the second phase is under which conditions RH activation take place does. It is of great interest whether reactions of chlorine and iodine compounds on salt surfaces are similar to those of bromine, and whether different RH compounds interact with each other. In addition, oxides of nitrogen might be important for their role in the reactivation of RH. Proposed field campaigns in Namibia and South Russia will allow us to investigate the sources, sinks and transformations of RH compounds. This work will be complemented by corresponding smog chamber experiments with measurements of different halogen oxides as well as photochemical model calculations.

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