API src

Found 54 results.

Related terms

Sonderforschungsbereich (SFB) 607: Wachstum oder Parasitenabwehr? Wettbewerb um Ressourcen in Nutzpflanzen aus Land- und Forstwirtschaft, Teilprojekt B1: Allometrie und Raumbesetzung von krautigen und holzigen Pflanzen. Integration von Pflanzen- und Bestandesebene

Das Projekt B1 'Allometrie und Raumbesetzung von krautigen und holzigen Pflanzen' ist Teil des Sonderforschungsbereiches 607 Wachstum und Parasitenabwehr und befindet sich bereits in der vierten Phase des seit 1998 laufenden Forschungsprojektes. Bisher wurde im Projekt B1 die Allometrie als Resultat der pflanzeninternen Steuerung der Allokation untersucht. Auf Individuenebene wurden Allometrie und ihre Veränderung für verschiedene Baumarten in verschiedenen ontogenetischen Stadien untersucht. Auf Bestandesebene wurden die self-thinning-Linien von Yoda und Reineke für krautige bzw. holzige Pflanzenbestände analysiert. Bisherige Allometriebestimmungen erbrachten für diese Arten zwar ähnliche Größenordnung aber auch charakteristische Unterschiede, die Ausdruck spezifischer Strategien der Raumbesetzung und -ausbeutung widerspiegeln. Die bisher vereinzelten Auswertungen sollen in Phase IV in eine übergreifende Analyse (versch. Arten, ontogenetische Stadien, Konkurrenzsituationen, Störfaktoren) der Allometrie auf Pflanzen- und Bestandesebene münden.

Hydrogeological and hydrochemical modelling of density-driven flow in the Tiberias Basin, in particular between Ha'on and Tiberias Regions, Jordan Valley

The aim of the current research is to identify regional sources and trans-boundary flow leading to the observed salinity of Lake Tiberias (LT) -also known as the Sea of Galilee or Lake Kinneret-, and its surroundings, which is considered the only natural surface fresh water reservoir of the area. The current study will include all sources of brines in the Tiberias Basin (TB) with specific emphasis of the relationship between the brines from the Ha'on and Tiberias Regions (HTR).The tasks will be achieved by a multidisciplinary approach involving: (i) numerical modelling of density-driven flow processes (i.e., coupled heat and dissolution of evaporites), (ii) hydrochemical studies, supplemented by investigations of subsurface structures.(i) Numerical modelling will be carried out by applying the commercial software FEFLOW® (WASY, GmbH) complemented with the open source code OpenGeoSys developed at the UFZ of Leipzig (Wang et al., 2009). The final goal is to build a 3D regional-scale model of density-driven flow that will result in: (1) revealing the different interactions between fresh groundwater and natural salinity sources (2) elucidate the driving mechanisms of natural brines and brackish water body's movements.(ii) Hydrochemical study will include major, minor and, if possible, rare earth elements (REE) as well as isotope studies. The samples will be analysed at the FU Berlin and UFZ Halle laboratories. Geochemical data interpretation and inverse modelling will be supported by PHREEQC. Hydrochemical field investigations will be carried out in Tiberias basin and its enclosing heights, i.e. the Golan, Eastern Galilee and northern Ajloun in order to search for indications of the presence of deep, relic saline groundwater infested by the inferred Ha'on mother-brine. The current approaches will be supplemented by seismic and statistical data analysis as well as GIS software applications for the definition of the subsurface structures. The key research challenges are: building a 3D structural model of selected regions of TB, adapting both structural and hydrochemical data to the numerical requirements of the model; calibrating the 3D regional-scale model with observational data. The results of this work are expected to establish suitable water-management strategies for the exploitation of freshwater from the lake and from the adjacent aquifers while reducing salinization processes induced by both local and regional brines.

Landschaftsveränderungsdienst - Laverdi

Die Erkennung von Veränderungen der Landbedeckung der Erdoberfläche auf der Basis von satellitengestützten Fernerkundungsdaten ist seit Jahrzehnten ein sehr aktives Forschungsfeld. Das Ziel des Landschaftsveränderungsdiensts ist es, freie Copernicus-Satellitendaten für eine automatische Ableitung von Landbedeckungsänderungen zu nutzen und diese Informationen regelmäßig für einzelne Landschaftselemente (z.B. für Waldgebiete, Wasserflächen, Landwirtschaftsflächen usw.) über einen Web Service bereitzustellen. Copernicus Daten eignen sich aufgrund der hohen zeitlichen (ca. 3-5 Tage, je nach Sensor) und mittleren räumlichen Auflösung (ab 10m) ideal für eine regelmäßige bundesweite flächendeckende Analyse der Landbedeckung. Um eine hohe Bearbeitungsleistung zu erreichen wird die 'Copernicus Data and Exploitation Platform - Deutschland' (CODE-DE) für die Datenverarbeitung und -analyse genutzt. Es können aktuelle und konsistenteste Informationen über Landdeckungsänderungen abgeleitet werden, um kontinuierlich Geodaten in einer einheitlichen Qualität zu pflegen (siehe Abbildung 1). Andererseits können die gewonnenen Informationen genutzt werden, um statistisch relevante Geoinformationen zur quantitativen Beschreibung der UN-SDG-Indikatoren zu extrahieren. Die 2015 verabschiedete Agenda 2030 mit 17 Entwicklungszielen (SDG) und 169 Unterzielen verknüpft das Prinzip der Nachhaltigkeit mit der ökonomischen, ökologischen und sozialen Entwicklung. Die Umsetzung erfordert einen soliden Überprüfungsmechanismus. Dieser soll durch eine regemäßige nationale Erfassung von ca. 200 definierten UN-SDG-Indikatoren erfolgen, mit dem Ziel Fortschritte zu monitoren und die Politik zu informieren.

Response of Arctic submarine continental slopes to global warming

This project aims at investigating a scientific and societal pressing subject which requires urgent attention: the geo-hazards associated with the imminent use of the Arctic Ocean under the changing conditions forced by Global Change. Due to the increasing temperatures, the Arctic region is experiencing a decline of glaciers and sea-ice. Sea-ice reduction will soon expose to exploration yet unknown seafloor and sub-seafloor geology. Given todays interest in natural resources exploitation, the Arctic regions will experience an increase in seafloor and sub-seafloor use and an accelerated development of infrastructures, especially in coastal and continental margin areas. The glacial environment of the Arctic land masses causes that physical processes along continental margins differ substantially from those at lower latitudes, where continental slopes are built with river-fed sediments and glacial influence is comparatively unimportant. Continental margins at lower latitudes are better studied because industrialized nations have previously focused their activities there. The response of the Arctic seafloor and sub-seafloor system to upcoming changes in physical oceanography and glacial conditions, and the resultant sedimentary processes are yet not understood. To evaluate the future response of the Arctic geological system to Global Change is necessary to further understand the interplay among past climate change, continental margin geology, and submarine slope stability. This project aims at filling that critical gap in understanding. The overarching goal of this project is to evaluate how the increase of temperature, within the bounds of current predictions, may change the behavior of the Arctic geological system and alter slope stability. To achieve the goal we will estimate the volume and rate of gas release into the atmosphere that might affect climate, and evaluate the potential feed back of climate change to gas-hydrate dissociation. We will analyze potential future scenarios of slope in-stability in the context of the combined effect of the removal of past ice loading, ongoing temperature change, and stability of the geological elements of the continental margin system.

Improvement of forest management key strategies: a contribution to conservation and sustainable land use

In spite of a variety of efforts, tropical forests are still threatened by exploitation and conversion to agricultural land-use. Besides legal protection, sustainable management concepts are essential for stable conservation of these ecosystems. This project aims at identifying and optimizing the potentials for forest management for three different ecosystems (Dry Forest, Tropical Mountain Rain Forest, Paramo) along a height- and climate gradient in Southern Ecuador. Therefore, multiple and locally differentiated aspects of forest management have to be considered: the direct provision of goods (timber and non-timber forest products) as well as ecosystem services (carbon sequestration, water regulation), which are of increasing importance; moreover, the effects of forest management on biodiversity and the impacts of climate change on resilience indicators and the potential distribution of selected species with high potential for sustainable management or conservation should be investigated. First of all, the most important forest structure types and possible improvements of management alternatives have to be identified at the three sites for the assessment of different management concepts. The alternatives will be tested on experimental field plots and consequently monitored for their impacts on the locally most important criteria of forest management. A sound decision support tool will be developed, taking into account uncertainties with regard to input parameters and the relevance of different criteria of forest management. Therefore, Multi Criteria Decision Analysis will be used to generate locally adapted management concepts for the different ecosystems. Those concepts should be able to consider the multiple functions of forest management and will represent the forestry component in sustainable land-use models. The comprehensive studies will be carried out in close cooperation with other scientific teams from Germany and Ecuador as well as local institutions of relevance for forest management. The direct involvement of Ecuadorian students and young academics and the integration of the investigations in educational concepts will contribute to capacity building and local efforts for the enhancement of environmental competencies. Moreover, the experimental field plots will serve in parts as demonstration objects for the implementation of sustainable forest management concepts.

Belowground niche separation and competition in tree species mixtures

Root competition for water and nutrient among species is an ubiquitous feature of terrestrial plant communities influencing abundance and distribution of plants and the dynamics of their communities. The relationship between biodiversity and ecosystem functioning has emerged as a central issue in ecological and environmental sciences. It is commonly believed that increasing species richness increases the stability of communities. Higher plant species diversity might lead to increased exploitation of spatially heterogeneous resources by spatial niche complementarity. Tree species mixtures are generally believed to enhance ecosystem functioning in forests by niche partitioning and complementary resource exploitation due to differences in tree height, crown form, root depth and/ or phenology. In the past, however, most studies focused on the aboveground interaction and coexistence of the tree species, while factors controlling belowground species interactions remain less clear. There is experimental evidence to suggest that below-ground competition in herbaceous communities is size-symmetric in homogeneous soil. However, recent studies in tree communities indicate that fine-root competition may be asymmetric. The main purpose of this project is to characterize the underground niche separation and competition in relation to tree species diversity in mixtures comprising spruce, beech, oak and Douglas fir. Structural traits and spatial distribution of fine roots were investigated using a soil core method and fine-root growth is being assessed using the ingrowth core technique at a site in Kaltenborn, which is part of the long-term biodiversity-ecosystem functioning experiment with tree species of temperate forests (BIOTREE). The objectives of this study were to test the following hypotheses: (1) overall level of soil exploitation increases with the tree species diversity; (2) competitive ability belowground is size-symmetric, and (3) the below-ground competitive ability is species specific. As part of this investigation, we will explore the potential of using Near-infrared reflectance spectroscopy to identify the species identity of fine roots of the different tree species and to quantify the contribution of different fine roots in mixed root samples.

Low Cost and High Efficiency CO2 Mobile Air Conditioning system for lower segment cars (B-COOL)

Objective: The Project objective is the development of a low cost and high efficiency air-conditioning system based on CO2 (R744) as refrigerant fluid. Methods to assess performance, fuel annual consumption and environmental impact will be identified and they will constitute a first step for EU new standards. The EU, as Greenhouse Gas emission reduction measure, proposed the ban for Mobile Air Conditioning systems of fluids having a Global Warming Potential lower than 50 (i.e. R-134a and R-152a) with complementary measures - e.g. measurement of the MAC fuel consumption - This represents a challenge and an opportunity for OEMs and Mobile A/C Suppliers. The CO2 - R-744 when used as a refrigerant - is the favourite candidate to replace the R-134a. Besides safety, reliability and efficiency, the present estimated additional cost, ranging from 70 up to 150 Euro with reference to the low priced car systems, represents a obstacle. The lower priced vehicles constitute up the 70Prozent of the present EU car market, this number will rise up to the 80Prozent with the EU enlargement. A low cost and high efficiency R 744 MAC will support the EU efforts reducing the resistance to the approval of the HFC ban, allowing a rapid diffusion of the new system with the related environmental benefits and making the EU industries more competitive. The consortium composition - 2 major OEMs, 4 suppliers and three acknowledged excellence centres - makes the risk acceptable assuring an effective exploitation. Finally the Project gathers the most skilled European scientists and engineers in this specific field, so high level scientific and technical know how are expected to be produced as well as scientific advances in the dynamic system modelling. This will contribute to strengthen EU industries position in other domains (e.g. domestic air conditioning). The BCOOL project forms a cluster with the project named TOPMACS,focused on innovative adsorption mobile air conditioning systems...

Schwerpunktprogramm (SPP) 1294: Bereich Infrastruktur - Atmospheric and Earth system research with the 'High Altitude and Long Range Research Aircraft' (HALO), Methods and algorithms for data exploitation of the imaging Fourier transform spectrometer GLORIA-AB on HALO - MaxiFTS -

GLORIA combines a Michelson interferometer with a detector array of 128 x 128 pixels and will be the first 2D infrared limb imaging spectrometer worldwide. It is designed for HALO and will measure the distribution of temperature and a considerable number of trace constituents along with cloud mapping with unprecedented spatial resolution in the free troposphere and lower stratosphere. It is an essential contribution to the HALO demo missions TACTS, POLSTRACC, and CIRRUS-RS. Imaging Fourier transform spectrometers impose a number of challenges with respect to instrument calibration / characterisation and for algorithm development. The work of the first proposal focused on characterisation and modeling of the instrument and on the development of methods and algorithms which are capable of generating calibrated spectra with high accuracy. Accurately calibrated spectra are a prerequisite for the retrieval of atmospheric parameters and the scientific data exploitation. Within this renewal proposal the developed characterisation methods will be applied to the instrument in flight configuration, and the new algorithms will be used to generate highly accurate calibrated spectra from the raw interferograms measured during the HALO demo missions. The work will be completed by a thorough error analysis for the calibrated spectra. Finally, instrument settings, calibration scenario and data processing shall be optimised with respect to data quality. This proposal contributes to the development of high technology sensors and instruments for the use on HALO.

Combined development of compact thermal energy storage technologies (COMTES)

The COMTES project has as goal to develop and demonstrate three novel systems for compact seasonal storage of solar thermal energy. These systems will contribute to the EU 20-20-20 targets by covering a larger share of the domestic energy demand with solar thermal energy. Main objective of COMTES is to develop and demonstrate systems for seasonal storage that are significantly better than water based systems. The three technologies are covered in COMTES by three parallel development lines: solid sorption, liquid sorption and supercooling PCM. Strength of this approach is the collaboration of three development groups in activities that pertain to the analyses, methods and techniques that concern all technologies, without risking the exchange of confidential material. In this way, the development is much more effective than in three separate projects. The project starts with a definition of system boundary conditions and target applications. Next comes the investigation of the best available storage materials. Detailed numerical modelling of the physical processes, backed by experimental validations, will lead to optimum component design. Full-scale prototypes are simulated, constructed and tested in the laboratory in order to optimize process design. One year of fully monitored operation in demonstration buildings is followed by an integrated evaluation of the systems and their potential. When deemed successful, the involved industry partners will pick up the developed storage concepts and bring them further to a commercial level. The COMTES project is a cooperation of key scientific institutions active in the above mentioned heat storage technologies. For the first time, all relevant research disciplines are covered in an international effort. For each development line, a top-Ieading industry partner contributes its know-how and experience, providing the basis for further industrial development and exploitation of project results.

TRansitions to the Urban Water Services of Tomorrow (TRUST)

The European project initiative TRUST will produce knowledge and guidance to support TRansitions to Urban Water Services of Tomorrow, enabling communities to achieve sustainable, low-carbon water futures without compromising service quality. We deliver this ambition through close collaboration with problem owners in ten participating pilot city regions under changing and challenging conditions in Europe and Africa. Our work provides research driven innovations in governance, modelling concepts, technologies, decision support tools, and novel approaches to integrated water, energy, and infrastructure asset management. An extended understanding of the performance of contemporary urban water services will allow detailed exploration of transition pathways. Urban water cycle analysis will include use of an innovative systems metabolism model, derivation of key performance indicators, risk assessment, as well as broad stakeholder involvement and an analysis of public perceptions and governance modes. A number of emerging technologies in water supply, waste and storm water treatment and disposal, in water demand management and in the exploitation of alternative water sources will be analysed in terms of their cost-effectiveness, performance, safety and sustainability. Cross-cutting issues include innovations in urban asset management and water-energy nexus strengthening. The most promising interventions will be demonstrated and legitimised in the urban water systems of the ten participating pilot city regions. TRUST outcomes will be incorporated into planning guidelines and decision support tools, will be subject to life-cycle assessment, and be shaped by regulatory considerations as well as potential environmental, economic and social impacts. Outputs from the project will catalyse transformation change in both the form and management of urban water services and give utilities increased confidence to specify innovative solutions to a range of pressing challenges.

1 2 3 4 5 6