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.

Fire, climate change and human impact in tropical ecosystems: paleoecological insights from the East African region

Fire is an important ecological factor of disturbance in African tropical ecosystems, driving vegetation dynamics and regulating nutrient cycling and biomass. The significance of wildfires for future environmental processes is underlined by recent projections of global warming, which predict more frequent and more intense extremes of natural events. Particularly in East Africa, where population growth and natural resource exploitation are among the highest in the world, strategies for sustainable economic development will have to deal with environmental changes at regional to continental scales. Understanding such complex responses to global change requires long-term records, since only they provide a way to observe the response of ecosystems to large-magnitude environmental change on decadal and longer time scales. We use high-resolution charcoal data from lake-sediment cores to reconstruct past fire/climate/human interactions in East Africa, aiming in particular 1) to understand how the fire regime influenced vegetation dynamics during the last millennia in savannah-type and sub-humid tropical ecosystems, 2) to test whether changes in fire regime are coupled with episodes of past climatic extremes inferred from the available sedimentological data, and 3) to detect early human deforestation and the timing of increased fire frequencies beyond its natural variability. Additionally, we will apply novel techniques such as molecular markers (benzene polycarboxylic acids, BPCAs) to complement the standard sedimentary approaches to reconstruct Holocene fire history. The proposed research addresses new, highly relevant questions for today's key issue of sustainability (economic development, natural resource management, adaptation of vulnerable communities to global change). Additionally, it will contribute with new high-quality data to ongoing multi-proxy research concerning the magnitude, frequency, and rates of past climate change in equatorial East Africa. Finally, the project will contribute to our understanding of tropical ecosystem functioning and its interaction with regional, cultural, and economic systems.

FP7-KBBE, Protection of consumers by microbial risk mitigation through combating segregation of expertise (PROMISE)

PROMISE strives for multidimensional networking thus fostering integration. The primary strategic objective of PROMISE is to improve and increase the integration, collaboration and knowledge transfer between the new member states, old member states (EU15) and candidate countries through a collaborative workplan of exchange of expertise and regional training and dissemination actions, to tackle common food safety threats. PROMISE strives for sustainability through involvement of risk communicators. A further strategic objective is to integrate stakeholders like public health authorities and national food safety authorities from the old and new member countries in order to ensure the exploitation of research results into standardisation and harmonisation efforts. PROMISE will enhance the knowledge on pathogen transmission. While legal imports are well monitored for contamination and alerts are registered through the Rapid Alert System for Food and Feed RASFF notification systems, gates into the EU-27 could exist where food supply chains are not controllled. These uncontrolled imports present the risk that new strains of traditional pathogens will be transferred from third countries into the European Union. Analysing, assessing and interpreting this risk of introducing new strains of pathogens is one of the main objectives of PROMISE.

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.

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.

Production of activated clays for low-cost building materials in developing countries

Building Materials are a basic need, which is often difficult to meet in developing countries. Concrete is the building material best suited to meet these demands, although cement, the central ingredient is often disproportionately expensive in developing counties. The most promising option to lower costs (and environmental impact) is to blend conventional Portland cement with pozzolanic materials. The aim of this project is to develop technologies appropriate for the small scale, local production of pozzolans from clay (a material widely available) in conjunction with the exploitation of waste biomass for combined heat and power production. The modular concept of a clay activation unit, CAU to be coupled with a biomass boiler, will give the flexibility to adapt the solution to local conditions. We have already demonstrated that relatively common (low grade) clayey soils can be activated to give a pozzolan similar in performance to fly ash (from coal fired electricity production) widely used in the developed world. Results also indicate that it is possible to improve their reactivity by using and optimizing flash calcination, to allow high levels of substitution and very significant improvements in cost/performance ratio. To achieve this we need also to look at the performance of the activated clays in concrete from the point of view of rheology, hardening and durability to enable optimum cost/performance to be achieved according to local materials and applications. The partnership between LMC, EPFL and two academic groups in Cuba has already been established in a previous project. Furthermore, one of the Cuban partners plays a leading role in ECOSUR (a Swiss NGO) which has established workshops, producing low cost building materials, in many developing countries. In the first part of the project significant scientific advances were made, which enabled a huge acceleration in progress, relative to previous work by the Cuban partners alone. In addition, 3 Cuban PhD students spent several months working in the Swiss laboratory and have now returned to Cuba to continue their research. In this project, funding is requested for one PhD student to be based in Switzerland, who will work closely with 3 Cuban PhD Student (funded be the Cuban government). On the Cuban side, funds are requested for essential equipment and to fund the stays of the students at EPFL. Each of the Cuban students will spend 4-8 months working at EPFL during the course of the project.

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.

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.

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.

1 2 3 4 5 6