API src

Found 46 results.

Patterns of evolution in the species complex of the tree-root endophyte Phialocephala fortinii

Das Projekt "Patterns of evolution in the species complex of the tree-root endophyte Phialocephala fortinii" wird/wurde gefördert durch: Eidgenössische Technische Hochschule Zürich. Es wird/wurde ausgeführt durch: Eidgenössische Technische Hochschule Zürich, Professur für Forstschutz und Dendrologie.Populations of P. fortinii from allover Europe are examined using microsatellites to construct gene genealogies and infer evolutionary history. The tree-root endophyte Phialocephala fortinii s.l. (mitosporic Ascomycota) is the dominant colonizer of conifer root systems in forests in the northern hemisphere. P. fortinii s.l. is genetically highly diverse and forms a complex of several cryptic species. Recombination occurs or has occurred within cryptic species and to some extent also among them (introgression). Cryptic species occur sympatrically and they can form large thalli, but it remains unclear whether the observed patterns of spatial distribution reflect local climax situations or are the results of recent gene and genotype flow. One of the key objectives will be to estimate population genetic parameters (eg. migration rates, genotype flow, recombination) within and among populations of cryptic species in forests where man-mediated genotype flow can be excluded. Other key objectives are the determination of the number, frequency, distribution and evolutionary history of the cryptic species in Europe and to identify the driving forces for speciation. The approach will be multidisciplinary and will include standard mycological and microbiological methods as well as molecular genetic techniques such as microsatellite fingerprinting and DNA sequencing. The evolutionary history of haplotypes at both the population and species level will be reconstructed and the results will be compared with known patterns of pleistocenic glaciations and postglacial recolonization of host trees. The project will be a significant contribution to the understanding of the population and evolutionary genetics of a versatile and ecologically extremely successful fungal genus and it will shed light on the effects of pleistocenic and postglacial climatic changes on fungal speciation.

High Elevation Treeline Research

Das Projekt "High Elevation Treeline Research" wird/wurde ausgeführt durch: Universität Basel, Botanisches Institut, Abteilung Pflanzenökologie.If one considers the high elevation treeline as a global phenomenon, many local drivers, which dominated the debate in the past, become less significant, they become modulators of a more fundamental, common cause. Our working hypothesis is that the major driver of treeline formation is the ability to form new structures, rather than the provision of raw materials for these structures. In other words, we suggest that the treeline is a sink (growth) rather then a source (photosynthesis) driven phenomenon, with temperature representing the single most important determinant. We do not question the influence of other factors, but we consider them to represent a suite of regional peculiarities, which may affect the actual position by not more then 100 m in elevation. A detailed discussion of the treeline issue can be found in: Our activities go in several directions. They include treering studies across the treeline ecotone (see ref. below), microclimate measurements at various latitudes and an assessment of the carbohydrate supply status at the tree limit. The worldwide treeline temperature assessment nears its end by 2001, when year-round data from ca. 30 different treeline sites around the globe will be available. As a standard procedure we measure root-zone temperature at 10 cm depth in the shade of tree crowns at the treeline using Tidbit (Onset Corp.) data loggers. Currently available data from 90 % of the stations average at seasonal mean ground temperatures of ca 6.5 C, with very little site to site variation, irrespective of latitude (minimum of 5.5 C on Mexican volcanos at 4000 m and maximum at some maritime temperate zone treelines of ca 7.5 C). The seasonal mean proved to be a better predictor of treeline position than warmest month temperatures or a suite of thermal sums tested. There are regions with no suitable treeline taxa where natural treelines occure at lower elevations (higher temperatures; e.g. Hawaii). In a work on carbohydrate pools we compare treelines in Mexico, the central Alps and in N-Sweden (Abisko). We see no decline of reserves as one approaches the existential limit of trees, in fact, carbohydrate and lipid stores reach a maximum at tree limit. Thus, it seems unlikely that carbon limitation is a cause of treeline formation.

Ökologische Bewertungskriterien für Desinfektionsmittel und deren Adaptierung in der Desinfektionsmittel-Datenbank der Stadt Wien

Das Projekt "Ökologische Bewertungskriterien für Desinfektionsmittel und deren Adaptierung in der Desinfektionsmittel-Datenbank der Stadt Wien" wird/wurde gefördert durch: Bundesministerium für Land- und Forstwirtschaft, Umwelt und Wasserwirtschaft Österreich / Wiener Umweltanwaltschaft (WUA). Es wird/wurde ausgeführt durch: Interuniversitäres Forschungszentrum für Technik, Arbeit und Kultur (IFZ).Das Projekt ÖkoKauf der Stadt Wien hat es sich zum Ziel gesetzt, durch die Erstellung von ökologischen Kriterien, Pilotprojekte und durch Bewusstseinsarbeit das Beschaffungswesen im Magistrat Wien weiter zu ökologisieren. In diesem Rahmen widmete sich der Arbeitskreis 'Desinfektionsmittel unter der Leitung der Wiener Umweltanwaltschaft (WUA) der Aufgabe, für Hygienefachleute ein Instrument zur Beurteilung der Auswirkungen von Desinfektionsmitteln auf Gesundheit und Umwelt zu erstellen. Das Österreichische Ökologie-Institut führte eine Daten- und Literaturrecherche durch, das Umweltbundesamt nahm ergän-zende ökotoxikologische Tests an Wirkstoffen und -produkten vor und 'die umweltberatung ermittelte stationsbezogene Desinfektionsmittelverbräuche in Wiener Krankenanstalten. Die Recherche- und Testergebnisse zu Desinfektionsmittelwirkstoffen und -produkten wurden in einer vom IFZ konzipierten und von der Magistratsabteilung 14 realisierten Datenbank zusammengefasst. Um die ökotoxikologischen Produkteigenschaften vergleichbar zu machen, wurde vom IFZ ein Bewertungsraster entwickelt und in die Datenbank integriert. Dabei werden nachteilige Wirkungen auf die Gesundheit anhand von vier Wirkungskategorien erfasst: Akute Giftigkeit; Reizwirkung auf die Haut; Sensibilisierung, allergenes Potenzial sowie Erbgutschädigende, krebserzeugende und fruchtschädigende Eigenschaften. Zusammen mit der Berücksichtigung des Verhaltens in Oberflächengewässern (Abbauverhalten, Bioakkumulationspotenzial, Toxizität für Wasserorganismen) sowie dem Verhalten in Kläranlagen werden insgesamt sechs Bewertungszahlen generiert, die auf einer Skala von 1 (vernachlässigbar) bis 5 (sehr hoch) das gesamte Gefährdungsprofil des Stoffes beschreiben sollen. Das Gefährdungsprofil eines Handelsproduktes errechnet sich aus den Gefährdungsprofilen der darin enthaltenen Wirkstoffe anhand eines Algorithmus: Dabei wird die Annahme getroffen, dass die Produkteigenschaften von der Konzentration der darin enthaltenen Wirkstoffe abhängen. Bei der Bewertung ist außerdem zu gewährleisten, dass ein Wirkstoff mit einem hohen Gefährdungspotenzial angemessen berücksichtigt wird, auch und gerade wenn seine Konzentration im Produkt gering ist. In der Literatur wird dazu eine logarithmische Skalierung vorgeschlagen. Die Bewertung berücksichtigt derzeit die Wirkstoffe sowie Anwendungsverdünnungen. Die Zusammenfassung der Produkte in Verwendungs- bzw. Expositionskategorien ermöglicht letztlich eine vergleichende Bewertung. Da das Bewertungsraster gerade auf eine vergleichende Bewertung von Produkten abzielt, unterliegt er einer ständigen kritischen Diskussion, die auch häufig von den Herstellern geführt wird. Dieser Umstand sowie das Faktum von Produktlebenszyklen erfordern ein ständiges Update der in der Datenbank enthaltenen Informationen und eine Anpassung des Bewertungsmodells an den aktuellen Stand von Forschung sowie Standards der Stoff- und Produktpolitik.

Ice2sea - estimating the future contribution of continental ice to sea-level rise (ICE2SEA)

Das Projekt "Ice2sea - estimating the future contribution of continental ice to sea-level rise (ICE2SEA)" wird/wurde gefördert durch: Kommission der Europäischen Gemeinschaften Brüssel. Es wird/wurde ausgeführt durch: Natural Environment Research Council.Objective: The melting of continental ice (glaciers, ice caps and ice sheets) is a substantial source of current sea-level rise, and one that is accelerating more rapidly than was predicted even a few years ago. Indeed, the most recent report from Intergovernmental Panel on Climate Change highlighted that the uncertainty in projections of future sea-level rise is dominated by uncertainty concerning continental ice, and that understanding of the key processes that will lead to loss of continental ice must be improved before reliable projections of sea-level rise can be produced. The ice2sea programme will draw together European and international partners, to reduce these uncertainties. We will undertake targeted studies of key processes in mountain glacier systems and ice caps (e.g. Svalbard), and in ice sheets in both polar regions (Greenland and Antarctica) to improve understanding of how these systems will respond to future climate change. We will improve satellite determinations of continental ice mass, and provide much-needed datasets for testing glacier-response models. Using newly developed ice-sheet/glacier models, we will generate detailed projections of the contribution of continental ice to sea-level rise over the next 200 years, and identify thresholds that commit the planet to long-term sea-level rise. We will deliver these results in forms accessible to scientists, policy-makers and the general public, which will include clear presentations of the sources of uncertainty. The ice2sea programme will directly inform the ongoing international debate on climate-change mitigation, and European debates surrounding coastal adaptation and sea-defence planning. It will leave a legacy of improved understanding of key cryospheric processes affecting development of the Earth System and the predictive tools for glacier-response modelling, and it will train a new generation of young European researchers who can use those tools for the future benefit of society.

Health effects of indoor pollutants: integrating microbial, toxicological and epidemiological approaches (HITEA)

Das Projekt "Health effects of indoor pollutants: integrating microbial, toxicological and epidemiological approaches (HITEA)" wird/wurde gefördert durch: Kommission der Europäischen Gemeinschaften Brüssel. Es wird/wurde ausgeführt durch: Terveyden ka Hyvinvoinnin Laitos.Objective: Healthy housing and good indoor air quality are important goals of public health. However, biological indoor pollution due to dampness, moisture and mold is an emerging environmental health issue, as recognized in EU indoor air policy documents. Prevalence of dampness is remarkable, and may still increase due to demands of energy savings and extreme weather periods and floods associated with climate change. The exposure may lead to long-term impacts such as asthma. The documentation is strong on association between building mold and health, but the causative agents and disease mechanisms are largely unknown, which impedes recognition of a mold-affected patient in health care. Efficient control and regulation are hampered by the insufficient understanding of these causalities. Understanding of the links between building practices and health is lacking. There is an urgent need for European-wide knowledge to form a basis for establishing building-associated criteria for healthy indoor environments. The aim of this proposal is to clarify the health impacts of indoor exposures on children and adults by providing comprehensive exposure data on biological and chemical factors in European indoor environments.

Optimized Strategies for Risk Assessment of Chemicals based on Intelligent Testing (OSIRIS)

Das Projekt "Optimized Strategies for Risk Assessment of Chemicals based on Intelligent Testing (OSIRIS)" wird/wurde gefördert durch: Kommission der Europäischen Gemeinschaften Brüssel. Es wird/wurde ausgeführt durch: Helmholtz-Zentrum für Umweltforschung GmbH - UFZ, Department Ökologische Chemie.The proposed regulation concerning the registration, evaluation, authorisation and restriction of chemicals (REACH) requires demonstration of the safe manufacture of chemicals and their safe use throughout the supply chain. There is therefore a strong need to strengthen and advance human and environmental risk assessment knowledge and practices with regard to chemicals, in accord with the precautionary principle. The goal of the project OSIRIS is to develop integrated testing strategies (ITS) fit for REACH that enable to significantly increase the use of non-testing information for regulatory decision making, and thus minimise the need for animal testing. To this end, operational procedures will be developed, tested and disseminated that guide a transparent and scientifically sound evaluation of chemical substances in a risk-driven, context-specific and substance-tailored (RCS) manner. The envisaged decision theory framework includes alternative methods such as chemical and biological read-across, in vitro results, in vivo information on analogues, qualitative and quantitative structure-activity relationships, thresholds of toxicological concern and exposure-based waiving, and takes into account cost-benefit analyses as well as societal risk perception. It is based on the new REACH paradigm to move away from extensive standard testing to a more intelligent, substance-tailored approach. The work will be organised in five interlinked research pillars (chemical domain, biological domain, exposure, integration strategies and tools, case studies), with a particular focus on more complex, long-term and high-cost endpoints. Case studies will demonstrate the feasibility and effectiveness of the new ITS methodologies, and provide guidance in concrete form. To ensure optimal uptake of the results obtained in this project, end-users in industry and regulatory authorities will be closely involved in monitoring and in providing specific technical contributions to this project.

Schwerpunktprogramm (SPP) 1158: Antarctic Research with Comparable Investigations in Arctic Sea Ice Areas; Bereich Infrastruktur - Antarktisforschung mit vergleichenden Untersuchungen in arktischen Eisgebieten, Neogene Paleoenvironmental changes in the McMurdo Sound region: High resolution chemical and sedimentological analysis of Miocene (ca17 Ma) to Pleistocene sediments from ANDRILL Site SMS

Das Projekt "Schwerpunktprogramm (SPP) 1158: Antarctic Research with Comparable Investigations in Arctic Sea Ice Areas; Bereich Infrastruktur - Antarktisforschung mit vergleichenden Untersuchungen in arktischen Eisgebieten, Neogene Paleoenvironmental changes in the McMurdo Sound region: High resolution chemical and sedimentological analysis of Miocene (ca17 Ma) to Pleistocene sediments from ANDRILL Site SMS" wird/wurde gefördert durch: Deutsche Forschungsgemeinschaft. Es wird/wurde ausgeführt durch: Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung - Fachbereich Geowissenschaften.At ANDRILL site SMS (Southern McMurdo Sound) an longer than 1000m sediment core will be drilled from a sea-ice platform covering Early/Middle Miocene (ca17 Ma) to Pleistocene strata of McMurdo Sound, Ross Sea, Antarctica. The target sediments were deposited on the western flank of the Victoria Land Basin (VLB), a structural half-graben that forms part of the West Antarctic Rift system, and experienced subsidence since late Eocene times. On this sediment core we propose to combine high-resolution on-ice measurement of chemical element concentrations using XRF core-scanner with off-ice high-precision chemical and sedimentological analysis on bulk samples (XRF, XRD, ICP-MS, biogenic components) and individual lithoclasts (LA-ICP-MS, electron microprobe, microscopy). The resulting multiple dataset will provide detailed information on sediment composition and, thus, contribute to several scientific objectives of ANDRILL such as the history of Ross/West Antarctic ice shelf expansion and retreat since ca17 million years, sea-ice presence/absence in the McMurdo region, and the history of Neogene sediment provenance and accumulation rates in the VLB. Our major goal is to improve our understanding of the Neogene paleoenvironmental evolution of Antarctica with a special focus on the Mid-Miocene climatic optimum (ca17-15 Ma) and the subsequent onset of major cooling (ca14 Ma) along with the key question on the stability of cold-polar climate conditions during the last 14 million years

Trees in multi-Use Landscapes in Southeast Asia (TUL-SEA): A Negotiation Support Toolbox for Integrated Natural Resource Management

Das Projekt "Trees in multi-Use Landscapes in Southeast Asia (TUL-SEA): A Negotiation Support Toolbox for Integrated Natural Resource Management" wird/wurde ausgeführt durch: Universität Hohenheim, Institut für Tropische Agrarwissenschaften (Hans-Ruthenberg-Institut), Fachgebiet Pflanzenbau in den Tropen und Subtropen (490e).Trees use water while storing carbon; tree crops replace natural forest while reducing poverty; market-oriented monocultures compete with risk-averse poly-cultures, trading off income and risk; plantations displace smallholders, trading off local rights and income opportunities; national reforestation programs use public resources, promising an increase in environmental services that may not happen. Trees in all these examples are closely linked to tradeoffs and conflict, exaggerated expectations and strong disappointment. Integrated Natural Resource Management (INRM) requires site-specific understanding of tradeoffs between and among the goods and services that trees in agro-ecosystems can provide. It is thus costly when compared to readily scalable green revolution technologies. Replicable, cost-effective approaches are needed in the hands of local professionals with interdisciplinary skills to help stakeholders sort out positive and negative effects of trees in multi-use landscapes ( agroforestry) on livelihoods, water and (agro) biodiversity, associated rights and rewards, and thus on Millenium Development Goals (reducing poverty - promoting equitable forms of globalisation - building peace). ICRAF in SE Asia has developed a negotiation support approach for reducing conflict in multi-use landscapes. The approach aims to bridge perception gaps between stakeholders (with their local, public/policy and scientific knowledge paradigms), increase recognition and respect for these multiple knowledge systems, provide quantification of tradeoffs between economic and environmental impacts at landscape scale, and allow for joint analysis of plausible scenarios. Building on the achievements of participatory rural appraisal, we can now add quantitative strengths with the toolbox for tradeoff analysis. The TUL-SEA project (NARS, ICRAF and Hohenheim) will in 3 years lead to: Tests of cost-effectiveness of appraisal tools for tradeoff analysis in a wide range of agroforestry contexts in SE Asia represented by 15 INRM case studies; building on ASB (Alternatives to Slash and Burn; http://www.asb.cgiar.org/) benchmark areas with significant positive local impacts on poverty, environment and peace (www.icraf.org/sea/Publications/searchpub.asp?publishid=1290); Enhanced national capacity in trade-off analysis, information-based INRM negotiations and ex ante impact assessments; An integrated toolbox ready for widespread application. The toolbox consists of instruments for rapid appraisal of landscape, tenure conflict, market, hydrology, agrobiodiversity and carbon stocks, and simulation models for scenario analysis of landscape-level impacts of changes in market access or agroforestry technology.

Belowground niche separation and competition in tree species mixtures

Das Projekt "Belowground niche separation and competition in tree species mixtures" wird/wurde gefördert durch: Deutscher Akademischer Austausch Dienst. Es wird/wurde ausgeführt durch: Universität Freiburg, Waldbau-Institut.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.

Coexistence of different functional types of indigenous trees of the Munessa Forest, Ethiopia: Carbon, water and nutrient relations

Das Projekt "Coexistence of different functional types of indigenous trees of the Munessa Forest, Ethiopia: Carbon, water and nutrient relations" wird/wurde gefördert durch: Deutsche Forschungsgemeinschaft. Es wird/wurde ausgeführt durch: Universität Bayreuth, Fachgruppe Biologie, Bayreuther Zentrum für Ökologie und Umweltforschung (BayCEER), Lehrstuhl für Pflanzenphysiologie.Ecophysiological traits (carbon, water and nutrient relations) allowing for the coexistence of different functional types (life-forms) of indigenous trees in Munessa Forest, Ethiopia is proposed. Above and below ground resource acquisition and utilization by Croton macrostachys (facultative deciduous), Podocarpus falcatus (evergreen gymnosperm) and Prunus africana (broad-leafed evergreen) will be investigated as influenced by site conditions and season. In addition to tree growth and canopy characteristics, photosynthesis, respiration and transpiration at different zones of tree crowns will be recorded. Whole-tree transpiration will be followed using the Granier stem-flux system. Partitioning of soil water among the trees will be assessed using 18O/16/O-signatures of xylem sap and of soil water collected from different depths. Seasonal water use of juvenile and adult trees will be compared and the seasonal patterns of fine root biomass production shall be analyzed. Data on nutrient relations, mycorrhizal networks and silvicultural characteristics of the trees, produced by the other collaborating groups will be integrated to explain the coexistence of the three functional types of trees. It is expected that species-specific requirements and strategies of survival and growth of the investigated tree species can be used for an ecologically sound reforestation program of a mixed forest.

1 2 3 4 5