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Effect of experimentally applied drought and warming stress on three oak species and provenances using C and O stable isotopes in leaves, shoots, stem and roots

Das Projekt "Effect of experimentally applied drought and warming stress on three oak species and provenances using C and O stable isotopes in leaves, shoots, stem and roots" wird vom Umweltbundesamt gefördert und von Eidgenössische Forschungsanstalt für Wald, Schnee und Landschaft, Eidgenössisches Institut für Schnee- und Lawinenforschung durchgeführt. The predicted climate change will have a profound effect on ecosystems in Switzerland, including forests. Tree species, for example oaks, which are more adapted to warmer and dryer conditions are expected to profit from the changing climate. Models predict a large increase in the distribution of oaks that are currently covering only 2Prozent of Swiss forests. Unfortunately, no long-term trials exist in Switzerland that could be used to test for climate sensitivity of the various oak species. At the Swiss Federal Institute WSL, therefore, an experiment in 16 open-top chambers was carried out to test how the three native oak species react to drought and warming. Regarding drought tolerance and temperature preference, the natural distribution suggests that Q. pubescens is the most drought-tolerant, followed by Q. petraea and Q. robur. The warming treatment is achieved by selecting two opening angles of the chamber window. Under less opened windows air and soil surface temperatures increases by 1 to 3 C. Automatically closing roofs exclude rain. An artificial drought treatment is achieved by reducing the mean local precipitation from April to October (600 mm) to less than half. While the control and warming treatment, receive water in regular intervals, the drought treatment and the warming and drought combination are only periodically watered. To prevent irreversible damage under drought stress trees usually close the stomata to minimize water loss via transpiration. This, however, reduces the net photosynthesis and thus the carbon fixation. The potential to optimize between water loss and carbon fixation is a key in understanding tree responses to climatic change. Besides stomata closure, photosynthesis is determined by other factors, including temperature. Both, stomata closure and photosynthetic capacity affect the fractionation of the stable carbon and oxygen isotopes. Therefore, the determination of the isotope ratios ?13C and ?18O in plant tissue allows to draw conclusion on how drought and warming affect the trees. The following samples are collected and are intended to be analyzed: a) fresh leaves, b) wood section from shoots, c) stemwood and d) root samples. The proposed study with the stable C and O isotopes will be an ideal complement to the other measurements, such as shoot elongation, biomass change, gas exchange, root growth and leaf size and nutrient content. Based on these results, potentially useful oak species and provenances for future seeding or planting can be identified and recommendations for the forest practice can be made. In addition, the derived isotope ratios would allow the identification of drought stressed trees.

Überwachung von Lawinen (DAS-A)

Das Projekt "Überwachung von Lawinen (DAS-A)" wird vom Umweltbundesamt gefördert und von Universität für Bodenkultur Wien, Institut für Alpine Naturgefahren durchgeführt. In diesem Projekt wird versucht verschiedenste Messmethoden auf ihre Tauglichkeit zur Überwachung von Lawinenabgängen zu untersuchen. Dazu werden im Projektgebiet Lech/Arlberg unterschiedlichste Messsysteme installiert. Nach künstlicher sowie natürlicher Lawinenauslösung werden die so gewonnen Daten aufbereitet, analysiert und gegenübergestellt. Zusätzlich werden die Lawinenabgänge mittels terrestrischen Laserscannens überwacht, um genaue Aussagen über Volumen, Auslauflänge und Größe treffen zu können.

Climate change, environmental contaminants and reproductive health (CLEAR)

Das Projekt "Climate change, environmental contaminants and reproductive health (CLEAR)" wird vom Umweltbundesamt gefördert und von Aarhus Universitetshospital, Aarhus Sygehus durchgeführt. Objective: The research project investigates the possible impact of global climate change on reproductive health in one Arctic and two European populations. The key questions to be addressed are, firstly, how may climate change influence human exposure to widespread environmental contaminants and, secondly, how may contaminants impact occurrence of reproductive disorders as sensitive indicators of health? To provide affirmative answers to these questions the proposal will as a first step identify and describe mechanisms by which a changing climate may affect the exposure of Arctic and other human populations to contaminants through change in chemical use and emissions, delivery to the arctic ecosystem as well as processing within the arctic physical environment and human food chain. This work relies on modelling of existing data. Secondly, the project will expand the existing knowledge database on human exposure to polybrominated biphenylethers, perfluorinated surfactants and phthalates by analyses of 1000 biobanked serum samples collected in a EU FP5 project. Thirdly, the project will increase the limited knowledge on links between human exposure to contaminants and reproductive health. This work relies on a large existing parent-child-cohort, where a follow-up survey provide new data that are fed into risk assessment. Furthermore we will perform reviews of experimental and epidemiological literature to identify critical reproductive effects and exposure-response data for selected compounds as input to the risk assessment. Finally the project will integrate data on climate induced changes in contaminant mobility and distribution and links between contaminant exposure and reproductive health into a risk evaluation providing insight into possible future risk scenarios related to global climate change. The project draws upon a network of experts in climate modelling and in experimental, epidemiological and risk assessment methodologies and builds upon three established cohorts in Greenland, Poland and Ukraine.

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