Description: Das Projekt "Climate change and tree physiological response in Siberia and in the Alps during warm and cold periods of the last 1500 years" wird vom Umweltbundesamt gefördert und von Paul Scherrer Institut, Labor für Atmosphärenchemie durchgeführt. High-latitude and high-altitude forests are sensitive ecosystems that are more exposed to global warming in recent decades than forests of the temperate zones. As a result of the accelerating climate change, these forests may undergo severe changes regarding spatial distribution and species composition, the carbon, water and nitrogen cycles. This will have tremendous consequences for the sustainable functioning of the ecosystems and potential feedbacks to the atmosphere, such as increased release of greenhouse gases from soils. Insight into extreme past climate conditions and the response of Boreal and Alpine forests to these conditions provides an invaluable analogy for the potential future response. Trees from temperature-limited sites are known as sensitive proxies for climate reconstruction, while the availability of well-preserved wood in these regions enable the deciphering of past environmental conditions for centuries up to millennia. In this project, our main goal is to obtain a comprehensive description of the climatic and environmental changes during pronounced warm and cool periods of the past 1500 years. We want to achieve this goal by addressing the following three objectives: 1) we aim to better quantify the magnitude of temperature and precipitation variability for known periods of extreme climate conditions, focusing on the cold anomaly around 536AD, the Medieval optimum period, the 'little ice age' period and the last century, 2) we will use the combined analysis of tree-ring width, carbon and oxygen isotopes and physiological models to decipher the response of the trees in terms of photosynthesis and water-use during these periods, 3) and we want to determine the spatial and temporal coherence of large-scale climate events for Europe and northern Eurasia. We have access to unique dated tree-ring material from three sites in Northern Siberia and one site from the Alps that cover the investigation periods. We will use ring-width as a measure of growth and stable isotope ratios of carbon and oxygen of tree-ring cellulose as a measure of photosynthesis and water-use, while both isotopes are also related to temperature and precipitation. By applying a coupled photosynthesis-isotope fractionation model, which is driven by microclimate, photosynthesis, and soil water balance, we will be able to relate climatic to physiological changes. The results of the project will enable us to better understand the response of trees in temperature-limited environment to a changing climate.
SupportProgram
Origin: /Bund/UBA/UFORDAT
Tags: Tierhaltungsanlage ? Sibirien ? Geografische Koordinaten ? Baum ? Zellulose ? Kohlenstoff ? Sauerstoff ? Gewächshaus ? Brunnen ? Treibhausgasemission ? Material ? Datierung ? Kohlendioxid ? Regenwasser ? Photosynthese ? Temperatur ? Topographie ? Wirkung ? Gasförmiger Stoff ? Globale Erwärmung ? Temperater Forst ? Gelöster organischer Kohlenstoff ? Standortwahl ? Artenzusammensetzung ? Hochgebirge ? Lebensalter ? Eurasien ? Stickstoffkreislauf ? Bodenwasserhaushalt ? Alpen ? Europa ? Bilanz ? Mikroklima ? Bodenökosystem ? Fraktionierung ? Isotop ? Kühlung ? Atmosphäre ? Klima ? Klimawandel ? Niederschlag ? Ökosystem ? Standortbedingung ? Umwelt ? Wald ? Maßnahme ? Abdeckung ? Arbeit ? Boden ? PROJEKT ? EIN ? FUNKTION ? NEU ? NOERDLICH ? EINGESCHRAENKT ? POTENZIAL ? PRAEZIPITATION ? BAEUME ? RAEUMLICHE VERTEILUNG ? Stall ? EINSATZ ? UMGESTALTUNG ? GEMISCHT ? UNTERSUCHUNG ? VERANTWORTUNG ? VERHAELTNIS ? Vermehrung ? Vorgang ? KAELTE ? Wachstum [biologisch] ? ZEITRAEUME ? ZUGANG ? Art [Spezies] ? KONSERVE ? BESCHREIBUNG ? ERGEBNIS ? NACHHALTIG ? BEZUG ? Bilanz [Betriebswirtschaft] ? DAUER ?
License: cc-by-nc-nd/4.0
Language: Englisch/English
Time ranges: 2009-02-01 - 2011-07-31
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