Obiettivo The aim of this proposal is to improve our understanding of mechanisms, controlling factors and coupling of gas exchange between the atmosphere and terrestrial ecosystems. On the one hand, we have a solid understanding of gas exchange processes at the leaf/cell level. On the other hand, we need to interpret data at the ecosystem scale. We will employ stable isotope techniques to bridge the gap between the two.Physical transport or biological activity during plant and soil gas exchange produce simultaneous changes in the concentrations and isotopic signatures of gases in canopy air. The interpretation of such changes requires a process-based knowledge of the isotopic signatures of ecosystem fluxes and their natural variability. To this end,1. we will develop a process-based model of ecosystem isotopic gas exchange. The model will simulate carbon, oxygen and water fluxes and their isotopic signatures in a novel multi-tracer approach to account for the close coupling of the cycling of carbon, oxygen and water at the ecosystem level.2. we will calibrate the model with measurements of the isotopic signatures of gas exchange during photosynthesis and respiration and during ecosystem gas exchange. A combination of chamber and eddy covariance techniques will be applied to provide flux and integrated ecosystem observations.3. we will determine in laboratory experiments the plant metabolic parameters relating to leaf/cell level mechanisms that are not well constrained but important for model predictions and the interpretation of field measurements.The process-based knowledge of isotopic gas exchange will directly contribute to ongoing efforts to partition ecosystem exchanges into photosynthesis and respiration. It will also improve the capacity of stable isotope methods as tools for the quantification and prediction of carbon sources and sinks. Thus, it addresses research needs identified in the EU Scientific Work Programme, Global Change and Ecosystems. Campo scientifico natural sciencesearth and related environmental sciencesatmospheric sciencesmeteorologybiospheranatural sciencesbiological sciencesecologyecosystemsnatural sciencesbiological sciencesbotany Parole chiave carbon-water interactions coupled carbon and oxygen cylces direct observations of carbon and oxygen isotope fractionation during plant gas exchange multi-tracer approach process-based model Programma(i) FP6-MOBILITY - Human resources and Mobility in the specific programme for research, technological development and demonstration "Structuring the European Research Area" under the Sixth Framework Programme 2002-2006 Argomento(i) MOBILITY-2.2 - Marie Curie Outgoing International Fellowships (OIF) Invito a presentare proposte FP6-2002-MOBILITY-6 Vedi altri progetti per questo bando Meccanismo di finanziamento OIF - Marie Curie actions-Outgoing International Fellowships Coordinatore THE CHANCELLOR, MASTERS AND SCHOLARS OF THE UNIVERSITY OF CAMBRIDGE Contributo UE Nessun dato Indirizzo Mostra sulla mappa Collegamenti Sito web Opens in new window Costo totale Nessun dato