![Hier klicken, um den Treffer aus der Auswahl zu entfernen](images/unchecked.gif) |
Titel |
Diurnal variation in respiratory CO2 flux in an arid ecosystem |
VerfasserIn |
Hella van Asperen, Thorsten Warneke, Simone Sabbatini, Martin Höpker, Tommaso Chiti, Giacomo Nicolini, Dario Papale, Michael Böhm, Justus Notholt |
Konferenz |
EGU General Assembly 2016
|
Medientyp |
Artikel
|
Sprache |
en
|
Digitales Dokument |
PDF |
Erschienen |
In: GRA - Volume 18 (2016) |
Datensatznummer |
250135424
|
Publikation (Nr.) |
EGU/EGU2016-16289.pdf |
|
|
|
Zusammenfassung |
The application of stable isotopes to study ecosystem processes is increasingly used. However, continuous in-situ observation of CO2 concentrations, CO2 fluxes, and their isotopic components are still sparse. In this study, we present results from an arid grassland in Italy, in which continuous measurements of δ13CO2 and CO2 were performed by means of an in-situ Fourier Transform Infrared Spectrometer connected to a concentration-tower set up and to soil flux chambers. By use of Keeling plots, daily nighttime Keeling plot-intercepts and hourly flux chamber Keeling plot-intercepts could be derived. The flux chambers solely showed CO2 emission, with respiration peaks during the day. Keeling plot intercepts from the tower, overlooking the arid grassland, showed more enriched δ13CO2 values than Keeling plot intercepts derived from chamber measurements, indicating different dominating respiratory sources in their footprint. Flux chamber respiratory δ13CO2 values showed a daily pattern with on average 3.5‰ more depleted δ13CO2 fluxes during the night. It is hypothesized that the observed diurnal variation in respiratory δ13CO2 is a consequence of the physical process of diffusive fractionation taking place during the nocturnal boundary layer build up. |
|
|
|
|
|