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| Titel |
Comparison of CO2 fluxes from eddy covariance and soil chambers measurements in a vineyard |
| VerfasserIn |
Nadia Vendrame, Luca Tezza, Franco Meggio, Andrea Pitacco |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250111626
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| Publikation (Nr.) |
 EGU/EGU2015-11764.pdf |
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| Zusammenfassung |
| In order to study the processes involved in the carbon balance of a vineyard, we set up a
long-term monitoring station of CO2, water vapour and energyfluxes. The experimental site is
located in an extensive flat vineyard in the north-east of Italy. We measure the net
ecosystem exchange with the eddy covariance (EC) technique using a Campbell
Scientific closed-path IRGA and sonic anemometer, and the soil CO2 flux using
a Li-Cor multiplexed system connected with six automatic dynamic chambers.
Ancillary meteorological and soil variables are also measured. The vineyard is planted
with north-south oriented rows spaced 2.2 m apart. Floor is grass covered, and a
strip 0.6 m wide on the rows is chemically treated. To represent the different soil
conditions existing in the EC footprint and to study the components of the CO2 soil
flux, we placed dark soil chambers both on the vineyard rows and in the inter-row
space.
A well-known limit of the EC technique is the underestimation of fluxes during calm
wind periods, mainly occurring at night. In the autumn/winter vine dormancy period, the
EC and soil chambers CO2 fluxes should be similar. We compared the CO2 fluxes
measured using the two methods to evaluate the reliability of EC measurements at
different atmospheric turbulent mixing conditions and stability. The EC technique
underestimates the ecosystem respiration during night time periods with friction
velocity lower than 0.1 m/s. The present comparison could enable the assessment of a
friction velocity threshold, representing the limit above which the EC fluxes can be
considered representative of the vegetation-atmosphere exchanges at our specific site. |
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