Swiss FluxNet

Contact
Nina Buchmann

Project members
Sebastian Wolf
Lutz Merbold
Werner Eugster

Project partners
Sonia Seneviratne
Jürg Fuhrer
Eberhard Parlow

Sites
Alp Weissenstein
Basel
Chamau
Davos
Dischma
Früebüel
Lägeren
Oensingen Cropland
Oensingen Grassland
Rietholzbach

Related projects
CarboEurope IP
ICOS
Maiolica
FoResp
GHG-Europe
FLUXNET

Poster Swiss FluxNet
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Context

The Swiss FluxNet initiative combines all ecosystem-scale CO₂ and H₂O vapour (at some sites also CH₄ and N₂O) flux measurement sites in Switzerland. It currently encompasses eight long-term ecosystem sites, covering the major land-use types in Switzerland: forest (deciduous: Lägeren; coniferous: Davos), cropland (Oensingen), grassland (Oensingen, Chamau, Früebüel, Alp Weissenstein, Rietholzbach) and an urban area (Basel). Further sites with short-term measurements such as Dischma (grassland-winter) provide additional information. Besides the Grassland Sciences Group, three further research groups contribute to Swiss Fluxnet (see Project partners).

 

Approach

Ecosystem flux measurements of CO₂, H₂O vapour, CH₄ and N₂O are typically performed with the eddy covariance (EC) method. The EC method is based on high frequency measurements (10–20 Hz) of turbulent fluctuations in vertical wind velocity and the mixing ratio of a trace gas. The ecosystem flux itself is calculated from the covariance between these two measurements using time averaging of typically 30 or 60 min.

Technical specifications

• Highest-quality infrared gas analyzers and laser spectroscopy (CH₄) to resolve turbulent short-term fluctuations in the trace gas mixing ratio
• Micrometeorology sensors: 3D sonic anemometer for wind speed and directions; radiation sensors, particularly for radiation balance
• Soil climate profiles (temperature, moisture, soil heat flux)
• Auxiliary instrumentation to measure variables such as soil CH₄ and N₂O fluxes, soil/stem/leaf respiration, xylem sap flow, phenology, leaf area index (LAI), biomass, precipitation, fog, etc.