LTER Zöbelboden, Austria, Metadata - Soil respiration autochambers

Automated soil CO2 efflux measurements were conducted with the Licor CO2 gas analyser (Licor-8100A, LICOR Biosciences, USA), multiplexer (Licor-8150, LICOR Biosciences, USA), and 6 automated soil respiration chambers (8100-104, LICOR Biosciences, USA) during the snow free season (May to November). In winter, the soil CO2 efflux device had to be removed due to harsh climatic conditions. The chambers were randomly distributed within the IP2 to capture the heterogeneous site conditions. Adjacent to each chamber, the major drivers of soil respiration, i.e. soil temperature and soil water potential were measured by MPS-2 Dielectric Water Potential Sensors (Decagon Devices Inc., USA) and stored as 15 minutes averages. Each chamber was measured in an hourly interval. After chamber closing, the measurements were done each second within a period of four minutes (i.e. observation length). The dead band (i.e. establishment of steady chamber mixing) was set to 30 seconds. The pre- and post-purge periods were set to five and one minute, respectively. The chamber offset used for calculation of the volume of air inside the soil collar were measured during the installation of the device and then checked trifold during the measurement period. The calculated fluxes (together with the starting time of each measurement, the curve fit type (i.e. exponential or linear), two quality indices (R2, SSN), and the number of measurements were extracted from the raw data and – together with the rawdata – transferred daily to the Environment Agency Austria. The extracted values were imported in the (environmental) data base of the Environment Agency Austria. The rawdata are stored separately.