Application of relaxed eddy accumulation (REA) on managed grassland

Titelangaben

Riederer, Michael ; Hübner, Jörg ; Ruppert, Johannes ; Brand, Willi A. ; Foken, Thomas:
Application of relaxed eddy accumulation (REA) on managed grassland.
In: Atmospheric Measurement Techniques Discussions. Bd. 7 (2014) . - S. 4987-5026.
ISSN 1867-8610
DOI: https://doi.org/10.5194/amtd-7-4987-2014

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Abstract

Relaxed eddy accumulation is applied for measuring fluxes of trace gases for which there is a lack of sensors fast enough in their resolution for eddy-covariance. On managed grasslands, the length of time between management events and the application of relaxed eddy accumulation has an essential influence on the determination of the proportionality factor b and thereby on the resulting flux. In this study this effect is discussed for the first time. Also, scalar similarity between proxy scalars and scalars of interest is affected until the ecosystem has completely recovered. Against this background, CO2 fluxes were continuously measured and 13CO2 isofluxes were determined with a high measurement precision on two representative days in summer 2010. This enabled the evaluation of the 13CO2 flux portion of the entire CO2 flux, in order to estimate potential influences on tracer experiments in ecosystem sciences and to compare a common method for the partitioning of the net ecosystem exchange into assimilation and respiration based on temperature and light response with an isotopic approach directly based on the isotope discrimination of the biosphere.