bei Google ScholarTitelangaben
Reth, Sascha ; Göckede, Mathias ; Falge, Eva:
CO₂ efflux from agricultural soils in Eastern Germany – comparison of a closed chamber system with eddy covariance measurements.
In: Theoretical and Applied Climatology.
Bd. 80
(2005)
Heft 2-4
.
- S. 105-120.
ISSN 1434-4483
DOI: https://doi.org/10.1007/s00704-004-0094-z
Abstract
In order to quantify the effects of temperature and soilwater content on soil respiration, during June and July 2002CO2 soil efflux was measured with a closed chamber (nonsteadystate, flow through) system in the field. The amountof CO2 emission was highly dependent on the land-use inthe observation area, which consisted of meadow soil andbrownfield. The CO2 emission from the brownfield rangedfrom 0.9 to 5.5 mmol CO2 m2 s1, and that for meadowsoil from 1.1 to 12.6 mmol CO2 m2 s1. Soil respiration, asa function of soil temperature (Tsoil), relative soil watercontent (RSWC), soil pH, and the soil carbon=nitrogenratio (C=N), was analysed by a modified closed non-linearregression model. Between 63% and 81% of the variationof soil CO2 emission could be explained with changes ofTsoil, RSWC, pH, and C=N for the individual chambers onthe brownfield.Subsequent analysis involved a comparison of the soilchamber results with eddy covariance (EC) measurementsof one week, and included a footprint analysis to accountfor the influence of the different land use types on the measurements.For this, EC data (143 measurements after qualitycheck) were restricted to those originating from the brown-field area with more than 90% of the flux. For a secondcomparison, the net ecosystem exchange (NEE) was calculatedfor different parts of the meadow using the SVATmodel PROXEL. Together with the respiration from thebrownfield, a weighted average of model NEE was producedusing the flux contribution determined by the footprintmodel. Acceptable agreement (r2¼0.69) was found betweenthe modelled data and individual EC measurements, except during situations where the performance of the footprintmodel was disturbed by internal boundary layer effects.