EGU23-3397, updated on 02 May 2023
https://doi.org/10.5194/egusphere-egu23-3397
EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Number of Chamber Measurement Locations for Accurate Quantification of Landscape-Scale Greenhouse Gas Fluxes: Importance of Land Use, Seasonality, and Greenhouse Gas Type

Elizabeth Wangari1, Ricky Mwanake1, David Kraus1, Christian Werner1, Gretchen Gettel2, Ralf Kiese1, Lutz Breuer3, Klaus Butterbach-Bahl1,4, and Tobias Houska3
Elizabeth Wangari et al.
  • 1Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research-Atmospheric Environmental Research (IMK-IFU), Garmisch-Partenkirchen, Germany
  • 2IHE Delft Institute for Water Education, Delft, The Netherlands
  • 3Institute for Landscape Ecology and Resources Management (ILR), Research Centre for BioSystems, Land Use and Nutrition (iFZ), Justus Liebig University Gießen, Gießen, Germany
  • 4Pioneer Center Land-CRAFT, Department of Agroecology, University of Aarhus, Denmark

Accurate quantification of landscape soil greenhouse gas (GHG) exchange from chamber
measurements is challenging due to the high spatial-temporal variability of fluxes, which results in large
uncertainties in upscaled regional and global flux estimates. We quantified landscape-scale (6 km2 in central
Germany) soil/ecosystem respiration (SR/ER-CO2), methane (CH4), and nitrous oxide (N2O) fluxes at
stratified sites with contrasting landscape characteristics using the fast-box chamber technique. We assessed
the influence of land use (forest, arable, and grassland), seasonality (spring, summer, and autumn), soil
types, and slope on the fluxes. We also evaluated the number of chamber measurement locations required to
estimate landscape fluxes within globally significant uncertainty thresholds. The GHG fluxes were strongly
influenced by seasonality and land use rather than soil type and slope. The number of chamber measurement
locations required for robust landscape-scale flux estimates depended on the magnitude of fluxes, which varied
with season, land use, and GHG type. Significant N2O-N flux uncertainties greater than the global mean
flux (0.67 kg ha−1 yr−1) occurred if landscape measurements were done at <4 and <22 chamber locations
(per km2) in forest and arable ecosystems, respectively, in summer. For CO2 and CH4 fluxes, uncertainties
greater than the global median CO2-C flux (7,500 kg ha−1 yr−1) and the global mean forest CH4-C uptake rate
(2.81 kg ha−1 yr−1) occurred at <2 forest and <6 arable chamber locations. This finding suggests that more
chamber measurement locations are required to assess landscape-scale N2O fluxes than CO2 and CH4, based on
these GHG-specific uncertainty thresholds.

How to cite: Wangari, E., Mwanake, R., Kraus, D., Werner, C., Gettel, G., Kiese, R., Breuer, L., Butterbach-Bahl, K., and Houska, T.: Number of Chamber Measurement Locations for Accurate Quantification of Landscape-Scale Greenhouse Gas Fluxes: Importance of Land Use, Seasonality, and Greenhouse Gas Type, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-3397, https://doi.org/10.5194/egusphere-egu23-3397, 2023.