University of Natural Resources and Life Sciences, Vienna (BOKU) - Research portal
Gewählte Master / Diploma Thesis:
Florian Egger
(2014):
Temperature and moisture sensitivity of CH4 and N2O fluxes from European soils.
Master / Diploma Thesis - Institut für Bodenforschung (IBF),
BOKU-Universität für Bodenkultur,
pp 105.
UB BOKU
obvsg
FullText
- Abstract:
- Soils are important sources and sinks for greenhouse gases such as methane (CH4) and nitrous oxide (N2O). Gas emissions as well as gas uptake can be attributed to microbial activity in soils. These processes are known to be sensitive to climate change. As part of the ÈCLAIRE EU-project, we examined CH4 and N2O fluxes from different land use types to better predict future feed-back effects on climate change. The nine study sites cover the four main land use types in Europe, incubation temperature and soil moisture served as modifiable climate parameters. Gas chromatography was used to determine gas concentration and gas fluxes were estimated by regression analysis. Thereby we hypothesized that (1) CH4 and N2O fluxes differ between the selected land use types, (2) CH4 and N2O fluxes increase with increasing soil moisture and that (3) the temperature sensitivity of CH4 and N2O fluxes differs between land use types. Our results indicate that CH4 and N2O fluxes are significantly different in soils from cropland, peatland, grassland and forest. We found soil moisture to be the main factor regulating CH4 and N2O emissions, as an increase in moisture content resulted in an exponential increase of CH4 (R2=0.28, p=0.000, peatland, UK-AMo) and N2O (best fit: R2=0.68, p=0.000, forest, IT-BFo) emissions. In contrast, CH4 uptake had its optimum at medium moisture content, illustrated by a polynomial function (R2=0.18, p=0.000, forest, FI-Hyy). Temperature sensitivity of CH4 fluxes differed between the sites and between CH4 emission (Q10=52.5, peatland, UK-AMo) and CH4 oxidation (Q10=2.5, forest, IT-IFo). Temperature sensitivity of N2O fluxes in mixed broadleaf stands (Q10=2.5 and 4.9, respectively) was lower compared to coniferous stands (Q10=12.9). Additionally, we could prove that the implementation of an electronic crimper had a significant positive effect on the accuracy of the conducted method.
- Beurteilende(r): Zechmeister-Boltenstern Sophie