Controls over N2O, NOx and CO2 fluxes in a calcareous mountain forest soil B. Kitzler1, S. Zechmeister-Boltenstern1, C. Holtermann2, U. Skiba3, and K. Butterbach-Bahl4 1Federal Research and Training Centre for Forests, Natural Hazards and Landscape (BFW), Seckendorff-Gudent-Weg 8, Vienna, Austria 2Sellenyg. 2–4/52, Vienna, Austria 3Institute of Terrestrial Ecology, Bush Estate, Penicuik, Midlothian EH26 OQB, Scotland 4Institute for Meteorology and Climate Research, Atmospheric Environmental Research, Forschungszentrum Karlsruhe, Kreuzeckbahnstrasse 19, 82467, Garmisch-Partenkirchen, Germany
Abstract. We measured nitrogen oxides (N2O and NOx), dinitrogen (N2)
and carbon dioxide (CO2) emissions from a spruce-fir-beech forest
soil in the North Tyrolean limestone Alps in Austria. The site received 10.6–11.9 kg N ha−1 y−1
nitrogen as bulk deposition. Fluxes of nitric oxide (NO) were
measured by an automatic dynamic chamber system on an hourly basis over a
two year period. Daily N2O emissions were obtained by a semi-automatic
gas measuring system. In order to cover spatial variability biweekly manual
measurements of N2O and CO2 emissions were carried out in addition.
For acquiring information on the effects of soil and
meteorological conditions and of N-deposition on N-emissions we chose the
auto-regression procedure (time-series analysis) as our means of
investigation. Hence, we could exclude the data's autocorrelation in the
course of the time. We found that soil temperature, soil moisture and bulk
N-deposition followed by air temperature and precipitation were the most
powerful influencing parameters effecting N-emissions. With these variables,
up to 89% of observed temporal variations of N-emissions could be
explained. During the two-year investigation period between 2.5 and 3.5%
of deposited N was reemitted in form of N2O whereas only 0.2% were
emitted as NO. At our mountain forest site the main end-product of microbial
activity processes was N2 and trace gases (N2O and NO) were only
of minor importance.
Citation: Kitzler, B., Zechmeister-Boltenstern, S., Holtermann, C., Skiba, U., and Butterbach-Bahl, K.: Controls over N2O, NOx and CO2 fluxes in a calcareous mountain forest soil, Biogeosciences, 3, 383-395, doi:10.5194/bg-3-383-2006, 2006.