Controls over N<sub>2</sub>O, NO<sub>x</sub> and CO<sub>2</sub> fluxes in a calcareous mountain forest soil
We measured nitrogen oxides (N<sub>2</sub>O and NO<sub>x</sub>), dinitrogen (N<sub>2</sub>) and carbon dioxide (CO<sub>2</sub>) emissions from a spruce-fir-beech forest soil in the North Tyrolean limestone Alps in Austria. The site received 10.6&nd...
Main Authors: | , , , , |
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Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2006-01-01
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Series: | Biogeosciences |
Online Access: | http://www.biogeosciences.net/3/383/2006/bg-3-383-2006.pdf |
Summary: | We measured nitrogen oxides (N<sub>2</sub>O and NO<sub>x</sub>), dinitrogen (N<sub>2</sub>) and carbon dioxide (CO<sub>2</sub>) 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<sup>−1</sup> y<sup>−1</sup> 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 N<sub>2</sub>O emissions were obtained by a semi-automatic gas measuring system. In order to cover spatial variability biweekly manual measurements of N<sub>2</sub>O and CO<sub>2</sub> 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 N<sub>2</sub>O whereas only 0.2% were emitted as NO. At our mountain forest site the main end-product of microbial activity processes was N<sub>2</sub> and trace gases (N<sub>2</sub>O and NO) were only of minor importance. |
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ISSN: | 1726-4170 1726-4189 |