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Titel |
N2O, NO and CH4 exchange, and microbial N turnover over a Mediterranean pine forest soil |
VerfasserIn |
P. Rosenkranz, N. Brüggemann, H. Papen, Z. Xu, G. Seufert, K. Butterbach-Bahl |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1726-4170
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Digitales Dokument |
URL |
Erschienen |
In: Biogeosciences ; 3, no. 2 ; Nr. 3, no. 2 (2006-03-16), S.121-133 |
Datensatznummer |
250000883
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Publikation (Nr.) |
copernicus.org/bg-3-121-2006.pdf |
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Zusammenfassung |
Trace gas exchange of N2O, NO/NO2 and CH4 between soil and
the atmosphere was measured in a typical Mediterranean pine (Pinus pinaster) forest during
two intensive field campaigns in spring and autumn 2003. Furthermore, gross
and net turnover rates of N mineralization and nitrification as well as soil
profiles of N2O and CH4 concentrations were determined. For both
seasons a weak but significant N2O uptake from the atmosphere into the
soil was observed. During the unusually dry and hot spring mean N2O
uptake was −4.32 µg N m-2 h-1, whereas during the wet and
mild autumn mean N2O uptake was −7.85 µg N m-2 h-1. The
observed N2O uptake into the soil was linked to the very low
availability of inorganic nitrogen at the study site. Organic layer gross N
mineralization decreased from 5.06 mg N kg-1 SDW d-1 in
springtime to 2.68 mg N kg-1 SDW d-1 in autumn. Mean NO emission
rates were significantly higher in springtime (9.94 µg N m-2
h-1) than in autumn (1.43 µg N m-2 h-1). A significant
positive correlation between NO emission rates and gross N mineralization as
well as nitrification rates was found. The negative correlation between NO
emissions and soil moisture was explained with a stimulation of aerobic NO
uptake under N limiting conditions. Since NO2 deposition was
continuously higher than NO emission rates the examined forest soil
functioned as a net NOx sink. Observed mean net CH4 uptake rates
were in spring significantly higher (−73.34 µg C m-2 h-1)
than in autumn (−59.67 µg C m-2 h-1). Changes in CH4
uptake rates were strongly negatively correlated with changes in soil
moisture. The N2O and CH4 concentrations in different soil depths
revealed the organic layer and the upper 0.1 m of mineral soil as the most
important soil horizons for N2O and CH4 consumption. |
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