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| Titel |
Nitrogen balance of a boreal Scots pine forest |
| VerfasserIn |
J. F. J. Korhonen, M. Pihlatie, J. Pumpanen, H. Aaltonen, P. Hari, J. Levula, A.-J. Kieloaho, E. Nikinmaa, T. Vesala, H. Ilvesniemi |
| 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 ; 10, no. 2 ; Nr. 10, no. 2 (2013-02-15), S.1083-1095 |
| Datensatznummer |
250017520
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| Publikation (Nr.) |
 copernicus.org/bg-10-1083-2013.pdf |
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| Zusammenfassung |
| The productivity of boreal forests is considered to be limited by low
nitrogen (N) availability. Increased atmospheric N deposition has altered the
functioning and N cycling of these N-sensitive ecosystems by increasing the
availability of reactive nitrogen. The most important components of N pools
and fluxes were measured in a boreal Scots pine stand in Hyytiälä,
Southern Finland. The measurements at the site allowed direct estimations of
nutrient pools in the soil and biomass, inputs from the atmosphere and
outputs as drainage flow and gaseous losses from two micro-catchments. N was
accumulating in the system, mainly in woody biomass, at a rate of
7 kg N ha−1 yr−1. Nitrogen input as atmospheric deposition was
7.4 kg N ha−1 yr−1. Dry deposition and organic N in wet
deposition contributed over half of the inputs in deposition. Total outputs
were 0.4 kg N ha−1 yr−1, the most important outputs being
N2O emission to the atmosphere and organic N flux in drainage flow.
Nitrogen uptake and retranslocation were equally important sources of N for
plant growth. Most of the assimilated N originated from decomposition of
organic matter, and the fraction of N that could originate directly from
deposition was about 30%. In conclusion, atmospheric N deposition
fertilizes the site considerably, but there are no signs of N saturation.
Further research is needed to estimate soil N2 fluxes (emission and
fixation), which may amount up to several kg N ha−1 yr−1. |
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