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Titel |
Water and nitrogen processes along a typical water flowpath and streamwater exports from a forested catchment and changes after clear-cutting: a modelling study |
VerfasserIn |
A. Laurén, L. Finér, H. Koivusalo, T. Kokkonen, T. Karvonen, S. Kellomäki, H. Mannerkoski, M. Ahtiainen |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1027-5606
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Digitales Dokument |
URL |
Erschienen |
In: Hydrology and Earth System Sciences ; 9, no. 6 ; Nr. 9, no. 6 (2005-12-31), S.657-674 |
Datensatznummer |
250007145
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Publikation (Nr.) |
copernicus.org/hess-9-657-2005.pdf |
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Zusammenfassung |
A two dimensional model, FEMMA, to describe water and nitrogen (N) fluxes
within and from a forested first-order catchment (Kangasvaara in Eastern
Finland) was constructed by linking the most significant processes affecting
the fluxes of water, ammonium, nitrate and dissolved organic nitrogen along a
hillslope from the water divide to the stream. The hillslope represents the
average flowpath of water in the catchment and the model was used to estimate
the N fluxes for a catchment in eastern Finland before and after
clear-cutting. The simulated results were in reasonable agreement with the
nitrate, dissolved organic N and dissolved total N measurements from the
study catchment and with other results in the literature. According to the
simulations, the major sinks of N after clear-cutting were immobilisation by
soil microbes, uptake by ground vegetation and sorption to soil. These sinks
increased downslope from the clear-cut area, indicating the importance of an
uncut buffer zone between the stream and the clear-cut area in reducing N
exports. The buffer zone retained 76% of the N flux coming from the
clear-cut area. Nitrification was a key process in controlling the N export
after clear-cutting and N increases were mainly as nitrate. Most of the
annual N export took place during the spring flood, when uptake of N by
plants was minimal. |
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