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| Titel |
Effect of clear cutting on nutrient fluxes in a subalpine forest at Fraser, Colorado |
| VerfasserIn |
J. O. Reuss, R. Stottlemyer, C. A. Troendle |
| 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 ; 1, no. 2 ; Nr. 1, no. 2, S.333-344 |
| Datensatznummer |
250000152
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| Publikation (Nr.) |
 copernicus.org/hess-1-333-1997.pdf |
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| Zusammenfassung |
Nutrient fluxes were investigated on a forested and
a clearcut plot in a mixed conifer high elevation (2900 m) forest at the
Fraser Experimental Forest in Fraser, Colorado, USA. Plots were located
on a coarse loamy mixed Dystric Cryochrept with relatively high base saturation
(30-90%) and underlain by an impermeable clay subsoil. Following harvest
in late 1984, annual mean NO3 concentrations of 195 to 198 μmol l-1 were
observed from 1988 through 1990 and concentrations were still above reference
levels in 1993. Total nitrogen loss attributable to leaching following
harvest was estimated at 48kg ha-1 over 8 years. Over this same period,
atmospheric nitrogen inputs exceeded annual outflow of NH4 plus NO3 from
the control plots by approximately 11 kg N ha-1. A slight enrichment Of
SO4 and Cl was observed from the harvested plot in 1986 but concentrations
later fell below control plot levels, apparently due to dilution by the
increased discharge from the harvested plot which was three to four times
that from the control plot.
Elevated Ca, Mg, and Na concentrations followed
a similar pattern to NO3 due to exchange reactions, while a depression
in alkalinity of about one-third the amount of NO3 found was also observed.
Enrichment of K occurred primarily in water collected at less than 1 m
depth. Increases in base cation loss due to leaching after harvest were
about twice the amount that can be accounted for by the increased flux
of NO3, SO4, and Cl anions. The excess reflects the increased water flux
and consequent leaching of base cations in association with HCO3 and organic
anions. |
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