Record Display for the EPA National Library Catalog

RECORD NUMBER: 5 OF 5470

OLS Field Name OLS Field Data
Main Title 15N Natural Abundance and (15)N Labelling Studies in Forest Ecosystems.
Author Nadelhoffer, K. J. ; Fry, B. ;
CORP Author Marine Biological Lab., Woods Hole, MA. Ecosystems Center.;Corvallis Environmental Research Lab., OR.
Publisher 1994
Year Published 1994
Report Number EPA/600/A-94/160;
Stock Number PB94-210580
Additional Subjects Nitrogen isotopes ; Forests ; Ecosystems ; Variations ; Soils ; Vegetation ; Plant tissues ; Distillation ; Biochemical cycles ; Nitrification ; Isotopic labeling ; Sampling ; Mathematical models ; Ammonium compounds ; Concentration(Composition) ; Natural abundances ; Patterns
Holdings
Library Call Number Additional Info Location Last
Modified
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Status
NTIS  PB94-210580 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. NTIS 11/11/1994
Collation 55p
Abstract
The relative amounts of the two stable isotopes of Nitrogen (N), 15N and 14N, vary predictably in soils and plant tissues of forests and other non-cultivated ecosystems. Slight fractionations, or discriminations against the heavier N isotope, that can occur as N cycles through vegetation, soils and microbial biomass act over the long term to deplete vegetation and litter of 15N and to enrich humus in 15N. In this chapter, the authors show that 15N natural abundances can be used to make inferences about (1) rates and patterns of N cycling, (2) the relative importance of N inputs versus soil processes in supplying N for plant uptake, (3) retention of N by forests and (4) forest ecosystem health. The authors also discuss uses of 15N-labelling ecosystem-scale experiments on whole forests. Such experiments offer possibilities for checking and improving estimates of N fluxes within and N losses from forests.