Skip to Main Content
Natural abundance 15N in soil and litter across a nitrate-output gradient in New HampshireAuthor(s): L.H. Pardo; H.F. Hemond; J.P. Montoya; J. Pett-Ridge
Source: Forest Ecology and Management. 251: 217-230.
Publication Series: Scientific Journal (JRNL)
Station: Northern Research Station
PDF: Download Publication (648.67 KB)
DescriptionStable isotopes of nitrogen are potentially a valuable tool for regional assessments of nitrogen saturation because they provide an integrated measure of the past nitrogen cycling history of a site. We measured δ15N of soil and litter, as well as net nitrification potential, at three sites across a nitrate-loss gradient in the White Mountains, New Hampshire to test the hypotheses: (1) that δ15N in soil and litter increase across a spatial gradient of nitrate loss; and (2) that δ15N in soil and litter is elevated when nitrification is elevated. δ15N was found not to vary significantly among the three sites. Patterns of leaf litter and forest floor δ15N, however, were strongly influenced by species composition in individual plots. Beech litter had significantly higher δ15N than yellow birch, sugar maple, and red maple. The conifer-dominated plots had significantly lower δ15N in both the organic soil horizons and in litter than did the hardwood-dominated plots. When we adjusted for spatial heterogeneity in mineral soil δ15N values by using an enrichment factor, δ15Nfoliar - δ15NBs, in place of absolute soil δ15N values, a positive relationship was found with net nitrification for hardwoods. δ15N may also be a useful tool for evaluating species differences in nitrogen cycling and nitrogen uptake. The distinct pattern we observed of decreasing d15N across the continuum from hardwood-dominated to conifer-dominated sites may suggest that local drivers (for example, nitrification rate) regulate the absolute value of foliar δ15N, while species-driven factors (e.g., timing and type of uptake) control the foliar δ15N value of one species relative to another in the same plot.
- Check the Northern Research Station web site to request a printed copy of this publication.
- Our on-line publications are scanned and captured using Adobe Acrobat.
- During the capture process some typographical errors may occur.
- Please contact Sharon Hobrla, firstname.lastname@example.org if you notice any errors which make this publication unusable.
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationPardo, L.H.; Hemond, H.F.; Montoya, J.P.; Pett-Ridge, J. 2007. Natural abundance 15N in soil and litter across a nitrate-output gradient in New Hampshire. Forest Ecology and Management. 251: 217-230.
Keywordsnitrogen cycling, N saturation, Species patterns
- Effect of moisture content on warp in hardwood 2 by 6`s for structural use
- Radial growth of hardwoods following the 1998 ice storm in New Hampshire and Maine
- Comparative growth trends of five northern hardwood and montane tree species reveal divergent trajectories and response to climate
XML: View XML