Regional Assessment of N Saturation using Foliar and Root ?15 N


TitleRegional Assessment of N Saturation using Foliar and Root ?15 N
Publication TypeJournal Article
Year of Publication2006
AuthorsPardo, LH, Templer, PH, Goodale, CL, Duke, S, Groffman, PM, Adams, MB, Boeckx, P, Boggs, J, Campbell, J, Colman, B, Compton, J, Emmett, B, Gundersen, P, ønaas, J, Lovett, G, Mack, M, Magill, A, Mbila, M, Mitchell, MJ, McGee, G, McNulty, S, Nadelhoffer, K, Ollinger, S, Ross, D, Rueth, H, Rustad, L, Schaberg, P, Schiff, S, Schleppi, P, Spoelstra, J, Wessel, W
JournalBiogeochemistry
Volume80
Issue2
Pagination143 - 171
Date Published10/2006
ISSN0168-2563
Abstract

N saturation induced by atmospheric N deposition can have serious consequences for forest health in many regions. In order
to evaluate whether foliar d
15
N may be a robust, regional-scale measure of the onset of N saturation in forest ecosystems, we
assembled a large dataset on atmospheric N deposition, foliar and root d
15
N and N concentration, soil C:N, mineralization and
nitrification. The dataset included sites in northeastern North America, Colorado, Alaska, southern Chile and Europe. Local drivers
of N cycling (net nitrification and mineralization, and forest floor and soil C:N) were more closely coupled with foliar d
15
N than the
regional driver of N deposition. Foliar d
15
N increased non-linearly with nitrification:mineralization ratio and decreased with forest
floor C:N. Foliar d
15
N was more strongly related to nitrification rates than was foliar N concentration, but concentration was more
strongly correlated with N deposition. Root d
15
N was more tightly coupled to forest floor properties than was foliar d
15
N. We
observed a pattern of decreasing foliar d
15
N values across the following species: American beech>yellow birch>sugar maple. Other
factors that affected foliar d
15
N included species composition and climate. Relationships between foliar d
15
N and soil variables were
stronger when analyzed on a species by species basis than when many species were lumped. European sites showed distinct patterns of
lower foliar d
15
N, due to the importance of ammonium deposition in this region. Our results suggest that examining d
15
N values of
foliage may improve understanding of how forests respond to the cascading effects of N deposition.

URLhttp://nrs.fs.fed.us/pubs/jrnl/2006/ne_2006_pardo_001.pdf
DOI10.1007/s10533-006-9015-9
Short TitleBiogeochemistry
Status: 
Published
Attributale Grant: 
IRWE
Grant Year: 
Year4 (Select this year for NEW RACC products)