Nitrogen Isotope Patterns in Alaskan Black Spruce Reflect Organic Nitrogen Sources and the Activity of Ectomycorrhizal Fungi
(2012) In Ecosystems 15(5). p.819-831- Abstract
- Global patterns in soil, plant, and fungal stable isotopes of N (delta N-15) show promise as integrated metrics of N cycling, particularly the activity of ectomycorrhizal (ECM) fungi. At small spatial scales, however, it remains difficult to differentiate the underlying causes of plant delta N-15 variability and this limits the application of such measurements to better understand N cycling. We conducted a landscape-scale analysis of delta N-15 values from 31 putatively N-limited monospecific black spruce (Picea mariana) stands in central Alaska to assess the two main hypothesized sources of plant delta N-15 variation: differing sources and ECM fractionation. We found roughly 20% of the variability in black spruce foliar N and delta N-15... (More)
- Global patterns in soil, plant, and fungal stable isotopes of N (delta N-15) show promise as integrated metrics of N cycling, particularly the activity of ectomycorrhizal (ECM) fungi. At small spatial scales, however, it remains difficult to differentiate the underlying causes of plant delta N-15 variability and this limits the application of such measurements to better understand N cycling. We conducted a landscape-scale analysis of delta N-15 values from 31 putatively N-limited monospecific black spruce (Picea mariana) stands in central Alaska to assess the two main hypothesized sources of plant delta N-15 variation: differing sources and ECM fractionation. We found roughly 20% of the variability in black spruce foliar N and delta N-15 values to be correlated with the concentration and delta N-15 values of soil NH4 (+) and dissolved organic N (DON) pools, respectively. However, N-15-based mixing models from 24 of the stands suggested that fractionation by ECM fungi obscures the N-15 signature of soil N pools. Models, regressions, and N abundance data all suggested that increasing dependence on soil DON to meet black spruce growth demands predicates increasing reliance on ECM-derived N and that black spruce, on average, received 53% of its N from ECM fungi. Future research should partition the delta N-15 values within the soil DON pool to determine how choice of soil delta N-15 values influence modeled ECM activity. The C balance of boreal forests is tightly linked to N cycling and delta N-15 values may be useful metrics of changes to these connections. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/3076488
- author
- Mayor, Jordan R. ; Schuur, Edward A. G. ; Mack, Michelle C. ; Hollingsworth, Terresa N. and Bååth, Erland LU
- organization
- publishing date
- 2012
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- 15N, black spruce, denitrifier method, dissolved organic nitrogen, ectomycorrhiza, isotope fractionation, mixing models
- in
- Ecosystems
- volume
- 15
- issue
- 5
- pages
- 819 - 831
- publisher
- Springer
- external identifiers
-
- wos:000306952400010
- scopus:84864754599
- ISSN
- 1432-9840
- DOI
- 10.1007/s10021-012-9548-9
- language
- English
- LU publication?
- yes
- id
- 261db4bd-e0e7-49c1-87a8-330cb3aeb437 (old id 3076488)
- date added to LUP
- 2016-04-01 13:36:21
- date last changed
- 2022-01-27 20:04:08
@article{261db4bd-e0e7-49c1-87a8-330cb3aeb437,
abstract = {{Global patterns in soil, plant, and fungal stable isotopes of N (delta N-15) show promise as integrated metrics of N cycling, particularly the activity of ectomycorrhizal (ECM) fungi. At small spatial scales, however, it remains difficult to differentiate the underlying causes of plant delta N-15 variability and this limits the application of such measurements to better understand N cycling. We conducted a landscape-scale analysis of delta N-15 values from 31 putatively N-limited monospecific black spruce (Picea mariana) stands in central Alaska to assess the two main hypothesized sources of plant delta N-15 variation: differing sources and ECM fractionation. We found roughly 20% of the variability in black spruce foliar N and delta N-15 values to be correlated with the concentration and delta N-15 values of soil NH4 (+) and dissolved organic N (DON) pools, respectively. However, N-15-based mixing models from 24 of the stands suggested that fractionation by ECM fungi obscures the N-15 signature of soil N pools. Models, regressions, and N abundance data all suggested that increasing dependence on soil DON to meet black spruce growth demands predicates increasing reliance on ECM-derived N and that black spruce, on average, received 53% of its N from ECM fungi. Future research should partition the delta N-15 values within the soil DON pool to determine how choice of soil delta N-15 values influence modeled ECM activity. The C balance of boreal forests is tightly linked to N cycling and delta N-15 values may be useful metrics of changes to these connections.}},
author = {{Mayor, Jordan R. and Schuur, Edward A. G. and Mack, Michelle C. and Hollingsworth, Terresa N. and Bååth, Erland}},
issn = {{1432-9840}},
keywords = {{15N; black spruce; denitrifier method; dissolved organic nitrogen; ectomycorrhiza; isotope fractionation; mixing models}},
language = {{eng}},
number = {{5}},
pages = {{819--831}},
publisher = {{Springer}},
series = {{Ecosystems}},
title = {{Nitrogen Isotope Patterns in Alaskan Black Spruce Reflect Organic Nitrogen Sources and the Activity of Ectomycorrhizal Fungi}},
url = {{http://dx.doi.org/10.1007/s10021-012-9548-9}},
doi = {{10.1007/s10021-012-9548-9}},
volume = {{15}},
year = {{2012}},
}