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Decoupling of soil carbon and nitrogen turnover partly explains increased net ecosystem production in response to nitrogen fertilization

Ehtesham, Emad LU and Bengtson, Per LU (2017) In Scientific Reports 7.
Abstract

During the last decade there has been an ongoing controversy regarding the extent to which nitrogen fertilization can increase carbon sequestration and net ecosystem production in forest ecosystems. The debate is complicated by the fact that increased nitrogen availability caused by nitrogen deposition has coincided with increasing atmospheric carbon dioxide concentrations. The latter could further stimulate primary production but also result in increased allocation of carbon to root exudates, which could potentially 'prime' the decomposition of soil organic matter. Here we show that increased input of labile carbon to forest soil caused a decoupling of soil carbon and nitrogen cycling, which was manifested as a reduction in respiration... (More)

During the last decade there has been an ongoing controversy regarding the extent to which nitrogen fertilization can increase carbon sequestration and net ecosystem production in forest ecosystems. The debate is complicated by the fact that increased nitrogen availability caused by nitrogen deposition has coincided with increasing atmospheric carbon dioxide concentrations. The latter could further stimulate primary production but also result in increased allocation of carbon to root exudates, which could potentially 'prime' the decomposition of soil organic matter. Here we show that increased input of labile carbon to forest soil caused a decoupling of soil carbon and nitrogen cycling, which was manifested as a reduction in respiration of soil organic matter that coincided with a substantial increase in gross nitrogen mineralization. An estimate of the magnitude of the effect demonstrates that the decoupling could potentially result in an increase in net ecosystem production by up to 51 kg C ha-1 day-1 in nitrogen fertilized stands during peak summer. Even if the effect is several times lower on an annual basis, the results still suggest that nitrogen fertilization can have a much stronger influence on net ecosystem production than can be expected from a direct stimulation of primary production alone.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Scientific Reports
volume
7
publisher
Nature Publishing Group
external identifiers
  • scopus:85017465611
  • wos:000399011700001
ISSN
2045-2322
DOI
10.1038/srep46286
language
English
LU publication?
yes
id
c480ede1-7d90-41cc-82ea-3e725b7e5aee
date added to LUP
2017-05-08 11:55:44
date last changed
2018-01-07 12:02:12
@article{c480ede1-7d90-41cc-82ea-3e725b7e5aee,
  abstract     = {<p>During the last decade there has been an ongoing controversy regarding the extent to which nitrogen fertilization can increase carbon sequestration and net ecosystem production in forest ecosystems. The debate is complicated by the fact that increased nitrogen availability caused by nitrogen deposition has coincided with increasing atmospheric carbon dioxide concentrations. The latter could further stimulate primary production but also result in increased allocation of carbon to root exudates, which could potentially 'prime' the decomposition of soil organic matter. Here we show that increased input of labile carbon to forest soil caused a decoupling of soil carbon and nitrogen cycling, which was manifested as a reduction in respiration of soil organic matter that coincided with a substantial increase in gross nitrogen mineralization. An estimate of the magnitude of the effect demonstrates that the decoupling could potentially result in an increase in net ecosystem production by up to 51 kg C ha<sup>-1</sup> day<sup>-1</sup> in nitrogen fertilized stands during peak summer. Even if the effect is several times lower on an annual basis, the results still suggest that nitrogen fertilization can have a much stronger influence on net ecosystem production than can be expected from a direct stimulation of primary production alone.</p>},
  articleno    = {46286},
  author       = {Ehtesham, Emad and Bengtson, Per},
  issn         = {2045-2322},
  language     = {eng},
  month        = {04},
  publisher    = {Nature Publishing Group},
  series       = {Scientific Reports},
  title        = {Decoupling of soil carbon and nitrogen turnover partly explains increased net ecosystem production in response to nitrogen fertilization},
  url          = {http://dx.doi.org/10.1038/srep46286},
  volume       = {7},
  year         = {2017},
}