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Relieving substrate limitation-soil moisture and temperature determine gross N transformation rates

Bengtson, Per LU ; Falkengren-Grerup, Ursula LU and Bengtsson, Göran LU (2005) In Oikos 111(1). p.81-90
Abstract
A field experiment was designed with the objective to reveal the interactions between soil moisture, temperature, total, dissolved, and phosphate buffer extractable C and N, and microbial activity in the control of in situ gross N mineralization and immobilization rates in a deciduous forest. We had three alternative hypotheses to explain variations of the gross N transformations: 1) microorganisms are C limited, 2) microorganisms are N limited, or 3) neither C nor N limit the microorganisms but moisture and temperature conditions. Each hypothesis had specific criteria to be fulfilled for its acceptance. The results demonstrated that gross N transformation rates were more dependent on and variable with soil moisture and temperature than... (More)
A field experiment was designed with the objective to reveal the interactions between soil moisture, temperature, total, dissolved, and phosphate buffer extractable C and N, and microbial activity in the control of in situ gross N mineralization and immobilization rates in a deciduous forest. We had three alternative hypotheses to explain variations of the gross N transformations: 1) microorganisms are C limited, 2) microorganisms are N limited, or 3) neither C nor N limit the microorganisms but moisture and temperature conditions. Each hypothesis had specific criteria to be fulfilled for its acceptance. The results demonstrated that gross N transformation rates were more dependent on and variable with soil moisture and temperature than the size of the different C and N pools. The immobilization of N was dependent on the gross mineralization rate, suggesting that the production of enzymes for mineralization of organic N and the immobilization of N from the surrounding soil is disconfirmed when the intracellular N content of the microorganisms is sufficiently high. If the microorganisms are starved for N, enzyme systems involved in both the assimilation and mineralization of N are activated. The mean in situ gross N mineralization rate was two orders of magnitude higher than the natural N deposition in the area and the N addition in the NITREX experiments, meaning that a reduction in the gross N mineralization rate of about 1% would be enough to compensate for the addition of inorganic N. This decrease would hardly be detectable given the great spatial and temporal variability of N transformation rates. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Oikos
volume
111
issue
1
pages
81 - 90
publisher
Wiley-Blackwell
external identifiers
  • wos:000231864900009
  • scopus:26444603035
ISSN
1600-0706
DOI
10.1111/j.0030-1299.2005.13800.x
language
English
LU publication?
yes
id
5a4f3b76-c23a-4b93-ba61-639313756b2e (old id 147050)
date added to LUP
2007-06-27 08:06:15
date last changed
2017-08-13 03:34:05
@article{5a4f3b76-c23a-4b93-ba61-639313756b2e,
  abstract     = {A field experiment was designed with the objective to reveal the interactions between soil moisture, temperature, total, dissolved, and phosphate buffer extractable C and N, and microbial activity in the control of in situ gross N mineralization and immobilization rates in a deciduous forest. We had three alternative hypotheses to explain variations of the gross N transformations: 1) microorganisms are C limited, 2) microorganisms are N limited, or 3) neither C nor N limit the microorganisms but moisture and temperature conditions. Each hypothesis had specific criteria to be fulfilled for its acceptance. The results demonstrated that gross N transformation rates were more dependent on and variable with soil moisture and temperature than the size of the different C and N pools. The immobilization of N was dependent on the gross mineralization rate, suggesting that the production of enzymes for mineralization of organic N and the immobilization of N from the surrounding soil is disconfirmed when the intracellular N content of the microorganisms is sufficiently high. If the microorganisms are starved for N, enzyme systems involved in both the assimilation and mineralization of N are activated. The mean in situ gross N mineralization rate was two orders of magnitude higher than the natural N deposition in the area and the N addition in the NITREX experiments, meaning that a reduction in the gross N mineralization rate of about 1% would be enough to compensate for the addition of inorganic N. This decrease would hardly be detectable given the great spatial and temporal variability of N transformation rates.},
  author       = {Bengtson, Per and Falkengren-Grerup, Ursula and Bengtsson, Göran},
  issn         = {1600-0706},
  language     = {eng},
  number       = {1},
  pages        = {81--90},
  publisher    = {Wiley-Blackwell},
  series       = {Oikos},
  title        = {Relieving substrate limitation-soil moisture and temperature determine gross N transformation rates},
  url          = {http://dx.doi.org/10.1111/j.0030-1299.2005.13800.x},
  volume       = {111},
  year         = {2005},
}