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Membrane probe array: Technique development and observation of CO2 and CH4 diurnal oscillations in peat profile

Panikov, N. S.; Mastepanov, Mikhail LU and Christensen, Torben LU (2007) In Soil Biology & Biochemistry 39(7). p.1712-1723
Abstract
The purpose of this study was to monitor the dynamics of gases such as CO2 and CH4 in a soil profile with sufficient temporal resolution to observe possible diurnal variations. A computer-controlled device called a membrane probes array (MPA) was developed that consisted of 9-12 individual membrane probes installed at various soil depths. Each probe was made of a stainless steel pipe with a 1 mm orifice covered with a silicone membrane. Soil gases diffuse through the membrane at a rate proportional to the ambient soil gas concentration. To measure diffusion rates, the probes are flushed with N-2 one-by-one at regular time intervals and accumulated gas is detected as a spike with IR and FID analyzers. The longer the period between flushings... (More)
The purpose of this study was to monitor the dynamics of gases such as CO2 and CH4 in a soil profile with sufficient temporal resolution to observe possible diurnal variations. A computer-controlled device called a membrane probes array (MPA) was developed that consisted of 9-12 individual membrane probes installed at various soil depths. Each probe was made of a stainless steel pipe with a 1 mm orifice covered with a silicone membrane. Soil gases diffuse through the membrane at a rate proportional to the ambient soil gas concentration. To measure diffusion rates, the probes are flushed with N-2 one-by-one at regular time intervals and accumulated gas is detected as a spike with IR and FID analyzers. The longer the period between flushings the higher the gas accumulation and the lower the detection limit for a particular soil gas. The developed MPA agreed well with conventional manual gas sampling in West-Siberian mesotrophic fen. In peat cores with intact Carex-Sphagnum vegetation incubated under constant temperature, water level and artificial light:dark (14: 10) cycles, regular diurnal oscillations of soil CO2 and CH4 occurred in the upper part of the peat core down to 19 cm. Gas content in the top layer (3 cm) grew during the light phase, and returned back during the dark phase. In layers further down in the soil, the same events were observed but with progressively increased time delay and lower amplitude. The obtained data agreed with the hypothesis that diurnal variations in soil CO2 and CH4 content are caused by periodic changes in intensity of root exudation that provide a major C- and energy source for soil microorganisms including methanogens. At a soil depth of 23 cm, where the peak of gas bubbles occurred, the signal for both gases became chaotic and not related to the light:dark cycle. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
methane, gradient, sensitivity, diffusion, membrane inlet, transient process, kinetics, gas profile, bubbles
in
Soil Biology & Biochemistry
volume
39
issue
7
pages
1712 - 1723
publisher
Elsevier
external identifiers
  • wos:000246633700032
  • scopus:34247185879
ISSN
0038-0717
DOI
10.1016/j.soilbio.2007.01.034
language
English
LU publication?
yes
id
d1b6a434-5a03-401f-84bb-3cc9f4b35d88 (old id 658042)
date added to LUP
2007-12-17 10:08:47
date last changed
2017-07-02 04:20:30
@article{d1b6a434-5a03-401f-84bb-3cc9f4b35d88,
  abstract     = {The purpose of this study was to monitor the dynamics of gases such as CO2 and CH4 in a soil profile with sufficient temporal resolution to observe possible diurnal variations. A computer-controlled device called a membrane probes array (MPA) was developed that consisted of 9-12 individual membrane probes installed at various soil depths. Each probe was made of a stainless steel pipe with a 1 mm orifice covered with a silicone membrane. Soil gases diffuse through the membrane at a rate proportional to the ambient soil gas concentration. To measure diffusion rates, the probes are flushed with N-2 one-by-one at regular time intervals and accumulated gas is detected as a spike with IR and FID analyzers. The longer the period between flushings the higher the gas accumulation and the lower the detection limit for a particular soil gas. The developed MPA agreed well with conventional manual gas sampling in West-Siberian mesotrophic fen. In peat cores with intact Carex-Sphagnum vegetation incubated under constant temperature, water level and artificial light:dark (14: 10) cycles, regular diurnal oscillations of soil CO2 and CH4 occurred in the upper part of the peat core down to 19 cm. Gas content in the top layer (3 cm) grew during the light phase, and returned back during the dark phase. In layers further down in the soil, the same events were observed but with progressively increased time delay and lower amplitude. The obtained data agreed with the hypothesis that diurnal variations in soil CO2 and CH4 content are caused by periodic changes in intensity of root exudation that provide a major C- and energy source for soil microorganisms including methanogens. At a soil depth of 23 cm, where the peak of gas bubbles occurred, the signal for both gases became chaotic and not related to the light:dark cycle.},
  author       = {Panikov, N. S. and Mastepanov, Mikhail and Christensen, Torben},
  issn         = {0038-0717},
  keyword      = {methane,gradient,sensitivity,diffusion,membrane inlet,transient process,kinetics,gas profile,bubbles},
  language     = {eng},
  number       = {7},
  pages        = {1712--1723},
  publisher    = {Elsevier},
  series       = {Soil Biology & Biochemistry},
  title        = {Membrane probe array: Technique development and observation of CO2 and CH4 diurnal oscillations in peat profile},
  url          = {http://dx.doi.org/10.1016/j.soilbio.2007.01.034},
  volume       = {39},
  year         = {2007},
}