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The effect of vascular plants on carbon turnover and methane emissions from a tundra wetland

Ström, Lena LU ; Ekberg, Anna LU ; Mastepanov, Mikhail LU and Christensen, Torben LU (2003) In Global Change Biology 9(8). p.1185-1192
Abstract
This paper investigates how vascular plants affect carbon flow and the formation and emission of the greenhouse gas methane (CH4 ) in an arctic wet tundra ecosystem in NE Greenland. We present a field experiment where we studied, in particular, how species-specific root exudation patterns affect the availability of acetate, a hypothesized precursor of CH4 formation. We found significantly higher acetate formation rates in the root vicinity of Eriophorum scheuchzeri compared with another dominating sedge in the wetland, i.e. Dupontia psilosantha . Furthermore a shading treatment, which reduced net photosynthesis, resulted in significantly decreased formation rates of acetate. We also found that the potential CH4 production of the peat... (More)
This paper investigates how vascular plants affect carbon flow and the formation and emission of the greenhouse gas methane (CH4 ) in an arctic wet tundra ecosystem in NE Greenland. We present a field experiment where we studied, in particular, how species-specific root exudation patterns affect the availability of acetate, a hypothesized precursor of CH4 formation. We found significantly higher acetate formation rates in the root vicinity of Eriophorum scheuchzeri compared with another dominating sedge in the wetland, i.e. Dupontia psilosantha . Furthermore a shading treatment, which reduced net photosynthesis, resulted in significantly decreased formation rates of acetate. We also found that the potential CH4 production of the peat profile was highly positively correlated to the concentration of acetate at the respective depths, whereas it was negatively correlated to the concentration of total dissolved organic carbon. This suggests that acetate is a substrate of importance to the methanogens in the studied ecosystem and that acetate concentration in this case can serve as a predictor of substrate quality. To further investigate the importance of acetate as a predecessor to CH4 , we brought an intact peat-plant monolith system collected at the field site in NE Greenland to the laboratory, sealed it hermetically and studied the decomposition of (14) C-labelled acetate injected at the depth of methanogenic activity. After 4 h, (14) CH4 emission from the monolith could be observed. In conclusion, allocation of recently fixed carbon to the roots of certain species of vascular plants affects substrate quality and influence CH4 formation. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
vascular plant effects, quality, substrate, methanogens, methane emission, acetate, arctic wetlands
in
Global Change Biology
volume
9
issue
8
pages
1185 - 1192
publisher
Wiley-Blackwell
external identifiers
  • wos:000184483200005
  • scopus:0042739619
ISSN
1354-1013
DOI
10.1046/j.1365-2486.2003.00655.x
language
English
LU publication?
yes
id
68f8cce6-acd6-40f0-8df0-b33b89805904 (old id 305047)
date added to LUP
2007-09-22 13:17:00
date last changed
2018-10-07 03:46:23
@article{68f8cce6-acd6-40f0-8df0-b33b89805904,
  abstract     = {This paper investigates how vascular plants affect carbon flow and the formation and emission of the greenhouse gas methane (CH4 ) in an arctic wet tundra ecosystem in NE Greenland. We present a field experiment where we studied, in particular, how species-specific root exudation patterns affect the availability of acetate, a hypothesized precursor of CH4 formation. We found significantly higher acetate formation rates in the root vicinity of Eriophorum scheuchzeri compared with another dominating sedge in the wetland, i.e. Dupontia psilosantha . Furthermore a shading treatment, which reduced net photosynthesis, resulted in significantly decreased formation rates of acetate. We also found that the potential CH4 production of the peat profile was highly positively correlated to the concentration of acetate at the respective depths, whereas it was negatively correlated to the concentration of total dissolved organic carbon. This suggests that acetate is a substrate of importance to the methanogens in the studied ecosystem and that acetate concentration in this case can serve as a predictor of substrate quality. To further investigate the importance of acetate as a predecessor to CH4 , we brought an intact peat-plant monolith system collected at the field site in NE Greenland to the laboratory, sealed it hermetically and studied the decomposition of (14) C-labelled acetate injected at the depth of methanogenic activity. After 4 h, (14) CH4 emission from the monolith could be observed. In conclusion, allocation of recently fixed carbon to the roots of certain species of vascular plants affects substrate quality and influence CH4 formation.},
  author       = {Ström, Lena and Ekberg, Anna and Mastepanov, Mikhail and Christensen, Torben},
  issn         = {1354-1013},
  keyword      = {vascular plant effects,quality,substrate,methanogens,methane emission,acetate,arctic wetlands},
  language     = {eng},
  number       = {8},
  pages        = {1185--1192},
  publisher    = {Wiley-Blackwell},
  series       = {Global Change Biology},
  title        = {The effect of vascular plants on carbon turnover and methane emissions from a tundra wetland},
  url          = {http://dx.doi.org/10.1046/j.1365-2486.2003.00655.x},
  volume       = {9},
  year         = {2003},
}