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Effects of simulated increased grazing on carbon allocation patterns in a high arctic mire

Falk, Julie Maria LU ; Schmidt, Niels Martin and Ström, Lena LU (2014) In Biogeochemistry 119(1-3). p.229-244
Abstract
Herbivory is an important part of most ecosystems, and grazing alone can have a considerable impact on the ecosystems carbon balance with both direct and indirect effects. Removal of above-ground biomass by consumption of herbivores will change the below-ground carbon stock; the reduction of litter that goes into the ground will influence the total ecosystem carbon content. Little is however known about how plant-herbivory interactions effect the carbon balance, in particular methane emissions, of high arctic mires. We hypothesized that increased grazing pressure will change carbon allocation patterns resulting in decreased net ecosystem uptake of carbon and subsequently in lower methane emissions. An in-situ field experiment was conducted... (More)
Herbivory is an important part of most ecosystems, and grazing alone can have a considerable impact on the ecosystems carbon balance with both direct and indirect effects. Removal of above-ground biomass by consumption of herbivores will change the below-ground carbon stock; the reduction of litter that goes into the ground will influence the total ecosystem carbon content. Little is however known about how plant-herbivory interactions effect the carbon balance, in particular methane emissions, of high arctic mires. We hypothesized that increased grazing pressure will change carbon allocation patterns resulting in decreased net ecosystem uptake of carbon and subsequently in lower methane emissions. An in-situ field experiment was conducted over 3 years in a high arctic mire at Zackenberg in NE Greenland. The experiment consisted of three treatments, with five replicates of each (1) control, (2) vascular plants were removed (NV), (3) clipped twice each growing season in order to simulate increased muskox grazing. Immediately after the initiation of the experiment net ecosystem uptake of CO2 decreased in clipped plots (mean total decrease for the three following years was 35 %). One year into the experiment a significantly lower CH4 emission was observed in these plots, the total mean reduction for the following 2 years was 26 %. Three years into the experiment significantly lower substrate (acetic acid) availability for CH4 production was observed (27 % reduction). NV plots had a mean decrease in CO2 uptake of 113 %, a 62 % decrease in ecosystem respiration and an 84 % decrease in CH4 emission (mean of all 3 years). Our study shows that increased grazing pressure in a high arctic mire can lead to significant changes in the carbon balance, with lower CO2 uptake leading to lower production of substrate for CH4 formation and in lower CH4 emission. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Arctic, Carbon, Grazing, Methane, Mire, Muskox, Organic acid
in
Biogeochemistry
volume
119
issue
1-3
pages
229 - 244
publisher
Springer
external identifiers
  • wos:000336028400015
  • scopus:84900805558
ISSN
1573-515X
DOI
10.1007/s10533-014-9962-5
project
BECC
language
English
LU publication?
yes
id
88005e26-96a2-49f1-bd3d-5f849e8ba25e (old id 4469796)
date added to LUP
2014-06-19 09:07:16
date last changed
2017-03-05 03:22:00
@article{88005e26-96a2-49f1-bd3d-5f849e8ba25e,
  abstract     = {Herbivory is an important part of most ecosystems, and grazing alone can have a considerable impact on the ecosystems carbon balance with both direct and indirect effects. Removal of above-ground biomass by consumption of herbivores will change the below-ground carbon stock; the reduction of litter that goes into the ground will influence the total ecosystem carbon content. Little is however known about how plant-herbivory interactions effect the carbon balance, in particular methane emissions, of high arctic mires. We hypothesized that increased grazing pressure will change carbon allocation patterns resulting in decreased net ecosystem uptake of carbon and subsequently in lower methane emissions. An in-situ field experiment was conducted over 3 years in a high arctic mire at Zackenberg in NE Greenland. The experiment consisted of three treatments, with five replicates of each (1) control, (2) vascular plants were removed (NV), (3) clipped twice each growing season in order to simulate increased muskox grazing. Immediately after the initiation of the experiment net ecosystem uptake of CO2 decreased in clipped plots (mean total decrease for the three following years was 35 %). One year into the experiment a significantly lower CH4 emission was observed in these plots, the total mean reduction for the following 2 years was 26 %. Three years into the experiment significantly lower substrate (acetic acid) availability for CH4 production was observed (27 % reduction). NV plots had a mean decrease in CO2 uptake of 113 %, a 62 % decrease in ecosystem respiration and an 84 % decrease in CH4 emission (mean of all 3 years). Our study shows that increased grazing pressure in a high arctic mire can lead to significant changes in the carbon balance, with lower CO2 uptake leading to lower production of substrate for CH4 formation and in lower CH4 emission.},
  author       = {Falk, Julie Maria and Schmidt, Niels Martin and Ström, Lena},
  issn         = {1573-515X},
  keyword      = {Arctic,Carbon,Grazing,Methane,Mire,Muskox,Organic acid},
  language     = {eng},
  number       = {1-3},
  pages        = {229--244},
  publisher    = {Springer},
  series       = {Biogeochemistry},
  title        = {Effects of simulated increased grazing on carbon allocation patterns in a high arctic mire},
  url          = {http://dx.doi.org/10.1007/s10533-014-9962-5},
  volume       = {119},
  year         = {2014},
}