Advanced

Carbon partitioning in a wet and a semiwet subarctic mire ecosystem based on in situ C-14 pulse-labelling

Olsrud, Maria and Christensen, Torben LU (2011) In Soil Biology & Biochemistry 43(2). p.231-239
Abstract
In this study we quantify the partitioning of recent assimilates to above- and below-ground carbon (C) pools in two subarctic mire ecosystems - wet minerotrophic and semiwet ombrotrophic mire - using in situ C-14 pulse-labelling. Ecosystem C partitioning to rhizomes, coarse roots, fine roots, dissolved organic carbon (DOC) and microbes were quantified twice during the growing season at three different soil depths. Finally the C-14-partitioning data from this and a previous study were combined to estimate the overall C partitioning of the three main vegetation types of a Scandinavian subarctic mire in early and late summer. The semiwet ombrotrophic ecosystem hosted a much larger root biomass on an area basis compared to the wet... (More)
In this study we quantify the partitioning of recent assimilates to above- and below-ground carbon (C) pools in two subarctic mire ecosystems - wet minerotrophic and semiwet ombrotrophic mire - using in situ C-14 pulse-labelling. Ecosystem C partitioning to rhizomes, coarse roots, fine roots, dissolved organic carbon (DOC) and microbes were quantified twice during the growing season at three different soil depths. Finally the C-14-partitioning data from this and a previous study were combined to estimate the overall C partitioning of the three main vegetation types of a Scandinavian subarctic mire in early and late summer. The semiwet ombrotrophic ecosystem hosted a much larger root biomass on an area basis compared to the wet minerotrophic ecosystem which might be due to differences in the soil nutrient level. Microbial C was found to be the largest C-pool in both ecosystems. Ecosystem C-14 partitioning was poorly related to plant biomass for the semiwet and the wet ecosystem. Overall a higher partitioning of recent assimilates to below-ground compartments was apparent in August-September compared to June-July, while the opposite was found for the above-ground C-pools. In the semiwet ecosystem twice as much C-14 was found in DOC compared to the wet ecosystem, where root density, litter and above-ground biomass were important controls of the C-14-recovery in DOC. Plant-derived DOC was estimated to be 15.4 versus 12.9 mg C m(-2) d(-1) in the semiwet and wet ecosystem, respectively. Graminoid dominated and dwarf shrub dominated vegetation types of the subarctic mire Stordalen differ with respect to the relative amount of recently assimilated C partitioned to C-pools with "slow" versus "fast" decomposition rate. The capacity for sequestration of recently fixed C within "slow" C-pools might affect the ecosystem C balance (NEE) and C-storage. The potential for vegetation changes might therefore be an important factor to consider in studies of response of ecosystem C-dynamics to global change factors in subarctic mires. (C) 2010 Elsevier Ltd. All rights reserved. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Below-ground, C-14 pulse-labelling, Carbon allocation, Carex rotundata, Eriophorum angustifolium, Minerotrophic, Mire ecosystem, Ombrotrophic, Subarctic
in
Soil Biology & Biochemistry
volume
43
issue
2
pages
231 - 239
publisher
Elsevier
external identifiers
  • wos:000286967800002
  • scopus:78650678827
ISSN
0038-0717
DOI
10.1016/j.soilbio.2010.09.034
project
MERGE
BECC
language
English
LU publication?
yes
id
f1b5fa9f-7e71-4cf0-a602-1515a1f80b92 (old id 1868841)
date added to LUP
2011-04-18 14:37:45
date last changed
2017-07-02 04:10:25
@article{f1b5fa9f-7e71-4cf0-a602-1515a1f80b92,
  abstract     = {In this study we quantify the partitioning of recent assimilates to above- and below-ground carbon (C) pools in two subarctic mire ecosystems - wet minerotrophic and semiwet ombrotrophic mire - using in situ C-14 pulse-labelling. Ecosystem C partitioning to rhizomes, coarse roots, fine roots, dissolved organic carbon (DOC) and microbes were quantified twice during the growing season at three different soil depths. Finally the C-14-partitioning data from this and a previous study were combined to estimate the overall C partitioning of the three main vegetation types of a Scandinavian subarctic mire in early and late summer. The semiwet ombrotrophic ecosystem hosted a much larger root biomass on an area basis compared to the wet minerotrophic ecosystem which might be due to differences in the soil nutrient level. Microbial C was found to be the largest C-pool in both ecosystems. Ecosystem C-14 partitioning was poorly related to plant biomass for the semiwet and the wet ecosystem. Overall a higher partitioning of recent assimilates to below-ground compartments was apparent in August-September compared to June-July, while the opposite was found for the above-ground C-pools. In the semiwet ecosystem twice as much C-14 was found in DOC compared to the wet ecosystem, where root density, litter and above-ground biomass were important controls of the C-14-recovery in DOC. Plant-derived DOC was estimated to be 15.4 versus 12.9 mg C m(-2) d(-1) in the semiwet and wet ecosystem, respectively. Graminoid dominated and dwarf shrub dominated vegetation types of the subarctic mire Stordalen differ with respect to the relative amount of recently assimilated C partitioned to C-pools with "slow" versus "fast" decomposition rate. The capacity for sequestration of recently fixed C within "slow" C-pools might affect the ecosystem C balance (NEE) and C-storage. The potential for vegetation changes might therefore be an important factor to consider in studies of response of ecosystem C-dynamics to global change factors in subarctic mires. (C) 2010 Elsevier Ltd. All rights reserved.},
  author       = {Olsrud, Maria and Christensen, Torben},
  issn         = {0038-0717},
  keyword      = {Below-ground,C-14 pulse-labelling,Carbon allocation,Carex rotundata,Eriophorum angustifolium,Minerotrophic,Mire ecosystem,Ombrotrophic,Subarctic},
  language     = {eng},
  number       = {2},
  pages        = {231--239},
  publisher    = {Elsevier},
  series       = {Soil Biology & Biochemistry},
  title        = {Carbon partitioning in a wet and a semiwet subarctic mire ecosystem based on in situ C-14 pulse-labelling},
  url          = {http://dx.doi.org/10.1016/j.soilbio.2010.09.034},
  volume       = {43},
  year         = {2011},
}