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Diatom blooms and associated vegetation shifts in a subarctic peatland : responses to distant volcanic eruptions?

Kokfelt, U. LU ; Muscheler, R. LU ; Mellström, A. LU ; Struyf, E. LU ; Rundgren, M. LU ; Wastegård, S. and Hammarlund, D. LU (2016) In Journal of Quaternary Science 31(7). p.723-730
Abstract

We test the hypothesis that rich occurrences of diatoms observed at transitions between major peat units representing different vegetation communities in a peat sequence from subarctic northern Sweden reflect responses to acid deposition from the Samalas AD 1257 and Laki AD 1783/1784 eruptions. We observe sudden changes in the mire ecosystem and thereby in the trophic status and biogeochemical cycling of the peatland. Both the eruptions are known to have been associated with significant acid deposition events and climatic anomalies, as recorded in polar ice cores. To test the hypothesis, new chronological analyses and age modelling were applied to existing biogeochemical and biological records from the peat sequence. This approach... (More)

We test the hypothesis that rich occurrences of diatoms observed at transitions between major peat units representing different vegetation communities in a peat sequence from subarctic northern Sweden reflect responses to acid deposition from the Samalas AD 1257 and Laki AD 1783/1784 eruptions. We observe sudden changes in the mire ecosystem and thereby in the trophic status and biogeochemical cycling of the peatland. Both the eruptions are known to have been associated with significant acid deposition events and climatic anomalies, as recorded in polar ice cores. To test the hypothesis, new chronological analyses and age modelling were applied to existing biogeochemical and biological records from the peat sequence. This approach yielded modelled age ranges of AD 1239–1284 (1σ)/AD 1210–1303 (2σ) (median: AD 1260) and AD 1674–1795 (1σ)/AD 1665–1875 (2σ) (median AD 1743), respectively, for the stratigraphic transitions. Hence, the modelled age ranges bracket the ages of the eruptions in question and the hypothesis could therefore not be rejected. Impacts of acid deposition from the eruptions are assumed to have caused instant acidification, vegetation damage, increased nutrient cycling and blooms of opportunistic epiphytic diatoms. In addition, cooling may have contributed to vegetation changes through permafrost inception, frost heave and thereby altered hydrological conditions.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
acid deposition, diatoms, permafrost peatland, vegetation changes, volcanic impact
in
Journal of Quaternary Science
volume
31
issue
7
pages
8 pages
publisher
John Wiley & Sons
external identifiers
  • scopus:84992467236
  • wos:000388437800007
ISSN
0267-8179
DOI
10.1002/jqs.2898
language
English
LU publication?
yes
id
03bc92ff-f709-4ace-8871-2618e1731864
date added to LUP
2016-11-16 12:51:29
date last changed
2017-09-18 11:30:30
@article{03bc92ff-f709-4ace-8871-2618e1731864,
  abstract     = {<p>We test the hypothesis that rich occurrences of diatoms observed at transitions between major peat units representing different vegetation communities in a peat sequence from subarctic northern Sweden reflect responses to acid deposition from the Samalas AD 1257 and Laki AD 1783/1784 eruptions. We observe sudden changes in the mire ecosystem and thereby in the trophic status and biogeochemical cycling of the peatland. Both the eruptions are known to have been associated with significant acid deposition events and climatic anomalies, as recorded in polar ice cores. To test the hypothesis, new chronological analyses and age modelling were applied to existing biogeochemical and biological records from the peat sequence. This approach yielded modelled age ranges of AD 1239–1284 (1σ)/AD 1210–1303 (2σ) (median: AD 1260) and AD 1674–1795 (1σ)/AD 1665–1875 (2σ) (median AD 1743), respectively, for the stratigraphic transitions. Hence, the modelled age ranges bracket the ages of the eruptions in question and the hypothesis could therefore not be rejected. Impacts of acid deposition from the eruptions are assumed to have caused instant acidification, vegetation damage, increased nutrient cycling and blooms of opportunistic epiphytic diatoms. In addition, cooling may have contributed to vegetation changes through permafrost inception, frost heave and thereby altered hydrological conditions.</p>},
  author       = {Kokfelt, U. and Muscheler, R. and Mellström, A. and Struyf, E. and Rundgren, M. and Wastegård, S. and Hammarlund, D.},
  issn         = {0267-8179},
  keyword      = {acid deposition,diatoms,permafrost peatland,vegetation changes,volcanic impact},
  language     = {eng},
  month        = {10},
  number       = {7},
  pages        = {723--730},
  publisher    = {John Wiley & Sons},
  series       = {Journal of Quaternary Science},
  title        = {Diatom blooms and associated vegetation shifts in a subarctic peatland : responses to distant volcanic eruptions?},
  url          = {http://dx.doi.org/10.1002/jqs.2898},
  volume       = {31},
  year         = {2016},
}