umu.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Incorporation of radiometric tracers in peat and implications for estimating accumulation rates
Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
College of William & Mary.
Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
2014 (English)In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 493, 170-177 p.Article in journal (Refereed) Published
Abstract [en]

Accurate dating of peat accumulation is essential for quantitatively reconstructing past changes in atmospheric metal deposition and carbon burial. By analyzing fallout radionuclides Pb-210, Cs-137, Am-241, and Be-7, and total Pb and Hg in 5 cores from two Swedish peatlands we addressed the consequence of estimating accumulation rates due to downwashing of atmospherically supplied elements within peat. The detection of Be-7 down to 18-20 cm for some cores, and the broad vertical distribution of Am-241 without a well-defined peak, suggest some downward transport by percolating rainwater and smearing of atmospherically deposited elements in the uppermost peat layers. Application of the CRS age-depth model leads to unrealistic peat mass accumulation rates (400-600 g m(-2) yr(-1)), and inaccurate estimates of past Pb and Hg deposition rates and trends, based on comparisons to deposition monitoring data (forest moss biomonitoring and wet deposition). After applying a newly proposed IP-CRS model that assumes a potential downward transport of Pb-210 through the uppermost peat layers, recent peat accumulation rates (200-300 g m(-2) yr(-1)) comparable to published values were obtained. Furthermore, the rates and temporal trends in Pb and Hg accumulation correspond more closely to monitoring data, although some off-set is still evident. We suggest that downwashing can be successfully traced using Be-7, and if this information is incorporated into age-depth models, better calibration of peat records with monitoring data and better quantitative estimates of peat accumulation and past deposition are possible, although more work is needed to characterize how downwashing may vary between seasons or years.

Place, publisher, year, edition, pages
2014. Vol. 493, 170-177 p.
Keyword [en]
Beryllium, Downwash, Lead, Mercury, Peat accumulation
National Category
Geochemistry
Identifiers
URN: urn:nbn:se:umu:diva-84160DOI: 10.1016/j.scitotenv.2014.05.088ISI: 2014PubMedID: 24946030Scopus ID: 493OAI: oai:DiVA.org:umu-84160DiVA: diva2:679741
Available from: 2013-12-16 Created: 2013-12-16 Last updated: 2017-12-06Bibliographically approved
In thesis
1. Incorporation and preservation of geochemical fingerprints in peat archives
Open this publication in new window or tab >>Incorporation and preservation of geochemical fingerprints in peat archives
2013 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The present status of the environment, including environmental problems such as heavy metal accumulation in aquatic and terrestrial ecosystems, is in part the consequence of long-term changes. Cores from peatlands and other natural archives provide us with the potential to study aspects of the atmospheric cycling of elements, such as metal pollutants, on timescales much longer than the decade or two available to us with atmospheric deposition monitoring programs. The past decade especially has seen a rapid increase in interest in the biogeochemical record preserved in peat, particularly as it relates to environmental changes (e.g. climate and pollution). Importantly, recent studies have shown that carbon dynamics, i.e., organic matter decomposition, may influence the record of atmospherically derived elements such as halogens and mercury. Other studies have shown that under certain conditions some downward movement of atmospherically deposited elements may also occur, which adds complexity to establishing reliable chronologies as well as inherent problems of estimating accurate accumulation rates of peat and past metal deposition. Thus, we still lack a complete understanding of the basic biogeochemical processes and their effects on trace element distributions. While many studies have validated the general temporal patterns of peat records, there has been a limited critical examination of accumulation records in quantitative terms. To be certain that we extract not only a qualitative record from peat, it is important that we establish a quantitative link between the archive and the few to several decades of data that are available from contemporary monitoring and research. The main objective of this doctoral thesis was to focus on improving the link between the long-term paleorecord and the contemporary monitoring data available from biomonitoring and direct deposition observations. The main research questions have therefore been: Are peat archives an absolute or relative record? And how are geochemical signals, including dating, incorporated in the peat archive? What temporal resolution is realistic to interpret by using peat cores?

Place, publisher, year, edition, pages
Umeå: Umeå Universitet, 2013. 36 p.
Keyword
Peat, Beryllium, bulk density, C/N-ratio, decomposition, deposition, downwash, elemental mobility, geochemistry, humification, lead, light transmission, mercury, peat accumulation, precipitation
National Category
Environmental Sciences
Research subject
biology, Environmental Science
Identifiers
urn:nbn:se:umu:diva-84161 (URN)978-91-7459-779-0 (ISBN)
Public defence
2014-01-24, KB3A9, KBC, Umeå University, Umeå, 10:00 (English)
Opponent
Supervisors
Available from: 2013-12-17 Created: 2013-12-16 Last updated: 2013-12-17Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textPubMedScopus

Search in DiVA

By author/editor
Hansson, Sophia V.Olid, CarolinaBindler, Richard
By organisation
Department of Ecology and Environmental Sciences
In the same journal
Science of the Total Environment
Geochemistry

Search outside of DiVA

GoogleGoogle Scholar

doi
pubmed
urn-nbn

Altmetric score

doi
pubmed
urn-nbn
Total: 282 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf