Change search
ReferencesLink to record
Permanent link

Direct link
Importance of vegetation type for mercury sequestration in the northern Swedish mire, Rödmossamyran:  
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.
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.
Show others and affiliations
2010 (English)In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 74, no 24, 7116-7126 p.Article in journal (Refereed) Published
Abstract [en]

Even if mires have proven to be relatively reliable archives over the temporal trends in atmospheric mercury deposition, there are large discrepancies between sites regarding the magnitude of the anthropogenic contribution to the global mercury cycle. A number of studies have also revealed significant differences in mercury accumulation within the same mire area. This raises the question of which factors, other than mercury deposition, affect the sequestration of this element in peat. One such factor could be vegetation type, which has the potential to affect both interception and retention of mercury. In order to assess how small-scale differences in vegetation type can affect mercury sequestration we sampled peat and living plants along three transects on a northern Swedish mire. The mire has two distinctly different vegetation types, the central part consists of an open area dominated by Sphagnum whereas the surrounding fen, in addition to Sphagnum mosses, has an understory of ericaceous shrubs and a sparse pine cover. A few main patterns can be observed in our data; (1) Both peat and Sphagnum-mosses have higher mercury content (both concentration and inventory) in the pine-covered fen compared to the open Sphagnum area (100% and 71% higher for peat and plants, respectively). These differences clearly exceed the 33% difference observed for lead-210, which is considered as a good analogue for atmospheric mercury deposition. (2) The differences in mercury concentration between peat profiles within a single vegetation type can largely be attributed to differences in peat decomposition. (3) When growing side by side in the open Sphagnum area, the moss species Sphagnum subsecundum has significantly higher mercury concentrations compared to S. centrale (24 ± 3 and 18 ± 2 ng Hg g−1, respectively). Based on these observations we suggest that species composition, vegetation type and decomposition can affect the mercury sequestration in a peat record, and that any changes in these properties over time, or space, have the potential to modify the mercury deposition signal recorded in the peat.

Place, publisher, year, edition, pages
Elsevier Ltd , 2010. Vol. 74, no 24, 7116-7126 p.
URN: urn:nbn:se:umu:diva-38044DOI: 10.1016/j.gca.2010.09.026ISI: 000285076600012OAI: diva2:371934
Available from: 2010-11-23 Created: 2010-11-23 Last updated: 2016-05-19Bibliographically approved
In thesis
1. Studies of an elusive element: processes that influence the net retention of mercury in lake sediments and peatlands
Open this publication in new window or tab >>Studies of an elusive element: processes that influence the net retention of mercury in lake sediments and peatlands
2010 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Because of its toxic nature mercury is a threat to both wildlife and human health, and thus, it is an element of concern in the environment. Currently much of the mercury emitted to the atmosphere is derived from anthropogenic sources – both direct emissions and re-emission of already deposited anthropogenic mercury. Following deposition mercury is affected by a long array of processes, and this thesis has focused on trying to increase our knowledge on the net retention of mercury in lake sediments and peatlands. This information is vital in order to understand how mercury behaves in the environment and where mercury is at risk of becoming a problem. Knowledge about the retention of mercury is also important when using lake sediments and peat records as environmental archives over past mercury deposition.

By using varved, annually laminated, sediments I have determined that lake sediments are reliable archives for inorganic mercury, but not for methylmercury. A study of the spatial distribution of mercury in a whole-lake basin shows that inorganic- and methylmercury are controlled by different sediment properties. Inorganic mercury is controlled by combination of fine-grained mineral matter and organic matter concentrations, whereas methylmercury is controlled by water depth and sulfur concentration. This study also shows that especially methylmercury have a very heterogeneous spatial distribution across the lake basin, something that might be of large importance when using lake sediments to calculate whole-lake burdens of mercury. In a study regarding the effects of vegetation on the net retention of mercury in a peatland I showed that there are considerable differences in both plant- and peat-mercury concentrations depending on vegetation type. This might have implications for the use of peat records as archives over atmospheric mercury deposition. Finally I have used a combination of a peat and a lake sediment record to study how past and recent climatic changes affects the stability of a peatland currently underlain by permafrost. Here we are able to show that destabilization of peatlands, as a result of permafrost melt, can cause a significant release of organically bound mercury from the mire to the surrounding aquatic environment. Considering the currently warming climate there is a risk of sub-arctic peatlands turning into mercury sources, which might be important to recognize when assessing current mercury pollution pathways.

Place, publisher, year, edition, pages
Umeå: Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2010. 20 p.
Mercury, retention, lake sediments, peatlands, environmental archives, sedimentation, diagenesis, vegetation, permafrost
Research subject
biology, Environmental Science
urn:nbn:se:umu:diva-38424 (URN)978-91-7459-113-2 (ISBN)
Public defence
2011-01-14, KBC-huset, KB3A9 (lilla hörsalen), Umeå universitet, Umeå, 10:00 (English)
Available from: 2010-12-21 Created: 2010-12-14 Last updated: 2010-12-21Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Rydberg, JohanKarlsson, JonNyman, RogerWanhatalo, IdaBindler, Richard
By organisation
Department of Ecology and Environmental Sciences
In the same journal
Geochimica et Cosmochimica Acta

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 289 hits
ReferencesLink to record
Permanent link

Direct link