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Landscape control o...
Landscape control on the hydrogeochemistry of As, Co and Pb in a boreal stream network
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- Wällstedt, Teresia (författare)
- Stockholms universitet,Institutionen för miljövetenskap och analytisk kemi,Stockholm University
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- Björkvald, Louise (författare)
- Stockholms universitet,Institutionen för geologiska vetenskaper,Stockholm University
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- Laudon, Hjalmar (författare)
- Swedish University of Agricultural Sciences,Sveriges lantbruksuniversitet,Institutionen för skogens ekologi och skötsel,Department of Forest Ecology and Management
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- Borg, Hans (författare)
- Stockholms universitet,Institutionen för miljövetenskap och analytisk kemi
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- Mörth, Carl-Magnus (författare)
- Stockholms universitet,Institutionen för geologiska vetenskaper
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(creator_code:org_t)
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- Elsevier BV, 2017
- 2017
- Engelska.
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Ingår i: Geochimica et Cosmochimica Acta. - : Elsevier BV. - 0016-7037 .- 1872-9533 .- 0046-564X. ; 211, s. 194-213
- Relaterad länk:
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https://urn.kb.se/re...
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https://doi.org/10.1...
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https://res.slu.se/i...
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Abstract
Ämnesord
Stäng
- In a boreal stream network, stream water concentrations of As, Co and Pb (filtered, <0.4 lm) of 10 nested streams were studied during two consecutive years in order to evaluate the influence of land cover on the temporal and spatial variability of metal concentrations and speciation. Mean concentrations of Co and Pb showed significant but contrasting relationship to landscape type, while As concentrations were not related to landscape type. Highest concentrations of Pb were found in the wetland dominated streams (>30% wetland), which was suggested to be controlled by atmospheric deposition in combination with high DOC release from the wetlands. For Co, the highest concentrations were found in the forest dominated sites (>98% forest), which were attributed to the weathering of minerogenic sources. Contrasting response to runoff events could also be related to landscape type; during the spring flood, decreasing concentrations of As, Co and Pb were observed in the wetland dominated catchments due to dilution, while increasing concentrations during spring flood were observed in the mixed catchments (2-30% wetland) and to some degree in the forested catchments, probably due to flushing of the organic-rich riparian sources. Further, metal speciation was calculated using the geochemical equilibrium model Visual MIN-TEQ. This suggests that dissolved inorganic species of As and Co dominated in headwater streams with low pH while DOC had a major influencing role for Pb. In the larger mixed streams where pH was higher and precipitation of e.g. colloidal Fe and Mn (hydr) oxides was favoured, the major influencing factor was instead adsorption to colloidal Fe for As and Pb, while association to organic matter and colloids of e.g. Mn influenced the concentrations of Co. We thus conclude that landscape type and the magnitude of the runoff events are of great importance for the spatial and temporal variations of As, Co and Pb in this boreal stream network. Projected climate change, with increasing runoff, may therefore influence riverine concentrations and fluxes differently, depending on the prevailing landscape type.
Ämnesord
- NATURVETENSKAP -- Geovetenskap och miljövetenskap (hsv//swe)
- NATURAL SCIENCES -- Earth and Related Environmental Sciences (hsv//eng)
- NATURVETENSKAP -- Biologi -- Ekologi (hsv//swe)
- NATURAL SCIENCES -- Biological Sciences -- Ecology (hsv//eng)
Nyckelord
- Metal geochemistry
- Geochemical modelling
- Visual MINTEQ
- Speciation
- DOC
- Iron
- geokemi
- Geochemistry
Publikations- och innehållstyp
- ref (ämneskategori)
- art (ämneskategori)
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