Increased Hg Methylation Risks in Management-Induced Terrain Depressions in Forests with Organic-Matter-Rich Soils
Mercury (Hg) is a toxic contaminant that bioaccumulates in trophic chains in its organic form—methylmercury (MeHg). Hg methylation is driven by microorganisms in favourable conditions, stagnant water pools being among potential methylation hotspots. In the present study, we estimated the total Hg an...
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| Format: | Article |
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MDPI AG
2024-02-01
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| Series: | Hydrology |
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| Online Access: | https://www.mdpi.com/2306-5338/11/2/26 |
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| author | Ivars Kļaviņš Arta Bārdule Zane Kļaviņa Zane Lībiete |
| author_facet | Ivars Kļaviņš Arta Bārdule Zane Kļaviņa Zane Lībiete |
| author_sort | Ivars Kļaviņš |
| collection | DOAJ |
| description | Mercury (Hg) is a toxic contaminant that bioaccumulates in trophic chains in its organic form—methylmercury (MeHg). Hg methylation is driven by microorganisms in favourable conditions, stagnant water pools being among potential methylation hotspots. In the present study, we estimated the total Hg and MeHg concentrations in the sediments of water-filled management-induced terrain depressions (ruts, mounding pits and a partly functional drainage ditch) and in nearby undisturbed soil in six hemiboreal forest sites with organic-matter-rich soils in Latvia. Environmental samples were taken in the spring, summer and autumn of 2022. Furthermore, we evaluated the risks of element leaching from the depressions using high-resolution digital terrain models (DTM) and meteorological data. The results suggested a possible leaching of Hg in the past as THg concentrations in the sediments of the depressions were significantly lower than in the surrounding soil. Furthermore, significantly higher MeHg and %MeHg concentrations were found in the sediments than in the surrounding soil identifying the management-induced depressions as Hg methylation hotspots. Spatial analysis of the DTMs pointed to a very likely periodical leaching of elements from the depressions during high precipitation episodes as well as during snowmelts. Moreover, it was observed that ruts left by heavy machinery often channel surface runoff. |
| first_indexed | 2024-03-07T22:29:55Z |
| format | Article |
| id | doaj.art-ab833af2c4c74abb9c9a1e289cf1d98a |
| institution | Directory Open Access Journal |
| issn | 2306-5338 |
| language | English |
| last_indexed | 2024-03-07T22:29:55Z |
| publishDate | 2024-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Hydrology |
| spelling | doaj.art-ab833af2c4c74abb9c9a1e289cf1d98a2024-02-23T15:19:01ZengMDPI AGHydrology2306-53382024-02-011122610.3390/hydrology11020026Increased Hg Methylation Risks in Management-Induced Terrain Depressions in Forests with Organic-Matter-Rich SoilsIvars Kļaviņš0Arta Bārdule1Zane Kļaviņa2Zane Lībiete3Latvian State Forest Research Institute “Silava”, Riga Street 111, LV-2169 Salaspils, LatviaLatvian State Forest Research Institute “Silava”, Riga Street 111, LV-2169 Salaspils, LatviaLatvian State Forest Research Institute “Silava”, Riga Street 111, LV-2169 Salaspils, LatviaLatvian State Forest Research Institute “Silava”, Riga Street 111, LV-2169 Salaspils, LatviaMercury (Hg) is a toxic contaminant that bioaccumulates in trophic chains in its organic form—methylmercury (MeHg). Hg methylation is driven by microorganisms in favourable conditions, stagnant water pools being among potential methylation hotspots. In the present study, we estimated the total Hg and MeHg concentrations in the sediments of water-filled management-induced terrain depressions (ruts, mounding pits and a partly functional drainage ditch) and in nearby undisturbed soil in six hemiboreal forest sites with organic-matter-rich soils in Latvia. Environmental samples were taken in the spring, summer and autumn of 2022. Furthermore, we evaluated the risks of element leaching from the depressions using high-resolution digital terrain models (DTM) and meteorological data. The results suggested a possible leaching of Hg in the past as THg concentrations in the sediments of the depressions were significantly lower than in the surrounding soil. Furthermore, significantly higher MeHg and %MeHg concentrations were found in the sediments than in the surrounding soil identifying the management-induced depressions as Hg methylation hotspots. Spatial analysis of the DTMs pointed to a very likely periodical leaching of elements from the depressions during high precipitation episodes as well as during snowmelts. Moreover, it was observed that ruts left by heavy machinery often channel surface runoff.https://www.mdpi.com/2306-5338/11/2/26mercurymethylmercuryrutsmounding pitssoil disturbancesediments |
| spellingShingle | Ivars Kļaviņš Arta Bārdule Zane Kļaviņa Zane Lībiete Increased Hg Methylation Risks in Management-Induced Terrain Depressions in Forests with Organic-Matter-Rich Soils Hydrology mercury methylmercury ruts mounding pits soil disturbance sediments |
| title | Increased Hg Methylation Risks in Management-Induced Terrain Depressions in Forests with Organic-Matter-Rich Soils |
| title_full | Increased Hg Methylation Risks in Management-Induced Terrain Depressions in Forests with Organic-Matter-Rich Soils |
| title_fullStr | Increased Hg Methylation Risks in Management-Induced Terrain Depressions in Forests with Organic-Matter-Rich Soils |
| title_full_unstemmed | Increased Hg Methylation Risks in Management-Induced Terrain Depressions in Forests with Organic-Matter-Rich Soils |
| title_short | Increased Hg Methylation Risks in Management-Induced Terrain Depressions in Forests with Organic-Matter-Rich Soils |
| title_sort | increased hg methylation risks in management induced terrain depressions in forests with organic matter rich soils |
| topic | mercury methylmercury ruts mounding pits soil disturbance sediments |
| url | https://www.mdpi.com/2306-5338/11/2/26 |
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