Effect of permafrost thawing on organic carbon and trace element colloidal speciation in the thermokarst lakes of western Siberia
To examine the mechanisms of carbon mobilization and biodegradation during permafrost thawing and to establish a link between organic carbon (OC) and other chemical and microbiological parameters in forming thermokarst (thaw) lakes, we studied the biogeochemistry of OC and trace elements (TEs) in a...
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ftdoajarticles:oai:doaj.org/article:4f1a9aae89984ef88c543a90e331beaf 2023-05-15T17:54:28+02:00 Effect of permafrost thawing on organic carbon and trace element colloidal speciation in the thermokarst lakes of western Siberia O. S. Pokrovsky L. S. Shirokova S. N. Kirpotin S. Audry J. Viers B. Dupré 2011-03-01T00:00:00Z https://doi.org/10.5194/bg-8-565-2011 https://doaj.org/article/4f1a9aae89984ef88c543a90e331beaf EN eng Copernicus Publications http://www.biogeosciences.net/8/565/2011/bg-8-565-2011.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-8-565-2011 1726-4170 1726-4189 https://doaj.org/article/4f1a9aae89984ef88c543a90e331beaf Biogeosciences, Vol 8, Iss 3, Pp 565-583 (2011) Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 article 2011 ftdoajarticles https://doi.org/10.5194/bg-8-565-2011 2022-12-31T01:33:31Z To examine the mechanisms of carbon mobilization and biodegradation during permafrost thawing and to establish a link between organic carbon (OC) and other chemical and microbiological parameters in forming thermokarst (thaw) lakes, we studied the biogeochemistry of OC and trace elements (TEs) in a chronosequence of small lakes that are being formed due to permafrost thawing in the northern part of western Siberia. Twenty lakes and small ponds of various sizes and ages were sampled for dissolved and colloidal organic carbon, metals and culturable heterotrophic bacterial cell number. We observed a sequence of ecosystems from peat thawing and palsa degradation due to permafrost subsidence in small ponds to large, km-size lakes that are subject to drainage to, finally, the khasyrey (drained lake) formation. There is a systematic evolution of both total dissolved and colloidal concentration of OC and TEs in the lake water along with the chronosequence of lake development that may be directly linked to the microbial mineralization of dissolved organic matter and the liberation of the inorganic components (Fe, Al, and TEs) from the organo-mineral colloids. In this chronosequence of lake development, we observed an apparent decrease in the relative proportion of low molecular weight <1 kDa (1 kDa ~ 1 nm) OC concentration along with a decrease in the concentration of total dissolved (<0.45 μm) OC. This decrease was accompanied by an increase in the small size organic ligands (probably autochthonous exometabolites produced by the phytoplankton) and a simultaneous decrease in the proportion of large-size organic (humic) complexes of allochthonous (soil) origin. This evolution may be due to the activity of heterotrophic bacterioplankton that use allochthonous organic matter and dissolved nutrients originating from peat lixiviation. Most insoluble TEs demonstrate a systematic decrease in concentration during filtration (5 μm, 0.45 μm) exhibiting a similar pattern among different samples. At the same time, there is an ... Article in Journal/Newspaper palsa permafrost Thermokarst Siberia Directory of Open Access Journals: DOAJ Articles Biogeosciences 8 3 565 583 |
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Directory of Open Access Journals: DOAJ Articles |
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ftdoajarticles |
language |
English |
topic |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
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Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 O. S. Pokrovsky L. S. Shirokova S. N. Kirpotin S. Audry J. Viers B. Dupré Effect of permafrost thawing on organic carbon and trace element colloidal speciation in the thermokarst lakes of western Siberia |
topic_facet |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
description |
To examine the mechanisms of carbon mobilization and biodegradation during permafrost thawing and to establish a link between organic carbon (OC) and other chemical and microbiological parameters in forming thermokarst (thaw) lakes, we studied the biogeochemistry of OC and trace elements (TEs) in a chronosequence of small lakes that are being formed due to permafrost thawing in the northern part of western Siberia. Twenty lakes and small ponds of various sizes and ages were sampled for dissolved and colloidal organic carbon, metals and culturable heterotrophic bacterial cell number. We observed a sequence of ecosystems from peat thawing and palsa degradation due to permafrost subsidence in small ponds to large, km-size lakes that are subject to drainage to, finally, the khasyrey (drained lake) formation. There is a systematic evolution of both total dissolved and colloidal concentration of OC and TEs in the lake water along with the chronosequence of lake development that may be directly linked to the microbial mineralization of dissolved organic matter and the liberation of the inorganic components (Fe, Al, and TEs) from the organo-mineral colloids. In this chronosequence of lake development, we observed an apparent decrease in the relative proportion of low molecular weight <1 kDa (1 kDa ~ 1 nm) OC concentration along with a decrease in the concentration of total dissolved (<0.45 μm) OC. This decrease was accompanied by an increase in the small size organic ligands (probably autochthonous exometabolites produced by the phytoplankton) and a simultaneous decrease in the proportion of large-size organic (humic) complexes of allochthonous (soil) origin. This evolution may be due to the activity of heterotrophic bacterioplankton that use allochthonous organic matter and dissolved nutrients originating from peat lixiviation. Most insoluble TEs demonstrate a systematic decrease in concentration during filtration (5 μm, 0.45 μm) exhibiting a similar pattern among different samples. At the same time, there is an ... |
format |
Article in Journal/Newspaper |
author |
O. S. Pokrovsky L. S. Shirokova S. N. Kirpotin S. Audry J. Viers B. Dupré |
author_facet |
O. S. Pokrovsky L. S. Shirokova S. N. Kirpotin S. Audry J. Viers B. Dupré |
author_sort |
O. S. Pokrovsky |
title |
Effect of permafrost thawing on organic carbon and trace element colloidal speciation in the thermokarst lakes of western Siberia |
title_short |
Effect of permafrost thawing on organic carbon and trace element colloidal speciation in the thermokarst lakes of western Siberia |
title_full |
Effect of permafrost thawing on organic carbon and trace element colloidal speciation in the thermokarst lakes of western Siberia |
title_fullStr |
Effect of permafrost thawing on organic carbon and trace element colloidal speciation in the thermokarst lakes of western Siberia |
title_full_unstemmed |
Effect of permafrost thawing on organic carbon and trace element colloidal speciation in the thermokarst lakes of western Siberia |
title_sort |
effect of permafrost thawing on organic carbon and trace element colloidal speciation in the thermokarst lakes of western siberia |
publisher |
Copernicus Publications |
publishDate |
2011 |
url |
https://doi.org/10.5194/bg-8-565-2011 https://doaj.org/article/4f1a9aae89984ef88c543a90e331beaf |
genre |
palsa permafrost Thermokarst Siberia |
genre_facet |
palsa permafrost Thermokarst Siberia |
op_source |
Biogeosciences, Vol 8, Iss 3, Pp 565-583 (2011) |
op_relation |
http://www.biogeosciences.net/8/565/2011/bg-8-565-2011.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-8-565-2011 1726-4170 1726-4189 https://doaj.org/article/4f1a9aae89984ef88c543a90e331beaf |
op_doi |
https://doi.org/10.5194/bg-8-565-2011 |
container_title |
Biogeosciences |
container_volume |
8 |
container_issue |
3 |
container_start_page |
565 |
op_container_end_page |
583 |
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1766162224510926848 |