Characterization of particulate organic matter in the Lena River delta and adjacent nearshore zone, NE Siberia – Part I: Radiocarbon inventories
Particulate organic matter (POM) derived from permafrost soils and transported by the Lena River represents a quantitatively important terrestrial carbon pool exported to Laptev Sea sediments (next to POM derived from coastal erosion). Its fate in a future warming Arctic, i.e., its remobilization an...
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Copernicus Publications
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ftdoajarticles:oai:doaj.org/article:79210608073f439b81678fc551baeb8c 2023-05-15T15:18:31+02:00 Characterization of particulate organic matter in the Lena River delta and adjacent nearshore zone, NE Siberia – Part I: Radiocarbon inventories M. Winterfeld T. Laepple G. Mollenhauer 2015-06-01T00:00:00Z https://doi.org/10.5194/bg-12-3769-2015 https://doaj.org/article/79210608073f439b81678fc551baeb8c EN eng Copernicus Publications http://www.biogeosciences.net/12/3769/2015/bg-12-3769-2015.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 1726-4170 1726-4189 doi:10.5194/bg-12-3769-2015 https://doaj.org/article/79210608073f439b81678fc551baeb8c Biogeosciences, Vol 12, Iss 12, Pp 3769-3788 (2015) Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 article 2015 ftdoajarticles https://doi.org/10.5194/bg-12-3769-2015 2022-12-31T03:11:27Z Particulate organic matter (POM) derived from permafrost soils and transported by the Lena River represents a quantitatively important terrestrial carbon pool exported to Laptev Sea sediments (next to POM derived from coastal erosion). Its fate in a future warming Arctic, i.e., its remobilization and remineralization after permafrost thawing as well as its transport pathways to and sequestration in marine sediments, is currently under debate. We present one of the first radiocarbon ( 14 C) data sets for surface water POM within the Lena Delta sampled in the summers of 2009–2010 and spring 2011 ( n = 30 samples). The bulk Δ 14 C values varied from −55 to −391 ‰ translating into 14 C ages of 395 to 3920 years BP. We further estimated the fraction of soil-derived POM to our samples based on (1) particulate organic carbon to particulate nitrogen ratios (POC : PN) and (2) on the stable carbon isotope (δ 13 C) composition of our samples. Assuming that this phytoplankton POM has a modern 14 C concentration, we inferred the 14 C concentrations of the soil-derived POM fractions. The results ranged from −322 to −884 ‰ (i.e., 3060 to 17 250 14 C years BP) for the POC : PN-based scenario and from −261 to −944 ‰ (i.e., 2370 to 23 100 14 C years BP) for the δ 13 C-based scenario. Despite the limitations of our approach, the estimated Δ 14 C values of the soil-derived POM fractions seem to reflect the heterogeneous 14 C concentrations of the Lena River catchment soils covering a range from Holocene to Pleistocene ages better than the bulk POM Δ 14 C values. We further used a dual-carbon-isotope three-end-member mixing model to distinguish between POM contributions from Holocene soils and Pleistocene Ice Complex (IC) deposits to our soil-derived POM fraction. IC contributions are comparatively low (mean of 0.14) compared to Holocene soils (mean of 0.32) and riverine phytoplankton (mean of 0.55), which could be explained with the restricted spatial distribution of IC deposits within the Lena catchment. Based on our newly ... Article in Journal/Newspaper Arctic Ice laptev Laptev Sea lena delta lena river permafrost Phytoplankton Siberia Directory of Open Access Journals: DOAJ Articles Arctic Laptev Sea Biogeosciences 12 12 3769 3788 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
spellingShingle |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 M. Winterfeld T. Laepple G. Mollenhauer Characterization of particulate organic matter in the Lena River delta and adjacent nearshore zone, NE Siberia – Part I: Radiocarbon inventories |
topic_facet |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
description |
Particulate organic matter (POM) derived from permafrost soils and transported by the Lena River represents a quantitatively important terrestrial carbon pool exported to Laptev Sea sediments (next to POM derived from coastal erosion). Its fate in a future warming Arctic, i.e., its remobilization and remineralization after permafrost thawing as well as its transport pathways to and sequestration in marine sediments, is currently under debate. We present one of the first radiocarbon ( 14 C) data sets for surface water POM within the Lena Delta sampled in the summers of 2009–2010 and spring 2011 ( n = 30 samples). The bulk Δ 14 C values varied from −55 to −391 ‰ translating into 14 C ages of 395 to 3920 years BP. We further estimated the fraction of soil-derived POM to our samples based on (1) particulate organic carbon to particulate nitrogen ratios (POC : PN) and (2) on the stable carbon isotope (δ 13 C) composition of our samples. Assuming that this phytoplankton POM has a modern 14 C concentration, we inferred the 14 C concentrations of the soil-derived POM fractions. The results ranged from −322 to −884 ‰ (i.e., 3060 to 17 250 14 C years BP) for the POC : PN-based scenario and from −261 to −944 ‰ (i.e., 2370 to 23 100 14 C years BP) for the δ 13 C-based scenario. Despite the limitations of our approach, the estimated Δ 14 C values of the soil-derived POM fractions seem to reflect the heterogeneous 14 C concentrations of the Lena River catchment soils covering a range from Holocene to Pleistocene ages better than the bulk POM Δ 14 C values. We further used a dual-carbon-isotope three-end-member mixing model to distinguish between POM contributions from Holocene soils and Pleistocene Ice Complex (IC) deposits to our soil-derived POM fraction. IC contributions are comparatively low (mean of 0.14) compared to Holocene soils (mean of 0.32) and riverine phytoplankton (mean of 0.55), which could be explained with the restricted spatial distribution of IC deposits within the Lena catchment. Based on our newly ... |
format |
Article in Journal/Newspaper |
author |
M. Winterfeld T. Laepple G. Mollenhauer |
author_facet |
M. Winterfeld T. Laepple G. Mollenhauer |
author_sort |
M. Winterfeld |
title |
Characterization of particulate organic matter in the Lena River delta and adjacent nearshore zone, NE Siberia – Part I: Radiocarbon inventories |
title_short |
Characterization of particulate organic matter in the Lena River delta and adjacent nearshore zone, NE Siberia – Part I: Radiocarbon inventories |
title_full |
Characterization of particulate organic matter in the Lena River delta and adjacent nearshore zone, NE Siberia – Part I: Radiocarbon inventories |
title_fullStr |
Characterization of particulate organic matter in the Lena River delta and adjacent nearshore zone, NE Siberia – Part I: Radiocarbon inventories |
title_full_unstemmed |
Characterization of particulate organic matter in the Lena River delta and adjacent nearshore zone, NE Siberia – Part I: Radiocarbon inventories |
title_sort |
characterization of particulate organic matter in the lena river delta and adjacent nearshore zone, ne siberia – part i: radiocarbon inventories |
publisher |
Copernicus Publications |
publishDate |
2015 |
url |
https://doi.org/10.5194/bg-12-3769-2015 https://doaj.org/article/79210608073f439b81678fc551baeb8c |
geographic |
Arctic Laptev Sea |
geographic_facet |
Arctic Laptev Sea |
genre |
Arctic Ice laptev Laptev Sea lena delta lena river permafrost Phytoplankton Siberia |
genre_facet |
Arctic Ice laptev Laptev Sea lena delta lena river permafrost Phytoplankton Siberia |
op_source |
Biogeosciences, Vol 12, Iss 12, Pp 3769-3788 (2015) |
op_relation |
http://www.biogeosciences.net/12/3769/2015/bg-12-3769-2015.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 1726-4170 1726-4189 doi:10.5194/bg-12-3769-2015 https://doaj.org/article/79210608073f439b81678fc551baeb8c |
op_doi |
https://doi.org/10.5194/bg-12-3769-2015 |
container_title |
Biogeosciences |
container_volume |
12 |
container_issue |
12 |
container_start_page |
3769 |
op_container_end_page |
3788 |
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1766348715006623744 |