Fundamental Drivers of Dissolved Organic Matter Composition across an Arctic Effective Precipitation Gradient
The standard model for aquatic ecosystems is to link hydrologic connectivity to dissolved organic carbon (DOC) concentration and dissolved organic matter (DOM) composition and, ultimately, reactivity. Studies across effective precipitation gradients have been suggested as models for predicting how c...
Published in: | Limnology and Oceanography |
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Digital Commons @ University of South Florida
2020
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Online Access: | https://digitalcommons.usf.edu/msc_facpub/1446 https://doi.org/10.1002/lno.11385 |
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ftusouthflorida:oai:digitalcommons.usf.edu:msc_facpub-2442 2023-07-30T04:01:34+02:00 Fundamental Drivers of Dissolved Organic Matter Composition across an Arctic Effective Precipitation Gradient Kellerman, Anne M. Arellano, Ana Podgorski, David C. Martin, Ellen E. Martin, Jonathan B. Deuerling, Kelly M. Bianchi, Thomas S. Spencer, Robert G. 2020-06-01T07:00:00Z https://digitalcommons.usf.edu/msc_facpub/1446 https://doi.org/10.1002/lno.11385 unknown Digital Commons @ University of South Florida https://digitalcommons.usf.edu/msc_facpub/1446 doi:10.1002/lno.11385 https://doi.org/10.1002/lno.11385 Marine Science Faculty Publications Life Sciences article 2020 ftusouthflorida https://doi.org/10.1002/lno.11385 2023-07-13T21:02:38Z The standard model for aquatic ecosystems is to link hydrologic connectivity to dissolved organic carbon (DOC) concentration and dissolved organic matter (DOM) composition and, ultimately, reactivity. Studies across effective precipitation gradients have been suggested as models for predicting how carbon cycling will change in Arctic aquatic ecosystems with projected drying (i.e., reduced hydrologic connectivity). To evaluate links between DOM dynamics and hydrologic connectivity, 41 stream samples from Greenland were analyzed across an effective precipitation gradient for DOM optical properties and elemental composition using ultrahigh-resolution mass spectrometry. Sites with negative effective precipitation and decreased hydrologic connectivity exhibited elevated specific conductivity (SpC) and DOC concentrations as well as DOM composition indicative of decreased hydrologic connectivity, for example, lower aromaticity, assessed using carbon-specific UV absorbance at 254 nm, decreased relative abundances of polyphenolic and condensed aromatic compounds, and increased relative abundances of highly unsaturated and phenolic compounds. Allochthonous inputs decreased as the summer progressed as exhibited by decreases in aromatic compounds. A decrease in molecular richness and N-containing compounds coincided with the decrease in allochthonous inputs. DOC concentrations increased over the summer but more slowly than SpC, suggesting degradation processes outweighed combined evapoconcentration and production. The patterns in DOM composition suggest evapoconcentration and photodegradation are dominant controls. However, when hydrologic connectivity was high, regardless of effective precipitation, DOM reflected allochthonous sources such as snowmelt-fed wetlands. These results highlight the challenges of modeling carbon cycling in aquatic ecosystems across effective precipitation gradients, particularly those with strong seasonality and regional variability in hydrologic inputs. Article in Journal/Newspaper Arctic Greenland University of South Florida St. Petersburg: Digital USFSP Arctic Greenland Limnology and Oceanography 65 6 1217 1234 |
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University of South Florida St. Petersburg: Digital USFSP |
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ftusouthflorida |
language |
unknown |
topic |
Life Sciences |
spellingShingle |
Life Sciences Kellerman, Anne M. Arellano, Ana Podgorski, David C. Martin, Ellen E. Martin, Jonathan B. Deuerling, Kelly M. Bianchi, Thomas S. Spencer, Robert G. Fundamental Drivers of Dissolved Organic Matter Composition across an Arctic Effective Precipitation Gradient |
topic_facet |
Life Sciences |
description |
The standard model for aquatic ecosystems is to link hydrologic connectivity to dissolved organic carbon (DOC) concentration and dissolved organic matter (DOM) composition and, ultimately, reactivity. Studies across effective precipitation gradients have been suggested as models for predicting how carbon cycling will change in Arctic aquatic ecosystems with projected drying (i.e., reduced hydrologic connectivity). To evaluate links between DOM dynamics and hydrologic connectivity, 41 stream samples from Greenland were analyzed across an effective precipitation gradient for DOM optical properties and elemental composition using ultrahigh-resolution mass spectrometry. Sites with negative effective precipitation and decreased hydrologic connectivity exhibited elevated specific conductivity (SpC) and DOC concentrations as well as DOM composition indicative of decreased hydrologic connectivity, for example, lower aromaticity, assessed using carbon-specific UV absorbance at 254 nm, decreased relative abundances of polyphenolic and condensed aromatic compounds, and increased relative abundances of highly unsaturated and phenolic compounds. Allochthonous inputs decreased as the summer progressed as exhibited by decreases in aromatic compounds. A decrease in molecular richness and N-containing compounds coincided with the decrease in allochthonous inputs. DOC concentrations increased over the summer but more slowly than SpC, suggesting degradation processes outweighed combined evapoconcentration and production. The patterns in DOM composition suggest evapoconcentration and photodegradation are dominant controls. However, when hydrologic connectivity was high, regardless of effective precipitation, DOM reflected allochthonous sources such as snowmelt-fed wetlands. These results highlight the challenges of modeling carbon cycling in aquatic ecosystems across effective precipitation gradients, particularly those with strong seasonality and regional variability in hydrologic inputs. |
format |
Article in Journal/Newspaper |
author |
Kellerman, Anne M. Arellano, Ana Podgorski, David C. Martin, Ellen E. Martin, Jonathan B. Deuerling, Kelly M. Bianchi, Thomas S. Spencer, Robert G. |
author_facet |
Kellerman, Anne M. Arellano, Ana Podgorski, David C. Martin, Ellen E. Martin, Jonathan B. Deuerling, Kelly M. Bianchi, Thomas S. Spencer, Robert G. |
author_sort |
Kellerman, Anne M. |
title |
Fundamental Drivers of Dissolved Organic Matter Composition across an Arctic Effective Precipitation Gradient |
title_short |
Fundamental Drivers of Dissolved Organic Matter Composition across an Arctic Effective Precipitation Gradient |
title_full |
Fundamental Drivers of Dissolved Organic Matter Composition across an Arctic Effective Precipitation Gradient |
title_fullStr |
Fundamental Drivers of Dissolved Organic Matter Composition across an Arctic Effective Precipitation Gradient |
title_full_unstemmed |
Fundamental Drivers of Dissolved Organic Matter Composition across an Arctic Effective Precipitation Gradient |
title_sort |
fundamental drivers of dissolved organic matter composition across an arctic effective precipitation gradient |
publisher |
Digital Commons @ University of South Florida |
publishDate |
2020 |
url |
https://digitalcommons.usf.edu/msc_facpub/1446 https://doi.org/10.1002/lno.11385 |
geographic |
Arctic Greenland |
geographic_facet |
Arctic Greenland |
genre |
Arctic Greenland |
genre_facet |
Arctic Greenland |
op_source |
Marine Science Faculty Publications |
op_relation |
https://digitalcommons.usf.edu/msc_facpub/1446 doi:10.1002/lno.11385 https://doi.org/10.1002/lno.11385 |
op_doi |
https://doi.org/10.1002/lno.11385 |
container_title |
Limnology and Oceanography |
container_volume |
65 |
container_issue |
6 |
container_start_page |
1217 |
op_container_end_page |
1234 |
_version_ |
1772812337828331520 |