Diatoms in Hyporheic Sediments Trace Organic Matter Retention and Processing in the McMurdo Dry Valleys, Antarctica
In low‐nutrient streams in cold and arid ecosystems, the spiraling of autochthonous particulate organic matter (POM) may provide important nutrient subsidies downstream. Because of its lability and the spatial heterogeneity of processing in hyporheic sediments, the downstream transport and fate of a...
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ftboisestateu:oai:scholarworks.boisestate.edu:geo_facpubs-1577 2023-10-29T02:31:50+01:00 Diatoms in Hyporheic Sediments Trace Organic Matter Retention and Processing in the McMurdo Dry Valleys, Antarctica Bergstrom, Anna J. 2021-02-01T08:00:00Z application/pdf https://scholarworks.boisestate.edu/geo_facpubs/572 https://scholarworks.boisestate.edu/context/geo_facpubs/article/1577/viewcontent/Bergstrom__Anna__2021__Diatoms_in_hyporheic_sediments___ILL.pdf unknown ScholarWorks https://scholarworks.boisestate.edu/geo_facpubs/572 https://scholarworks.boisestate.edu/context/geo_facpubs/article/1577/viewcontent/Bergstrom__Anna__2021__Diatoms_in_hyporheic_sediments___ILL.pdf This document was originally published in JGR Biogeosciences by Wiley on behalf of the American Geophysical Union. Copyright restrictions may apply. https://doi.org/10.1029/2020JG006097 Geosciences Faculty Publications and Presentations benthic processes biogeochemical cycles processes and modeling carbon cycling groundwater/surface water interactions nitrogen cycling biogenic silica Earth Sciences Geophysics and Seismology text 2021 ftboisestateu 2023-09-29T15:21:38Z In low‐nutrient streams in cold and arid ecosystems, the spiraling of autochthonous particulate organic matter (POM) may provide important nutrient subsidies downstream. Because of its lability and the spatial heterogeneity of processing in hyporheic sediments, the downstream transport and fate of autochthonous POM can be difficult to trace. In Antarctic McMurdo Dry Valley (MDV) streams, any POM retained in the hyporheic zone is expected to be derived from surface microbial mats that contain diatoms with long‐lasting silica frustules. We tested whether diatom frustules can be used to trace the retention of autochthonous POM in the hyporheic zone and whether certain geomorphic locations promote this process. The accumulation of diatom frustules in hyporheic sediments, measured as biogenic silica, was correlated with loss‐on‐ignition organic matter and sorbed ammonium, suggesting that diatoms can be used to identify locations where POM has been retained and processed over long timescales, regardless of whether the POM remains intact. In addition, by modeling the upstream sources of hyporheic diatom assemblages, we found that POM was predominantly derived from N‐fixing microbial mats of the genus Nostoc. In terms of spatial variability, we conclude that the hyporheic sediments adjacent to the stream channel that are regularly inundated by daily flood pulses are where the most POM has been retained over long timescales. Autochthonous POM is retained in hyporheic zones of low‐nutrient streams beyond the MDVs, and we suggest that biogenic silica and diatom composition can be used to identify locations where this transfer is most prevalent. Text Antarc* Antarctic Antarctica McMurdo Dry Valleys Boise State University: Scholar Works |
institution |
Open Polar |
collection |
Boise State University: Scholar Works |
op_collection_id |
ftboisestateu |
language |
unknown |
topic |
benthic processes biogeochemical cycles processes and modeling carbon cycling groundwater/surface water interactions nitrogen cycling biogenic silica Earth Sciences Geophysics and Seismology |
spellingShingle |
benthic processes biogeochemical cycles processes and modeling carbon cycling groundwater/surface water interactions nitrogen cycling biogenic silica Earth Sciences Geophysics and Seismology Bergstrom, Anna J. Diatoms in Hyporheic Sediments Trace Organic Matter Retention and Processing in the McMurdo Dry Valleys, Antarctica |
topic_facet |
benthic processes biogeochemical cycles processes and modeling carbon cycling groundwater/surface water interactions nitrogen cycling biogenic silica Earth Sciences Geophysics and Seismology |
description |
In low‐nutrient streams in cold and arid ecosystems, the spiraling of autochthonous particulate organic matter (POM) may provide important nutrient subsidies downstream. Because of its lability and the spatial heterogeneity of processing in hyporheic sediments, the downstream transport and fate of autochthonous POM can be difficult to trace. In Antarctic McMurdo Dry Valley (MDV) streams, any POM retained in the hyporheic zone is expected to be derived from surface microbial mats that contain diatoms with long‐lasting silica frustules. We tested whether diatom frustules can be used to trace the retention of autochthonous POM in the hyporheic zone and whether certain geomorphic locations promote this process. The accumulation of diatom frustules in hyporheic sediments, measured as biogenic silica, was correlated with loss‐on‐ignition organic matter and sorbed ammonium, suggesting that diatoms can be used to identify locations where POM has been retained and processed over long timescales, regardless of whether the POM remains intact. In addition, by modeling the upstream sources of hyporheic diatom assemblages, we found that POM was predominantly derived from N‐fixing microbial mats of the genus Nostoc. In terms of spatial variability, we conclude that the hyporheic sediments adjacent to the stream channel that are regularly inundated by daily flood pulses are where the most POM has been retained over long timescales. Autochthonous POM is retained in hyporheic zones of low‐nutrient streams beyond the MDVs, and we suggest that biogenic silica and diatom composition can be used to identify locations where this transfer is most prevalent. |
format |
Text |
author |
Bergstrom, Anna J. |
author_facet |
Bergstrom, Anna J. |
author_sort |
Bergstrom, Anna J. |
title |
Diatoms in Hyporheic Sediments Trace Organic Matter Retention and Processing in the McMurdo Dry Valleys, Antarctica |
title_short |
Diatoms in Hyporheic Sediments Trace Organic Matter Retention and Processing in the McMurdo Dry Valleys, Antarctica |
title_full |
Diatoms in Hyporheic Sediments Trace Organic Matter Retention and Processing in the McMurdo Dry Valleys, Antarctica |
title_fullStr |
Diatoms in Hyporheic Sediments Trace Organic Matter Retention and Processing in the McMurdo Dry Valleys, Antarctica |
title_full_unstemmed |
Diatoms in Hyporheic Sediments Trace Organic Matter Retention and Processing in the McMurdo Dry Valleys, Antarctica |
title_sort |
diatoms in hyporheic sediments trace organic matter retention and processing in the mcmurdo dry valleys, antarctica |
publisher |
ScholarWorks |
publishDate |
2021 |
url |
https://scholarworks.boisestate.edu/geo_facpubs/572 https://scholarworks.boisestate.edu/context/geo_facpubs/article/1577/viewcontent/Bergstrom__Anna__2021__Diatoms_in_hyporheic_sediments___ILL.pdf |
genre |
Antarc* Antarctic Antarctica McMurdo Dry Valleys |
genre_facet |
Antarc* Antarctic Antarctica McMurdo Dry Valleys |
op_source |
Geosciences Faculty Publications and Presentations |
op_relation |
https://scholarworks.boisestate.edu/geo_facpubs/572 https://scholarworks.boisestate.edu/context/geo_facpubs/article/1577/viewcontent/Bergstrom__Anna__2021__Diatoms_in_hyporheic_sediments___ILL.pdf |
op_rights |
This document was originally published in JGR Biogeosciences by Wiley on behalf of the American Geophysical Union. Copyright restrictions may apply. https://doi.org/10.1029/2020JG006097 |
_version_ |
1781052640609697792 |