Nitrogen supply and physical disturbance shapes Arctic stream nitrogen uptake through effects on metabolic activity
Climate change in the Arctic is altering the delivery of nutrients from terrestrial to aquatic ecosystems. The impact of these changes on downstream lakes and rivers is influenced by the capacity of small streams to retain such inputs. Given the potential for nutrient limitation in oligotrophic Arct...
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Umeå universitet, Institutionen för ekologi, miljö och geovetenskap
2021
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Online Access: | http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-177434 https://doi.org/10.1111/fwb.13734 |
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ftumeauniv:oai:DiVA.org:umu-177434 2023-10-09T21:48:31+02:00 Nitrogen supply and physical disturbance shapes Arctic stream nitrogen uptake through effects on metabolic activity Myrstener, Maria Thomas, Steven A. Giesler, Reiner Sponseller, Ryan A. 2021 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-177434 https://doi.org/10.1111/fwb.13734 eng eng Umeå universitet, Institutionen för ekologi, miljö och geovetenskap School of Natural Resources, University of Nebraska–Lincoln, Lincoln, NE, USA Freshwater Biology, 0046-5070, 2021, 66:8, s. 1502-1514 orcid:0000-0003-0943-641X orcid:0000-0002-6381-4509 orcid:0000-0002-5758-2705 http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-177434 doi:10.1111/fwb.13734 ISI:000656619300001 Scopus 2-s2.0-85107359743 info:eu-repo/semantics/openAccess Arctic catchment metabolism nutrient uptake tundra Physical Geography Naturgeografi Article in journal info:eu-repo/semantics/article text 2021 ftumeauniv https://doi.org/10.1111/fwb.13734 2023-09-22T13:54:54Z Climate change in the Arctic is altering the delivery of nutrients from terrestrial to aquatic ecosystems. The impact of these changes on downstream lakes and rivers is influenced by the capacity of small streams to retain such inputs. Given the potential for nutrient limitation in oligotrophic Arctic streams, biotic demand should be high, unless harsh environmental conditions maintain low biomass standing stocks that limit nutrient uptake capacity. We assessed the drivers of nutrient uptake in two contrasting headwater environments in Arctic Sweden: one stream draining upland tundra and the other draining an alluvial valley with birch forest. At both sites, we measured nitrate (NO3−) uptake biweekly using short-term slug releases and estimated rates of gross primary production (GPP) and ecosystem respiration from continuous dissolved oxygen measurements. Catchment characteristics were associated with distinct stream chemical and biological properties. For example, the tundra stream maintained relatively low NO3− concentrations (average: 46 µg N/L) and rates of GPP (0.2 g O2 m−2 day−1). By comparison, the birch forest stream was more NO3− rich (88 µg N/L) and productive (GPP: 1.7 g O2 m−2 day−1). These differences corresponded to greater areal NO3− uptake rate and increased NO3− use efficiency (as uptake velocity) in the birch forest stream (max 192 µg N m−2 min−1 and 96 mm/hr) compared to its tundra counterpart (max 52 µg N m−2 min−1 and 49 mm/hr) during 2017. Further, different sets of environmental drivers predicted temporal patterns of nutrient uptake at these sites: abiotic factors (e.g. NO3− concentration and discharge) were associated with changes in uptake in the tundra stream, while metabolic activity was more important in the birch forest stream. Between sites, variation in uptake metrics suggests that the ability to retain pulses of nutrients is linked to nutrient supply regimes controlled at larger spatial and temporal scales and habitat properties that promote biomass accrual and thus biotic demand. ... Article in Journal/Newspaper Arctic Climate change Tundra Umeå University: Publications (DiVA) Arctic Freshwater Biology |
institution |
Open Polar |
collection |
Umeå University: Publications (DiVA) |
op_collection_id |
ftumeauniv |
language |
English |
topic |
Arctic catchment metabolism nutrient uptake tundra Physical Geography Naturgeografi |
spellingShingle |
Arctic catchment metabolism nutrient uptake tundra Physical Geography Naturgeografi Myrstener, Maria Thomas, Steven A. Giesler, Reiner Sponseller, Ryan A. Nitrogen supply and physical disturbance shapes Arctic stream nitrogen uptake through effects on metabolic activity |
topic_facet |
Arctic catchment metabolism nutrient uptake tundra Physical Geography Naturgeografi |
description |
Climate change in the Arctic is altering the delivery of nutrients from terrestrial to aquatic ecosystems. The impact of these changes on downstream lakes and rivers is influenced by the capacity of small streams to retain such inputs. Given the potential for nutrient limitation in oligotrophic Arctic streams, biotic demand should be high, unless harsh environmental conditions maintain low biomass standing stocks that limit nutrient uptake capacity. We assessed the drivers of nutrient uptake in two contrasting headwater environments in Arctic Sweden: one stream draining upland tundra and the other draining an alluvial valley with birch forest. At both sites, we measured nitrate (NO3−) uptake biweekly using short-term slug releases and estimated rates of gross primary production (GPP) and ecosystem respiration from continuous dissolved oxygen measurements. Catchment characteristics were associated with distinct stream chemical and biological properties. For example, the tundra stream maintained relatively low NO3− concentrations (average: 46 µg N/L) and rates of GPP (0.2 g O2 m−2 day−1). By comparison, the birch forest stream was more NO3− rich (88 µg N/L) and productive (GPP: 1.7 g O2 m−2 day−1). These differences corresponded to greater areal NO3− uptake rate and increased NO3− use efficiency (as uptake velocity) in the birch forest stream (max 192 µg N m−2 min−1 and 96 mm/hr) compared to its tundra counterpart (max 52 µg N m−2 min−1 and 49 mm/hr) during 2017. Further, different sets of environmental drivers predicted temporal patterns of nutrient uptake at these sites: abiotic factors (e.g. NO3− concentration and discharge) were associated with changes in uptake in the tundra stream, while metabolic activity was more important in the birch forest stream. Between sites, variation in uptake metrics suggests that the ability to retain pulses of nutrients is linked to nutrient supply regimes controlled at larger spatial and temporal scales and habitat properties that promote biomass accrual and thus biotic demand. ... |
format |
Article in Journal/Newspaper |
author |
Myrstener, Maria Thomas, Steven A. Giesler, Reiner Sponseller, Ryan A. |
author_facet |
Myrstener, Maria Thomas, Steven A. Giesler, Reiner Sponseller, Ryan A. |
author_sort |
Myrstener, Maria |
title |
Nitrogen supply and physical disturbance shapes Arctic stream nitrogen uptake through effects on metabolic activity |
title_short |
Nitrogen supply and physical disturbance shapes Arctic stream nitrogen uptake through effects on metabolic activity |
title_full |
Nitrogen supply and physical disturbance shapes Arctic stream nitrogen uptake through effects on metabolic activity |
title_fullStr |
Nitrogen supply and physical disturbance shapes Arctic stream nitrogen uptake through effects on metabolic activity |
title_full_unstemmed |
Nitrogen supply and physical disturbance shapes Arctic stream nitrogen uptake through effects on metabolic activity |
title_sort |
nitrogen supply and physical disturbance shapes arctic stream nitrogen uptake through effects on metabolic activity |
publisher |
Umeå universitet, Institutionen för ekologi, miljö och geovetenskap |
publishDate |
2021 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-177434 https://doi.org/10.1111/fwb.13734 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Climate change Tundra |
genre_facet |
Arctic Climate change Tundra |
op_relation |
Freshwater Biology, 0046-5070, 2021, 66:8, s. 1502-1514 orcid:0000-0003-0943-641X orcid:0000-0002-6381-4509 orcid:0000-0002-5758-2705 http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-177434 doi:10.1111/fwb.13734 ISI:000656619300001 Scopus 2-s2.0-85107359743 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1111/fwb.13734 |
container_title |
Freshwater Biology |
_version_ |
1779311600593797120 |