Seasonal changes in light availability modify the temperature dependence of ecosystem metabolism in an arctic stream
Light and temperature are key ecosystem drivers, but their synchronous annual cycles typically confound partitioning of their relative influence. Arctic spring‐streams, subject to extreme annual fluctuations in light but stable water temperatures, provide a rare contrast that allows the parsing of t...
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crwiley:10.1890/13-1963.1 2024-06-23T07:50:02+00:00 Seasonal changes in light availability modify the temperature dependence of ecosystem metabolism in an arctic stream Huryn, Alexander D. Benstead, Jonathan P. Parker, Stephanie M. 2014 http://dx.doi.org/10.1890/13-1963.1 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1890%2F13-1963.1 https://esajournals.onlinelibrary.wiley.com/doi/pdf/10.1890/13-1963.1 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Ecology volume 95, issue 10, page 2826-2839 ISSN 0012-9658 1939-9170 journal-article 2014 crwiley https://doi.org/10.1890/13-1963.1 2024-06-06T04:21:51Z Light and temperature are key ecosystem drivers, but their synchronous annual cycles typically confound partitioning of their relative influence. Arctic spring‐streams, subject to extreme annual fluctuations in light but stable water temperatures, provide a rare contrast that allows the parsing of their independent effects. Over 30 months, we assessed the effects of light and temperature on ecosystem metabolism and nutrient uptake in Ivishak Spring, Alaska, USA. (latitude 69° N, water temperature range ∼4°–7°C) using open‐channel methods and short‐term NH 4 + ‐N, NO 3 − ‐N, and P additions, respectively. We predicted that rates of ecosystem respiration (ER) would mirror seasonal patterns of gross primary production (GPP), rather than temperature, due to relatively constant rates of metabolic demand year‐round, resulting in carbon limitation during winter (October–March) when photosynthesis effectively ceases. Because patterns of nutrient uptake and GPP are often coupled due to assimilatory demand, we also predicted that extreme annual cycles of light would result in equally extreme cycles of nutrient uptake, with demand being relaxed during winter. In accordance with our prediction, we found that ER scaled linearly with GPP. Peak summer rates of GPP (>4.0 g C·m −2 ·d −1 ) and ER (>5.0 g C·m −2 ·d −1 ) were surprisingly high, being comparable to those of productive streams at temperate latitudes. Winter rates (GPP ∼0.0, ER <1.0 g C·m −2 ·d −1 ) were low, however, and Arrhenius plots showed clear deviations from theoretical temperature dependence of GPP and ER during winter when other factors assumed primacy. For GPP, this factor was undoubtedly light availability, but for ER, carbon limitation is implicated due to low GPP. Significant nutrient uptake occurred only for NH 4 + ‐N, indicating N limitation, and rates of uptake were also synchronous with cycles of light availability. Consequently, light, rather than temperature, was the major driver of annual patterns of ER and nutrient cycles in this arctic ... Article in Journal/Newspaper Arctic Alaska Wiley Online Library Arctic Ecology 95 10 2826 2839 |
institution |
Open Polar |
collection |
Wiley Online Library |
op_collection_id |
crwiley |
language |
English |
description |
Light and temperature are key ecosystem drivers, but their synchronous annual cycles typically confound partitioning of their relative influence. Arctic spring‐streams, subject to extreme annual fluctuations in light but stable water temperatures, provide a rare contrast that allows the parsing of their independent effects. Over 30 months, we assessed the effects of light and temperature on ecosystem metabolism and nutrient uptake in Ivishak Spring, Alaska, USA. (latitude 69° N, water temperature range ∼4°–7°C) using open‐channel methods and short‐term NH 4 + ‐N, NO 3 − ‐N, and P additions, respectively. We predicted that rates of ecosystem respiration (ER) would mirror seasonal patterns of gross primary production (GPP), rather than temperature, due to relatively constant rates of metabolic demand year‐round, resulting in carbon limitation during winter (October–March) when photosynthesis effectively ceases. Because patterns of nutrient uptake and GPP are often coupled due to assimilatory demand, we also predicted that extreme annual cycles of light would result in equally extreme cycles of nutrient uptake, with demand being relaxed during winter. In accordance with our prediction, we found that ER scaled linearly with GPP. Peak summer rates of GPP (>4.0 g C·m −2 ·d −1 ) and ER (>5.0 g C·m −2 ·d −1 ) were surprisingly high, being comparable to those of productive streams at temperate latitudes. Winter rates (GPP ∼0.0, ER <1.0 g C·m −2 ·d −1 ) were low, however, and Arrhenius plots showed clear deviations from theoretical temperature dependence of GPP and ER during winter when other factors assumed primacy. For GPP, this factor was undoubtedly light availability, but for ER, carbon limitation is implicated due to low GPP. Significant nutrient uptake occurred only for NH 4 + ‐N, indicating N limitation, and rates of uptake were also synchronous with cycles of light availability. Consequently, light, rather than temperature, was the major driver of annual patterns of ER and nutrient cycles in this arctic ... |
format |
Article in Journal/Newspaper |
author |
Huryn, Alexander D. Benstead, Jonathan P. Parker, Stephanie M. |
spellingShingle |
Huryn, Alexander D. Benstead, Jonathan P. Parker, Stephanie M. Seasonal changes in light availability modify the temperature dependence of ecosystem metabolism in an arctic stream |
author_facet |
Huryn, Alexander D. Benstead, Jonathan P. Parker, Stephanie M. |
author_sort |
Huryn, Alexander D. |
title |
Seasonal changes in light availability modify the temperature dependence of ecosystem metabolism in an arctic stream |
title_short |
Seasonal changes in light availability modify the temperature dependence of ecosystem metabolism in an arctic stream |
title_full |
Seasonal changes in light availability modify the temperature dependence of ecosystem metabolism in an arctic stream |
title_fullStr |
Seasonal changes in light availability modify the temperature dependence of ecosystem metabolism in an arctic stream |
title_full_unstemmed |
Seasonal changes in light availability modify the temperature dependence of ecosystem metabolism in an arctic stream |
title_sort |
seasonal changes in light availability modify the temperature dependence of ecosystem metabolism in an arctic stream |
publisher |
Wiley |
publishDate |
2014 |
url |
http://dx.doi.org/10.1890/13-1963.1 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1890%2F13-1963.1 https://esajournals.onlinelibrary.wiley.com/doi/pdf/10.1890/13-1963.1 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Alaska |
genre_facet |
Arctic Alaska |
op_source |
Ecology volume 95, issue 10, page 2826-2839 ISSN 0012-9658 1939-9170 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1890/13-1963.1 |
container_title |
Ecology |
container_volume |
95 |
container_issue |
10 |
container_start_page |
2826 |
op_container_end_page |
2839 |
_version_ |
1802640774434652160 |