The Sensitivity of Subsurface Microbes to Ocean Warming Accentuates Future Declines in Particulate Carbon Export
Under future warming Earth System Models (ESMs) project a decrease in the magnitude of downward particulate organic carbon (POC) export, suggesting the potential for carbon storage in the deep ocean will be reduced. Projections of POC export can also be quantified using an alternative physiologicall...
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ftdoajarticles:oai:doaj.org/article:2981dbca94d049e5a12399060995756d 2023-05-15T18:25:54+02:00 The Sensitivity of Subsurface Microbes to Ocean Warming Accentuates Future Declines in Particulate Carbon Export Emma Louise Cavan Stephanie A. Henson Philip W. Boyd 2019-01-01T00:00:00Z https://doi.org/10.3389/fevo.2018.00230 https://doaj.org/article/2981dbca94d049e5a12399060995756d EN eng Frontiers Media S.A. https://www.frontiersin.org/article/10.3389/fevo.2018.00230/full https://doaj.org/toc/2296-701X 2296-701X doi:10.3389/fevo.2018.00230 https://doaj.org/article/2981dbca94d049e5a12399060995756d Frontiers in Ecology and Evolution, Vol 6 (2019) particulate carbon export microbes warming metabolic theory activation energy Evolution QH359-425 Ecology QH540-549.5 article 2019 ftdoajarticles https://doi.org/10.3389/fevo.2018.00230 2022-12-31T13:45:48Z Under future warming Earth System Models (ESMs) project a decrease in the magnitude of downward particulate organic carbon (POC) export, suggesting the potential for carbon storage in the deep ocean will be reduced. Projections of POC export can also be quantified using an alternative physiologically-based approach, the Metabolic Theory of Ecology (MTE). MTE employs an activation energy (Ea) describing organismal metabolic sensitivity to temperature change, but does not consider changes in ocean chemistry or physics. Many ESMs incorporate temperature dependent functions, where rates (e.g., respiration) scale with temperature. Temperature sensitivity describes how temperature dependence varies across metabolic rates or species. ESMs acknowledge temperature sensitivity between rates (e.g., between heterotrophic and autotropic processes), but due to a lack of empirical data cannot parameterize for variation within rates, such as differences within species or biogeochemical provinces. Here we investigate how varying temperature sensitivity affects heterotrophic microbial respiration and hence future POC export. Using satellite-derived data and ESM temperature projections we applied microbial MTE, with varying temperature sensitivity, to estimates of global POC export. In line with observations from polar regions and the deep ocean we imposed an elevated temperature sensitivity (Ea = 1.0 eV) to cooler regions; firstly to the Southern Ocean (south of 40°S) and secondly where temperature at 100 m depth <13°C. Elsewhere in both these scenarios Ea was set to 0.7 eV (moderate sensitivity/classic MTE). Imposing high temperature sensitivity in cool regions resulted in projected declines in export of 17 ± 1% (< 40°S) and 23 ± 1% (< 13°C) by 2100 relative to the present day. Hence varying microbial temperature sensitivity resulted in at least 2-fold greater declines in POC export than suggested by classic MTE derived in this study (12 ± 1%, Ea = 0.7 eV globally) or ESMs (1–12%). The sparse observational data ... Article in Journal/Newspaper Southern Ocean Directory of Open Access Journals: DOAJ Articles Southern Ocean Frontiers in Ecology and Evolution 6 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
particulate carbon export microbes warming metabolic theory activation energy Evolution QH359-425 Ecology QH540-549.5 |
spellingShingle |
particulate carbon export microbes warming metabolic theory activation energy Evolution QH359-425 Ecology QH540-549.5 Emma Louise Cavan Stephanie A. Henson Philip W. Boyd The Sensitivity of Subsurface Microbes to Ocean Warming Accentuates Future Declines in Particulate Carbon Export |
topic_facet |
particulate carbon export microbes warming metabolic theory activation energy Evolution QH359-425 Ecology QH540-549.5 |
description |
Under future warming Earth System Models (ESMs) project a decrease in the magnitude of downward particulate organic carbon (POC) export, suggesting the potential for carbon storage in the deep ocean will be reduced. Projections of POC export can also be quantified using an alternative physiologically-based approach, the Metabolic Theory of Ecology (MTE). MTE employs an activation energy (Ea) describing organismal metabolic sensitivity to temperature change, but does not consider changes in ocean chemistry or physics. Many ESMs incorporate temperature dependent functions, where rates (e.g., respiration) scale with temperature. Temperature sensitivity describes how temperature dependence varies across metabolic rates or species. ESMs acknowledge temperature sensitivity between rates (e.g., between heterotrophic and autotropic processes), but due to a lack of empirical data cannot parameterize for variation within rates, such as differences within species or biogeochemical provinces. Here we investigate how varying temperature sensitivity affects heterotrophic microbial respiration and hence future POC export. Using satellite-derived data and ESM temperature projections we applied microbial MTE, with varying temperature sensitivity, to estimates of global POC export. In line with observations from polar regions and the deep ocean we imposed an elevated temperature sensitivity (Ea = 1.0 eV) to cooler regions; firstly to the Southern Ocean (south of 40°S) and secondly where temperature at 100 m depth <13°C. Elsewhere in both these scenarios Ea was set to 0.7 eV (moderate sensitivity/classic MTE). Imposing high temperature sensitivity in cool regions resulted in projected declines in export of 17 ± 1% (< 40°S) and 23 ± 1% (< 13°C) by 2100 relative to the present day. Hence varying microbial temperature sensitivity resulted in at least 2-fold greater declines in POC export than suggested by classic MTE derived in this study (12 ± 1%, Ea = 0.7 eV globally) or ESMs (1–12%). The sparse observational data ... |
format |
Article in Journal/Newspaper |
author |
Emma Louise Cavan Stephanie A. Henson Philip W. Boyd |
author_facet |
Emma Louise Cavan Stephanie A. Henson Philip W. Boyd |
author_sort |
Emma Louise Cavan |
title |
The Sensitivity of Subsurface Microbes to Ocean Warming Accentuates Future Declines in Particulate Carbon Export |
title_short |
The Sensitivity of Subsurface Microbes to Ocean Warming Accentuates Future Declines in Particulate Carbon Export |
title_full |
The Sensitivity of Subsurface Microbes to Ocean Warming Accentuates Future Declines in Particulate Carbon Export |
title_fullStr |
The Sensitivity of Subsurface Microbes to Ocean Warming Accentuates Future Declines in Particulate Carbon Export |
title_full_unstemmed |
The Sensitivity of Subsurface Microbes to Ocean Warming Accentuates Future Declines in Particulate Carbon Export |
title_sort |
sensitivity of subsurface microbes to ocean warming accentuates future declines in particulate carbon export |
publisher |
Frontiers Media S.A. |
publishDate |
2019 |
url |
https://doi.org/10.3389/fevo.2018.00230 https://doaj.org/article/2981dbca94d049e5a12399060995756d |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
Frontiers in Ecology and Evolution, Vol 6 (2019) |
op_relation |
https://www.frontiersin.org/article/10.3389/fevo.2018.00230/full https://doaj.org/toc/2296-701X 2296-701X doi:10.3389/fevo.2018.00230 https://doaj.org/article/2981dbca94d049e5a12399060995756d |
op_doi |
https://doi.org/10.3389/fevo.2018.00230 |
container_title |
Frontiers in Ecology and Evolution |
container_volume |
6 |
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1766207605060927488 |