Photosynthetic maximum quantum yield increases are an essential component of the Southern Ocean phytoplankton response to iron
It is well established that an increase in iron supply causes an increase in total oceanic primary production in many regions, but the physiological mechanism driving the observed increases has not been clearly identified. The Southern Ocean iron enrichment experiment, an iron fertilization experime...
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ftpubmed:oai:pubmedcentral.nih.gov:2290768 2023-05-15T13:57:37+02:00 Photosynthetic maximum quantum yield increases are an essential component of the Southern Ocean phytoplankton response to iron Hiscock, Michael R. Lance, Veronica P. Apprill, Amy M. Bidigare, Robert R. Johnson, Zackary I. Mitchell, B. Greg Smith, Walker O. Barber, Richard T. 2008-03-25 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2290768 http://www.ncbi.nlm.nih.gov/pubmed/18349145 https://doi.org/10.1073/pnas.0705006105 en eng National Academy of Sciences http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2290768 http://www.ncbi.nlm.nih.gov/pubmed/18349145 http://dx.doi.org/10.1073/pnas.0705006105 © 2008 by The National Academy of Sciences of the USA Freely available online through the PNAS open access option. Biological Sciences Text 2008 ftpubmed https://doi.org/10.1073/pnas.0705006105 2013-09-01T17:41:28Z It is well established that an increase in iron supply causes an increase in total oceanic primary production in many regions, but the physiological mechanism driving the observed increases has not been clearly identified. The Southern Ocean iron enrichment experiment, an iron fertilization experiment in the waters closest to Antarctica, resulted in a 9-fold increase in chlorophyll (Chl) concentration and a 5-fold increase in integrated primary production. Upon iron addition, the maximum quantum yield of photosynthesis (φm) rapidly doubled, from 0.011 to 0.025 mol C·mol quanta−1. Paradoxically, this increase in light-limited productivity was not accompanied by a significant increase in light-saturated productivity (Pmaxb). Pmaxb, maximum Chl normalized productivity, was 1.34 mg C·mg Chl−1·h−1 outside and 1.49 mg C·mg Chl−1·h−1 inside the iron-enriched patch. The importance of φm as compared with Pmaxb in controlling the biological response to iron addition has vast implications for understanding the ecological response to iron. We show that an iron-driven increase in φm is the proximate physiological mechanism affected by iron addition and can account for most of the increases in primary production. The relative importance of φm over Pmaxb in this iron-fertilized bloom highlights the limitations of often-used primary productivity algorithms that are driven by estimates of Pmaxb but largely ignore variability in φm and light-limited productivity. To use primary productivity models that include variability in iron supply in prediction or forecasting, the variability of light-limited productivity must be resolved. Text Antarc* Antarctica Southern Ocean PubMed Central (PMC) Southern Ocean Proceedings of the National Academy of Sciences 105 12 4775 4780 |
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English |
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Biological Sciences |
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Biological Sciences Hiscock, Michael R. Lance, Veronica P. Apprill, Amy M. Bidigare, Robert R. Johnson, Zackary I. Mitchell, B. Greg Smith, Walker O. Barber, Richard T. Photosynthetic maximum quantum yield increases are an essential component of the Southern Ocean phytoplankton response to iron |
topic_facet |
Biological Sciences |
description |
It is well established that an increase in iron supply causes an increase in total oceanic primary production in many regions, but the physiological mechanism driving the observed increases has not been clearly identified. The Southern Ocean iron enrichment experiment, an iron fertilization experiment in the waters closest to Antarctica, resulted in a 9-fold increase in chlorophyll (Chl) concentration and a 5-fold increase in integrated primary production. Upon iron addition, the maximum quantum yield of photosynthesis (φm) rapidly doubled, from 0.011 to 0.025 mol C·mol quanta−1. Paradoxically, this increase in light-limited productivity was not accompanied by a significant increase in light-saturated productivity (Pmaxb). Pmaxb, maximum Chl normalized productivity, was 1.34 mg C·mg Chl−1·h−1 outside and 1.49 mg C·mg Chl−1·h−1 inside the iron-enriched patch. The importance of φm as compared with Pmaxb in controlling the biological response to iron addition has vast implications for understanding the ecological response to iron. We show that an iron-driven increase in φm is the proximate physiological mechanism affected by iron addition and can account for most of the increases in primary production. The relative importance of φm over Pmaxb in this iron-fertilized bloom highlights the limitations of often-used primary productivity algorithms that are driven by estimates of Pmaxb but largely ignore variability in φm and light-limited productivity. To use primary productivity models that include variability in iron supply in prediction or forecasting, the variability of light-limited productivity must be resolved. |
format |
Text |
author |
Hiscock, Michael R. Lance, Veronica P. Apprill, Amy M. Bidigare, Robert R. Johnson, Zackary I. Mitchell, B. Greg Smith, Walker O. Barber, Richard T. |
author_facet |
Hiscock, Michael R. Lance, Veronica P. Apprill, Amy M. Bidigare, Robert R. Johnson, Zackary I. Mitchell, B. Greg Smith, Walker O. Barber, Richard T. |
author_sort |
Hiscock, Michael R. |
title |
Photosynthetic maximum quantum yield increases are an essential component of the Southern Ocean phytoplankton response to iron |
title_short |
Photosynthetic maximum quantum yield increases are an essential component of the Southern Ocean phytoplankton response to iron |
title_full |
Photosynthetic maximum quantum yield increases are an essential component of the Southern Ocean phytoplankton response to iron |
title_fullStr |
Photosynthetic maximum quantum yield increases are an essential component of the Southern Ocean phytoplankton response to iron |
title_full_unstemmed |
Photosynthetic maximum quantum yield increases are an essential component of the Southern Ocean phytoplankton response to iron |
title_sort |
photosynthetic maximum quantum yield increases are an essential component of the southern ocean phytoplankton response to iron |
publisher |
National Academy of Sciences |
publishDate |
2008 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2290768 http://www.ncbi.nlm.nih.gov/pubmed/18349145 https://doi.org/10.1073/pnas.0705006105 |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Antarc* Antarctica Southern Ocean |
genre_facet |
Antarc* Antarctica Southern Ocean |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2290768 http://www.ncbi.nlm.nih.gov/pubmed/18349145 http://dx.doi.org/10.1073/pnas.0705006105 |
op_rights |
© 2008 by The National Academy of Sciences of the USA Freely available online through the PNAS open access option. |
op_doi |
https://doi.org/10.1073/pnas.0705006105 |
container_title |
Proceedings of the National Academy of Sciences |
container_volume |
105 |
container_issue |
12 |
container_start_page |
4775 |
op_container_end_page |
4780 |
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1766265321891561472 |