Bacterial community composition responds to changes in copepod abundance and alters ecosystem function in an Arctic mesocosm study
Combining a minimum food web model with Arctic microbial community dynamics, we have suggested that top-down control by copepods can affect the food web down to bacterial consumption of organic carbon. Pursuing this hypothesis further, we used the minimum model to design and analyse a mesocosm exper...
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ftunivbergen:oai:bora.uib.no:1956/19349 2023-05-15T14:54:43+02:00 Bacterial community composition responds to changes in copepod abundance and alters ecosystem function in an Arctic mesocosm study Tsagaraki, Tatiana Margo Pree, Bernadette Leiknes, Øystein Larsen, Aud Bratbak, Gunnar Øvreås, Lise Egge, Jorun Karin Spanek, Roman Paulsen, Maria Lund Olsen, Yngvar Vadstein, Olav Thingstad, T. Frede 2018-09-28T07:39:09Z application/pdf http://hdl.handle.net/1956/19349 https://doi.org/10.1038/s41396-018-0217-7 eng eng Springer Nature Norges forskningsråd: 225956 EC/FP7: 603773 urn:issn:1751-7370 urn:issn:1751-7362 http://hdl.handle.net/1956/19349 https://doi.org/10.1038/s41396-018-0217-7 cristin:1606314 Attribution CC BY http://creativecommons.org/licenses/by/4.0 Copyright 2018 The Authors The ISME Journal Peer reviewed Journal article 2018 ftunivbergen https://doi.org/10.1038/s41396-018-0217-7 2023-03-14T17:41:42Z Combining a minimum food web model with Arctic microbial community dynamics, we have suggested that top-down control by copepods can affect the food web down to bacterial consumption of organic carbon. Pursuing this hypothesis further, we used the minimum model to design and analyse a mesocosm experiment, studying the effect of high (+Z) and low (-Z) copepod density on resource allocation, along an organic-C addition gradient. In the Arctic, both effects are plausible due to changes in advection patterns (affecting copepods) and meltwater inputs (affecting carbon). The model predicts a trophic cascade from copepods via ciliates to flagellates, which was confirmed experimentally. Auto- and heterotrophic flagellates affect bacterial growth rate and abundance via competition for mineral nutrients and predation, respectively. In +Z, the model predicts low bacterial abundance and activity, and little response to glucose; as opposed to clear glucose consumption effects in –Z. We observed a more resilient bacterial response to high copepods and demonstrate this was due to changes in bacterial community equitability. Species able to use glucose to improve their competitive and/or defensive properties, became predominant. The observed shift from a SAR11-to a Psychromonodaceae – dominated community suggests the latter was pivotal in this modification of ecosystem function. We argue that this group used glucose to improve its defensive or its competitive abilities (or both). Adding such flexibility in bacterial traits to the model, we show how it creates the observed resilience to top-down manipulations observed in our experiment. publishedVersion Article in Journal/Newspaper Arctic Copepods University of Bergen: Bergen Open Research Archive (BORA-UiB) Arctic The ISME Journal 12 11 2694 2705 |
institution |
Open Polar |
collection |
University of Bergen: Bergen Open Research Archive (BORA-UiB) |
op_collection_id |
ftunivbergen |
language |
English |
description |
Combining a minimum food web model with Arctic microbial community dynamics, we have suggested that top-down control by copepods can affect the food web down to bacterial consumption of organic carbon. Pursuing this hypothesis further, we used the minimum model to design and analyse a mesocosm experiment, studying the effect of high (+Z) and low (-Z) copepod density on resource allocation, along an organic-C addition gradient. In the Arctic, both effects are plausible due to changes in advection patterns (affecting copepods) and meltwater inputs (affecting carbon). The model predicts a trophic cascade from copepods via ciliates to flagellates, which was confirmed experimentally. Auto- and heterotrophic flagellates affect bacterial growth rate and abundance via competition for mineral nutrients and predation, respectively. In +Z, the model predicts low bacterial abundance and activity, and little response to glucose; as opposed to clear glucose consumption effects in –Z. We observed a more resilient bacterial response to high copepods and demonstrate this was due to changes in bacterial community equitability. Species able to use glucose to improve their competitive and/or defensive properties, became predominant. The observed shift from a SAR11-to a Psychromonodaceae – dominated community suggests the latter was pivotal in this modification of ecosystem function. We argue that this group used glucose to improve its defensive or its competitive abilities (or both). Adding such flexibility in bacterial traits to the model, we show how it creates the observed resilience to top-down manipulations observed in our experiment. publishedVersion |
format |
Article in Journal/Newspaper |
author |
Tsagaraki, Tatiana Margo Pree, Bernadette Leiknes, Øystein Larsen, Aud Bratbak, Gunnar Øvreås, Lise Egge, Jorun Karin Spanek, Roman Paulsen, Maria Lund Olsen, Yngvar Vadstein, Olav Thingstad, T. Frede |
spellingShingle |
Tsagaraki, Tatiana Margo Pree, Bernadette Leiknes, Øystein Larsen, Aud Bratbak, Gunnar Øvreås, Lise Egge, Jorun Karin Spanek, Roman Paulsen, Maria Lund Olsen, Yngvar Vadstein, Olav Thingstad, T. Frede Bacterial community composition responds to changes in copepod abundance and alters ecosystem function in an Arctic mesocosm study |
author_facet |
Tsagaraki, Tatiana Margo Pree, Bernadette Leiknes, Øystein Larsen, Aud Bratbak, Gunnar Øvreås, Lise Egge, Jorun Karin Spanek, Roman Paulsen, Maria Lund Olsen, Yngvar Vadstein, Olav Thingstad, T. Frede |
author_sort |
Tsagaraki, Tatiana Margo |
title |
Bacterial community composition responds to changes in copepod abundance and alters ecosystem function in an Arctic mesocosm study |
title_short |
Bacterial community composition responds to changes in copepod abundance and alters ecosystem function in an Arctic mesocosm study |
title_full |
Bacterial community composition responds to changes in copepod abundance and alters ecosystem function in an Arctic mesocosm study |
title_fullStr |
Bacterial community composition responds to changes in copepod abundance and alters ecosystem function in an Arctic mesocosm study |
title_full_unstemmed |
Bacterial community composition responds to changes in copepod abundance and alters ecosystem function in an Arctic mesocosm study |
title_sort |
bacterial community composition responds to changes in copepod abundance and alters ecosystem function in an arctic mesocosm study |
publisher |
Springer Nature |
publishDate |
2018 |
url |
http://hdl.handle.net/1956/19349 https://doi.org/10.1038/s41396-018-0217-7 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Copepods |
genre_facet |
Arctic Copepods |
op_source |
The ISME Journal |
op_relation |
Norges forskningsråd: 225956 EC/FP7: 603773 urn:issn:1751-7370 urn:issn:1751-7362 http://hdl.handle.net/1956/19349 https://doi.org/10.1038/s41396-018-0217-7 cristin:1606314 |
op_rights |
Attribution CC BY http://creativecommons.org/licenses/by/4.0 Copyright 2018 The Authors |
op_doi |
https://doi.org/10.1038/s41396-018-0217-7 |
container_title |
The ISME Journal |
container_volume |
12 |
container_issue |
11 |
container_start_page |
2694 |
op_container_end_page |
2705 |
_version_ |
1766326480794550272 |