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More severe disturbance regimes drive the shift of a kelp forest to a sea urchin barren in south-eastern Australia

Climate change is influencing the frequency and severity of extreme events. This means that systems are experiencing novel or altered disturbance regimes, making it difficult to predict and manage for this impact on ecosystems. While there is established theory regarding how the frequency of disturb...

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Autores principales: Carnell, Paul E., Keough, Michael J.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7347924/
https://www.ncbi.nlm.nih.gov/pubmed/32647344
http://dx.doi.org/10.1038/s41598-020-67962-y
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author Carnell, Paul E.
Keough, Michael J.
author_facet Carnell, Paul E.
Keough, Michael J.
author_sort Carnell, Paul E.
collection PubMed
description Climate change is influencing the frequency and severity of extreme events. This means that systems are experiencing novel or altered disturbance regimes, making it difficult to predict and manage for this impact on ecosystems. While there is established theory regarding how the frequency of disturbance influences ecosystems, how this interacts with severity of disturbance is difficult to tease apart, as these two are inherently linked. Here we investigated a subtidal kelp (Ecklonia radiata) dominated community in southern Australia to assess how different disturbance regimes might drive changes to a different ecosystem state: sea urchin barrens. Specifically, we compared how the frequency of disturbance (single or triple disturbance events over a three month period) influenced recruitment and community dynamics, when the net severity of disturbance was the same (single disturbance compared to triple disturbances each one-third as severe). We crossed this design with two different net severities of disturbance (50% or 100%, kelp canopy removal). The frequency of disturbance effect depended on the severity of disturbance. When 50% of the canopy was removed, the highest kelp recruitment and recovery of the benthic community occurred with the triple disturbance events. When disturbance was a single event or the most severe (100% removal), kelp recruitment was low and the kelp canopy failed to recover over 18 months. The latter case led to shifts in the community composition from a kelp bed to a sea-urchin barren. This suggests that if ecosystems experience novel or more severe disturbance scenarios, this can lead to a decline in ecosystem condition or collapse.
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spelling pubmed-73479242020-07-14 More severe disturbance regimes drive the shift of a kelp forest to a sea urchin barren in south-eastern Australia Carnell, Paul E. Keough, Michael J. Sci Rep Article Climate change is influencing the frequency and severity of extreme events. This means that systems are experiencing novel or altered disturbance regimes, making it difficult to predict and manage for this impact on ecosystems. While there is established theory regarding how the frequency of disturbance influences ecosystems, how this interacts with severity of disturbance is difficult to tease apart, as these two are inherently linked. Here we investigated a subtidal kelp (Ecklonia radiata) dominated community in southern Australia to assess how different disturbance regimes might drive changes to a different ecosystem state: sea urchin barrens. Specifically, we compared how the frequency of disturbance (single or triple disturbance events over a three month period) influenced recruitment and community dynamics, when the net severity of disturbance was the same (single disturbance compared to triple disturbances each one-third as severe). We crossed this design with two different net severities of disturbance (50% or 100%, kelp canopy removal). The frequency of disturbance effect depended on the severity of disturbance. When 50% of the canopy was removed, the highest kelp recruitment and recovery of the benthic community occurred with the triple disturbance events. When disturbance was a single event or the most severe (100% removal), kelp recruitment was low and the kelp canopy failed to recover over 18 months. The latter case led to shifts in the community composition from a kelp bed to a sea-urchin barren. This suggests that if ecosystems experience novel or more severe disturbance scenarios, this can lead to a decline in ecosystem condition or collapse. Nature Publishing Group UK 2020-07-09 /pmc/articles/PMC7347924/ /pubmed/32647344 http://dx.doi.org/10.1038/s41598-020-67962-y Text en © The Author(s) 2020 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
spellingShingle Article
Carnell, Paul E.
Keough, Michael J.
More severe disturbance regimes drive the shift of a kelp forest to a sea urchin barren in south-eastern Australia
title More severe disturbance regimes drive the shift of a kelp forest to a sea urchin barren in south-eastern Australia
title_full More severe disturbance regimes drive the shift of a kelp forest to a sea urchin barren in south-eastern Australia
title_fullStr More severe disturbance regimes drive the shift of a kelp forest to a sea urchin barren in south-eastern Australia
title_full_unstemmed More severe disturbance regimes drive the shift of a kelp forest to a sea urchin barren in south-eastern Australia
title_short More severe disturbance regimes drive the shift of a kelp forest to a sea urchin barren in south-eastern Australia
title_sort more severe disturbance regimes drive the shift of a kelp forest to a sea urchin barren in south-eastern australia
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7347924/
https://www.ncbi.nlm.nih.gov/pubmed/32647344
http://dx.doi.org/10.1038/s41598-020-67962-y
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