| Grazing intensity influences the strength of an associational refuge on temperate reefs. | |
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MedLine Citation:
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PMID: 18975012 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Recent studies have emphasized the role of positive interactions in ecological communities, but few have addressed how positive interactions are mediated by abiotic stress and biotic interactions. Here, I investigate the effect of a facilitator species on the abundance of macroalgae over a gradient of herbivory. Grazing by sea urchins can be intense on temperate reefs along the California coast, with benthic macroalgae growing exclusively in physical refuges and interspersed within colonies of the strawberry anemone, Corynactis californica. Field experiments indicated that the net effect of C. californica on turf algae was strongly nonlinear over a gradient in density of sea urchins. At low intensities of urchin grazing, the anemone and macroalgae competed for space, with algae capable of overgrowing C. californica. At intermediate grazing intensities, C. californica provided a refuge for turf algae but not for juvenile kelp. Neither turf algae nor kelp benefited from the presence of C. californica at the highest levels of grazing intensity, as sea urchins consumed nearly all macroalgae. The hump-shaped effect observed for C. californica contrasts with the prevailing view in ecological theory that positive interactions are more common in harsh environmental conditions. The results reported here qualify this view and underscore the need to evaluate positive interactions over a range of abiotic stress and consumer pressure. |
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Authors:
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Stuart Levenbach |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't Date: 2008-10-31 |
Journal Detail:
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Title: Oecologia Volume: 159 ISSN: 0029-8549 ISO Abbreviation: Oecologia Publication Date: 2009 Feb |
Date Detail:
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Created Date: 2009-01-20 Completed Date: 2009-05-28 Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 0150372 Medline TA: Oecologia Country: Germany |
Other Details:
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Languages: eng Pagination: 181-90 Citation Subset: IM |
Affiliation:
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Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA, 93106, USA. stuart_levenbach@omb.eop.gov |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Algae
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physiology Anemone / physiology* Animals Ecosystem* Feeding Behavior / physiology* Sea Urchins / physiology* |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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