Document Detail

On the relationship between productivity and food chain length at different ecological levels.
MedLine Citation:
PMID:  17206585     Owner:  NLM     Status:  MEDLINE    
The effects of energy on food web structure have been debated for at least 80 years. Nevertheless, the empirical evidence is meager, especially from terrestrial ecosystems. We analyzed long-term temporal variation in food chain length in a semiarid continental ecosystem, where productivity shows large interannual variations. Incidence of nonherbivorous prey in predator diet was used as a proxy of trophic position, allowing us to analyze the effect of productivity on food chain length within the assemblage of top predators (which comprises the most abundant and persistent top predators in the system) and to compare observed patterns at the species and assemblage levels. At the species level, the relationship between trophic position and productivity took different forms, varying in magnitude and shape. This pattern contrasts with the consistent increase in food chain length, with productivity observed at the assemblage level. Our results indicate that productivity can be a main determinant of food chain length, but not necessarily because of energy limitation. Further, the increase in food chain length with available energy probably represents an aggregate attribute, driven to a large extent by predators with higher consumption rates, rather than being the result of compensatory responses among predators.
Matías Arim; Pablo A Marquet; Fabian M Jaksic
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2006-12-04
Journal Detail:
Title:  The American naturalist     Volume:  169     ISSN:  1537-5323     ISO Abbreviation:  Am. Nat.     Publication Date:  2007 Jan 
Date Detail:
Created Date:  2007-01-08     Completed Date:  2007-02-28     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  2984688R     Medline TA:  Am Nat     Country:  United States    
Other Details:
Languages:  eng     Pagination:  62-72     Citation Subset:  IM    
Center for Advanced Studies in Ecology and Biodiversity, Pontificia Universidad Católica de Chile, Casilla 114-D, Santiago CP 6513677, Chile.
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MeSH Terms
Food Chain*
Models, Biological

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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