Document Detail


Long-term nutrient enrichment decouples predator and prey production.
MedLine Citation:
PMID:  20018677     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Increased nutrient mobilization by human activities represents one of the greatest threats to global ecosystems, but its effects on ecosystem productivity can differ depending on food web structure. When this structure facilitates efficient energy transfers to higher trophic levels, evidence from previous large-scale enrichments suggests that nutrients can stimulate the production of multiple trophic levels. Here we report results from a 5-year continuous nutrient enrichment of a forested stream that increased primary consumer production, but not predator production. Because of strong positive correlations between predator and prey production (evidence of highly efficient trophic transfers) under reference conditions, we originally predicted that nutrient enrichment would stimulate energy flow to higher trophic levels. However, enrichment decoupled this strong positive correlation and produced a nonlinear relationship between predator and prey production. By increasing the dominance of large-bodied predator-resistant prey, nutrient enrichment truncated energy flow to predators and reduced food web efficiency. This unexpected decline in food web efficiency indicates that nutrient enrichment, a ubiquitous threat to aquatic ecosystems, may have unforeseen and unpredictable effects on ecosystem structure and productivity.
Authors:
John M Davis; Amy D Rosemond; Susan L Eggert; Wyatt F Cross; J Bruce Wallace
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, Non-P.H.S.     Date:  2009-12-14
Journal Detail:
Title:  Proceedings of the National Academy of Sciences of the United States of America     Volume:  107     ISSN:  1091-6490     ISO Abbreviation:  Proc. Natl. Acad. Sci. U.S.A.     Publication Date:  2010 Jan 
Date Detail:
Created Date:  2010-01-18     Completed Date:  2010-03-09     Revised Date:  2010-09-27    
Medline Journal Info:
Nlm Unique ID:  7505876     Medline TA:  Proc Natl Acad Sci U S A     Country:  United States    
Other Details:
Languages:  eng     Pagination:  121-6     Citation Subset:  IM    
Affiliation:
Odum School of Ecology, University of Georgia, Athens, GA 30602, USA. jmdavis@isu.edu
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MeSH Terms
Descriptor/Qualifier:
Animals
Biomass
Ecosystem
Feeding Behavior / physiology*
Food*
Food Chain*
Fresh Water
Humans
Predatory Behavior / physiology*
Rivers
Urodela
Comments/Corrections

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


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