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The coupling between grazing and detritus food chains and the strength of trophic cascades across a gradient of nutrient enrichment

Attayde, Jose Luiz and Ripa, Jörgen LU (2008) In Ecosystems 11(6). p.980-990
Abstract
A minimal food web model was constructed comprising one grazing and one detritus food chain coupled by nutrient cycling and generalist carnivores to investigate how prey preference by carnivores may affect the strength of trophic cascades across a gradient of nutrient enrichment. The equilibrium or mean abundance of each food web component and the magnitude of the carnivore effect on lower trophic levels were calculated for different values of the prey preference and nutrient input parameters. Our model predicts that nutrient enrichment increases the mean abundances of carnivores, autotrophs and detritus, but the magnitude of this effect is dependent on the prey preference term. On the other hand, herbivores and detritivores are relatively... (More)
A minimal food web model was constructed comprising one grazing and one detritus food chain coupled by nutrient cycling and generalist carnivores to investigate how prey preference by carnivores may affect the strength of trophic cascades across a gradient of nutrient enrichment. The equilibrium or mean abundance of each food web component and the magnitude of the carnivore effect on lower trophic levels were calculated for different values of the prey preference and nutrient input parameters. Our model predicts that nutrient enrichment increases the mean abundances of carnivores, autotrophs and detritus, but the magnitude of this effect is dependent on the prey preference term. On the other hand, herbivores and detritivores are relatively unaffected by enrichment but are strongly affected by carnivore preference. Carnivores have a negative effect on herbivores and a positive effect on autotrophs and detritus, whereas the effect on detritivores can be both positive and negative. At high preference for herbivores, carnivores have a positive effect on detritivores, because the positive effect of increased detritus availability due to reduced herbivore grazing outweighs the negative effect of predation. At high preference for detritivores, the balance is changed in the other direction. We argue that in systems where authochtonous primary production is the major source of detritus, herbivores can control the rates of detritus production and have indirect effects on detritivores, which may feed back into effects on herbivores through their shared enemies. This positive feedback is probably one mechanism affecting the resilience of alternative stable states in shallow lakes. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
nutrient cycling, habitat coupling, food webs, adaptive foraging, eutrophication, shallow lakes, trophic dynamics
in
Ecosystems
volume
11
issue
6
pages
980 - 990
publisher
Springer
external identifiers
  • wos:000259564600011
  • scopus:52949121758
ISSN
1432-9840
DOI
10.1007/s10021-008-9174-8
language
English
LU publication?
yes
id
917ec0f6-0b43-4847-b99d-88f72d24fb71 (old id 1286767)
date added to LUP
2009-01-29 15:41:46
date last changed
2017-05-14 03:59:32
@article{917ec0f6-0b43-4847-b99d-88f72d24fb71,
  abstract     = {A minimal food web model was constructed comprising one grazing and one detritus food chain coupled by nutrient cycling and generalist carnivores to investigate how prey preference by carnivores may affect the strength of trophic cascades across a gradient of nutrient enrichment. The equilibrium or mean abundance of each food web component and the magnitude of the carnivore effect on lower trophic levels were calculated for different values of the prey preference and nutrient input parameters. Our model predicts that nutrient enrichment increases the mean abundances of carnivores, autotrophs and detritus, but the magnitude of this effect is dependent on the prey preference term. On the other hand, herbivores and detritivores are relatively unaffected by enrichment but are strongly affected by carnivore preference. Carnivores have a negative effect on herbivores and a positive effect on autotrophs and detritus, whereas the effect on detritivores can be both positive and negative. At high preference for herbivores, carnivores have a positive effect on detritivores, because the positive effect of increased detritus availability due to reduced herbivore grazing outweighs the negative effect of predation. At high preference for detritivores, the balance is changed in the other direction. We argue that in systems where authochtonous primary production is the major source of detritus, herbivores can control the rates of detritus production and have indirect effects on detritivores, which may feed back into effects on herbivores through their shared enemies. This positive feedback is probably one mechanism affecting the resilience of alternative stable states in shallow lakes.},
  author       = {Attayde, Jose Luiz and Ripa, Jörgen},
  issn         = {1432-9840},
  keyword      = {nutrient cycling,habitat coupling,food webs,adaptive foraging,eutrophication,shallow lakes,trophic dynamics},
  language     = {eng},
  number       = {6},
  pages        = {980--990},
  publisher    = {Springer},
  series       = {Ecosystems},
  title        = {The coupling between grazing and detritus food chains and the strength of trophic cascades across a gradient of nutrient enrichment},
  url          = {http://dx.doi.org/10.1007/s10021-008-9174-8},
  volume       = {11},
  year         = {2008},
}