Advanced

The influence of productivity and width of littoral zone on the trophic position of a large-bodied omnivore.

Stenroth, Patrik LU ; Holmqvist, Niklas LU ; Nyström, Per LU ; Berglund, Olof LU ; Larsson, Per LU and Granéli, Wilhelm LU (2008) In Oecologia 156. p.681-690
Abstract
Omnivory is common in many food webs. Omnivores in different habitats can potentially change their feeding behaviour and alter their trophic position and role according to habitat conditions. Here we examine the trophic level and diet of the omnivorous signal crayfish (Pacifastacus leniusculus) in gradients of trophic status and lake size, both of which have been previously suggested to affect trophic position of predators separately or combined as productive space. We found the trophic position of omnivorous crayfish to be positively correlated with lake trophic status, but found no evidence for any influence of lake size or productive space on crayfish trophic position. The higher trophic position of crayfish in eutrophic lakes was... (More)
Omnivory is common in many food webs. Omnivores in different habitats can potentially change their feeding behaviour and alter their trophic position and role according to habitat conditions. Here we examine the trophic level and diet of the omnivorous signal crayfish (Pacifastacus leniusculus) in gradients of trophic status and lake size, both of which have been previously suggested to affect trophic position of predators separately or combined as productive space. We found the trophic position of omnivorous crayfish to be positively correlated with lake trophic status, but found no evidence for any influence of lake size or productive space on crayfish trophic position. The higher trophic position of crayfish in eutrophic lakes was largely caused by a shift in crayfish diet and not by an increase in trophic links in basal parts of the food web. Hence, our results support the "productivity hypothesis," suggesting that food chains can be longer in more productive systems. Furthermore, stable isotope data indicated that larger crayfish are more predatory than smaller crayfish in lakes with wider littoral zones. Wider littoral zones promoted the development of intrapopulation differences in trophic position whereas narrow littoral zones did not. Hence, differences in habitat quality between and within lakes seem to influence the trophic positions of omnivorous crayfish. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Trophic structure - Food chain length - Lake food webs - Stable isotopes - Crayfish
in
Oecologia
volume
156
pages
681 - 690
publisher
Springer
external identifiers
  • pmid:18368427
  • wos:000255680000019
  • scopus:43349093205
ISSN
1432-1939
DOI
10.1007/s00442-008-1019-9
language
English
LU publication?
yes
id
7cb10a91-3ce9-4dd3-98d2-7ec130dae7ee (old id 1052136)
date added to LUP
2008-04-28 12:26:45
date last changed
2017-08-20 04:01:26
@article{7cb10a91-3ce9-4dd3-98d2-7ec130dae7ee,
  abstract     = {Omnivory is common in many food webs. Omnivores in different habitats can potentially change their feeding behaviour and alter their trophic position and role according to habitat conditions. Here we examine the trophic level and diet of the omnivorous signal crayfish (Pacifastacus leniusculus) in gradients of trophic status and lake size, both of which have been previously suggested to affect trophic position of predators separately or combined as productive space. We found the trophic position of omnivorous crayfish to be positively correlated with lake trophic status, but found no evidence for any influence of lake size or productive space on crayfish trophic position. The higher trophic position of crayfish in eutrophic lakes was largely caused by a shift in crayfish diet and not by an increase in trophic links in basal parts of the food web. Hence, our results support the "productivity hypothesis," suggesting that food chains can be longer in more productive systems. Furthermore, stable isotope data indicated that larger crayfish are more predatory than smaller crayfish in lakes with wider littoral zones. Wider littoral zones promoted the development of intrapopulation differences in trophic position whereas narrow littoral zones did not. Hence, differences in habitat quality between and within lakes seem to influence the trophic positions of omnivorous crayfish.},
  author       = {Stenroth, Patrik and Holmqvist, Niklas and Nyström, Per and Berglund, Olof and Larsson, Per and Granéli, Wilhelm},
  issn         = {1432-1939},
  keyword      = {Trophic structure - Food chain length - Lake food webs - Stable isotopes - Crayfish},
  language     = {eng},
  pages        = {681--690},
  publisher    = {Springer},
  series       = {Oecologia},
  title        = {The influence of productivity and width of littoral zone on the trophic position of a large-bodied omnivore.},
  url          = {http://dx.doi.org/10.1007/s00442-008-1019-9},
  volume       = {156},
  year         = {2008},
}