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Tritrophic interactions in a soil community enhance decomposition rates

Hedlund, Katarina LU and Öhrn, Maria Sjögren LU (2000) In Oikos 88(3). p.585-591
Abstract
Microbivorous soil fauna can influence decomposition rates by regulating biomass and composition of the microbial community. The idea that predators at higher trophic levels regulate population densities of microbivorous fauna and thus indirectly increase microbial growth and activity has often been suggested but rarely examined in soil ecosystems. In this paper the effects of tritrophic interactions on decomposition processes in the soil are studied and expressed as soil respiration, hyphal lengths, cellulase and chitinase activities. The experiments were carried out in soil microcosms in a factorial design with three fungal species (Alternaria alternata, Fusarium oxysporum, Trichoderma viride), the fungivorous collembolan Folsomia... (More)
Microbivorous soil fauna can influence decomposition rates by regulating biomass and composition of the microbial community. The idea that predators at higher trophic levels regulate population densities of microbivorous fauna and thus indirectly increase microbial growth and activity has often been suggested but rarely examined in soil ecosystems. In this paper the effects of tritrophic interactions on decomposition processes in the soil are studied and expressed as soil respiration, hyphal lengths, cellulase and chitinase activities. The experiments were carried out in soil microcosms in a factorial design with three fungal species (Alternaria alternata, Fusarium oxysporum, Trichoderma viride), the fungivorous collembolan Folsomia fimetaria and the predatory mite Hypoaspis aculeifer. The respiration rate was significantly higher with three trophic levels than in those with two and lowest in those with only fungi present. This indicates that a low level of grazing stimulates microbial respiration more than a high level or no grazing at ail. The effect was similar for all three fungal species but most pronounced in microcosms with the fungus A. alternata which was a preferred food source by the collembolans. Hyphal lengths were in all cases but with T, viride reduced in the presence of collembolans and predatory mites. T. viride had a slightly higher chitinase activity than the other fungi but increased numbers of trophic levels did not affect the enzymatic activities of any of the fungi. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Oikos
volume
88
issue
3
pages
585 - 591
publisher
Wiley-Blackwell
external identifiers
  • scopus:0342545873
ISSN
1600-0706
DOI
10.1034/j.1600-0706.2000.880315.x
language
English
LU publication?
yes
id
211d937f-8155-4a9f-88e2-84f867ae44bc (old id 146056)
date added to LUP
2007-06-26 08:11:02
date last changed
2017-02-12 03:29:23
@article{211d937f-8155-4a9f-88e2-84f867ae44bc,
  abstract     = {Microbivorous soil fauna can influence decomposition rates by regulating biomass and composition of the microbial community. The idea that predators at higher trophic levels regulate population densities of microbivorous fauna and thus indirectly increase microbial growth and activity has often been suggested but rarely examined in soil ecosystems. In this paper the effects of tritrophic interactions on decomposition processes in the soil are studied and expressed as soil respiration, hyphal lengths, cellulase and chitinase activities. The experiments were carried out in soil microcosms in a factorial design with three fungal species (Alternaria alternata, Fusarium oxysporum, Trichoderma viride), the fungivorous collembolan Folsomia fimetaria and the predatory mite Hypoaspis aculeifer. The respiration rate was significantly higher with three trophic levels than in those with two and lowest in those with only fungi present. This indicates that a low level of grazing stimulates microbial respiration more than a high level or no grazing at ail. The effect was similar for all three fungal species but most pronounced in microcosms with the fungus A. alternata which was a preferred food source by the collembolans. Hyphal lengths were in all cases but with T, viride reduced in the presence of collembolans and predatory mites. T. viride had a slightly higher chitinase activity than the other fungi but increased numbers of trophic levels did not affect the enzymatic activities of any of the fungi.},
  author       = {Hedlund, Katarina and Öhrn, Maria Sjögren},
  issn         = {1600-0706},
  language     = {eng},
  number       = {3},
  pages        = {585--591},
  publisher    = {Wiley-Blackwell},
  series       = {Oikos},
  title        = {Tritrophic interactions in a soil community enhance decomposition rates},
  url          = {http://dx.doi.org/10.1034/j.1600-0706.2000.880315.x},
  volume       = {88},
  year         = {2000},
}