Advanced

Snails have stronger indirect positive effects on submerged macrophyte growth attributes than zooplankton

Mormul, Roger Paulo; Ahlgren, Johan LU and Brönmark, Christer LU (2017) In Hydrobiologia p.1-9
Abstract

Phytoplankton and epiphyton often compete with submerged macrophytes. Grazing by zooplankton and/or epiphyton grazers should promote an indirect positive effect on submerged macrophyte growth rate. Hence, we mimicked shallow lakes conditions in mesocosms using a factorial design to evaluate the indirect effects of no grazers, zooplankton, snails or both grazers on macrophyte growth attributes. After 16 weeks, both snails and zooplankton had positive effects on macrophyte stem length and biomass. However, only snails had positive effects on macrophyte number of sprouts and root biomass. In addition, the positive effect size of snails on the submerged macrophytes was twice as large as the effect size of the zooplankton. Our study suggests... (More)

Phytoplankton and epiphyton often compete with submerged macrophytes. Grazing by zooplankton and/or epiphyton grazers should promote an indirect positive effect on submerged macrophyte growth rate. Hence, we mimicked shallow lakes conditions in mesocosms using a factorial design to evaluate the indirect effects of no grazers, zooplankton, snails or both grazers on macrophyte growth attributes. After 16 weeks, both snails and zooplankton had positive effects on macrophyte stem length and biomass. However, only snails had positive effects on macrophyte number of sprouts and root biomass. In addition, the positive effect size of snails on the submerged macrophytes was twice as large as the effect size of the zooplankton. Our study suggests that benthic food chains might be more capable of increasing resilience and affecting the stability of the clear-water state in shallow lakes than pelagic food chains. However, long-term experiments with varying relative proportions of herbivores and different macrophyte species, as well as in situ experiments, will be necessary to test the generality of our findings. Understanding the relative effects of benthic versus pelagic grazers on submerged macrophytes may increase the success of shallow lake restoration and should be taken into account when designing management and restoration efforts for shallow lake systems.

(Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
epub
subject
keywords
Food chain, Herbivory, Regime shifts, Snails, Zooplankton
in
Hydrobiologia
pages
9 pages
publisher
Springer
external identifiers
  • scopus:85031115564
  • wos:000417867600011
ISSN
0018-8158
DOI
10.1007/s10750-017-3391-0
language
English
LU publication?
yes
id
3bde732d-fc19-4497-9232-0e296ceb0343
date added to LUP
2017-10-26 13:58:20
date last changed
2018-01-16 13:24:24
@article{3bde732d-fc19-4497-9232-0e296ceb0343,
  abstract     = {<p>Phytoplankton and epiphyton often compete with submerged macrophytes. Grazing by zooplankton and/or epiphyton grazers should promote an indirect positive effect on submerged macrophyte growth rate. Hence, we mimicked shallow lakes conditions in mesocosms using a factorial design to evaluate the indirect effects of no grazers, zooplankton, snails or both grazers on macrophyte growth attributes. After 16 weeks, both snails and zooplankton had positive effects on macrophyte stem length and biomass. However, only snails had positive effects on macrophyte number of sprouts and root biomass. In addition, the positive effect size of snails on the submerged macrophytes was twice as large as the effect size of the zooplankton. Our study suggests that benthic food chains might be more capable of increasing resilience and affecting the stability of the clear-water state in shallow lakes than pelagic food chains. However, long-term experiments with varying relative proportions of herbivores and different macrophyte species, as well as in situ experiments, will be necessary to test the generality of our findings. Understanding the relative effects of benthic versus pelagic grazers on submerged macrophytes may increase the success of shallow lake restoration and should be taken into account when designing management and restoration efforts for shallow lake systems.</p>},
  author       = {Mormul, Roger Paulo and Ahlgren, Johan and Brönmark, Christer},
  issn         = {0018-8158},
  keyword      = {Food chain,Herbivory,Regime shifts,Snails,Zooplankton},
  language     = {eng},
  month        = {10},
  pages        = {1--9},
  publisher    = {Springer},
  series       = {Hydrobiologia},
  title        = {Snails have stronger indirect positive effects on submerged macrophyte growth attributes than zooplankton},
  url          = {http://dx.doi.org/10.1007/s10750-017-3391-0},
  year         = {2017},
}