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Updated: Jun 21, 2026
10:20
Linking Predation Risk, Herbivore Physiological Stress and Microbial Decomposition of Plant Litter
Published on: March 12, 2013
Herbivore release through cascading risk effects
Martin H Schmidt-Entling1, Eva Siegenthaler
1Institute of Ecology and Evolution, University of Bern, Balzerstrasse 6, 3012 Bern, Switzerland. martin.schmidt@iee.unibe.ch
Biology Letters
|July 10, 2009
Summary
Predators like wolf spiders reduce intermediate prey density. Their presence, even without direct killing, enhances herbivore populations through risk effects, demonstrating complex ecological interactions.
Area of Science:
- Ecology
- Predator-prey dynamics
- Behavioral ecology
Background:
- Predators impact prey via consumption and risk effects (e.g., emigration).
- Wolf spiders (Lycosidae) are key predators in meadow ecosystems.
- Understanding trait-mediated effects is crucial for ecological dynamics.
Purpose of the Study:
- To differentiate between consumption and risk effects of wolf spiders on arthropod communities.
- To investigate the cascading effects of wolf spider predation risk on lower trophic levels.
Main Methods:
- Field experiment with three treatments: intact wolf spiders (predation), wolf spiders with glued chelicers (risk effect), and no spiders (control).
- Monitoring of young wolf spiders, sheetweb spiders (Linyphiidae), and plant/leafhoppers (Auchenorrhyncha) densities.
- Quantifying top-down effects including consumption and risk-mediated behaviors.
Main Results:
- Young wolf spiders were negatively impacted by adult wolf spiders.
- Sheetweb spider densities decreased significantly in the presence of both intact and risk spiders.
- Plant- and leafhopper densities increased in the presence of both intact and risk spiders.
Conclusions:
- Sub-adult wolf spiders act as top predators, reducing intermediate predator populations.
- Cascading risk effects from wolf spiders can enhance herbivore populations, contrary to some previous findings.
- Predation risk, not just consumption, significantly shapes arthropod community structure and trophic interactions.
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