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Updated: Jul 12, 2026
10:20
Linking Predation Risk, Herbivore Physiological Stress and Microbial Decomposition of Plant Litter
Published on: March 12, 2013
Spatial refuge from intraguild predation: implications for prey suppression and trophic cascades
Deborah L Finke1, Robert F Denno
1Department of Entomology, University of Maryland, College Park, MD, 20742, USA. dfinke@wsu.edu
Oecologia
|May 19, 2006
Summary
Habitat complexity, like thatch in salt marshes, can strengthen predator effects on herbivores and boost plant growth by reducing negative interactions among predators. This enhances trophic cascades in ecosystems.
Area of Science:
- Ecology
- Ecosystem Dynamics
- Predator-Prey Interactions
Background:
- Trophic cascades, where predators influence lower trophic levels, can be affected by habitat structure.
- Intraguild predation (predators attacking other predators) can weaken cascading effects in simple habitats.
- Complex habitats may offer refuges, reducing intraguild predation and strengthening trophic cascades.
Purpose of the Study:
- To investigate how habitat complexity influences predator-prey interactions and trophic cascades in salt marsh ecosystems.
- To determine the role of thatch in mediating intraguild predation and its effect on herbivore suppression and plant biomass.
Main Methods:
- Field study in Atlantic coastal salt marshes comparing simple (thatch-free) and complex (thatch-rich) vegetation.
- Assessed the impact of a predator assemblage (wolf spiders, web-building spiders, mirid bugs) on planthopper herbivores and Spartina cordgrass biomass.
- Laboratory experiments to observe intraguild predation rates with and without thatch.
Main Results:
- Complex, thatch-rich habitats enhanced the suppression of planthoppers by the predator assemblage.
- Thatch acted as a refuge, reducing intraguild predation (including cannibalism) among predators.
- Reduced negative interactions among predators led to stronger top-down control on herbivores and increased plant biomass.
Conclusions:
- Habitat complexity significantly enhances trophic cascades by moderating interactions within predator communities.
- Complex habitats facilitate predator assemblages to more effectively control herbivores, positively impacting primary productivity.
- Conservation and restoration of complex habitats can bolster ecosystem functions and resilience.
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