Keystone Predation: What Is It, and Is It Supported by Empirical Evidence?

Area of Science:

• Ecology
• Community Ecology
• Predator-Prey Dynamics

Background:

• Keystone predation is a fundamental ecological concept, but empirical evidence remains largely unreviewed.
• The process differs from keystone species, focusing on indirect facilitation via predator-prey interactions.
• Understanding keystone predation's prevalence is crucial for community ecology.

Purpose of the Study:

• To systematically review empirical evidence for keystone predation.
• To assess the prevalence and context dependencies of keystone predation.
• To identify research gaps and provide recommendations for future studies.

Main Methods:

• Conducted a literature review of studies explicitly testing or mentioning keystone predation.
• Analyzed publication data for geographical and habitat distributions.
• Categorized studies based on experimental manipulation of predator abundance and reported support for keystone predation.

Main Results:

• Nearly 2000 publications mentioned keystone predation, but only 73 detailed the process.
• Most studies originated from North America, temperate regions, and aquatic habitats.
• Only 25 studies experimentally tested keystone predation, with mixed results: 10 supported it, 7 showed context-dependent effects, and 8 found no support.

Conclusions:

• Empirical evidence for keystone predation is limited, making its prevalence and importance difficult to ascertain.
• Environmental factors, species traits, and dispersal likely modify keystone predation.
• Further research using precise terminology and diverse conditions is needed to understand this ecological process.