Predator traits determine food-web architecture across ecosystems

Area of Science:

• Ecology
• Food Web Dynamics
• Ecosystem Stability

Background:

• Natural ecosystems exhibit a universal food web architecture where predators are consistently larger than their prey.
• High predator-prey body-mass ratios are theorized to stabilize communities and maintain ecosystem functioning.
• Identifying these key interactions in complex food webs is challenging.

Purpose of the Study:

• To develop predator-trait models for predicting average predator-prey body-mass ratios.
• To analyze how species traits influence the body-size architecture of food webs.
• To understand the role of body-size scaling in ecosystem stability.

Main Methods:

• Utilized a comprehensive database of 290 food webs from freshwater, marine, and terrestrial ecosystems globally.
• Developed predator-trait models to predict body-mass ratios based on species characteristics.
• Analyzed the impact of species traits, metabolic types, and movement strategies on body-size scaling.

Main Results:

• Identified specific predator trait combinations, such as small vertebrates and large aquatic/aerial predators, associated with high body-mass ratios.
• Demonstrated that predator traits significantly influence the slope of predator-prey body-mass scaling.
• Showcased that incorporating metabolic and movement traits enhances the prediction accuracy of high body-mass ratio interactions.

Conclusions:

• Species traits are key determinants of body-size architecture in natural food webs.
• These trait-driven patterns in body-size scaling are fundamental to ecosystem stability and functioning.
• The findings offer a pathway for effective community-level management of complex ecosystems.