Competition in di- and tri-trophic food web modules

Area of Science:

• Ecology
• Theoretical Ecology
• Food Web Dynamics

Background:

• Apparent competition occurs when species share a predator.
• Food web modules with many competing species are crucial for understanding community stability.
• Predator foraging strategies (fixed vs. flexible) influence population dynamics.

Purpose of the Study:

• To investigate competition in di- and tri-trophic food web modules.
• To analyze the impact of predator foraging flexibility on species coexistence and food web robustness.
• To determine how environmental carrying capacity and food web connectance affect these dynamics.

Main Methods:

• Modeling of food web modules, including apparent competition and diamond-like structures.
• Analysis of predator behavior: fixed prey preference versus flexible foraging for fitness maximization.
• Mathematical analysis using Lyapunov functions to assess global stability.

Main Results:

• Optimal flexible foraging significantly weakens apparent competition, promoting species coexistence.
• Food web robustness (proportion of surviving species) is not negatively correlated with increased connectance.
• Flexible prey switching results in population equilibria similar to those with specialized predators.

Conclusions:

• Predator foraging flexibility is a key factor influencing species richness and community responses to environmental changes.
• Flexible foraging can stabilize food webs and enhance coexistence, even with increased complexity.
• Understanding predator behavior is essential for predicting food web stability and resilience.