Robust coexistence in competitive ecological communities

Area of Science:

• Ecology
• Theoretical Ecology
• Community Ecology

Background:

• Intraspecific competition is a cornerstone of ecological theory, influencing coexistence and community stability.
• Strong intraspecific competition aids population recovery after disturbances.

Purpose of the Study:

• To investigate how intraspecific competition affects the existence (feasibility) of a steady state in large, competition-dominated ecological communities.
• To determine the relationship between intraspecific competition, feasibility, and stability in these communities.

Main Methods:

• Mathematical modeling of large random ecological communities.
• Derivation of a general expression for the probability of feasibility.
• Analysis of the asymptotic behavior of feasibility and stability transitions as species number increases.

Main Results:

• A critical level of intraspecific competition exists, above which a feasible steady state is guaranteed.
• In large communities, stability transitions precede feasibility transitions.
• This ordering of transitions persists even with species extinctions, as community dynamics prune species.

Conclusions:

• In large competitive communities, feasible equilibria are inherently stable.
• Sustained oscillations or chaotic dynamics are unlikely in such systems.
• Intraspecific competition plays a crucial role in ensuring predictable and stable community dynamics.