Will a large complex model ecosystem be viable? The essential role of positive interactions

Area of Science:

• Ecology
• Theoretical Ecology
• Ecosystem Dynamics

Background:

• Ecological systems exhibit characteristics promoting persistence.
• Robert May's 1970s work suggested complexity negatively impacts local stability.
• Local stability loss does not equate to total ecosystem extinction.

Purpose of the Study:

• To challenge the notion that ecosystem complexity inherently leads to instability and extinction.
• To propose a more general criterion for ecosystem viability: long-term persistence of surviving species.
• To investigate the relationship between ecosystem complexity and persistence.

Main Methods:

• Theoretical modeling of ecosystem dynamics.
• Analysis of species interactions and niche creation.
• Simulation of ecosystem persistence under varying complexity levels.

Main Results:

• Ecosystem persistence increases with complexity, contradicting previous findings.
• Loss of local stability does not preclude long-term ecosystem survival.
• Positive interactions are key drivers of niche formation and biodiversity maintenance.

Conclusions:

• Ecosystem complexity can enhance, rather than diminish, long-term persistence.
• Positive interactions are critical for sustaining biodiversity in complex ecosystems.
• A revised understanding of ecosystem viability is needed, focusing on persistence over complete local stability.