Diversity Waves in Collapse-Driven Population Dynamics.

Area of Science:

• Ecology
• Theoretical Ecology
• Biodiversity Dynamics

Background:

• Ecosystem resource availability limits population growth, necessitating resource redistribution.
• Neutral biodiversity models typically assume incremental changes via stochastic births and deaths.
• Existing models do not fully capture dynamics driven by abrupt, large-scale population collapses.

Purpose of the Study:

• To propose and model a novel redistribution mechanism for ecosystem populations.
• To investigate the emergent dynamics resulting from abrupt species population collapses.
• To analyze the resulting diversity waves, species abundance distributions, and long-term memory effects.

Main Methods:

• Development of a mathematical model simulating population dynamics with collapse-driven resource redistribution.
• Analysis of emergent cyclic "diversity waves" triggered by dominant population collapses.
• Characterization of time-aggregated species abundance distributions and their hierarchical peak structure.

Main Results:

• The model generates cyclic "diversity waves" characterized by initial high diversity that exponentially decreases.
• Species abundances exhibit a bimodal time-aggregated distribution with distinct peaks for collapsed/new and surviving species.
• A self-organized hierarchical peak structure with long-term memory and a scale-free tail (exponent 1.7) was observed.

Conclusions:

• Abrupt population collapses can drive significant ecosystem dynamics, creating "diversity waves".
• The proposed mechanism generates complex, emergent patterns including hierarchical structures and long-term memory.
• The model's dynamics are robust to variations in environmental factors and species-specific traits.