Competition and initial-sensitivity shape spatiotemporal patterns in multi-timescale three species systems

Spatiotemporal pattern formation is fundamental to predicting species dynamics and ecosystem stability. Here, we investigate a three-species system with multi-timescale coupling to unravel how competition and initial-condition sensitivity jointly shape pattern formation within a reaction–diffusion framework. Using bifurcation analysis and non-equilibrium potential landscape theory, we reveal that reduced intraspecific competition in apex predators induces symmetry breaking via period-doubling bifurcations, driving transitions from periodic oscillations to chaos. Simultaneously, timescale asymmetries amplify sensitivity to initial conditions, enabling the coexistence of multi-periodic attractors across space and time. We further identify an interplay between diffusion-driven wave propagation and competition-induced restructuring: diffusion promotes traveling wavefronts, boundary expansion, and fragmentation, while interspecific competition sculpts localized clusters under resource constraints. These findings establish competition and initial sensitivity as key regulators of dispersal plasticity, offering a general dynamical framework for predicting ecosystem stability.