Quenching of Chaos in externally driven metacommunities

Abstract The chaotic population dynamics of ecosystems across diverse spatial scales have been extensively investigated over the past three decades. Chaotic fluctuations in species populations, except under specific conditions, have generally been shown to increase extinction risk through cascading effects, environmental noise, and frequent periods of low species density. The persistence of chaotic ecosystems has been attributed to internal and external mechanisms of chaos control, which may be mediated by the ecosystems themselves or by environmental factors such as habitat heterogeneity. However, the control and particularly the quenching of chaos in metacommunities resulting from internal habitat heterogeneity remain unexplored. This study addresses this gap by analyzing the dynamics of a metacommunity composed of five chaotic ecosystems, each located in a distinct patch. The first patch functions as the drive, exerting external influence on the dynamics of the remaining four response patches. Each patch contains an inherently chaotic tritrophic food web, with habitat heterogeneity present among patches. Results indicate that in a drive-response metacommunity, strong influence from the drive quenches dynamical chaos in both drive and response patches, often leading to steady states. This phenomenon is observed in two distinct meta-community network structures. The heterogeneity of the response systems and the dissimilarity between drive and response systems are found to play significant roles in suppressing chaotic population dynamics. These findings strongly imply that the persistence of inherently chaotic metacommunities may result from the quenching of chaos through the interplay of chaos, habitat heterogeneity, and network structure shaped by dispersal. Furthermore, metacommunities composed of inherently chaotic patches are also susceptible to extinction due to dispersal-induced synchronization. Accordingly, this study also investigates dispersal-induced complete synchronization among the constituent patches of the drive-response metacommunities.