Dispersal asymmetry and dispersal distance shape dynamics and extinction risk in predator-prey metacommunities.

Dispersal asymmetry is common in advective environments, such as winds dispersing seeds and ocean currents transporting larvae, yet their consequences for the dynamics of interacting species remain difficult to predict. In spatially structured predator-prey metacommunities, prey and predators may experience different degrees of directional transport and dispersal scale (e.g., larval duration), generating connectivity mismatches that alter trophic coupling. Here, we investigate how dispersal asymmetry, interspecific mismatches in dispersal, and dispersal distance shape spatial population structure, dynamical regimes, and extinction risk in marine systems with pelagic larvae. We show that small mismatches in dispersal asymmetry promote sustained oscillatory dynamics with relatively homogeneous mean densities, whereas larger mismatches weaken trophic coupling and lead to asymptotically stable but spatially heterogeneous equilibria. Dispersal distance further modulates extinction risk by altering the depth and duration of population minima, without necessarily changing the qualitative dynamical regime.