Impact of higher-order interactions on dynamics of plant-pollinator-herbivore systems

Complex interactions exist among plants, pollinators, and herbivores, involving not only predation and mutualism but also higher-order interactions. This study devotes to exploring how higher-order interactions between pollinators and herbivores affect the dynamics of such systems. An interference parameter is introduced to characterize the interaction. Qualitative analysis is conducted to investigate the existence and stability of various ecological equilibria, and to reveal bifurcation phenomena such as transcritical and hopf bifurcations. Sensitivity analysis confirms the significant effect of the interference parameter. Theoretical analyses and numerical simulations reveal the following facts: (1) herbivore interference increases the extinction risk of pollinators while exerting limited impact on the plant population; (2) interference can induce transitions between oscillatory and stable coexistence states; (3) strong mutualistic interactions promote pollinator persistence yet can destabilize the coexistence equilibrium, and in contrast, a low intrinsic growth rate of plants facilitates three-species coexistence, though it does not enhance equilibrium stability; (4) higher-order interactions affect the stability of the system and cause complex dynamical behaviors.