Stability of plant–pollinator–ant co-mutualism

Abstract

This paper considers plant–pollinator–ant systems in which both the plant–pollinator interaction and plant–ant interaction are mutualistic, but where the second mutualism affects the first, because ants prevent pollinators from visiting plants. We assume the two mutualistic interactions exhibit Beddington–DeAngelis functional responses while the ant-pollinator interaction exhibits a Holling type II formula. Using dynamical systems theory, it is shown that the ant and pollinator can coexist upon the plant in the sense of uniform persistence. Moreover, we define a threshold in the ant aggressiveness against pollinators, which varies with parameters (factors) in the systems. When the level of ant aggressiveness is below the threshold, pollination mutualism is shown to persist in the presence of ants. When the level is above the threshold, the model demonstrates that pollination mutualisms will be driven into extinction by ant aggressiveness.