Coexistence theory and the frequency-dependence of priority effects

Priority effects are commonly used to describe a broad suite of phenomena capturing the influence of species arrival order on the diversity, composition and function of ecological communities. Several studies have suggested reframing priority effects around the stabilizing and equalizing concepts of coexistence theory. We show that the only compatible priority effects are those characterized by positive frequency-dependence, irrespective of whether they emerge in equilibrium or non-equilibrium systems. Priority effects refer to changes in the diversity, composition or function of a community according to the arrival order of species. Here, the authors show that only effects that are compatible with coexistence theory are characterized by positive frequency-dependence.