Unlocking consumer coexistence: The role of self-organised spatial heterogeneity

In metacommunities, habitat heterogeneity facilitates species coexistence if superior competitors disperse maladaptively towards unfavourable habitats or if they hedge insufficiently against fluctuating environmental conditions. We show that similar mechanisms also operate in metacommunities with homogeneous habitat quality when heterogeneous biomass distributions emerge from self-organised pattern formation. Depending on whether the induced biomass patterns are static or fluctuating, either lower or higher dispersal rates can allow inferior competitors to coexist with their superior counterparts. Coexistence is further promoted when the inferiors can plastically reduce emigration from resource-rich patches. Furthermore, if the competitors differ in their abilities to induce pattern formation, a novel coexistence mechanism akin to relative non-linearity emerges, where the temporarily dominant competitor modifies the spatio-temporal variation in the biomass distributions such that it favours the recovery of the currently rare competitor. Self-organised pattern formation thus generically provides mechanisms for maintaining diversity in metacommunities without requiring a priori habitat heterogeneity.