Abstract
Higher order interactions (HOIs) have been suggested to stabilize diverse ecological communities. However, their role in maintaining species coexistence from the perspective of modern coexistence theory is unknown. Here, using a three-species Lotka-Volterra model, we derive a general rule for species coexistence modulated by HOIs. We show that negative HOIs that intensify pairwise competition, can promote coexistence across a wide range of fitness differences, provided that HOIs strengthen intraspecific competition more than interspecific competition. In contrast, positive HOIs that alleviate pairwise competition can also stabilize coexistence across a wide range of fitness differences, irrespective of differences in strength of inter- and intraspecific competition. Furthermore, we extend our three-species analytical result to multispecies competitive community and show, using simulations, that feasible multispecies coexistence is possible provided that strength of negative intraspecific HOIs is higher than interspecific HOIs. In addition, multispecies communities, however, become unstable with positive HOIs as such higher-order interactions could lead to disproportionately infeasible growth rates. This work provides crucial insights on the underlying mechanisms that could maintain species diversity and links HOIs with modern coexistence theory.
