Impacts of consumer-resource interaction transitions on persistence and long-term interaction outcomes of random ecological networks

23 February 2019

Yan, Chuan; Zhang, Zhibin

Despite the prevalence of context-dependent interaction transitions in ecological systems, their impacts on persistence and interaction diversity have scarcely been explored in complex ecological networks. By using multispecies bi-directional and unidirectional consumer-resource models, representing a continuum of interaction transitions (sign change of interaction outcomes), we investigated the effects of structural interaction transitions on persistence (the fraction of remaining species) and long-term interaction outcomes in random ecological networks. We found that high interaction strength of exploiting resources generally decreased persistence, and high strength of providing resources increased persistence when the strength of exploiting resources was low in more complex networks; also, the networks with high persistence had a high proportion of mutualistic interactions relative to antagonistic interactions present initially and over the long term. The shifting of interaction strengths shaped the long-term interaction compositions. Meanwhile, population dynamics, especially species extinction, affected the difference between initial and long-term interactions. Based on classical consumer-resource theory, these results establish a transitional continuum of interaction outcomes in ecological networks and imply a theoretical association among interaction transition, community persistence and interaction diversity.