Impact of compatibility on the organization of mutualistic networks

Distinct relationships such as activation, inhibition, cooperation, and competition are not established independently but in a correlated manner in complex systems. Thus the patterns of one type of interaction may reflect the impacts of other classes of interactions, but its quantitative understanding remains to be done. Referring to the plant-pollinator mutualistic networks, here we propose and investigate the structural features of a model bipartite network, in which the mutualistic relationship between two different types of nodes is established under the influence of the compatibility among the nodes of the same type. Interestingly, we find that the degree distributions obtained for extremely broad compatibility distributions are similar to those for a constant compatibility, both of which deviate from those for the Gaussian compatibility distributions. We present the analytic arguments to explain this finding. Also the dependence of the topological similarity of two nodes on their compatibility is illustrated. We discuss the application of our findings to complex systems.