Abundant equals nested

Abstract

How ecological network structures are influenced by species coexistence, community stability and perturbations is a topic of debate. It seems that one overlooked correlate of nested structures is species abundances. See Letter p.449 Cooperation among species tends to result in mutualistic networks with a nested structure. Although nestedness may increase biodiversity and persistence, theoretical work suggests that nested networks tend to be less stable than unstructured ones. This paper shows analytically that nested networks result from a mechanism that maximizes species abundances in mutualistic communities and that the abundance of the nested species is directly linked to the resilience of the community. This work offers a model for the study of how ecological factors and evolutionary history shape ecological networks.