Amos Maritan (Università di Padova)
Abstract: Mutualistic networks are formed when the interactions between two classes of species are mutually beneficial and they are important examples of cooperation shaped by evolution. The topological properties of the ecological interaction networks have been the subject of sparkling research and they indicate non-random pattern of community organization. Indeed, ecologists have collected extensive data on species interactions showing that, independently of species composi- tion and latitude, mutualistic networks (such as plant-pollinator systems) have nested architectures: specialist species, with only few mutualistic links, tend to interact with a proper subset of the many mutualistic partners of any of the generalist species. Despite sustained efforts to explain observed network struc- ture on the basis of community-level stability or persistence, such correlative studies have reached minimal consensus. It will be show how nested interac- tion networks emerge as a consequence of an optimization-variational principle. Nested networks also attenuates the impact of the propagation of perturbations on species abundance through localization of the principal eigenvector of the linearized dynamics.
Joint work with: Samir Suweis, Jayanth Banavar, Jacopo Grilli and Filippo Simini.
References
[1] S. Suweis, J. Grilli, J.R. Banavar and A. Maritan, Effect of localization on the stability of mutualistic ecological networks, Nat. Comm., 6 (2015), DOI: 10.1038/ncomms10179.
[2] S. Suweis, F. Simini, J.R. Banavar and A. Maritan, Emergence of struc- tural and dynamical properties of ecological mutualistic networks, Nature, 500 (2015) 449-452.