Fuzzy modeling of plankton networks

This work aims to show the trophic structure of a real plankton community from Angra dos Reis estuary using in situ flow cytometry for data acquisition, and how competition, as a non-trophic interaction, is structured amid the trophic interactions – predation and herbivory. As no previous information is given, a great research challenge is how to mathematically represent such relations and their interaction strengths. For this purpose, such data were modeled by a fuzzy complex network through a multigraph view. To reduce its complexity, an ant colony algorithm was employed to detect its substructures called communities or compartiments. These approaches have allowed the discrimination and the quantification of relevant linkages and process, search into topological characteristics as triangles or loop distribution to the node degrees, and access the number of communities within network. Futhermore, it was considered the distribution of organisms acording to their sizes and ecological roles. Comparisons with other network indices and patterns found in the literature and in nature, respectively, indicate that our approach is adequate.