How does interaction intimacy influences the modularity of mutualistic networks?

• Grant number: 13/25891-5
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): March 01, 2014
• Effective date (End): December 31, 2014
• Field of knowledge: Biological Sciences - Ecology - Theoretical Ecology
• Principal researcher: Paulo Roberto Guimarães Junior
• Grantee: Lucas Paoliello de Medeiros
• Home Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Mutualisms between plants and animals affect evolutionary processes and have a fundamental role in maintaining biodiversity. The set of mutualistic interactions between plant and animal species that occur in an ecological community can be represented as an interaction network. The network approach enables us to visualize, quantify and compare the structure of communities with a large number of species and interactions. Some mutualisms are characterized by modules, which are groups of species that more frequently interact with each other than with species in other modules. Aspects of the natural history of the interactions can be associated with modularity. High-intimacy interactions (e.g. protective ants and myrmecophytes), by instance, generate networks that are more modular than low-intimacy interactions (e.g. seed dispersal by vertebrates). A next step to better understand the factors that shape the organization of mutualisms is to investigate the association between the internal structure of modules and the degree of interaction intimacy. The goal of this project is to compare the structure of interactions inside modules between networks of different types of mutualisms: ant-myrmecophyte, pollination and seed dispersal, in order to understand how interaction intimacy influences modularity. A total of 30 mutualistic networks will be analyzed. It is expected that in networks with high-interaction intimacy species will have few interactions inside their modules and interactions between different modules will be scarce. On the other hand, in networks with low-interaction intimacy, it is expected a higher variance in the number of interactions across species. Furthermore, in those networks, different modules will be highly connected.