Department of Entomology

Title: Cascading effects in mutualists networks

Abstract: In ecological communities, species are connected to each other through ecological interactions. Thus, disturbances in one species can ripple throughout the community, creating cascading effects that indirectly affect other species. For example, the extinction of a bee species could negatively affect the reproduction of plant species, potentially leading it to extinction. In this sense, the current biodiversity crisis affects not only species, but also species interactions, with critical implications for ecosystem function. In this talk I will explore how network structure affects its robustness to different extinction drivers—such as species loss—and how robustness changes as communities assemble. I will combine empirical data on mutualistic networks (plantpollinator and plant-seed dispersal) with theoretical networks to (i) investigate how network structure affects how perturbations spread in ecological networks; (ii) how robustness to different extinction drivers, in addition to cascading effects, is related to the two most commonly explored network metrics (nestedness and modularity); (iii) how the robustness of plant-pollinator communities changes as community assembles; and (iv) which traits are related to how flexible species are in their interaction partners. If we are to protect and restore ecological communities, it is essential to unravel the relationship between network structure and community robustness to extinction drivers, and to understand how network structure and robustness changes as communities change through time.