Speaker
Description
How invasions of ecosystems by novel species or variants unfold and their ripple effects on the community are central questions in ecology and evolution. In this work, we explore how an invader can replace a resident species in different ecological networks and/or models. Through the lens of modern coexistence theory and invasion rates, we analyze feasibility and stability of invaded multi-species equilibria, along with persistence of associated species. As invader growth rate increases, there is either generically a gradual transition from invasion to replacement or non-generically an abrupt bifurcation where invasion and replacement occur simultaneously. We find an analytical means for predicting which species are replaced in different scenarios, particularly in the non-generic case which includes specific cases of Lotka-Volterra, consumer-resource and predator-prey networks. In these examples, we also study how the presence and functional form of trade-offs can lead to distinct convergent ecosystem structures.
