Modelling Biotic Interactions, Dispersal Effects and the Stability of Multi-species Community Compositions

A key problem in ecology is to predict the distributions of species across a geographical location. Numerous experimental studies have suggested several ecological factors that can determine species distributions: biotic interactions (e.g. competition, predation), abiotic components (e.g. climate, elevation) and dispersal process. While various ecological factors have been considered, less attention has been given to the problem of understanding the interaction between dispersal and distinct ecological factors in shaping multi-species ecosystems. By employing a mathematical model consisting of biotic interactions, environmental suitability and dispersal components, the combined influences between dispersal, biotic interactions and environmental factors on community assembly are examined. Our analysis shows the conditions under which species coexistence and priority effects occur as dispersal intensity changes. In particular, we employ numerical continuation methods and techniques from dynamical systems to demonstrate the existence of different dynamics in our model e.g. stable steady-state (or attractor) and alternative stable states. We also observe the occurrence of transcritical and saddle-node bifurcations, which can determine the overall dynamics and the stability of community compositions.