Soil disturbances can suppress the invasion of alien plants under plant–soil feedback

Understanding biotic and abiotic ecological processes that affect the invasion of alien plants is important for the successful management of terrestrial ecosystems. In this study, we investigated the effect of disturbances on invasive plants depending on whether soil biota is also disturbed. Disturbances that removed only aboveground biota did not affect the invasion condition, coexistence, or frequency after invasion, but did increase the growth rate of the invader when it was rare. In contrast, if disturbances affected both aboveground and belowground biota, the invader required a higher competitive ability compared to the situation of no disturbances, implying a suppression of alien species. As the probability of disturbance increased, the mean frequency of alien species either increased or decreased depending on its competitive ability. In conclusion, plant–soil feedback strongly affects the invasion of alien plants when the environment is subjected to physical disturbances.