<i>Carduus nutans</i> and <i>Carduus acanthoides</i> , two invasive thistle species, strongly rebound from disturbances

Abstract The establishment and spread of invasive species are often facilitated by disturbance. Once established, however, individuals of invasive species are themselves subject to damage from disturbance; their responses to these perturbations could be an important component of invasive species' ability to persist in local environments. We quantified the impact of physical disturbances on individual invasive plants by conducting a field experiment to examine the effect of three physical disturbances (simulated hail, partial burial with gravel, and simulated trampling) interacting with two levels of warming (warmed and ambient) on the performance of two non‐native, invasive thistle species, Carduus nutans L. and Carduus acanthoides L. We found complete recovery from all three physical disturbance treatments, regardless of warming treatment, for both maximum plant height and number of stems (which can increase in response to physical damage due to loss of apical dominance). Physical disturbance and warming had no effect on the number of capitula produced by C. nutans ; however, simulated trampling interacted with warming to reduce the production of capitula by 45% in C. acanthoides . This was the lone significant change to any measured life history trait of either species in the entire experiment. While disturbance is generally considered to be both a cause and a consequence of invasion, our results demonstrate that established individuals of both species also have a strong capacity to rebound from subsequent disturbance. This suggests that within‐generation, individual response to disturbance could be an important component of an invasive species' ability to persist in the environment.