Contrasting effects of phylogenetic relatedness on plant invader success in experimental grassland communities

1. Identifying the factors determining the success of invasive species is critical for management of biological invasions. Darwin's naturalization conundrum states that exotic species closely related to natives should be successful because of a shared affinity for local environmental conditions, but at the same time close relatives often compete more intensively, limiting ‘niche’ opportunities for the invaders. Previous studies have generally considered these two ‘opposing’ hypotheses as mutually exclusive, yet evidence for both of them abounds, indicating a practical dilemma for management of biological invasions. 2. In this study, we sowed the seeds of the invasive exotic Ambrosia artemisiifolia L. into 369 experimental plant communities to mimic an introduction of the exotics into a series of new habitats. We further linked the establishment and growth performance of the invader in these experimental communities to the phylogenetic relatedness between the invader and the community re...