No consistent pollinator-mediated impacts of alien plants on natives

The introduction of an alien plant is widely assumed to have negative consequences for the pollinator-mediated fitness of nearby natives. Indeed, a number of studies, including a highly cited meta-analysis, have concluded that the trend for such interactions is ompetitive. Here we provide evidence that publication bias and study design have obscured our ability to ssess the pollinator-mediated impacts of alien plants. In a meta-analysis of 76 studies, we demonstrate that alien/native status does not predict the outcome of pollinator-mediated interactions among plants. oreover, we found no evidence that similarity in floral traits or phylogenetic distance between species pairs influences the outcome of pollinator-mediated interactions. Instead, we report that aspects of study design, such as distance between the control and nearest neighbour, and/or the arrangement of study plants better predict the impact of a neighbour than does alien/native status. Our study sheds new light on t...