Ordination plot of qualitative environmental parameters. Each dot represents a sampled site. The size of the dots increases with L. hexapetala cover, considered as a continuous variable; reference measurements are provided in the legend. The colour of the dots also gets darker with increasing L. hexapetala % cover. Black crosses represent uninvaded sites where L. hexapetala cover = 0. The black arrow shows the post-hoc analysis result, indicating the direction in which L. hexapetala cover increases. The blue arrows indicate the direction of each environmental parameter. Acronyms: G = grain size; T = transparency; D = site disturbance level. For the category explanation of transparency and site disturbance level, see Suppl. material 2.