Clonal diversity amongst island populations of alien, invasive Lemna minuta kunth

Invasive alien species can negatively impact on newly colonised ecosystems. Thus, it is important to understand factors that facilitate invasiveness. Genetic diversity will enable a species to exploit a variety of environmental conditions. Yet, the process of dispersal to a new ecosystem will commonly create a genetic bottleneck and, hence, result in low diversity. Here we explored variability at genetic and morpho-physiological level of island of Ireland populations of alien, invasive Lemna minuta. A comparison of nine clones of L. minuta with nine clones of co-generic, native Lemna minor shows similar levels of genetic diversity across both species. Thus, the successful invasion of Ireland by L. minuta is associated with substantial, intraspecific diversity. It is hypothesised that increased biodiversity is due to repeated invasions from continental Europe, which occurred despite the geographic barriers separating the island from mainland Europe.