Ordination diagram (PCA) of proportion of the number of alien and native species in the river ports. The first two axes explain 99% of the total variation, individual regions account for 33% of variation. Circles = ports, squares = countries; closed symbols = ports and regions on the Elbe-Vltava waterway; open symbols = ports and regions on the Danube waterway.

  Part of: Jehlík V, Dostálek J, Frantík T (2019) Alien plants in Central European river ports. NeoBiota 45: 93-115. https://doi.org/10.3897/neobiota.45.33866