Figure 4. Results of Hot Spot Analysis showing statistically significant spatial clusters of non-native taxa within highland areas in Iceland (color scale—see details on the figure): 1: around Mývatn lake including Rejkjahlið, Námafjall, Krafla volcano; 2: Viðidalur and Vegaskarð, 3: areas W from Vatnajökull glacier (including i.e. Landmannalaugar and Jökulheimar); 4: highland areas bordering with the S part of Skagafjörður.

Occurrences of non-native plant taxa were marked with green points.