Delaunay triangulation plot based on the investigated lakes. The red squares indicate triangles of high dissimilarity (i.e. larger than mean + one standard deviation) between the three corner sampling sites. Community dissimilarities were calculated based on wheighted distances using the distance function x=((1-distance)/maximal triangle leg). The areas of high dissimilarity occur nearly exclusively along mountain ranges, in particular along the Alpes, the Pyrenees, the High Tatras, the Carpathian mountains and the Sierra Nevada.