Figure 5.

Mapping of sampled sites for sporocarps in Western and Central Europe (for details see Additional file 2). Colour of circles indicates tree species; green: Alnus alnobetula; black: A. cordata; red = A. glutinosa; blue: A. incana. Large circles: at least three species sampled (sites visited for this study); small circles: one or two species sampled (occasional visits on sites or collections sent by correspondents).