Alpha-diversity (circles) of belowground fungal communities associated with Norway spruce along an altitudinal gradient in the Bavarian Alps.

Each sample is labelled according to the age of the host tree ('O' for old, 'Y' for young individuals), the altitude ('I','II','III', see Fig 1). The three replicates for each sample are plotted together in a panel with different colors ('1': red, '2': yellow, '3': green). For each sample, Hill numbers for different values of q (order of diversity) were calculated, giving different weights to species abundances. Green dotted lines show minimum and maximum across all samples, pink dotted lines show the median.