Figure 5. Proportions of identified phyla and classes in the four sampling cases.

The legend on the right shows the color codes of the phyla, or, for three of them, the occurring classes listed within boxes in the legend as follows: Bacteroidetes (green tints); Firmicutes (blue tints); Proteobacteria (purple tints). The larger central pie chart shows the situation of the constant core of taxa shared by all four cases, constituting the putative Sardinia air microbiome, supposedly independent from place and weather conditions. The four inner-diamond small pies show the taxa shared pairwise by the ‘locality pairs’ (Cagliari or Sassari) or by the ‘whether condition pairs’ (dust or control). The four outer-corners small pies show the unshared (specific) fraction of each case. Pies diameters not drawn in scale with sequences frequency number.