Fig. 3

A Relative abundance of the 25 most abundant ASVs in each sample (N = 395) shown clustered at genus level (bar plots). The coloured bars at the circumference of the iris plot denote biogeographic region for each biofilm sample. Iris plots for individual ecological groups of taxa are shown in the Supplementary Fig. S7. B Composition of the core microbiome for biofilms in each biogeographic region (N = 395). The core microbiome was defined as comprising ASVs with ≥ 95% prevalence and > 1% relative abundance. Small pie charts indicate the core versus variable microbiome, and large pie charts show the taxonomic composition of ASVs in each core microbiome clustered at genus level