Fig. 2.

Surface materials governed the functional traits of pier surface microbiomes. a Two-way hierarchical clustering of all genes identified in the contigs of each sample. Genes that are present or absent are indicated by dark and light blue colors, respectively. Genes (column) were hierarchically clustered based on their presence/absence in the samples. The four gene clusters of the vertical dendrogram are highlighted. b Principal coordinate analysis of the binary Jaccard distance based on the presence/absence of genes in the surface microbiomes. Each point represents a sample