Fig. 3

Microbial community composition and core floodplain microbiome. a Taxa at the phylum or class level detected across samples and floodplains, samples are in numerical order (Table S1, Additional File 1:) from the upstream to the downstream floodplain. b Taxonomic composition of genomes in the core floodplain microbiome (core), genomes associated with 1 floodplain (one site), and genomes associated with two floodplains (two sites). UMAP showing clustering of Hellinger-transformed genome abundances of c genomes in the core floodplain microbiome (n = 42; in teal) and genomes not in the core floodplain microbiome (n = 242; red), and d overlay of the coefficient of variation (ratio of standard deviation to the mean) of genome abundances across samples, and e overlay of genomes associated with individual, pairs, or all floodplains based on an Indicator Species Analysis (ISA). Genomes that were present in 89 samples or more (teal) were not associated with any particular floodplain by ISA (group 7 in brown) and their abundance displayed a low coefficient of variation across samples. ISA genome associations: with floodplain G (1), with floodplain L (2), with floodplain Z (3), with both floodplain G and floodplain L (4), with both floodplain G and floodplain Z (5), with both floodplain L and floodplain Z (6), and not associated with any particular floodplain (7)