Table 4 ANOVA results for taxonomic rank “order”. Tukey’s multiple comparison test results after 5000 replications significant p-values (α = 0.01) were averaged and counted for Tukey’s groups (Boston-New York-Sacramento). In general terms, when comparing two cities if letters (‘a’, ‘b’ and ‘c’) are all the same, we conclude that the means are not significantly different. If the letters are different we conclude city means are significantly different in terms of bacterial abundances. As for example, “order” enterobacteriales, shows minimum, average and maximum p-value out of 5000 replications, and 4967 times out of 5000 replications the three city means were found to be significantly different ‘a’-‘b’-‘c‘; 30 times Boston and New York mean bacterial abundances remain the same but Sacramento is different (‘a’-‘a’-‘b’) and only in 3 cases Boston, and Sacramento are the same but New-York (‘a’-‘b’-‘a’) is different deemed by Tukey’s multiple comparison test. Taxonomic rank names (“order”) are presented in the same order for all groups (‘a’-‘b’-‘c’, ‘a’-‘a’-‘b’, ‘a’-‘b’-‘b’, ‘a’-‘b’-‘a’)

Enterobacteriales

[8.45E-17, 3.08E-8, 1.46E-5]

a-b-c

Clostridiales

[1.75E-30, 2.42E-19, 3.13E-16]

Rhizobiales

[5.18E-16, 3.37E-6, 3.25E-4]

Pseudomonadales

[5.37E-15, 6.63E-6, 1.27E-3]

Xanthomonadales

[1.14E-16, 2.01E-11, 3.38E-9]

Flavobacteriales

[1.24E-20, 1.46E-14, 7.18E-12]

Vibrionales

[4.51E-19, 2.3E-13, 1.89E-11]

Sphingobacteriales

[8.56E-16, 1.41E-11, 1.7E-9]

Bacillales

[5.03E-19, 9.78E-14, 1.99E-11]

Alteromonadales

[8.15E-23, 1.22E-16, 4.13E-14]

Bacteroidales

[1.09E-26, 5.25E-18, 4.08E-15]

Rhodobacterales

[9.85E-8, 2.91E-4, 4.53E-3]

Pasteurellales

[2.74E-18, 1.04E-12, 2.15E-10]

Rickettsiales

[4.03E-9, 7.4E-4, 5.75E-3]

Lactobacillales

[4.54E-27, 2.6E-17, 5.45E-15]

Actinomycetales

[1.9E-7, 8.94E-4, 4.56E-3]

Burkholderiales

[6.92E-8, 1.26E-3, 5.4E-3]

Sphingomonadales

[1.76E-8, 9.08E-4, 3.62E-3]

Rhodospirillales

[2.34E-6, 6.66E-4, 2.78E-3]

Enterobacteriales

[6.64E-11, 6.3E-7, 8.58E-6]

a-a-b

Clostridiales

[2.6E-24, 6.04E-19, 3.07E-17]

Rhizobiales

[3.29E-8, 8.12E-5, 1.8E-3]

Pseudomonadales

[2.58E-8, 9.45E-5, 2.22E-3]

Xanthomonadales

[6.43E-17, 4.36E-11, 4.84E-9]

Flavobacteriales

[4.06E-21, 4.38E-14, 7.69E-12]

Vibrionales

[4.48E-20, 5.02E-13, 7.33E-11]

Sphingobacteriales

[1.01E-16, 4.25E-11, 3.17E-8]

Bacillales

[6.69E-20, 1.19E-13, 9.96E-11]

Alteromonadales

[1.87E-24, 3.04E-16, 7.47E-14]

Bacteroidales

[7.59E-28, 1.91E-17, 2.23E-14]

Rhodobacterales

[6.23E-8, 9.45E-4, 9.91E-3]

Pasteurellales

[3.69E-19, 2.08E-12, 3.97E-10]

Rickettsiales

[3.36E-7, 4.13E-3, 9.96E-3]

Lactobacillales

[1.14E-25, 1.13E-16, 6.48E-14]

Actinomycetales

[1.01E-5, 4.01E-3, 9.95E-3]

Burkholderiales

[2.04E-5, 4.94E-3, 9.74E-3]

Sphingomonadales

Rhodospirillales

[4.49E-4, 5.1E-3, 9.91E-3]

Enterobacteriales

a-b-b

Clostridiales

Rhizobiales

[4.35E-9, 4.86E-5, 4.36E-4]

Pseudomonadales

Xanthomonadales

Flavobacteriales

Vibrionales

Sphingobacteriales

Bacillales

Alteromonadales

Bacteroidales

Rhodobacterales

Pasteurellales

Rickettsiales

[3.84E-7, 2.83E-3, 9.99E-3]

Lactobacillales

Actinomycetales

[1.18E-5, 2.72E-3, 9.32E-3]

Burkholderiales

[6.45E-9, 2.92E-3, 10E-3]

Sphingomonadales

[1.63E-5, 3.33E-3, 9.99E-3]

Rhodospirillales

[5.42E-3, 7.22E-3, 10E-3]

Enterobacteriales

[6.46E-11, 6.52E-9, 1.94E-8]

a-b-a

Clostridiales

Rhizobiales

Pseudomonadales

[1.38E-12, 5.01E-6, 4.48E-4]

Xanthomonadales

Flavobacteriales

Vibrionales

Sphingobacteriales

Bacillales

Alteromonadales

Bacteroidales

Rhodobacterales

[9.6E-8, 1.02E-3, 9.81E-3]

Pasteurellales

Rickettsiales

[3.52E-4, 4.95E-3, 8.88E-3]

Lactobacillales

Actinomycetales

[1.01E-5, 3.83E-3, 9.88E-3]

Burkholderiales

[6.81E-3, 6.81E-3, 6.81E-3]

Sphingomonadales

[7.24E-5, 4.92E-3, 9.75E-3]

Rhodospirillales

[1.43E-6, 4.15E-3, 9.97E-3]