PERMANOVA main tests of bacterial community composition based on Bray-Curtis dissimilarities of OTUs (16S ribosomal amplicon pyrosequencing; ‘no dilution’ and ‘serial dilution’).

1Significant results (p (perm)Displayed are tests for the factors ‘season’, ‘dilution’, ‘pH’ and their interactions and the partitioning of multivariate variation for ’no dilution’ and ‘serial dilution’ treatments. p-values were obtained using type III sums of squares and 999 permutations under the full model. d.f.: degrees of freedom, SS: sums of squares, Sq. root: square root of the component of variation attributable to that factor in the model, in units of Bray-Curtis dissimilarities.