Table 1. One-way ANOVA and Duncan grouping method to assess β-diversity at the levels of technical replicates, biological replicates and treatments based on the combined OTUs from both forward and reverse primers.

	Data sizea	With singletons				Singletons removed
		Sørensen		Bray-Curtis		Sørensen		Bray-Curtis
		β-Diversityb	Significancec	β-Diversityb	Significancec	β-Diversityb	Significancec	β-Diversityb	Significancec
Technical replicate	42	0.756	c	0.763	c	0.734	c	0.475	b
Biological replicate	322	0.814	b	0.866	a	0.798	b	0.533	a
Warming	196	0.83	a	0.854	b	0.815	a	0.526	a
Clipping	196	0.834	a	0.853	b	0.82	a	0.525	a

Abbreviation: ANOVA, analysis of variance.

^aData sizes (n) are the number of data points of the pairwise comparisons within the technical replicates, biological replicates or treatments.

^bWe calculate two popular β-diversity dissimilarity measurements, Sørensen and Bray-Curtis, in which Sørensen dissimilarity is based on OTUs richness and Bray-Curtis dissimilarity takes OTUs abundance into account.

^cSignificance at [pr(>F)]<0.05, using Duncan grouping method is shown. a, b and c represent the significance of β-diversity differences between technical replicates, biological replicates and treatments. a marks the highest β-diversity, the one less than the highest but not significant is still marked with a, then the ones significantly lower than the highest is marked with b or c.