TABLE 5.

Main effects on bacterial and fungal α-diversity (Richness and Shannon index) and β-diversity (Bray–Curtis dissimilarities) of forest sites (Chamoson, Neunkirch, Saillon), soil depths (soil layers: L1: 0–10 cm, L2: 15–25 cm, L3: 45–55 cm, L4: 75–85 cm, L5: 110–125 cm, L6: 140–155 cm, L7: 180–200 cm), tree genera (beech, oaks), and substrates (bulk soil, fine roots).

		α-diversity*
		Richness		Shannon		β-diversity+
	DF#	F	p	F	p	F	p
Bacteria:
Site	2	51.3	<0.001	17.5	<0.001	12.8	<0.001
Depth	6	16.8	<0.001	4.9	<0.001	5.7	<0.001
Tree	1	8.4	0.004	0.6	0.43	7.2	<0.001
Substrate	1	459	<0.001	288	<0.001	77.7	<0.001
Fungi:
Site	2	16.9	<0.001	1.7	0.18	8.7	<0.001
Depth	6	38.5	<0.001	4.8	<0.001	2.8	<0.001
Tree	1	8.8	0.003	142	<0.001	28.9	<0.001
Substrate	1	517	<0.001	444	<0.001	60.8	<0.001

*Effects of site, soil depth, tree genus, and substrate were assessed by analysis of variance (ANOVA).

⁺Effects of site, soil depth, tree species and substrate were assessed by permutational multivariate analysis of variance (PERMANOVA).

^#Values represent degrees of freedom (DF), the F-ratio (F), and the level of significance (p); significant values (p < 0.05) are in bold.