Table 3.

Results from mixed models evaluating the statistical significance of effects of trenching and layer on relative abundances of functional guilds of fungi, fungal biomass, ¹⁵N relative abundance and activities of selected extracellular enzymes in organic soil profiles of a boreal forest 1 year (fungal guilds, biomass and δ¹⁵N) and 4 years (all variables except δ¹⁵N) after disruption of root connections by trenching

Variable	trenching		layer		trenching x layer
	F df	P	F df	P	F df	P
Fungal biomass (µg ergosterol gOM−1):
1 year after trenching	0.001,38	0.97	8.85,57	<0.0001	1.85,57	0.14
4 years after trenching	11.41,16	0.004 (−)	4.85,54	0.001	3.05,54	0.02
Fungal guilds (% of ITS markers), 1 year after trenching:
Ectomycorrhizal fungi	14.31,22	0.001 (−)	9.05,58	<0.0001	1.45,58	0.23
Root basidiomycetes	1.81,23	0.19	7.45,57	<0.0001	1.25,57	0.33
Root ascomycetes	3.71,24	0.07	18.95,59	<0.0001	2.95,59	0.02
Litter Agaricomycetes	0.31,13	0.63	16.95,53	<0.0001	0.25,53	0.98
Litter ascomycetes	7.21,27	0.01 (+)	113.85,52	<0.0001	0.65,52	0.74
Yeasts and moulds	5.31,27	0.03 (+)	43.25,57	<0.0001	1.55,57	0.20
Fungal guilds (% of ITS markers), 4 years after trenching:
Ectomycorrhizal fungi	147.81,31	<0.0001 (−)	29.95,60	<0.0001	8.45,60	<0.0001
Root basidiomycetes	3.81,24	0.06	6.55,55	<0.0001	1.25,55	0.34
Root ascomycetes	0.01,23	0.95	61.15,59	<0.0001	1.15,59	0.36
Litter Agaricomycetes	0.91,18	0.37	43.15,54	<0.0001	0.75,54	0.66
Litter ascomycetes	0.31,33	0.60	115.65,48	<0.0001	1.25,48	0.31
Yeasts and moulds	6.81,22	0.02 (+)	38.25,58	<0.0001	0.95,58	0.46
Enzyme activities (nmol gOM−1 s−1), 4 years after trenching:
Total peroxidase	59.31,30	<0.0001 (− )	8.94,56	<0.0001	6.34,56	0.0003
Mn peroxidase	20.91,31	<0.0001 ( −)	1.55,64	0.22	4.15,64	0.003
Laccase	0.11,27	0.82	47.35,65	<0.0001	1.55,65	0.20
BG	3.31,24	0.08	8.35,65	<0.0001	0.45,65	0.82
CBH	6.31,23	0.02 (−)	13.15,63	<0.0001	1.05,63	0.43
NAG	10.41,24	0.004 (−)	10.75,67	<0.0001	1.55,67	0.19
CiBH	6.81,25	0.02 (− )	4.45,66	0.002	0.75,56	0.64
δ15N, 1 year after trenching:
	0.31,20	0.59	179.65,68	<0.0001	1.85,68	0.13

Significant values (P < 0.05) are presented in bold and the direction of response is indicated in parenthesis. Degrees of freedom (df) for F values are given as subscripts (effect, error) after each F value