Table 2.

Multiple regressions between potential soil respiration at 11 °C, and soil chemistry, bacterial community structure, and root density in soils from different depths in control and decadal in situ deep-thaw plots

				Control samples		Deep-thaw samples		Deep-thaw (treatment) effect
	AICc	R 2	Variable	Slope (±SE)	p	Slope (±SE)	p	Intercept (±SE)	p
Predictors of bulk respiration (per g DW)
Soil × treatment	48.30	0.848	Soil PC1	0.823 ± 0.074	< 0.001	−0.892 ± 0.126	< 0.001	−0.300 ± 0.146	0.066
(Soil + bacteria) × treatment	39.81	0.901	Soil PC1	0.687 ± 0.075	< 0.001	0.755 ± 0.119	< 0.001	−0.376 ± 0.123	0.012
			Bacterial PCo1	−1.176 ± 0.381	0.011	−1.344 ± 0.514	0.028
(Soil + root density) × treatment	49.15	0.871	Soil PC1	0.776 ± 0.080	< 0.001	0.896 ± 0.120	< 0.001	−0.451 ± 0.168	0.023
			Root density	0.341 ± 0.235	0.177	0.140 ± 0.086	0.138
(Root density + soil + bacteria) × treatment	46.84	0.903	Soil PC1	0.687 ± 0.078	< 0.001	0.775 ± 0.127	< 0.001	−0.392 ± 0.156	0.031
			Root density	0.011 ± 0.243	0.964	0.052 ± 0.092	0.589
			Bacterial PCo1	−1.165 ± 0.472	0.036	−1.169 ± 0.611	0.092
Bacteria × treatment	86.82	0.538	Bacterial PCo1	−3.079 ± 0.772	0.002	−2.830 ± 0.811	0.006	−0.778 ± 0.243	0.009
Predictors of intrinsic respiration (per g SOM)
Soil × treatment	97.65	0.367	Soil PC1	0.716 ± 0.226	0.009	−0.445 ± 0.184	0.036	−0.161 ± 0.295	0.597
(Soil + bacteria) × treatment	93.33	0.539	Soil PC1	0.402 ± 0.240	0.125	−0.268 ± 0.182	0.176	−0.195 ± 0.265	0.477
			Bacterial PCo1	−2.826 ± 1.198	0.040	1.744 ± 0.787	0.054
(Soil + root density) × treatment	101.93	0.408	Soil PC1	0.657 ± 0.247	0.024	−0.450 ± 0.178	0.032	−0.260 ± 0.358	0.484
			Root density	0.485 ± 0.723	0.518	−0.181 ± 0.128	0.192
(Root density + soil + bacteria) × treatment	100.16	0.549	Soil PC1	0.405 ± 0.245	0.133	−0.292 ± 0.195	0.172	0.054 ± 0.333	0.875
			Root density	−0.466 ± 0.766	0.558	−0.065 ± 0.141	0.656
			Bacterial PCo1	−3.314 ± 1.463	0.050	1.524 ± 0.939	0.144
Bacteria × treatment	92.45	0.456	Bacterial PCo1	−3.941 ± 1.051	0.003	2.251 ± 0.734	0.012	−0.228 ± 0.263	0.407

Soil soil PC1, Bacteria bacterial PCo1

All variables are scaled and centered before analyses; bold text denotes significant p-values (p < 0.05)