Table 2.

Mean Q ₁₀ and R ₁₀ values (± SE, n = 3) of soil respiration rates, extracellular enzyme activities [β‐glucosidase (BG), cellobiohydrolase (CBH), N‐acetyl‐glucosaminidase (NAG), leucine aminopeptidase (LAP), phenoloxidase (POX), and peroxidase (PEX)], substrate use efficiency and its components, mass‐specific respiration (Rmass), and gross N mineralization. Soil was incubated at temperatures ranging from 3 to 23 °C. (n.s. not significant; n.a. not analyzed)

Process	Q 10			R 10
	Control	Warmed	t‐Test	Control	Warmed	t‐Test
Soil respiration
Intact soil cores (μmol CO2 m−2 s−1)	2.56 ± 0.04	2.52 ± 0.06	n.s.	2.30 ± 0.11	2.77 ± 0.23	n.s.
Sieved soil cores (μmol CO2 m−2 s−1)	2.45 ± 0.04	2.45 ± 0.06	n.s.	2.34 ± 0.29	2.31 ± 0.15	n.s.
Roots (μmol CO2 m−2 s−1)	1.85 ± 0.02	1.81 ± 0.05	n.s.	0.73 ± 0.02	0.73 ± 0.24	n.s.
Extracellular enzyme activities
BG (pmol g−1 dry soil s−1)	2.06 ± 0.06	1.95 ± 0.18	n.s.	12.6 ± 1.5	17.3 ± 0.8	n.s.
CBH (pmol g−1 dry soil s−1)	1.46 ± 0.04	1.49 ± 0.08	n.s.	66.0 ± 5.5	71.4 ± 4.7	n.s.
NAG (pmol g−1 dry soil s−1)	1.48 ± 0.07	1.56 ± 0.13	n.s.	172 ± 18.3	142 ± 8.9	n.s.
LAP (pmol g−1 dry soil s−1)	1.61 ± 0.03	1.66 ± 0.05	n.s.	33.7 ± 4.0	27.2 ± 1.0	n.s.
POX (pmol g−1 dry soil s−1)	4.77 ± 0.24	4.21 ± 0.32	n.s.	20.1 ± 7.0	16.6 ± 1.5	n.s.
PEX (pmol g−1 dry soil s−1)	2.82 ± 0.19	2.85 ± 0.10	n.s.	101 ± 29.4	78.5 ± 5.3	n.s.
Ratio of C : N acquisition	n.s.	n.s.	n.a.	n.s.	n.s.	n.a.
Substrate use efficiency
13C respiration (pmol C g−1 dry soil s−1)	1.47 ± 0.04	1.47 ± 0.02	n.s.	11.2 ± 0.7	10.2 ± 0.8	n.s.
13C incorp. (pmol C g−1 dry soil s−1)	n.s.	n.s.	n.a.	n.s.	n.s.	n.a.
Substrate use efficiency	0.88 ± 0.01	0.84 ± 0.03	n.s.	0.72 ± 0.02	0.74 ± 0.01	n.s.
Microbial C (μmol g−1 dry soil)	n.s.	n.s.	n.a.	n.s.	n.s.	n.a.
SOM respiration (pmol C g−1 dry soil s−1)	2.75 ± 0.17	2.54 ± 0.23	n.s.	45.3 ± 7.83	42.4 ± 10.1	n.s.
Rmass (nmol C g−1 Mic C s−1)	2.62 ± 0.25	2.45 ± 0.19	n.s.	37.1 ± 5.55	42.0 ± 11.4	n.s.
Gross nitrogen processes
N mineralization	n.s.	n.s.	n.a.	n.s.	n.s.	n.a.