Table 2.

Pearson’s correlations (r) between community size (qAOA, qAOB, and AOA/AOB), nitrifying activity (NEA), and soil properties (OM, ${\text{N - NO}}_3^{-},{\text{N - NH}}_4^{+},$ pH, moisture and clay), calculated as average values per soil between September 2009 and October 2010.

	OM	${\text{N - NO}}_3^{-}$	${\text{N - NO}}_4^{+}$	pH	Moisture	Clay	qAOA	qAOB	AOA/AOB	NEA
OM	1	NS	NS	NS	*	NS	NS	NS	NS	NS
${\text{N - NO}}_3^{-}$	0.57	1	*	NS	NS	NS	NS	NS	NS	NS
${\text{N - NO}}_4^{+}$	0.55	0.74*	1	NS	NS	NS	NS	NS	NS	NS
pH	−0.44	−0.58	−0.23	1	NS	*	*	NS	NS	*
Moisture	0.76*	0.47	0.33	−0.09	1	NS	NS	NS	NS	NS
Clay	−0.12	−0.39	0.25	0.72*	−0.06	1	NS	NS	NS	NS
qAOA	0.17	−0.04	0.34	0.73*	−0.13	0.49	1	**	NS	*
qAOB	0.35	0.22	0.24	0.15	0.06	0.04	0.84**	1	NS	NS
AOA/AOB	0.10	−0.02	0.29	0.05	0.19	0.41	−0.06	−0.46	1	NS
NEA	0.16	−0.28	0.09	0.70*	−0.15	0.48	0.74*	0.45	0.41	1

NEA, potential nitrifying enzyme activity; AOA, ammonia oxidizing archaeal; AOB, ammonia oxidizing bacteria; NS, not significant; ***P < 0.001, **P < 0.01; *0.01 < P < 0.05. Values in bold are significant.