Table 5. Pearson’s correlation of site index and soil physical and chemical properties of the soil horizons in Quercus mongolica stands.

Variables	Site index	Sand (%)	Silt (%)	Clay (%)	PH	OM	TN	C/N	P2O5	Ca2+	Mg2+	K+	Na+	CEC
Site index	1.00
Sand (%)	0.07	1.00					A horizon
Silt (%)	−0.17	−0.84	1.00
Clay (%)	0.12	−0.58	0.05	1.00
pH	−0.17	−0.26	0.46	−0.21	1.00
OM	−0.01	0.09	−0.11	0.00	−0.28	1.00
TN	0.05	−0.02	−0.08	0.16	−0.43	0.79	1.00
C/N	−0.03	0.14	−0.01	−0.25	0.19	0.43	−0.13	1.00
P2O5	0.08	−0.03	−0.20	0.36	−0.47	0.49	0.70	−0.17	1.00
Ca2+	0.02	−0.06	0.17	−0.13	0.43	0.08	0.09	0.03	0.20	1.00	0.83
Mg2+	−0.01	−0.11	0.21	−0.11	0.41	0.02	0.03	0.00	−0.01	0.83	1.00
K+	0.02	−0.06	0.26	−0.28	0.27	0.19	0.11	0.22	−0.09	0.42	0.41	1.00
Na+	−0.02	−0.17	0.11	0.14	0.05	0.03	0.06	0.01	0.08	0.01	0.05	0.08	1.00
CEC	−0.09	−0.12	0.15	−0.01	−0.15	0.79	0.77	0.16	0.39	0.13	0.13	0.26	0.05	1.00
Variables	Site index	Sand (%)	Silt (%)	Clay (%)	PH	OM	TN	C/N	P2O5	Ca2+	Mg2+	K+	Na+	CEC
Site index	1.00
Sand (%)	−0.01	1.00					B horizon
Silt (%)	−0.09	−0.82	1.00
Clay (%)	0.13	−0.69	0.15	1.00
pH	−0.25	0.05	0.31	−0.47	1.00
OM	0.11	−0.31	0.16	0.33	−0.27	1.00
TN	0.17	−0.43	0.20	0.49	−0.48	0.87	1.00
C/N	−0.01	0.18	−0.03	−0.27	0.35	0.12	−0.21	1.00
P2O5	0.10	−0.34	0.09	0.47	−0.43	0.66	0.80	−0.14	1.00
Ca2+	0.09	−0.22	0.15	0.19	0.01	0.29	0.37	−0.05	0.51	1.00
Mg2+	−0.05	−0.20	0.21	0.07	0.22	0.10	0.16	−0.04	0.27	0.68	1.00
K+	−0.24	−0.14	0.19	−0.01	0.20	0.04	0.03	0.07	0.05	0.25	0.39	1.00
Na+	−0.05	−0.16	0.18	0.05	0.08	0.03	0.03	0.04	−0.01	0.05	0.14	0.27	1.00
CEC	0.10	−0.43	0.37	0.28	−0.14	0.82	0.83	−0.05	0.57	0.36	0.28	0.13	0.04	1.00