Table 3. Regressional relationships of SOC and STC determined between by the elemental analyzer and by the modified Walkley-Black (MWB) method in 9 soil types (accroding to the GSCC, Genetic Soil Classification of China) on the Tibetan Plateau using a linear regression passing through the origin.

Soil type		SOCCNS vs. SOCMWB			SOCCNS vs. STC
	n	Slope	R2	P	Slope	R2	P
Felty soils	139	1.047	0.975	<0.001	0.963	0.987	<0.001
Meadow soils	80	1.089	0.988	<0.001	0.823	0.944	<0.001
Frigid frozen soils	20	1.091	0.986	<0.001	0.769	0.973	<0.001
Castanozems	100	1.106	0.980	<0.001	0.802	0.970	<0.001
Dark felty soils	36	1.131	0.952	<0.001	0.968	0.917	<0.001
Cold calcic soils	39	1.135	0.984	<0.001	0.745	0.952	<0.001
Chernozems	20	1.165	0.975	<0.001	0.715	0.982	<0.001
Brown pedocals	38	1.213	0.986	<0.001	0.596	0.986	<0.001
Frigid calcic soils	240	1.215	0.983	<0.001	0.672	0.913	<0.001

SOC_CNS, the difference between STC and SIC; SOC_MWB, SOC determined by the MWB method.