Table 1.

Multiple regression analysis of soil C and N responses as a function of the first 3 principal components (PC) axes that describe litter chemical composition

Soil response	PC axis	Slope (SE)	R2	t	P
Total CO2 respired	PC1	163.7 (5.9)	0.262	27.7	<0.0001
	PC2	−292.7 (7.1)	0.609	−41.2	<0.0001
	PC3	134.1 (8.9)	0.087	15.1	<0.0001
Net N mineralization	PC1	0.02 (0.03)	0.008	0.74	0.46
	PC2	0.25 (0.02)	0.275	10.8	<0.0001
	PC3	−0.42 (0.04)	0.223	−10.8	<0.0001
Microbial biomass N	PC1	0.02 (0.02)	0.066	0.68	0.50
	PC2	0.04 (0.02)	0.007	2.3	<0.05
	PC3	−0.04 (0.03)	0.001	−1.3	0.19

Multiple regression models contained scores from the first 3 PC axes, and significant interaction terms among PC axes, which are not shown here. Data for total CO₂ respired were not transformed, and net N mineralization and microbial biomass N data were natural log-transformed prior to analysis.