. 2014 Feb 7;9(2):e86042. doi: 10.1371/journal.pone.0086042

Table 8. Regressions of foliar variables versus stand age (years)/species successional status (years).

Foliar variables	Combined	Stand age	Successional status
Linear regression models and model comparisons
N:P	0.05 (8) 260***	0.01 (2) 261 NS	0.05 (15) 261***
		14***	1 NS
C:N	0.01 (2) 256 NS	0.00 (1) 257 NS	0.01 (4) 257*
		4	0 NS
δ¹⁵N	0.24 (43) 260****	0.18 (57) 261****	0.22 (74) 261****
		23****	9**
δ¹³C	0.20 (33) 258****	0.01 (3) 258 NS	0.17 (52) 258****
		31.3****	5.39*
Standardized slope values
N:P	−0.57 NS/1.90***	NS	0.62
C:N	NS	NS	−1.65
δ¹⁵N	−0.33/−0.52**	−0.66	−0.73
δ¹³C	0.02**/−0.07**	NS	−0.05

Statistics provided are Adj-R ² (F) df and P-value. Model comparisons are conducted using the F-test in R and P-values are presented as: blank <0.1, *<0.05, **<0.01, ***<0.001, ****<0.0001.