Table 2: Pearson correlation coefficients (r) of environmental variables with site index and overfitted regression significance levels () for a site index model with all independent environmental variables by species for stands sampled in the Southern Appalachian Mountains of North Carolina, USA.
Environmental
Pearson correlation (r)
Variable significance ()
Red oak
Yellow-poplar
A-horizon thickness
0.82
0.89
Solum thickness
0.78
0.1
Elevation
0.16
0.85
Aspect
0.93
0.61
Gradient
0.5
0.1
Landform index
0.02
0.01
Model significance
0.05
0.05
a
Pearson correlation coefficient was not significant at
bPearson correlation coefficient was significant at .