Table 1. Degree of correlation between four site variables and the growth Ratio Index (dbh/age). Summary of the PROC RSQUARE SAS procedure evaluating various combinations of models and the PROC GLM SAS procedure to determine the intercept (a) and the coefficients (b, c, d) of the selected models. These models were selected using the R² value, Mallow’s C(p) statistic and the number of variables being considered within each model. Model form: GRI= a + b*(variable 1) + c*(variable 2) + d* (variable 3).

Model	Intercept	Variables	R²	Cp	#Obs.
	(coefficients)
All	0.433**	^{sdwk set cp} (-0.001) (0.001) (0.018)	0.01	3.00	540
Acer platnoides	0.252**	^{sdwk set cp}^ (-0.009) (0.001) (0.069)^	0.14**	3.05	79
Acer rubrum	0.308**	^sdwk ^** set ps (0.018)^* (0.003) (-0.001)	0.14**	3.70	67
Acer saccharinum	0.510**	^{ps cp} (-0.002) (0.072)	0.04	1.92	51
Acer saccharum	0.404**	^{sdwk ps cp} (0.001) (0.003) (-0.005)	0.01	3.00	65
Fraxinus sp.	0.505**	^{sdwk set cp} (-0.006) (0.003) (-0.044)	0.09^*	3.00	61
Gleditsia Triacanthos	0.289**	^{sdwk set cp}^* (0.008) (0.001) (0.092)	0.14**	3.40	47
Platanus x acerifolia	0.416**	^{sdwk set cp} (0.007) (0.0005) (0.055)	0.05	3.09	67
Quercus palustris	0.885**	^{sdwk set cp} (0.005) (-0.004) (-0.066)	0.07^*	3.04	66
Tilia sp.	0.529**	^{sdwk set cp}^* (0.007) (0.002) (0.089)	0.14^*	3.02	37

↵sdwk = sidewalk extension
set = house setback
cp = competition
ps = pervious surface
↵* * =significant at 5%
↵** ** =significant at 1 %