Table 2.

Significant social and biophysical factors affecting variation in mean annual growth increment of sampled street trees. Significance codes: 0 (***), 0.001 (**), 0.01 (*). Interaction effects are noted (+).

Mean annual growth increment regression coefficients	Estimate	P-value
Street tree mean annual increment (Adjusted R-squared = 0.2031)
Tree age	−0.04911	<0.0001 ***
Shade trees	0.1025	0.0003 ***
Neighborhood resident groups	0.2028	0.0063 **
Group size (# participants during planting year)	0.0058	0.0056 **
Existing % canopy cover	0.0033	0.0055 **
Tree age + Group longevity (total # years active)	0.0031	0.0231 *
Yard tree mean annual increment (Adjusted R-squared = 0.3491)
Tree age	−0.0654	0.0002 ***
Shade trees	0.3613	<0.0001 ***
Group longevity (# years active as of planting year)	−0.1457	0.0038 **
Group size (average # participants)	0.0231	<0.0001 ***
Social service/non-profit groups	0.3244	0.0017 **
Group longevity + Tree age	0.0170	0.0031 **
Park tree mean annual increment (Adjusted R-squared = 0.4728)
Tree age	−0.0658	<0.0001 ***
Ornamental trees	0.5840	0.0004 ***
Ornamental trees + Existing % canopy cover	−0.0280	<0.0001 ***
Vacant lot tree mean annual increment (Adjusted R-squared = 0.2702)
Tree age	−0.0927	<0.0001 ***
Shade trees	0.2407	0.0080 **
Group experience (# trees planted as of planting year)	0.0208	0.0263 *
Group longevity (total # years active)	0.0571	0.0509
Neighborhood resident groups	−0.2650	0.0126 *