Predictor Importance Values for red maple (Acer rubrum)

Predictor Name	Importance Score	Rank
Annual precipitation (mm)	42.54	3
Mean May-September precipitation (mm)	40.61	5
Mean annual temperature (°C)	28.31	34
Mean May-September temperature (°C)	28.27	35
Mean temperature of coldest month (°C)	33.4	22
Mean temperature of warmest month (°C)	36.44	15
Annual aridity index	34.14	18
Minimum elevation	32.29	24
Maximum elevation	40.3	8
Average elevation	28.66	31
Median elevation	33.99	19
Range of elevation	30.59	28
Elevation coefficient ofvariation	44.2	2
Elevation standard deviation	33.08	23
Annual daylength coefficient of variation	27.56	37
Total available water capacity (cm, to 150 cm)	35.6	17
Total available water supply (cm, to 150 cm)	39.85	9
Depth to water table (cm)	48.32	1
Soil permeability rate (cm/hr)	39.16	11
Soil calcium carbonate (% by weight)	31.81	25
Soil cation-exchange capacity	30.9	27
Soil pH	40.61	6
Soil bulk density (g/cm3)	39.49	10
Organic matter content (% by weight)	28.08	36
Potential soil productivity	33.65	21
Soil erodibility factor, rock fragment free	31.18	26
Soil erosion by wind (tons/acre/year)	40.43	7
Percent soil passing sieve No. 10 (coarse)	27.36	38
Percent soil passing sieve No. 200 (fine)	28.5	33
Percent clay (< 0.002 mm size)	28.63	32
Percent sand (< 0.002 mm size)	29.7	29
Percent silt (< 0.002 mm size)	33.95	20
Percent of texture clayey	23.92	40
Percent of texture loamy	37.61	14
Percent of texture sandy	37.85	13
Percent of texture other	28.67	30
Alfisol (%)	38.4	12
Aridisol (%)	1.36	45
Entisol (%)	15.8	43
Histosol (%)	21.44	42
Inceptisol (%)	35.77	16
Mollisol (%)	40.94	4
Spodosol (%)	24.28	39
Ultisol (%)	22.79	41
Vertisol (%)	15.27	44