Predictor Importance Values for northern red oak (Quercus rubra)

Predictor Name	Importance Score	Rank
Annual precipitation (mm)	36.31	6
Mean May-September precipitation (mm)	38.72	2
Mean annual temperature (°C)	34.21	9
Mean May-September temperature (°C)	36.28	7
Mean temperature of coldest month (°C)	31.06	17
Mean temperature of warmest month (°C)	37.49	4
Annual aridity index	31.96	14
Minimum elevation	24.61	35
Maximum elevation	24.73	34
Average elevation	22.08	37
Median elevation	25.51	32
Range of elevation	34.31	8
Elevation coefficient ofvariation	32.94	12
Elevation standard deviation	38.04	3
Annual daylength coefficient of variation	28.51	24
Total available water capacity (cm, to 150 cm)	29.87	23
Total available water supply (cm, to 150 cm)	25.74	30
Depth to water table (cm)	42.3	1
Soil permeability rate (cm/hr)	30.05	22
Soil calcium carbonate (% by weight)	27.87	25
Soil cation-exchange capacity	31	18
Soil pH	25.9	29
Soil bulk density (g/cm3)	33.47	11
Organic matter content (% by weight)	30.68	20
Potential soil productivity	27.31	27
Soil erodibility factor, rock fragment free	25.09	33
Soil erosion by wind (tons/acre/year)	34.19	10
Percent soil passing sieve No. 10 (coarse)	30.2	21
Percent soil passing sieve No. 200 (fine)	31.16	16
Percent clay (< 0.002 mm size)	27.45	26
Percent sand (< 0.002 mm size)	25.65	31
Percent silt (< 0.002 mm size)	30.86	19
Percent of texture clayey	19.13	40
Percent of texture loamy	26.83	28
Percent of texture sandy	31.63	15
Percent of texture other	21.95	38
Alfisol (%)	32.84	13
Aridisol (%)	-1.24	45
Entisol (%)	12.91	43
Histosol (%)	18.5	41
Inceptisol (%)	37.4	5
Mollisol (%)	22.18	36
Spodosol (%)	16.25	42
Ultisol (%)	19.82	39
Vertisol (%)	11.88	44