Predictor Importance Values for bur oak (Quercus macrocarpa)

Predictor Name	Importance Score	Rank
Annual precipitation (mm)	20.24	11
Mean May-September precipitation (mm)	22.22	3
Mean annual temperature (°C)	10.64	40
Mean May-September temperature (°C)	12.07	39
Mean temperature of coldest month (°C)	15.85	30
Mean temperature of warmest month (°C)	12.28	38
Annual aridity index	18.59	17
Minimum elevation	20.7	8
Maximum elevation	23.64	1
Average elevation	15.88	28
Median elevation	19.74	14
Range of elevation	16.5	25
Elevation coefficient ofvariation	21.4	6
Elevation standard deviation	21.78	5
Annual daylength coefficient of variation	12.34	37
Total available water capacity (cm, to 150 cm)	17.31	22
Total available water supply (cm, to 150 cm)	16.26	26
Depth to water table (cm)	21.24	7
Soil permeability rate (cm/hr)	20.54	9
Soil calcium carbonate (% by weight)	18.76	15
Soil cation-exchange capacity	17.46	21
Soil pH	17.48	20
Soil bulk density (g/cm3)	15.71	31
Organic matter content (% by weight)	12.75	36
Potential soil productivity	16.06	27
Soil erodibility factor, rock fragment free	20.29	10
Soil erosion by wind (tons/acre/year)	18	18
Percent soil passing sieve No. 10 (coarse)	20.13	12
Percent soil passing sieve No. 200 (fine)	14.28	32
Percent clay (< 0.002 mm size)	15.87	29
Percent sand (< 0.002 mm size)	18.73	16
Percent silt (< 0.002 mm size)	17.89	19
Percent of texture clayey	13.14	33
Percent of texture loamy	16.65	24
Percent of texture sandy	12.84	35
Percent of texture other	16.72	23
Alfisol (%)	21.91	4
Aridisol (%)	-1	45
Entisol (%)	10.16	43
Histosol (%)	10.44	41
Inceptisol (%)	19.79	13
Mollisol (%)	22.45	2
Spodosol (%)	13.14	34
Ultisol (%)	10.43	42
Vertisol (%)	6.17	44