Predictor Importance Values for black walnut (Juglans nigra)

Predictor Name	Importance Score	Rank
Annual precipitation (mm)	27.55	3
Mean May-September precipitation (mm)	27.98	2
Mean annual temperature (°C)	27.47	4
Mean May-September temperature (°C)	23.95	12
Mean temperature of coldest month (°C)	25.39	7
Mean temperature of warmest month (°C)	29.12	1
Annual aridity index	23.65	13
Minimum elevation	15.37	40
Maximum elevation	20.23	28
Average elevation	21.68	22
Median elevation	23.37	15
Range of elevation	20.97	26
Elevation coefficient ofvariation	12.6	43
Elevation standard deviation	19.52	32
Annual daylength coefficient of variation	25.27	8
Total available water capacity (cm, to 150 cm)	25.83	5
Total available water supply (cm, to 150 cm)	20.23	29
Depth to water table (cm)	19.62	31
Soil permeability rate (cm/hr)	21.28	25
Soil calcium carbonate (% by weight)	22.2	19
Soil cation-exchange capacity	21.95	21
Soil pH	22.07	20
Soil bulk density (g/cm3)	23.05	16
Organic matter content (% by weight)	24.03	11
Potential soil productivity	19.62	30
Soil erodibility factor, rock fragment free	23.59	14
Soil erosion by wind (tons/acre/year)	24.11	10
Percent soil passing sieve No. 10 (coarse)	16.66	36
Percent soil passing sieve No. 200 (fine)	17.45	35
Percent clay (< 0.002 mm size)	22.86	17
Percent sand (< 0.002 mm size)	24.28	9
Percent silt (< 0.002 mm size)	20.76	27
Percent of texture clayey	16.08	37
Percent of texture loamy	21.46	23
Percent of texture sandy	15.6	39
Percent of texture other	22.39	18
Alfisol (%)	19.27	33
Aridisol (%)	1.13	45
Entisol (%)	14.25	41
Histosol (%)	15.64	38
Inceptisol (%)	25.48	6
Mollisol (%)	21.32	24
Spodosol (%)	6.82	44
Ultisol (%)	18.87	34
Vertisol (%)	12.86	42