Predictor Importance Values for American holly (Ilex opaca)

Predictor Name	Importance Score	Rank
Annual precipitation (mm)	16.76	15
Mean May-September precipitation (mm)	14	27
Mean annual temperature (°C)	9.1	38
Mean May-September temperature (°C)	10.09	37
Mean temperature of coldest month (°C)	8.75	40
Mean temperature of warmest month (°C)	11.91	34
Annual aridity index	21.67	2
Minimum elevation	18.51	7
Maximum elevation	18.81	6
Average elevation	17.97	12
Median elevation	15	25
Range of elevation	13.01	32
Elevation coefficient ofvariation	16.73	16
Elevation standard deviation	13.49	29
Annual daylength coefficient of variation	11.26	35
Total available water capacity (cm, to 150 cm)	13.2	31
Total available water supply (cm, to 150 cm)	12.38	33
Depth to water table (cm)	16.18	20
Soil permeability rate (cm/hr)	17.36	13
Soil calcium carbonate (% by weight)	15.38	24
Soil cation-exchange capacity	18.15	9
Soil pH	22.09	1
Soil bulk density (g/cm3)	19.62	4
Organic matter content (% by weight)	8.97	39
Potential soil productivity	18.11	10
Soil erodibility factor, rock fragment free	19.86	3
Soil erosion by wind (tons/acre/year)	13.45	30
Percent soil passing sieve No. 10 (coarse)	18.91	5
Percent soil passing sieve No. 200 (fine)	15.41	23
Percent clay (< 0.002 mm size)	17.99	11
Percent sand (< 0.002 mm size)	15.98	21
Percent silt (< 0.002 mm size)	16.42	18
Percent of texture clayey	16.94	14
Percent of texture loamy	8.04	41
Percent of texture sandy	13.73	28
Percent of texture other	16.55	17
Alfisol (%)	16.2	19
Aridisol (%)	1.33	45
Entisol (%)	7.53	42
Histosol (%)	6.17	43
Inceptisol (%)	14.73	26
Mollisol (%)	5.4	44
Spodosol (%)	11.03	36
Ultisol (%)	18.36	8
Vertisol (%)	15.63	22