Predictor Importance Values for boxelder (Acer negundo)

Predictor Name	Importance Score	Rank
Annual precipitation (mm)	18.83	33
Mean May-September precipitation (mm)	22.42	23
Mean annual temperature (°C)	20.49	30
Mean May-September temperature (°C)	26.67	3
Mean temperature of coldest month (°C)	21.71	26
Mean temperature of warmest month (°C)	24.77	8
Annual aridity index	27.45	2
Minimum elevation	24.62	9
Maximum elevation	24.54	11
Average elevation	24.55	10
Median elevation	20.86	28
Range of elevation	23.49	17
Elevation coefficient ofvariation	20.26	31
Elevation standard deviation	20.92	27
Annual daylength coefficient of variation	24.47	12
Total available water capacity (cm, to 150 cm)	12.39	42
Total available water supply (cm, to 150 cm)	7.67	44
Depth to water table (cm)	23.27	19
Soil permeability rate (cm/hr)	29.35	1
Soil calcium carbonate (% by weight)	18.66	34
Soil cation-exchange capacity	16.95	35
Soil pH	25.13	6
Soil bulk density (g/cm3)	22.01	25
Organic matter content (% by weight)	22.14	24
Potential soil productivity	24.01	13
Soil erodibility factor, rock fragment free	25.41	5
Soil erosion by wind (tons/acre/year)	23.53	16
Percent soil passing sieve No. 10 (coarse)	24.01	14
Percent soil passing sieve No. 200 (fine)	23.35	18
Percent clay (< 0.002 mm size)	25.91	4
Percent sand (< 0.002 mm size)	23.25	20
Percent silt (< 0.002 mm size)	20.13	32
Percent of texture clayey	15.31	38
Percent of texture loamy	20.8	29
Percent of texture sandy	16.1	36
Percent of texture other	23.64	15
Alfisol (%)	25.02	7
Aridisol (%)	1	45
Entisol (%)	13.24	39
Histosol (%)	13.22	40
Inceptisol (%)	22.85	21
Mollisol (%)	22.62	22
Spodosol (%)	12.61	41
Ultisol (%)	15.42	37
Vertisol (%)	8.34	43