Predictor Importance Values for black spruce (Picea mariana)

Predictor Name Importance Score Rank
Annual precipitation (mm)15.818
Mean May-September precipitation (mm)1711
Mean annual temperature (°C)13.5129
Mean May-September temperature (°C)19.944
Mean temperature of coldest month (°C)16.0916
Mean temperature of warmest month (°C)19.45
Annual aridity index14.7225
Minimum elevation16.0517
Maximum elevation14.8722
Average elevation18.866
Median elevation17.379
Range of elevation15.220
Elevation coefficient ofvariation15.2619
Elevation standard deviation16.4415
Annual daylength coefficient of variation17.1410
Total available water capacity (cm, to 150 cm)14.8623
Total available water supply (cm, to 150 cm)21.081
Depth to water table (cm)12.8932
Soil permeability rate (cm/hr)14.6726
Soil calcium carbonate (% by weight)12.8833
Soil cation-exchange capacity16.5814
Soil pH10.439
Soil bulk density (g/cm3)13.3231
Organic matter content (% by weight)14.0228
Potential soil productivity15.0321
Soil erodibility factor, rock fragment free17.458
Soil erosion by wind (tons/acre/year)14.4327
Percent soil passing sieve No. 10 (coarse)20.033
Percent soil passing sieve No. 200 (fine)16.8612
Percent clay (< 0.002 mm size)11.2538
Percent sand (< 0.002 mm size)13.3830
Percent silt (< 0.002 mm size)16.7713
Percent of texture clayey9.7541
Percent of texture loamy14.8524
Percent of texture sandy17.627
Percent of texture other12.6435
Alfisol (%)9.8940
Aridisol (%)-145
Entisol (%)5.9742
Histosol (%)11.937
Inceptisol (%)20.062
Mollisol (%)12.0736
Spodosol (%)12.7834
Ultisol (%)0.2644
Vertisol (%)3.8643