Nitrogen content of soil 0.595871 Integer number of consecutive months where Tavg >= 5 deg C (Length of potential growing season) 0.675165 Precipitation during the wettest quarter 0.807315 Elevation 0.92781 Precipitation during the driest quarter 1.00257 Compound topographic index (relative wetness) 1.00346 Temperature during the hottest quarter 1.21589 Available water holding capacity of soil 1.63588 Bulk density of soil 1.83641 Carbon content of soil 1.8673 Sum of monthly Tavg where Tavg >=5 deg C 2.09522 Ratio of precipitation to potential evapotranspiration 2.15955 Solar interception 2.58077 Precipitation during the hottest quarter 3.51939 Precipitation during the coldest quarter 3.98267 Temperature during the coldest quarter 4.50905 Day/night diurnal temperature difference 5.28344