Precipitation during the wettest quarter 0.301676 Precipitation during the coldest quarter 0.384003 Integer number of consecutive months where Tavg >= 5 deg C (Length of potential growing season) 0.394358 Carbon content of soil 0.405016 Temperature during the hottest quarter 0.407537 Ratio of precipitation to potential evapotranspiration 0.589875 Precipitation during the hottest quarter 0.598976 Precipitation during the driest quarter 0.650276 Nitrogen content of soil 0.766654 Compound topographic index (relative wetness) 0.864999 Bulk density of soil 1.47678 Sum of monthly Tavg where Tavg >=5 deg C 1.78979 Day/night diurnal temperature difference 1.96907 Temperature during the coldest quarter 2.52838 Available water holding capacity of soil 3.17944 Solar interception 3.19627