Sum of monthly Tavg where Tavg >=5 deg C 0.439827 Precipitation during the hottest quarter 0.46853 Precipitation during the coldest quarter 0.581919 Ratio of precipitation to potential evapotranspiration 0.748543 Integer number of consecutive months where Tavg >= 5 deg C (Length of potential growing season) 0.810554 Nitrogen content of soil 1.07135 Carbon content of soil 1.08877 Solar interception 1.11286 Compound topographic index (relative wetness) 1.19501 Bulk density of soil 1.22427 Precipitation during the driest quarter 1.27671 Precipitation during the wettest quarter 1.32371 Available water holding capacity of soil 1.60155 Elevation 1.63098 Temperature during the coldest quarter 1.8042 Temperature during the hottest quarter 1.82803 Day/night diurnal temperature difference 8.59399