Sum of monthly Tavg where Tavg >=5 deg C 0.519589 Carbon content of soil 0.572059 Precipitation during the hottest quarter 0.5855 Nitrogen content of soil 0.590051 Integer number of consecutive months where Tavg >= 5 deg C (Length of potential growing season) 0.644607 Precipitation during the coldest quarter 0.706075 Ratio of precipitation to potential evapotranspiration 0.799008 Precipitation during the driest quarter 0.808633 Solar interception 0.854849 Day/night diurnal temperature difference 0.858999 Precipitation during the wettest quarter 0.872938 Bulk density of soil 0.922497 Compound topographic index (relative wetness) 1.17 Available water holding capacity of soil 2.26759 Temperature during the hottest quarter 2.28556 Temperature during the coldest quarter 2.75559