Sum of monthly Tavg where Tavg >=5 deg C 1.04893 Carbon content of soil 1.26919 Precipitation during the driest quarter 1.3294 Nitrogen content of soil 1.46377 Day/night diurnal temperature difference 1.70047 Integer number of consecutive months where Tavg >= 5 deg C (Length of potential growing season) 1.77494 Precipitation during the wettest quarter 1.83789 Bulk density of soil 2.51793 Compound topographic index (relative wetness) 2.55208 Available water holding capacity of soil 2.60782 Temperature during the hottest quarter 3.53152 Ratio of precipitation to potential evapotranspiration 3.54915 Precipitation during the coldest quarter 4.14344 Precipitation during the hottest quarter 5.11299 Temperature during the coldest quarter 5.71416 Solar interception 6.68727