Precipitation during the wettest quarter 0.306289 Carbon content of soil 0.698997 Nitrogen content of soil 0.759959 Precipitation during the driest quarter 0.875609 Sum of monthly Tavg where Tavg >=5 deg C 0.967128 Day/night diurnal temperature difference 1.07595 Bulk density of soil 1.15195 Solar interception 1.36719 Available water holding capacity of soil 1.61991 Temperature during the hottest quarter 1.62638 Integer number of consecutive months where Tavg >= 5 deg C (Length of potential growing season) 2.2556 Compound topographic index (relative wetness) 2.88735 Precipitation during the coldest quarter 3.62607 Temperature during the coldest quarter 3.73603 Precipitation during the hottest quarter 3.84228 Ratio of precipitation to potential evapotranspiration 4.3562