Compound topographic index (relative wetness) 1.2671 Precipitation during the wettest quarter 1.54422 Precipitation during the driest quarter 1.79658 Nitrogen content of soil 1.93273 Elevation 2.26626 Carbon content of soil 2.30679 Bulk density of soil 2.36548 Solar interception 2.58053 Temperature during the hottest quarter 2.67614 Sum of monthly Tavg where Tavg >=5 deg C 2.74035 Available water holding capacity of soil 3.09308 Ratio of precipitation to potential evapotranspiration 3.49704 Precipitation during the coldest quarter 4.10469 Precipitation during the hottest quarter 5.1005 Integer number of consecutive months where Tavg >= 5 deg C (Length of potential growing season) 5.40411 Temperature during the coldest quarter 5.63815 Day/night diurnal temperature difference 6.42631