Nitrogen content of soil 0.271344 Compound topographic index (relative wetness) 0.3361 Precipitation during the hottest quarter 0.351034 Integer number of consecutive months where Tavg >= 5 deg C (Length of potential growing season) 0.387867 Elevation 0.43265 Ratio of precipitation to potential evapotranspiration 0.450138 Precipitation during the driest quarter 0.527877 Temperature during the hottest quarter 0.605857 Available water holding capacity of soil 0.687133 Precipitation during the coldest quarter 0.711345 Precipitation during the wettest quarter 0.742091 Bulk density of soil 0.85802 Solar interception 0.912463 Carbon content of soil 0.918792 Sum of monthly Tavg where Tavg >=5 deg C 1.13972 Temperature during the coldest quarter 1.75982 Day/night diurnal temperature difference 2.03338