Sum of monthly Tavg where Tavg >=5 deg C 0.348342 Temperature during the coldest quarter 0.463274 Bulk density of soil 0.614711 Precipitation during the hottest quarter 0.698245 Nitrogen content of soil 0.875032 Precipitation during the wettest quarter 0.947457 Precipitation during the coldest quarter 1.0173 Elevation 1.19914 Precipitation during the driest quarter 1.43584 Compound topographic index (relative wetness) 1.45522 Carbon content of soil 1.48999 Solar interception 1.57996 Ratio of precipitation to potential evapotranspiration 1.61814 Integer number of consecutive months where Tavg >= 5 deg C (Length of potential growing season) 1.85582 Available water holding capacity of soil 1.90323 Temperature during the hottest quarter 2.69852 Day/night diurnal temperature difference 6.82713