Precipitation during the wettest quarter 0.11053 Day/night diurnal temperature difference 0.131252 Temperature during the hottest quarter 0.277645 Compound topographic index (relative wetness) 0.281971 Precipitation during the driest quarter 0.44325 Nitrogen content of soil 0.497 Carbon content of soil 0.558317 Integer number of consecutive months where Tavg >= 5 deg C (Length of potential growing season) 0.615575 Elevation 0.667127 Bulk density of soil 1.015 Sum of monthly Tavg where Tavg >=5 deg C 1.36266 Precipitation during the coldest quarter 1.41166 Precipitation during the hottest quarter 1.45827 Available water holding capacity of soil 1.47316 Ratio of precipitation to potential evapotranspiration 1.53941 Solar interception 1.87831 Temperature during the coldest quarter 3.07026