Precipitation during the wettest quarter 0 Precipitation during the driest quarter 0.473317 Carbon content of soil 0.542723 Nitrogen content of soil 0.547491 Solar interception 1.11965 Bulk density of soil 1.13473 Temperature during the hottest quarter 1.59809 Day/night diurnal temperature difference 2.03482 Available water holding capacity of soil 2.21317 Ratio of precipitation to potential evapotranspiration 2.61486 Compound topographic index (relative wetness) 2.68054 Sum of monthly Tavg where Tavg >=5 deg C 3.44497 Precipitation during the hottest quarter 3.51684 Temperature during the coldest quarter 3.55611 Precipitation during the coldest quarter 4.13232 Integer number of consecutive months where Tavg >= 5 deg C (Length of potential growing season) 4.72057