Precipitation during the coldest quarter 0.345076 Nitrogen content of soil 0.457682 Ratio of precipitation to potential evapotranspiration 0.565711 Precipitation during the driest quarter 0.579705 Precipitation during the hottest quarter 0.60064 Integer number of consecutive months where Tavg >= 5 deg C (Length of potential growing season) 0.620966 Sum of monthly Tavg where Tavg >=5 deg C 0.79664 Bulk density of soil 0.804361 Precipitation during the wettest quarter 0.806311 Compound topographic index (relative wetness) 0.823394 Solar interception 0.833914 Available water holding capacity of soil 0.958449 Temperature during the hottest quarter 1.32102 Elevation 1.40985 Carbon content of soil 1.41479 Temperature during the coldest quarter 1.45946 Day/night diurnal temperature difference 4.60441