Precipitation during the wettest quarter 0.09686 Sum of monthly Tavg where Tavg >=5 deg C 0.35134 Bulk density of soil 0.442359 Nitrogen content of soil 0.770142 Precipitation during the hottest quarter 0.891455 Precipitation during the driest quarter 1.0549 Compound topographic index (relative wetness) 1.30769 Precipitation during the coldest quarter 1.41709 Carbon content of soil 1.49669 Integer number of consecutive months where Tavg >= 5 deg C (Length of potential growing season) 1.50207 Available water holding capacity of soil 1.61791 Solar interception 2.10506 Elevation 2.1284 Temperature during the coldest quarter 2.17447 Ratio of precipitation to potential evapotranspiration 2.20361 Temperature during the hottest quarter 2.66522 Day/night diurnal temperature difference 5.12974