Precipitation during the wettest quarter 0.000476 Compound topographic index (relative wetness) 0.70462 Precipitation during the coldest quarter 0.723949 Ratio of precipitation to potential evapotranspiration 0.732535 Precipitation during the hottest quarter 0.744225 Precipitation during the driest quarter 0.786698 Nitrogen content of soil 0.831231 Solar interception 0.996972 Carbon content of soil 1.11819 Sum of monthly Tavg where Tavg >=5 deg C 1.50715 Temperature during the hottest quarter 1.83739 Bulk density of soil 1.9085 Integer number of consecutive months where Tavg >= 5 deg C (Length of potential growing season) 2.03166 Elevation 2.31315 Day/night diurnal temperature difference 2.47899 Temperature during the coldest quarter 2.85136 Available water holding capacity of soil 3.61498