Available water holding capacity of soil 0.52028 Nitrogen content of soil 0.794381 Sum of monthly Tavg where Tavg >=5 deg C 0.833685 Precipitation during the driest quarter 1.15273 Compound topographic index (relative wetness) 1.18922 Precipitation during the wettest quarter 1.45031 Elevation 1.72644 Ratio of precipitation to potential evapotranspiration 1.89538 Solar interception 2.09297 Integer number of consecutive months where Tavg >= 5 deg C (Length of potential growing season) 2.24272 Temperature during the hottest quarter 2.46327 Carbon content of soil 2.58311 Temperature during the coldest quarter 2.7338 Precipitation during the hottest quarter 3.22254 Bulk density of soil 3.50449 Precipitation during the coldest quarter 3.73181 Day/night diurnal temperature difference 9.94397