Nitrogen content of soil 0.465354 Temperature during the coldest quarter 0.510588 Bulk density of soil 0.542189 Integer number of consecutive months where Tavg >= 5 deg C (Length of potential growing season) 0.607097 Ratio of precipitation to potential evapotranspiration 0.643398 Precipitation during the coldest quarter 0.657891 Precipitation during the driest quarter 0.682173 Sum of monthly Tavg where Tavg >=5 deg C 0.751386 Precipitation during the hottest quarter 0.84832 Compound topographic index (relative wetness) 0.897552 Solar interception 0.993428 Precipitation during the wettest quarter 1.04862 Available water holding capacity of soil 1.23286 Carbon content of soil 1.35752 Temperature during the hottest quarter 1.46498 Elevation 1.74666 Day/night diurnal temperature difference 5.50753