Sum of monthly Tavg where Tavg >=5 deg C 0.439827 Ratio of precipitation to potential evapotranspiration 0.769938 Precipitation during the coldest quarter 0.842096 Precipitation during the hottest quarter 0.946065 Nitrogen content of soil 1.00573 Solar interception 1.19754 Bulk density of soil 1.20129 Carbon content of soil 1.23632 Compound topographic index (relative wetness) 1.26661 Precipitation during the wettest quarter 1.3237 Precipitation during the driest quarter 1.42905 Temperature during the coldest quarter 1.74677 Integer number of consecutive months where Tavg >= 5 deg C (Length of potential growing season) 1.75474 Temperature during the hottest quarter 1.92084 Available water holding capacity of soil 2.1033 Elevation 2.10621 Day/night diurnal temperature difference 6.73011