Sum of monthly Tavg where Tavg >=5 deg C 0.308501 Precipitation during the driest quarter 0.435553 Nitrogen content of soil 0.561508 Precipitation during the wettest quarter 0.563242 Integer number of consecutive months where Tavg >= 5 deg C (Length of potential growing season) 0.676683 Available water holding capacity of soil 0.695465 Bulk density of soil 0.751387 Carbon content of soil 0.817914 Solar interception 0.844305 Day/night diurnal temperature difference 0.925126 Temperature during the hottest quarter 1.09378 Compound topographic index (relative wetness) 1.96927 Precipitation during the coldest quarter 2.39952 Precipitation during the hottest quarter 2.62139 Ratio of precipitation to potential evapotranspiration 2.83918 Temperature during the coldest quarter 3.99214