Precipitation during the wettest quarter 0.066806 Precipitation during the hottest quarter 0.335325 Carbon content of soil 0.348236 Integer number of consecutive months where Tavg >= 5 deg C (Length of potential growing season) 0.522518 Precipitation during the coldest quarter 0.522794 Precipitation during the driest quarter 0.797576 Temperature during the hottest quarter 0.84899 Nitrogen content of soil 0.886243 Ratio of precipitation to potential evapotranspiration 1.09234 Compound topographic index (relative wetness) 1.36248 Bulk density of soil 1.56878 Sum of monthly Tavg where Tavg >=5 deg C 1.61407 Temperature during the coldest quarter 1.62118 Available water holding capacity of soil 2.90609 Day/night diurnal temperature difference 2.98453 Solar interception 3.60791