Solar interception 0.281943 Sum of monthly Tavg where Tavg >=5 deg C 0.314402 Bulk density of soil 0.467975 Integer number of consecutive months where Tavg >= 5 deg C (Length of potential growing season) 0.57489 Precipitation during the driest quarter 0.608604 Day/night diurnal temperature difference 0.638541 Nitrogen content of soil 0.650228 Precipitation during the wettest quarter 0.783149 Carbon content of soil 0.861451 Precipitation during the coldest quarter 0.906289 Compound topographic index (relative wetness) 0.915667 Precipitation during the hottest quarter 0.925028 Available water holding capacity of soil 0.944106 Temperature during the hottest quarter 1.33925 Ratio of precipitation to potential evapotranspiration 1.46642 Temperature during the coldest quarter 1.85584