Compound topographic index (relative wetness) 0.140879 Precipitation during the wettest quarter 0.216612 Bulk density of soil 0.227725 Elevation 0.244635 Nitrogen content of soil 0.262283 Temperature during the hottest quarter 0.263197 Sum of monthly Tavg where Tavg >=5 deg C 0.343735 Integer number of consecutive months where Tavg >= 5 deg C (Length of potential growing season) 0.3504 Precipitation during the driest quarter 0.354267 Day/night diurnal temperature difference 0.417609 Ratio of precipitation to potential evapotranspiration 0.487806 Available water holding capacity of soil 0.506918 Solar interception 0.514682 Carbon content of soil 0.531761 Precipitation during the coldest quarter 0.594812 Temperature during the coldest quarter 1.04417 Precipitation during the hottest quarter 1.38094