Precipitation during the driest quarter 0.630357 Integer number of consecutive months where Tavg >= 5 deg C (Length of potential growing season) 0.702205 Nitrogen content of soil 0.782509 Precipitation during the wettest quarter 0.87396 Temperature during the hottest quarter 0.937571 Compound topographic index (relative wetness) 1.03988 Available water holding capacity of soil 1.09757 Elevation 1.3506 Bulk density of soil 1.87813 Carbon content of soil 2.45259 Sum of monthly Tavg where Tavg >=5 deg C 2.66688 Temperature during the coldest quarter 3.61107 Precipitation during the coldest quarter 4.12764 Precipitation during the hottest quarter 5.10523 Day/night diurnal temperature difference 5.20312 Ratio of precipitation to potential evapotranspiration 5.35303 Solar interception 5.64429