Nitrogen content of soil 0.910733 Compound topographic index (relative wetness) 1.0407 Integer number of consecutive months where Tavg >= 5 deg C (Length of potential growing season) 1.07992 Precipitation during the wettest quarter 1.1147 Elevation 1.11724 Temperature during the hottest quarter 1.19257 Precipitation during the driest quarter 1.20591 Ratio of precipitation to potential evapotranspiration 2.15955 Available water holding capacity of soil 2.22207 Bulk density of soil 2.29544 Day/night diurnal temperature difference 2.38739 Carbon content of soil 2.45718 Solar interception 2.58077 Sum of monthly Tavg where Tavg >=5 deg C 2.96911 Precipitation during the hottest quarter 3.5889 Precipitation during the coldest quarter 4.28235 Temperature during the coldest quarter 5.26002