Nitrogen content of soil 0.88462 Integer number of consecutive months where Tavg >= 5 deg C (Length of potential growing season) 1.0274 Compound topographic index (relative wetness) 1.07422 Precipitation during the driest quarter 1.2295 Elevation 1.24156 Precipitation during the wettest quarter 1.26461 Temperature during the hottest quarter 1.49172 Available water holding capacity of soil 1.90525 Ratio of precipitation to potential evapotranspiration 2.15955 Bulk density of soil 2.42606 Solar interception 2.58077 Carbon content of soil 2.59106 Sum of monthly Tavg where Tavg >=5 deg C 3.30327 Precipitation during the hottest quarter 3.51939 Precipitation during the coldest quarter 4.00523 Day/night diurnal temperature difference 5.28344 Temperature during the coldest quarter 5.34081