Precipitation during the wettest quarter 0.005354 Solar interception 0.091533 Day/night diurnal temperature difference 0.143576 Sum of monthly Tavg where Tavg >=5 deg C 0.211691 Nitrogen content of soil 0.218591 Carbon content of soil 0.227248 Bulk density of soil 0.287918 Precipitation during the driest quarter 0.313218 Ratio of precipitation to potential evapotranspiration 0.365059 Available water holding capacity of soil 0.41859 Precipitation during the coldest quarter 0.423329 Precipitation during the hottest quarter 0.501597 Compound topographic index (relative wetness) 0.568764 Temperature during the hottest quarter 0.8395 Integer number of consecutive months where Tavg >= 5 deg C (Length of potential growing season) 1.15994 Temperature during the coldest quarter 1.35255