Figure 3: Observed site index for yellow-poplar from the 14 stands sampled in this study was within the 95% confidence limits (two dashed lines) for individual predictions from a model (solid line) reported in a previous study [9] conducted throughout the Southern Appalachian Mountains (SAM). The length of the solid line indicates the range of landform index (0.15 to 0.40) used in development of the SAM model. The inset shows the significant relationship ( ) between yellow-poplar site index observed in this study (x-axis) and site index predicted by the SAM model (y-axis). The diagonal dashed line in the inset represents perfect correlation between observed site index and site index predicted by the SAM model.