Table 2 Summary statistics of the periodic mean annual stand dominant height increment model (Eq. 10) as a function of conventional site index (\(SI\)) and periodic site index (\(pSI\)) (R2, coefficient of determination
SI | Variables | Std.Error | t-value | Pr( >|t|) | \(R^2\) | \(RMSE\) | \(AIC\) | n | |
|---|---|---|---|---|---|---|---|---|---|
Parameter | Estimate | ||||||||
\(SI\) | \({\alpha }_{1}\) | 0.02476 | 0.00229 | 10.813 | < 0.0001 | 0.746 | 0.097 | –9883 | 5435 |
\({\alpha }_{2}\) | 0.99061 | 0.04768 | 20.775 | < 0.0001 | |||||
\({\alpha }_{3}\) | –0.09421 | 0.00257 | –36.728 | < 0.0001 | |||||
\({\alpha }_{4}\) | –0.00005 | 0.00001 | –8.982 | < 0.0001 | |||||
\({\boldsymbol{\alpha }}_{5}\) | 0.05339 | 0.00093 | 57.660 | < 0.0001 | |||||
\(pSI\) | \({\alpha }_{1}\) | 0.03722 | 0.00286 | 13.012 | < 0.0001 | 0.816 | 0.083 | –11,639 | 5435 |
\({\alpha }_{2}\) | 0.82060 | 0.04111 | 19.961 | < 0.0001 | |||||
\({\alpha }_{3}\) | –0.08638 | 0.00220 | –39.289 | < 0.0001 | |||||
\({\alpha }_{4}\) | –0.00003 | 0.00001 | –6.949 | < 0.0001 | |||||
\({\boldsymbol{\alpha }}_{5}\) | 0.05288 | 0.00067 | 79.080 | < 0.0001 | |||||