Prediction of Crown Width & Tree Height from Diameter at Breast Height

This study was carried out at El-Nour Natural Forest Reserve in Blue Nile State, Sudan with objective to predict the crown width and total tree height from its diameter at breast height. Ten models for predicting crown width and fifteen for tree height using diameter at breast height were tested for six selected species. For each species, dbh, total height, bole height and crown width were recorded. DataFit-9 statistical package of the Oakadale Engineering was used to fit the selected models. Akaike¿s information criterion (AIC), adjusted coefficient of determination (Ra2), root mean squared error (RMSE), numerical and graphical analyses of the residuals were used for evaluating the models. Results showed that, for crown width-dbh relationship at least seven out of the ten fitted models were found to give satisfactory results with Ra2 range of 0.52 to 0.74 and RMSE of 1.12 to 2.03. The AIC values range from 114.4 for Balanites aegyptiaca and Combretum hartimannianum to 350.5 for Anogeissus leiocarpus. While for total tree height-dbh relationship at least twelve out of fifteen fitted models were found to give satisfactory results with Ra2 range of 0.52 - 0.75 and RMSE of 1.6 to 2.2.