Diameter at breast height-crown width prediction models for Anogeissus Leiocarpus (DC.) Guill &Perr and Combretum Hartmannianum Schweinf

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Research Publisher- Discovery that Matters


This study was carried out at El-Nour Natural Forest Reserve, Rosaries district, Blue Nile State with objective of predicting Crown width from Diameter at Breast Height for Anogeissus leiocarpus (DC.) Guill & Perr, and Combretum hartmannianum Schweinf species. Five models for predicting crown width were tested for these two species. For each species, dbh, total height and crown width were recorded. DataFit-9 statistical package of the Oakdale 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. The results of the study showed that, all fitted models were found to give satisfactory results with Ra2 range of 0.65 to 0.74 and RMSE of 1.12 to 1.40. The AIC values range from 114.8 for Combretum hartmannianum Schweinf and to 356.4 for Anogeissus leiocarpus (DC.) Guill & Perr. The study concluded that, the crown width could be estimated by the mean of diameter at breast height as it is easy to measure for ground-based inventory and stand structure determination. The crown width-diameter models examined in this study produced reasonably precise estimates for crown width and could be used to predict the crown width of the species under consideration. The study recommended that, Future research is needed with a greater variety of site and stand conditions in addition to a greater variety of tree sizes and ages. It should be noted that, the models used by this study were based on data collected from El-Nour Natural Forest Reserve in Blue Nile State; therefore, it should be used with caution outside this area.


JOURNAL OF FOREST PRODUCTS & INDUSTRIES, 2014, 3(4), 191-197 ISSN:2325–4513(PRINT) ISSN 2325 - 453X (ONLINE)


Forest canopy, Tree crown, Crown width, Diameter-breast height, Non-linear regression, Models evaluation