Diameter at breast height-crown width prediction models for Anogeissus Leiocarpus (DC.) Guill &Perr and Combretum Hartmannianum Schweinf
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Date
2014
Journal Title
Journal ISSN
Volume Title
Publisher
Research Publisher- Discovery that Matters
Abstract
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.
Description
JOURNAL OF FOREST PRODUCTS & INDUSTRIES, 2014, 3(4), 191-197 ISSN:2325–4513(PRINT) ISSN 2325 - 453X (ONLINE)
Keywords
Forest canopy, Tree crown, Crown width, Diameter-breast height, Non-linear regression, Models evaluation