TITLE:
Ecological Structure and Prediction Equations for Estimating Tree Age, and Dendometric Parameters of Acacia senegal in the Senegalese Semi-Arid Zone—Ferlo
AUTHORS:
Aly Diallo, Emile Codjo Agbangba, Ousmane Ndiaye, Aliou Guisse
KEYWORDS:
Ecological Structure; Stem Diameter at Breast; Stem Basal Diameter; Crown Diameter; Crown Depth; Tree Height; Age; Correlation; Regression; Acacia senegal; Northern Senegal
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.4 No.5,
May
29,
2013
ABSTRACT: The development of equations
to predict tree height, crown diameter, crown depth from stem diameter of a
tree species enables arborists, researchers, and urban forest managers to model
costs and benefits, analyze alternative management scenarios, and determine the
best management practices for sustainable forests. The objective of this study
was to develop regression prediction models for tree age, tree height, crown
diameter, crown ratio and crown depth for A. senegal growing in Ferlo, in the northern Senegal. Four plantations
of different years old (ISRA, 10 years
old plantations, Ndodj, 8 years old plantations, Boulal,
5 years old plantations and Déali, 4
years old plantations) were selected. The following dendometric variables: crown height, crown diameter, stem diameter at the breast height, stem basal
diameter (at 0.30 m) and the height from the tree base to first branch were
measured on a total of 489 trees. The results suggested that the ecological structure of the different
year old A. Senegal plantation
revealed a bell-shaped form with left dissymmetric distribution indicating a
predominance of individuals with small diameter at breast height. Allometry study of A. Senegal showed highly significant
positive correlations (p = 0.00) between stem diameter
at breast height, stem basal diameter, tree height, crown diameter and crown
depth. Positive correlations were also found between crown diameter, tree
height and crown height. Prediction models derived from these relationships can
be used to estimate the tree height, stem diameter at breast height and crown
depth from crown diameter with greater precision. As for A. Senegal age estimation, the established model is not strong as
it can explain only 49.1% of the age variation.