Prediction Models for Ceiba pentandra in the Guinea Savanah Ecological Zone of Ghana

Abstract

This study investigated the relationships between seven dendrometry variables in Ceiba pentandra. The relationships between stem diameter at breast height, total tree height, crown diameter, crown height, crown ratio, crown projection area and number of branches. Also, the relationship between Crown diameter and total tree height was studied. Regression prediction models were derived using simple linear regression analysis. Pearson correlation between variables was done using the Pearson’s Correlation coefficient. Stem diameter at breast height and crown diameter were used as independent variables as they are readily easy to measure with high accuracy. The study showed that positive correlations exited between stem diameter at breast height and total tree height, crown diameter, crown height, crown projection area, number of branches and crown ratio. Again, a positive correlation exited between the crown diameter and total height (0.39). The value of Pearson correlation coefficient (r) between the stem diameter at breast height, total tree height, crown diameter and crown height was 0.98; that between stem diameter at breast height and crown projection area was 0.95; between stem diameter at breast height, number of branches and crown ratio was 0.96. The correlation coefficient between crown diameter and total height was also 0.98. The coefficient of determination (Ar2) between the stem diameter at breast height, total tree height and crown height was 0.9; between stem diameter at breast height and crown diameter was 0.91; between stem diameter at beast height and crown projection area was 0.84; and 0.88 between stem diameter at breast height, number of branches and crown ratio. The coefficient of determination between crown diameter and total tree height was 0.9. Thus, the stem diameter at breast height accounted for about 90% of the total tree and crown heights. Also stem diameter accounted for 91% of crown diameter, 84% of crown projection area, and 88% of both crown ratio and number of branches. The crown diameter, on the other hand, accounted for 90% of the crown projection area. P-values were significant at 0.05 for all the variables studied (P ≤ 0.05). The models developed will enhance decision making in forest management and save cost and time spent in collecting data on these dendrometry variables studied.