Slenderness coefficient and growth characteristics of Africa giant bamboo: Bambusa vulgaris Schrad. ex J.C. Wendl

Abstract

The tree slenderness coefficient (SC) has been widely used as an index of the resistance of trees to windthrow, and the slenderness coefficients of different tree species have been intensively studied. However, very little or no information is available for the slenderness coefficients of bamboo in many parts of the world including Nigeria. Here, we evaluated the slenderness coefficient of African giant bamboo (Bambusa vulgaris) in order to ascertain its level of resistance to windthrow and its suitability as a wind break. The study was undertaken in three states of south-western Nigeria (Osun, Oyo and Ondo states), with the diameter at breast height (DBH) and total height (TH) of the bamboo culms being measured. The volume, basal area and slenderness coefficient were evaluated and the relationship among the parameters and the slenderness coefficient was enumerated through correlation analysis. Regression analysis was undertaken to form models for the prediction of the slenderness coefficient for the study areas. The slenderness coefficients of bamboo culms were negatively correlated with diameter at breast height (DBH), volume and basal area but positively correlated with height for the three states. The graphical results indicated that bamboo has a slenderness coefficient below 70 and may not be at high-risk for windthrow, based on the model developed to predict slenderness coefficient values from (i) DBH and (ii) Height. The DBH function provided the best predictions and a Power model was found to have the best fit for prediction. We conclude that B. vulgaris has a low slenderness coefficient and it can be used as a wind break.