A semi-empirical model for predicting crown diameter of cedrela odorata L) using age and breast-height diameter

Abstract

A semi-empirical model relating age and breast height has been developed to predict individual tree crown diameter for Cedrela odorata (L) plantation in the moist evergreen forest zones of Ghana. The model was based on field records of 269 trees, and could determine the crown cover dynamics, forecast time of canopy closure (when stand pruning and thinning could be undertaken) and also sequence food crops integration. Tree crown diameter was deduced as function of tree breast-height diameter and stand age, and the best fit model accounted for more than 87 % of the total variation in tree crown diameter. The predicted crown diameter showed no con-sistent under-estimation or over-estimation. An independent data set of a representative population in similar ecological zone was used to validate the model. The average prediction biases were not significant at significa-nce level of 1 %, indicating that the model appropriately described the data and performed well when predicti-ons were made. The model can be applied to assess thinning intensity for specific stand age and determine stand age at canopy closure for different planting spaces.

Journal of Applied Science and Technology Vol. 13 (1 & 2) 2008: pp. 114-121