Local growth model in modelling the crown diameter of plantation-grown Dryobalanops aromatica.

AHMAD ZUHAIDI Y. 2009. Local growth model in modelling the crown diameter of plantation-grown Dryobalanops aromatica. The importance of crown data in improving the construction of growth models for stand management has long been established for many temperate and a few tropical species. Growth models will assist in determining the allometric relationship between crown and tree diameter, optimum planting distance and expected final crop tree density. This study examined the allometric relationship of plantation-grown Dryobalanops aromatica by regression of curvilinear models between projected crown and measured tree diameter at breast height (dbh). The study was carried out in 2005 at Bukit Lagong Forest Reserve, Selangor, Peninsular Malaysia. Results indicate that model as a function of dbh and dbh 2 explained a significant proportion of the variation in the crown diameter at 62.9%. The model possessed a standard error of estimate at 1.197. Overall results of the modelling were negatively biased and underestimated (0.266 m) the predicted crown diameter of the species. The information provided by this study could serve as a guide in formulating a standard growth model, realistic production targets, planting density and limiting stocking in future plantations of the species.