Individual-Tree Growth Patterns and Modeling for Fokienia hodginsii Plantations

This study focused on a 36-year-old Fokienia hodginsii plantation in Shanghang County,Fujian Province.Annual growth data for diameter at breast height(DBH),tree height and stem volume were obtained from sample trees using the stem analysis method.Five classic theoretical growth equations,including Richards and Korf,were fitted through non-linear regression to select the optimal growth models.The results indicated that:①the single-tree growth of F.hodginsii followed a typical 'S’-shaped curve,but significant allometry existed in the growth rhythms among different mensuration factors.②The Richards equation was the optimal model for DBH and stem volume growth,while the Korf equation was optimal for tree height growth.③Validated both internally with stem analysis data and externally with plot-measured data,the optimal models showed high agreement between predicted and measured values,with all relative errors below 5% and no significant differences between them(P>0.05);the selected Richards and Korf equations can accurately simulate and predict the single-tree growth dynamics of F.hodginsii,providing a scientific reference for the precision forestry and sustainable management of its plantations.