MODELING DOMINANT HEIGHT GROWTH - EUCALYPTUS PLANTATIONS IN PORTUGAL

Difference forms of the well-known Chapman-Richards and Lundqvist-Korf biological growth models are derived for use in modeling dominant hei ght growth using data from remeasured permanent plots, The performance of these models is compared with the performance of the McDill-Amatei s difference model for describing dominant height growth of eucalyptus plantations in Portugal. The final model is a difference form of the Chapman-Richards equation with the m shape parameter constrained by in itial stand conditions, The model is regional in that there are differ ent estimated parameter values for highly productive sites in the coas tal region of Portugal compared to lower productivity sites in the int erior, The effect of using overlapping or nonoverlapping measurement i ntervals in the estimation process is examined with independent data; there appears to be little difference in the predictive ability of the resulting models.