PRELIMINARY GROWTH AND YIELD MODELS FOR

Preliminary stand growth and yield models were constructed for even-aged Cupressus lusitanica Mill. and C. macrocarpa Hartw. plantations in New Zealand. Models that predict mean top height, basal area, initial basal area, post-thinning basal area, mortality, and total standing volume per hectare were fitted to permanent sample plot data biased towards younger ages. A wide range of height growth rates were observed, with site index estimates ranging from 15 to 35 m mean top height at age 30. Basal area models predicted greater basal area growth for C. macrocarpa. Exponential models predicted different rates of C. macrocarpa mortality in the North and the South Islands of New Zealand. All suitable data were used to fit models, preventing separation of independent validation data. The models were tested as a system of equations by comparing total standing volume predictions with data used to fit the models. Volume predictions were relatively imprecise, but unbiased overall across the range of available data