Refereed Articles Indicative growth and yield models for stringybark eucalypt plantations in northern New Zealand
J. Berrill and A. Errol Hay
Demand for growth and yield information prompted development of predictive models using very limited data collected from even-aged Eucalyptus eugenoides Sieb. ex Spreng., E. globoidea Blakely, E. muelleriana Howitt, and E. pilularis Smith plantations around northern New Zealand. The models can be used in combination to obtain indicative predictions of height growth, total standing volume yield, average tree size, and log grade recovery based on inputs of site index or height-age data and stand density (stocking). Results indicated that volume yield was strongly influenced by stocking and site quality. Site index estimates for the 35 sample plots ranged from 12.5 m to 32.6 m mean top height at base age 15 years. Most volume yield predictions were within 25% of actual yields and average diameter predictions within 20% of actual data. Sawlog grade recovery was found to increase with average tree size, but varied widely between the small number of stands sampled. (no keywords)
NZIF wishes to thank the donations and support of corporates and individuals in the funding the back issue scanning project for this website.
For more information on the sponsors of this project, click here