Ricardo Methol Ph.D. candidate Growth and yield modelling Taper modelling

email: rme26@student.canterbury.ac.nz

My Ph.D. project involves comparisons of growth and yield modelling approaches for forest plantations. All the approaches being compared provide individual-tree (or diameter-class) level outputs, which are fully compatible with stand-level aggregates.

As the results of these types of comparisons are likely to be data-dependent, I am using three contrasting datasets. These include Eucalyptus grandis grown in Uruguay, and Pinus radiata & Psedotsuga menziesii (Douglas-fir) grown in New Zealand. A simple stand-level web-based model for radiata pine is available here.

Another component of the project is concerned with the development of taper models. One particular topic under analysis is the accuracy of "bark" models that predict the under-bark diameter given over-bark diameter, height, dbhob and total tree height. These models have been used to reduce the number of under-bark measurements when collecting data for taper modelling. However, the effect of applying these sub-models (as compared to using actual under-bark measurements only) has not been evaluated before.