Can individual tree traits be used to predict future stand productivity?
There is some debate about the merits of using height, diameter, form factor, or individual tree volume, or a combination of traits to predict future stand productivity. For example, the optimum age for ranking families or clones for height in a genetic test is usually lower than that for predicting volume productivity. What is the best age to predict future productivity? There is some debate as to the best age at which reliable predictions of future productivity can be made. Given that trees and stands follow a sigmoid (s-shaped) growth curve, reliable productivity predictions are only possible around half rotation age, which is the point of inflection in the s-curve. Zobel and Talbert (1984) suggest that half rotation age is suitable for productivity assessment, but that many other traits such as disease resistance can be assessed earlier. White et al. (2007) provides a good discussion of early selection and optimum selection age in forest tree breeding. Can stand volume enhancement
