Comparison of nine alternative parameter estimation schemes.

Crown shape parameters were either estimated separately for each species (full fit); reduced to single axis of variation requiring one free parameter per species (single-axis); or reduced to a single crown shape for all species (one-shape). Depth bias Vbias,j was either estimated separately for each species; set to a single value for all species (global); or fixed at 0. The table gives, for each scheme, the number of free parameters (top left), the maximum log-likelihood (top right), and the value of the AIC and BIC information criteria (bottom left bottom right respectively). Numbers are given to the nearest integer. Lower values of AIC and BIC indicate statistically superior models.