Based on a data set from 937 Alberta Land and Forest Services permanent sample plots, two sets of stand-level, two-stage ingrowth models were developed to predict periodic annual ingrowth for white spruce (Picea glauca (Moench) Voss), trembling aspen (Populus tremuloides Michx), lodgepole pine (Pinus contorta var. latifolia Engelm), and black spruce (Picea mariana Mill.) Britton) grown in the boreal mixed-species stands in Alberta. One set was developed based on all trees with DBH $\ge$ 1.1 cm, and another one based on all trees with DBH $\ge$ 9.1 cm. The first stage predicts the probability of the ingrowth occurrence, and the second stage model predicts the annual amount of ingrowth, given that it is known to occur.

The second part of this study evaluated the effects of site productivity and density on white spruce and aspen growth and survival, and presented models for the early growth of planted white spruce and naturally regenerated aspen at the first 5 years after field planting. (Abstract shortened by UMI.)