Growth and yield models play very important roles in forest management because of their abilities to update inventory, predict future yield, and explore management options and silviculture alternatives. This thesis reports on studies of large tree mortality, juvenile tree growth and mortality, and combined diameter increment of juvenile and large trees in Alberta boreal mixedwood forests for three major species: white spruce (Picea glauca (Moench) Voss), trembling aspen (Populus tremuloides Michx), and lodgepole pine (Pinus contorta var. latifolia Engelm).

Under the framework of an individual tree distance-independent growth model, a generalized logistic model of individual tree mortality was developed for mature mixedwood stands. The maximum likelihood estimator was derived in this study and implemented using the quasi-Newton algorithm. The effects of tree diameter, diameter increment, stand basal area, species composition, and site productivity on mortality were evaluated.

Basic growth and mortality relationships were developed for regenerated juvenile stands. The relationships included the tree height as a function of tree age, regeneration method, damage agents, stand density, species composition, and site productivity; the Weibull age distribution models at 2, 4, 6, 8, and 12 years since regeneration; and the logistic model relating the two-year survival probability to tree age, height, regeneration method, damage agents, stand density, species composition, and site productivity.

Using an appropriately selected unimoidal-shaped base function, and the method of parameter estimation, an annual diameter increment model was developed to predict individual tree diameter increment based on tree diameter, height, total basal area of larger trees, stand basal area, species composition, and site productivity. The selected base function prevented the model from underestimating the diameter increment for small trees, and the nonlinear fitting method allowed data including trees with zero increment or decrement produced by natural variation in stem size.

To extend the mortality study from periodic survival to longer term survival, a lifetime distribution analysis was applied to juvenile trees. Nonparametric analysis was used to portray the survival data, and provided a reasonable theoretical model of the lifetime distribution. A parametric regression model was developed to relate the parameters of the lifetime distribution to tree age, height, regeneration method, damage agents, stand density, species composition, and site productivity.