Assessment of survival and growth prospects of seedlings of Douglas fir, Psuedotsuga [sic] menziesii.

The object of this work was to study the survival and growth of Douglas fir seedlings in relation to their morphological grade, and in relation to various pruning treatments. The material used consisted of two-year-old Douglas fir seedlings, grown in the campus nursery at the University of British Columbia under various organic and inorganic fertilizer treatments. These fertilizer treatments produced seedlings which varied in quality, and which were therefore suitable for use in a study of survival and growth in relation to seedling grade. Experiments were carried out under greenhouse, nursery, and field conditions. Statistical methods of analysis were used to determine the significance of the experimental results. In all cases, mortality increased directly with decrease in seedling grade. This relationship was not affected by variations of site quality in the field, the percentage of successful establishment increasing with increase in seedling grade on all sites. Shoot growth, root growth, and growth in diameter under bark were closely related to grade of seedling. Root pruning retarded bud bursting. Mortality was increased by root pruning in conjunction with top pruning, but not by root pruning alone. Shoot growth, root growth, and growth in diameter under bark were not affected by root pruning. Shoot growth, and growth in diameter under bark at the root collar were reduced by shoot and root pruning combined.Forestry, Faculty ofGraduat