Factors Influencing the Density of Natural Regeneration in Uniform Shelterwoods Dominated by Douglas-fir in the Sub-Boreal Spruce Zone

This study investigates the factors influencing natural regeneration in uniform shelterwood systems, specifically focusing on Douglas-fir in the Sub-Boreal Spruce Zone. The study details methods for assessing seedfall density, seed predation, seedbed distribution, and the germination and survival rates of seedlings under various harvesting treatments. The core purpose is to understand how these elements interact to determine successful conifer regeneration, particularly noting that rotting wood and mineral soil are superior seedbeds compared to forest floor and moss, and that while harvesting can increase mineral soil exposure, it is often insufficient to maximize regeneration without additional scarification. The findings suggest that while all tested shelterwood methods promote adequate regeneration and frost protection, lower residual basal areas combined with significant forest floor disturbance are most favorable for Douglas-fir seedling growth and survival.