Grant: CCI Applied Research and Development Grants

White spruce (Picea glauca) is one of the most important species in the forestry industry, because they are used to produce pulp and lumber for construction. White spruce is often found growing with deciduous trees in Boreal mixed wood forests across Canada, but aspen (Populus tremuloides) competition limits the growth of white spruce and decreases merchantable volumes. Pesticides and thinning have often been used to manage deciduous competition, but there are concerns regarding their effectiveness and environmental impacts. Bending and breaking (BB) is a promising alternative method to control conifer competition. Here, we implement and optimize the Bend and Break method, which is a manual method where stems are bent over to a 90-degree angle, to limit aspen competition and regeneration. The method of BB differs from manual cutting, because the former keeps a section of the cambium alive. As a result, resources are allocated to the broken section, limiting regeneration through suckering. The Northern Alberta Institute of Technology (NAIT) has partnered with Tolko Industries Ltd., a Canadian forestry leader, to initiate a multi-year study investigating the large-scale implementation of BB in northern Alberta. The objectives include determining the amount of area to treat around spruce, the optimal time to apply treatments, and the ideal stand ages. We also aim to assess the repeatability of results in forest cut blocks. We will set up 8 forest cut blocks, and within each block we will set up plots where 1, 1.5, or 2 m of aspen trees are treated around spruce. Plots will also be set up, where trees are treated in the Spring, Summer, or Fall. Plots will be treated in 2023, 2025 and 2027 to assess stand age effects. Multiple plots will be set up within the blocks to determine the repeatability of results. This project will optimize BB methods in mixed-wood boreal forests and improve our understanding of how BB can be incorporated into forest land management plans as a tool for enhancing white spruce growth and productivity. The results are significant as forestry companies can increase forest yield while respecting Indigenous rights as BB will not contaminate the land with pesticides. Results will provide valuable information to the forestry industry for improving merchantable white spruce volume while minimizing environmental and social impacts.