Shelterwood Harvest
Definition
Even-aged management technique practiced on older stands to establish new crop or release existing crop of desirable seedlings before next or final overstory harvest. One or more partial cuts of overstory often utilized to provide conditions favourable for establishment and growth of natural regeneration. With exception of legacy trees, final harvest normally occurs when desired regeneration attains height of 1-3 m.
Also acceptable as single pass where retained trees have no prospect of being harvested and left for ecological purposes. Single pass aims to release advanced regeneration already present at sufficient or greater than sufficient levels. At least 50% of desired advanced regeneration protected within leave strips.
Can be applied uniformly or in patches, depending on site requirements.
Eligibility Criteria
Softwood stands: Must contain at least 20 m²/ha of desired species (eastern hemlock, red spruce, white spruce, black spruce, white pine, white ash, red oak, yellow birch, sugar maple, red maple) with at least 12 m²/ha being softwood species (eastern hemlock, red spruce, white pine). Must contain >30 m²/ha of merchantable basal area.
Hardwood stands: Must contain at least 12 m²/ha of desired species (red oak, white ash, yellow birch, sugar maple, red maple, eastern hemlock, red spruce, white spruce, black spruce, white pine, balsam fir) with at least 8 m²/ha being hardwood species (red oak, white ash, yellow birch, sugar maple, red maple). Must contain >20 m²/ha of merchantable basal area.
Residual trees: minimum 30% live crown, good health and form.
Guidelines and Assessment Procedures
- For stands lacking consistent favorable regeneration: maximum 40% of original basal area removed
- May be increased to 60% if stand is sheltered and consists of well rooted trees with consistent advanced regeneration (favorable species, >1400 stems/ha throughout). Prioritize protection and retention of advanced regeneration. Stands left at least 5 years following harvest before understory thinning
- Partial cuttings should remove poorest quality trees and maximize residual stand content of desired species (exceptions acceptable for wildlife habitat enhancement)
- Can be done in strips (preferably at right angles to seed dispersing winds) or patch method with opening of 0.3 ha or less, distributed uniformly when possible
- Residual stand must have sufficient vigour to remain healthy for 20 years following treatment
- Minimize damage; maximum 5% damaged crop trees