Implementation of an updated tree marking prescription for selection-managed northern hardwood forests: Effects on stand vigour, quality and value recovery

In selection-managed northern hardwood forests, tree markers select trees for harvest based on their vigour and quality, which are assessed based on the presence or absence of defects. Recent research has shown that trees that develop crown dieback decline in vigour, but not necessarily in quality, and tree marking simulations indicate that prioritizing the harvest of these high-quality salvage trees increases value recovery by 17–18% compared to existing prescriptions. However, this is likely an overestimate because the tree marking simulations did not account for various operational constraints. We developed an operational tree marking prescription that prioritizes recovery of high-quality salvage trees and conducted a field trial to compare it to two prescriptions commonly used in Ontario. Few high-quality salvage trees were marked under the existing prescriptions, but most were marked under the new prescription, which also retained more high-vigour trees. The new prescription also recovered 15-16% more value, though this difference was not statistically significant. Our results demonstrate that prioritizing high-quality salvage trees increases stand vigour while maintaining or potentially increasing value recovery under operational conditions.