Planning under uncertainty: Explaining divergences between planned and harvested areas in Québec’s public forests (1999–2013)

This study examines planning-implementation gaps in Québec’s public forests under the historical Timber Supply and Forest Management Agreements (CAAF) regime (1999–2013). Using a mixed-methods approach, spatial and temporal divergences between planned and realized harvesting were quantified, and the patterns were interpreted through interviews with forest managers. Results reveal persistent gaps: at the annual operational level, 50-100% of planned areas remained unharvested, while 10-100% of harvesting occurred outside of initial planned locations. These trends were consistent across ecological zones. Partial harvesting showed higher non-implementation rates than clearcutting, while off-plan harvesting was primarily driven by operational adjustments rather than changes in silvicultural prescriptions. Planning-implementation gaps stemmed first from internal planning challenges, including fine-scale economic profitability constraints, access limitations, and inventory uncertainties, which were further exacerbated by external disruptions such as market volatility and climatic disturbances. The findings suggest that discrepancies between initial plans and execution reflected the short-term adaptive flexibility inherent to the iterative, pre-permit planning exercise. This study provides an empirical baseline of implementation fidelity under industry-led management and emphasizes the need to account for operational realities and profitability when evaluating hierarchical planning systems, offering key guidance to support the design of future planning frameworks.