Twenty-year recovery of managed stand, in structure and composition, in boreal mixedwood stands of northwestern Quebec

Abstract

The Natural Disturbance Based Management (NDBM) aims to maintain specific structural and compositional attributes of natural forests in managed stands. Operationally, NDBM relies on diversifying and adapting silvicultural practices, including partial harvesting (PC), to expand the range of options beyond that of simply clearcuts (CC). Established in 1998, the SAFE (Sylviculture et Aménagement Forestier Écosystémique) project evaluates this potential in hardwood, mixedwood and coniferous stands in northwestern Québec, Canada. Our results confirmed a part of the NDBM objectives i.e., PC allowed the maintenance of stands with mixed structure and composition, constituting an interesting complement to CC, which reset stand regeneration. However, PC did not accelerate the stands transition to later stages with less intensive harvesting or to earlier stages with more intensive harvesting. We essentially had an initial impact, delaying or stopping the stands evolution which dissipates over time and more quickly with less intensive harvesting. Furthermore, our results did not support the ability of PC to enhance the development of old-growth attributes like deadwood. Despite the 20-year horizon of this study further field surveys will be required in the future to better understand the impact of different silvicultural treatments on forest productivity and biodiversity preservation throughout a forest rotation.