A new silvicultural approach to the management of uneven-aged Northern hardwoods: frequent low-intensity harvesting

We report a new silvicultural approach that is well suited for the management of uneven-aged forests in which timber production is an important objective. The approach recognizes two main components in the stand, i.e. a fiber production component, which provides veneer/sawlog quality products from the high-quality trees (HQT), and an ecological component, which contributes to the overall ecosystem functioning through the lower value stems. The objective of the study was to verify if it is possible to sustainably harvest only HQT in northern hardwood (NH) and thereby produce a viable alternative to high-grading the stands. To do so, a simple stand growth simulator, based on empirical growth rates of HQT in Sugar Maple/Yellow Birch stands in southwestern Quebec, was combined with an optimization tool. The optimization parameters aimed to identify possible tree marking regimes (TMRs) under 10-year rotation partial cutting, which would ensure that the basal area of HQT was maintained for 40 years. Results suggest that sustainability is achievable starting from very different initial stand structures and the application of a wide range of alternative TMRs. We argue that this new approach is one way to apply emerging concepts in forest management, such as ecological integrity, attempts to emulate natural disturbance regimes and provides new possibilities managing for resilience and for adaptation to climate change.