Capacity for post-fire and post-harvesting regeneration, rehabilitation and growth of juvenile/immature stands in the boreal forest
The results will enable forest managers to assess the extent to which forestry can be developed in these northern areas and using which practices, taking into account natural disturbances influenced by climate change. In addition, better anticipation of the consequences of climate change will improve the ability to manage the forest in such a way as to maintain productive stands and thereby achieve sustainable forest management.
The southern Canadian boreal forest is an important source of fibre for the forest industry and its forest biomass and soils represent a significant carbon reservoir. This forest, which is mainly composed of black spruce, is sustainably managed based on present productivity. Along its northern edge, closed commercial forest is becoming increasingly open.
The effects of climate change will be even greater at the latitudes of the Canadian boreal forest. The combined effect of natural disturbances, forest management and biophysical, meteorological and climactic conditions could have significant repercussions on forest growth and regeneration, the dynamics of ecological systems and the ability to achieve sustainable forest management.
Better understand the factors that affect the density and growth of stands situated at the limit of the closed boreal forest following natural disturbances or silvicultural treatments, with a view towards sustainable forest management.
Evaluate and compare forest growth and regeneration after harvesting and after fires to identify the factors responsible for forest resilience following disturbance.
Reconstruct the fire dynamic and its impact on forest functioning on a time scale of centuries.
Model future landscapes taking into account natural and anthropogenic disturbances.
Develop forest management practices and strategies aimed at maintaining maximum closed forest in a context of climate change.
The Rapport du Comité scientifique chargé d'examiner la limite nordique des forêts attribuables [report of the scientific committee to examine the northern harvestable forest boundary] (Ministère des Ressources naturelles du Québec, 2013) distinguished portions of the boreal forest where the risk posed by sustainable development practices could be classed from high to low. This project aimed to document the effect of climate change on that zoning and to suggest adaptation strategies.
The project made it possible to measure the risk posed by regeneration accidents in places where fire cycles are short or very short. After a few decades, losses of productive areas will accumulate significantly. These losses of productive land, to which are added the reductions in production in other areas that have remained productive, may considerably affect the expected wood production in the coming decades.
The project also measured the risk posed by paludification in the areas located on the Cochrane Till, that is, the northwestern part of the clay belt that runs through Ontario and Quebec between Cochrane District and Abitibi-Témiscamingue.
Projections associated with climate change do not show any significant improvement in the current constraints. In fact, more fires are expected, and productivity will be uncertain and could drop.
Although fires are expected to increase, they can only rarely boost the productivity of sites that are already severely paludified. Over time, fire will remove a quantity of wood that must be subtracted from the supply. As the age structure of the forest gradually becomes younger, more and more young, non-marketable stands will burn, and salvage harvesting offers few mitigation options.
There are solutions for reducing the extent of the problems that have been documented, but their effectiveness is variable and they draw significant amounts from forestry and road budgets.
Figure 1. Summary of the potential sensitivity of black spruce and jack pine to temperature increases and drought according to post-fire recruitment stage. Sensitivity to temperature (T°) and to drought are classified by species along a gradient from very sensitive (—) to insensitive (~) (Boucher et al. 2019).
Benefits for adaptation
Benefits for adaptation
The results of the project will assist in the development of a risk management approach that will enable forest management decisions to be made by controlling the risk factors that can compromise the success of management strategies.
The results apply more broadly to the entire Canadian boreal forest. The benefits are therefore significant for the forest industry, which plays a major role in the Canadian economy.
Management strategies should allow for potential problems based on the level of risk that can be associated with them in all portions of the boreal forest.
Bureau du forestier en chef
Coopérative de solidarité en recherche et développement forestier de l’Abitibi-Témiscamingue et du Nord du Québec
Direction de la recherche forestière et Direction des inventaires forestiers, Ministère des Forêts, Faune et Parcs
Centre de recherche en foresterie des Laurentides, Service Canadien des Forêts
Université de Montpellier
Université de Montréal