Theme 2 | Identification and Selection of Suitable Tree Species

We know that global change is making life increasingly difficult for Canadian trees; Temperatures and precipitations are changing, natural disturbances such as fires are expected to become more frequent and intense, and exotic pests and diseases are on the move. But trees are not all the same: some species, and some populations within species, will tolerate these new conditions better than others.

Changes in the climate have happened in the past. As the climate changed, tree species moved within their range, expanded and shrunk their range, and adapted to new conditions. 

A similar process is expected to take place in Canada in the future due to anthropogenic climate change. But the speed of these changes will likely not give enough time for some tree species to move or adapt. These new conditions are also expected to alter disturbance regimes (fires, insect outbreaks, wind events, etc.). Global changes are then adding to this situation increasing likelihoods of invasion by new pests and disease. These new conditions will reduce the resilience of forests, and increase the likelihood that they shift into new states, or into new ecosystems. This will limit the ability of forests to provide many ecosystem services : water, wood, biodiversity, shelter, food, and so on.

With human intervention, we can favor species that will help maintain the health of tomorrow’s forests. We can speed up the process of species displacement by planting new tree provenances or species in new locations (a process called “assisted migration”). We can also favor some species over others through management decisions, therefore changing the composition of forests to make it more adapted to future conditions.

But such endeavors only make sense if we can predict which tree species will be most adapted to future climate conditions and expected disturbances in a given area. This is the aim of theme 2 : to find out what tree species are more adapted to future local conditions across Canada so that they can be favored in forest management.

Theme 2 will use data from Theme 1 concerning the vulnerability of tree species in Canada and their functional traits. It will then define functional groups for each of our research sites based on a measure that distinguishes how tree species differ from each other in terms of functional traits. For each management unit, we’ll end up grouping species into functional groups.

Once this is done, we will create guides recommending species of functional groups to plant in different bioclimatic regions of Canada. By recommending functional groups rather than species, we will give more flexibility and options to forest managers around Canada to ensure that their local knowledge can be put to good use. This should give forest managers an easy-to-use tool to increase the resilience of forests to future conditions.