Climate Change

Managing Forests under Climate Change

Climate change is predicted to significantly affect our forests, and therefore our landscape and our society.


The resiliency of our forests depends on site conditions, interactions among plants and animals, the amount of forest, and historical and current human pressures.  It also depends on genetic fitness and diversity. Our forests are diverse in species, but each species is also made up of unique, locally adapted populations and individuals.  So any plan to adapt to climate change must consider these complex factors in any local area.

As the climate changes, some individual trees or even whole local populations of a species may not prove adapted, nor have the capacity or time to evolve.  And they may not be able to migrate to more favourable conditions – there is evidence that the climate is changing faster than natural migration, via wind, water and animals, has occurred in the past.  Another barrier to migration is the effect that temperature and other weather extremes could have on flowering and seed production.

So our forests’ capacity to adapt, thrive and provide the many benefits our society needs, depends on the quality of today’s efforts  – our ability to conserve, manage and restore our  forests as outlined below.  We will also depend on our neighbours’ success – forests in northern USA may contain options for southern Ontario’s future forests – both southern populations of our native species and species new to us.  Likewise our northern neighbours will rely on our forests.

1. Conserve Forests Strategically within local landscapes

  • To conserve diversity within species = the many unique local populations and individuals
  • To maximize habitat for all species
  • To conserve soil and local water systems
  • To facilitate natural migration processes
  • To maintain local climate moderation function

2. Restore Forests Strategically

3. Bank local material off site (ex-situ)

  • Collect and bank source-identified seed of species that can be stored long term
  • Plant seed of other species outside of their origin = assisted migration, to become seed production areas for future climates

4. Monitor local forests and assisted migration plantings

  • to learn more about species’ basic biology and determine their vulnerabilities and strengths
  • to observe climate change effects on different species, sites and ecosystems
  • to communicate the results to local landowners and forest managers

Climate Change Resources
The big picture and local considerations:

Assisted Migration

Assisted Migration is a strategy involving moving seed and stock from milder climates to assist with natural migration processes which are predicted to be slower than the pace of climate change.
The Role of Assisted Migration in Southern Ontario – (PDF 230 kB)

Seed Collection

Quality and Source of seed is critical to the resilience of the planted forests.
Seed Collection Guidelines under Climate Change – (PDF 77 kB)

Effects on our Forests

Read more to understand how climate change is already having an effect on our forest.
Climate Change and Ontario Forests  – (PDF 18 kB)