Biodiversity

SHAPE of Nature: State of Canada's Trees

Wildlife Conservation Society Canada [WCS Canada]

Access

---

This evaluation reports on the conservation status of tree species in Canada.

Key points

• Almost 1 in 4 species of trees is at-risk in Canada.
• At–risk trees occur in every province of Canada. Ontario, Quebec, and BC have the highest number of at–risk trees.
• The greatest threats to Canada’s at-risk trees are habitat loss, invasive species, and climate change.

Abstract

Almost one in four species of trees is at risk in Canada.

Canada has 234 species of native trees. This includes wild species, subspecies, varieties, or other important units of biological diversity. Of these, 57 have been assessed at risk in Canada or globally (Figure 1) (see Data Sources & Methods for definition of ‘tree’).

Almost half of Canada’s at-risk trees are of global conservation concern and have been ranked as imperilled or vulnerable by NatureServe and/or Critically Endangered, Endangered, Vulnerable or Near Threatened on the IUCN Red List of Threatened Species.

At-risk trees occur in every province of Canada. Ontario (39), Quebec (12), and BC (11) have the highest number of at-risk trees (Figure 1).

Four species of trees have disappeared from Canada. Four species are nationally endemic and do not occur in other countries.

The greatest threats to Canada’s at-risk trees are habitat loss, invasive species, and climate change.

Some at-risk trees species found in Canada are threatened because of current or projected steep declines in numbers (e.g., Butternut, Limber Pine). Others are threatened because they have small populations or ranges that makes them vulnerable to national or global extinction (e.g., Pacific Bayberry, Murray’s Birch).

Many at-risk tree species with small ranges, such as Swamp Cottonwood in southern Ontario will trigger Key Biodiversity Areas.

Insects and other wildlife depend on trees, and tree diversity, for their survival. The important role that trees play in wildlife habitat, ecosystem functions, and human well-being make our actions to conserve trees particularly critical for protecting biodiversity and halting extinctions.

Recommended citation

Wildlife Conservation Society Canada [WCS Canada] (2023). SHAPE of Nature: State of Canada's Trees. Wildlife Conservation Society Canada [WCS Canada]. https://wcscanada.org/resources/shape-of-nature-state-of-canadas-trees/