State of Canada’s Trees

Addressing the biodiversity crisis in Canada will require transformative change. See our backgrounder on transformative change for more information. Specific actions for the conservation of at-risk trees include:

Federal, provincial, territorial & Indigenous governments

• Develop a robust National Biodiversity Strategy and Action Plan to implement the goals and targets of the Kunming-Montreal Biodiversity Framework, with a focus on protected and conserved areas, recovery of threatened species, and invasive species to help safeguard trees in Canada. 
• Prevent the introduction and spread of invasive species and support research to develop biocontrols and other tools to manage existing invasive insects and diseases. Support implementation of existing invasive species strategies. 
• Ensure tree planting and reforestation (including Canada’s Two Billion Tree Commitment) are conservation-focussed and include a variety of locally sourced native species. Include species that are rare and declining when they can be locally sourced, is biologically appropriate, and supports species recovery actions. 
• Restore Indigenous land stewardship practices that promote tree diversity and ecosystem health and resilience. 

• Support efforts to identify and conserve trees that are resistant to introduced pests and pathogens (e.g., Forest Gene Conservation Association). 
• Establish and effectively manage and restore protected and conserved areas to protect the habitat for at-risk trees, particularly those with small ranges. 
• Invest in actions to accelerate the identification and conservation of Key Biodiversity Areas in Canada that include at-risk tree species. 
• Support Conservation Data Centres across Canada to continue to survey and rank at-risk trees. 

 Local governments & communities

• Develop programs and capacity to monitor and manage invasive species. 
• Inventory and protect at-risk tree species in your jurisdiction. 
• Include at-risk and other native trees in planting projects where biologically appropriate.

Civil societies, community organizations, universities, colleges & museums

• Target a–risk tree species for land protection and stewardship actions. 
• Research how planting at–risk tree species outside of their current range and conserving climate refugia could help them to adapt to climate change.  
• Develop and maintain seed banks for at–risk tree species in Canada that capture genetic diversity across their range. 
• Support and advocate for the designation of Key Biodiversity Areas that include at–risk tree species with small ranges.

Businesses & corporations

• Avoid projects that could impact at-risk tree species and their habitat and seek opportunities for ‘nature-positive’ actions that will improve their status. 
• “Adopt” a- risk tree species and fund communities and organizations that are protecting these species.

Everyone

• Learn and talk about at–risk tree species found in your area. If possible, source locally grown at–risk trees and grow them. 
• Support early detection of invasive species. Learn about these species in your areas and report sightings using iNaturalist or EDDMapS. 
• Join societies and local groups that advocate for the conservation of threatened biodiversity. 
• Support Key Biodiversity Areas or other conservation projects near you that help to highlight and conserve at-risk trees and other threatened species. Volunteer as a KBA caretaker or create a caretaker group.

NatureServe and the IUCN Red List use complimentary, but different criteria for assessing conservation status. Status assessments by NatureServe have been completed for a much larger number of species than IUCN Red List assessments. 

Additional background in species assessments can be found in in our backgrounder on species assessment and these sites:

IUCN Red List

NatureServe

COSEWIC

High confidence – this information is based on published assessments by the IUCN Red List and status ranks assigned by NatureServe. 

Most species of trees have been identified and ranked in Canada. Not all the tree species that we included may meet the definition of a ‘tree’ throughout their range (see Data Sources & Methods). 

The list of tree species was developed based on lists of trees from five different sources: 

• Natural Resources Canada – Index of Trees
• Database of Vascular Plants of Canada (VASCAN) – Checklist builder (Plants with the habit: ‘trees’) 
• State of the World’s Trees – Global Tree Portal – Country Search (‘Canada’) 
• Data sharing for conservation: A standardized checklist of US native tree species and threat assessments to prioritize and coordinate action (Carrero et al., 2022) – Supporting Information 
• Trees Canada – Trees of Canada online database 

These lists, and field guides of trees in Canada (e.g., Lauriault, 1989) all have variations on the number of native tree species found in Canada and the definition of ‘tree’. We followed the definition of Beech et al. (2017) used by Carrero et al. (2022), the IUCN Global Tree Specialist Group, and the standard for the Global Tree Assessment initiative:

A tree is a woody plant with usually a single stem growing to a height of at least two meters, or if multi-stemmed, then at least one vertical stem five centimeters in diameter at breast height. 

There are several species on our list, such as Smooth Alder, Eastern Burning Bush, and Dwarf Hackberry that, depending on location and site conditions, may not always meet the definition of tree we use in this analysis. 

We included tree species and infraspecies but not hybrids. The final list of trees from Canada was cross-checked with most recent information in NatureServe Biotics database to confirm they are native to Canada. The NatureServe Biotics database was also used to identify national and global status and range in Canada. Species with rounded national ranks of N1, N2, N3, NH and NX were included, along with species assessed on the IUCN Red List of Threatened Species as Critically Endangered, Endangered, Vulnerable, and Near Threatened. 

The preliminary assessment of threats was based on published information in Red List and COSEWIC assessments and ranking information by NatureServe. Threats were categorized based on the IUCN threats classification. Threat categories of 1.1 Housing & urban areas, 2.1 Annual & perennial non-timber crops, 2.2 Wood & pulp plantations, and 3.2 Mining & quarrying were combined as ‘habitat loss’.  

See our backgrounder on species assessments for more information on the methods used by NatureServe, COSEWIC and the IUCN Red List.