Forests Ontario

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How are Crown Forests Replenished?

Posted: July 25, 2017

by MJ Kettleborough

How are Crown Forests Replenished?

­­­­­­­­­­­­­­­­­­­­Forest Regeneration

Approximately 87% of Ontario is made up of Crown land, providing opportunities for tourism, recreation, and economic development. Trees are one of the province’s most valuable resources, and are harvested from Crown forests to produce a variety of products. Regeneration refers to the act of growing back forest by either natural or artificial means after harvesting. By law, forest managers must ensure adequate regeneration of the forests they tend.

­­­­­­­­­­­­­­­­­­­­The MNRF’s Role

The Ministry of Natural Resources and Forestry (MNRF) is responsible for managing Ontario’s natural resources in an ecologically sustainable manner, ensuring their abundance for future generations. They achieve this through a range of legislation, policies, and programs. Sustainable Forest License holders use this framework—in consultation with indigenous peoples and the public—to develop Forest Management Plans, including detailed regeneration plans.

Mike Brienesse, Policy Advisor with the MNRF says, “The plans differ for every area of forest that needs regeneration. Forest managers factor in different elements of the land to see what’s possible.” These elements can include the sustainability of the soil, the types of trees already growing in the area, the types of competing vegetation expected to grow, and the kind of forest desired for the future.  “What it comes down to is working with nature, not against it.”

Site Preparation, Methods of Regeneration, and Maintenance

Forest managers must decide on natural forest regeneration, artificial regeneration, or a combination thereof. “The total amount of natural or artificial regeneration that occurs is the sum of all the individual site decisions,” Mike explains. Whatever method is chosen, the site will likely need to be prepared. This usually includes tilling the ground and collecting and disposing of debris and undesired vegetation.

Natural regeneration is the preferred method for Crown forests, as it is low cost and ensures that only trees suited to the site are established. Forests can regenerate naturally from root stump sprouts, root sprouts, seeding from adjacent forests and continued growth of young trees remaining at the site.

If artificial—or ‘assisted’—regeneration is chosen, the options are seeding or planting. Though more expensive than natural methods, artificial regeneration tends to be the quicker of the two. Additionally, artificial regeneration gives forest managers more control, all the way down to trees’ DNA and introducing desirable genetic traits.

Young renewal sites are tended over time to control competing vegetation. This may or may not include thinning or spacing, and weeding or cleaning. Herbicides may also be used to help control unwanted vegetation growth. Of course, only herbicides that have been approved by the Ministry of Environment can be used. These are applied from either the ground or the air under strict regulation.


There are some misconceptions about Crown forest regeneration claimed as fact online and elsewhere. There is a belief, for example, that a specific number of trees are planted to replace every one tree harvested. “The truth is much more complex,” according to Mike. “In terms of planting numbers, there’s really no specific formula.”

When it comes to the number of trees planted, seeded, or naturally regenerated of Crown land to replace those harvested, it is very difficult to obtain accurate data. There are varied opinions on what even counts as ‘a tree.’ When does a seedling become a viable tree? Is that determined by height? We know that many young trees don’t survive due to weather, disease, or simply because they were eaten by wildlife.

“I can tell you that in in the 2013/2014 fiscal year there were 63.4 million trees planted for Crown forest renewal,” Mike offers.

The MNRF are one of many organizations, programs and individuals working to re-green our province. Forests Ontario’s Green Leaf Challenge encourages tree planting and keeps a running tally, viewable online at


MJ has thoroughly enjoyed learning about forestry since joining Forests Ontario’s Communications Department this past winter.  She enjoys good music, bad YouTube, and is far too excited about this season of Game of Thrones. Winter is coming!