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Tree Marker Profile: Al Corlett

Posted: October 31, 2019

Tree marking involves the careful selection of trees for harvest or retention based on tree size, health, quality, biodiversity and wildlife habitat. In short, tree markers work to create healthy forests.

I had the pleasure of chatting with Al Corlett, Silviculture Specialist for Forests Ontario and Coordinator for the Ontario Tree Marker Training Program, about his experiences as a tree marker and thoughts on the profession as a whole.


Al Corlett helping Forests Ontario sell Christmas trees at the Toronto Christmas Market.

In your opinion, what’s the best thing about being a tree marker?

The responsibility of it. By that, I mean the responsibility of having to see the big picture. Tree markers look at tree biology; strategies for regenerating, managing, and improving a forest; forestry; and wildlife habitat values. They must recognize the values they encounter and adapt management to satisfy the needs of those values – and they are providing many of the values that society demands, including high value forest products and healthy forests.


I’ve interviewed a few tree markers for this series and one thing I keep hearing is that there is a shortage of tree markers in Ontario. Why do you think that is?

I think that a lot of tree markers in the industry are moving on to different positions or retiring and there’s a lack of younger people seeking tree marker training and moving into the entry-level positions. There’s an awareness issue in that [forestry] graduates don’t realize that these jobs are available. By the same token, a lot of employers looking for qualified technicians or foresters to blend into their programs don’t specifically say, “You’re going to be expected to do tree marking.” We need to increase awareness of job opportunities, and that will lead to more young forestry graduates seeking tree marker training.


How did you start your career?

I graduated from the University of Toronto with a degree in Forestry in 1975. My first tree marking job was right out of school; I was hired by the Ministry of Natural Resources and assigned to Lanark District (now Lanark County). I was the Management Forester there and I had the responsibility for the Crown forests there and the Lanark County Agreement Forest.


Did you take a tree marking course?

There wasn’t one back when I started!  The Selection Management System and the Uniform Shelterwood System were still in their infancy.


So how did you learn the ins and outs of tree marking?

My manager expected me to do a lot of tree marking in my first months there because he thought it was the best way for me to learn the area and the species, the biology of those species, and the sites they grow on. So, I was put with a crew of technicians who were much more experienced at tree marking than I was; they were my mentors.

A few years later, tree marking courses started being developed by a forester called Mac McLean and a research scientist named Harvey Anderson. They built the science around it and trained a lot of people. I eventually had the opportunity to take my first tree marking course in the Tweed area.


How did you get into teaching tree marking?

In the late 80s I took a position as Algonquin Regional Silviculture Specialist, and part of my job was to provide training to people in the region. The area I covered was from Parry Sound to Pembroke, including Algonquin Park and Bancroft. I helped out with local district courses put on by the forester in each of those districts.

Then, around 1992, there was a proposal that tree marking be made a certified position.  This meant that there needed to be a single course that everyone working in the Great Lakes St. Lawrence Forest Region needed to take to have a consistent level of training and the same information – the same science.


I’ve heard that every tree marker has at least one weird story from being out in the bush. What’s yours?

I’ve heard of strange things that other people have found… but me? Most of the neat stuff was wildlife encounters.

Hmmm… oh, I know! I was doing a tree marking audit in Algonquin Park and I needed to get the field work done because I couldn’t come back the next day. I was working on my own, but there were other people working in the forest – I could hear trucks and so on, until everyone went home at 5pm.

I was still there at 7pm and it was totally quiet. I’m walking through this hardwood area and I see this bear sign. There were these beech trees in there with claw marks (indicating that the bear had climbed up to eat the beech nuts in the crown) and I knew there were bears around there. So, I’m being kind of cautious, looking around… and suddenly this thing just EXPLODES out of the brush by my feet.

I just about had a heart attack! Turns out it was only a fawn – a little, spotted 30-pound fawn.

But I decided I’d had quite enough of that audit and headed straight back to the truck. I’ll never forget that moment.

Interested in tree marking? Certification through the Tree Marker Training Program is necessary to become a tree marker in Ontario. This tri-level program is delivered by Forests Ontario and CIF. For more information, please visit