by Jay Malcolm

It’s something that I’ve heard over and over again in my 25 years teaching at a forestry school. I was talking to an older, highly respected forester in the woods the other day and he turned to me and said: “You know, Jay, if we could just educate people about what foresters actually do, they’d see that we’re doing a great job. We wouldn’t have these ‘wars in the woods'”.

When it comes to the way that we manage our forests in the boreal zone, however, this sentiment increasingly rings hollow. No doubt, some part of the Canadian public is skeptical about what foresters are doing in the boreal forest: they see the clearcuts and wonder whether they can be a good thing. The science behind forestry is now showing that this gut feeling is well placed. With the growing pace and scale of clearcutting in the boreal forest, foresters are doing our wildlife resources a disservice and actually increasing the rate of global climate change.

It is useful to start with the idea of clearcutting. How did it become a key part of boreal forest management? Although forest fires and clearcuts are not the same by any means, they share a key characteristic: both reset the forest to age zero. If one thinks about a natural boreal forest, it will have been exposed to thousands of years of natural fires. The net effect is a mosaic of forests of a diverse array of ages, which helps to support a huge diversity of wildlife. Some species such as moose love young forests with their abundant browse close to the ground. Others, such as caribou and many woodpeckers, specialize on the features that older forests provide, such as abundant lichen for food and dead trees for feeding and nesting.

From a global climate change perspective, clearcuts might not seem to be such a bad thing either. Global warming is caused by a buildup of greenhouse gases in the atmosphere, principal among them being carbon dioxide. Of course, trees suck that carbon out of the atmosphere as they grow; that is, they “sequester” it. In process of photosynthesis, they remove the atmospheric carbon dioxide and combine it with water to make wood and other carbon compounds. Trees grow fastest and sequester the most carbon when they are relatively young, typically less that 100 years old. From this perspective, young forests seem to be an ally in efforts to reduce the amount of carbon in the atmosphere, a potential “nature-based” climate solution.

But there is a much darker side to clearcut-based forest management. Unfortunately, we simply make far too many of them and in the process liquidate too much old forest. Again, there is a certain logic to it, although twisted. The logic from a forester’s perspective comes if one thinks of trees as simply a crop to be harvested. If just the right amount of forest is harvested every year, over time the forest landscape can be maintained at a young enough age such that any further harvesting is “optimized” from a timber perspective. Once the forest is at that sweet spot, you can keep harvesting relatively young forests every year that are at a perfect size from a production perspective. Their volume growth over time is at its maximum. Beyond that point, about 100 years of age, foresters call them “decadent”.

The problem with this approach though is that it has no parallel in nature. As the old forest is removed to make way for these young “optimized” forests, those species that need the older forests lose out. Caribou are now either gone or are on their way out from every place that we commercially log in the boreal forest. Older forests are not “decadent” but instead are a key resource for hundreds of boreal species.

From a climate perspective, things are a bit more nuanced, but equally alarming. I mentioned earlier that young trees take carbon out of the atmosphere at a great rate: what’s not to love about that? This may be the second most common sentiment I hear from foresters: “we need young, quickly growing forests to sequester carbon”! The problem though, is that as we remove the older forests, we remove the huge amounts of carbon that is already stored in them and much of it goes into the atmosphere. In the transition from natural forests to production forests, it turns out that about one-half of the forest carbon it is released into the atmosphere. This “debt” of carbon emitted into the atmosphere gradually builds up.

In theory, the debt can be paid off as the harvested wood is turned into products that keep carbon out of the atmosphere. Many will argue that using wood pellets to generate electricity instead of fossil fuels can also help to pay off the debt. The problem in our boreal forests though, is the rate at which we pay off the debt is not even close to the rate at which it is created. Many aspects of harvesting emit carbon into the atmosphere. We leave a lot of wood behind (such as logging slash and tree tops) that rots and releases its carbon into the atmosphere. We use fossil fuels to harvest the wood, transport it, and process it. The carbon in many wood products doesn’t actually stay out of the atmosphere very long because paper products have a half-life of only a few years. Much wood ends up in landfills that vent greenhouse gases. Wood pellets must be milled, dried, and transported. The net effect is that the carbon expenditures during and after the harvest can outweigh any carbon savings. A recent “life-cycle” analysis of the forestry sector in the United States; that is, an accounting that carefully measured all of these emissions and savings, revealed that the carbon expenditures actually outweighed any savings. Under those conditions, the debt can not be paid off at all. Even if we use the wood to replace fossil fuels, for example during electricity generation or during building construction, research shows that the rate at which we pay off the debt is much too slow to help global warming at all, taking 100 years or more.

So, what about the three sentiments that I continue to hear: “if they only knew”, “young forests are the name of the game”, and “let’s use wood pellets as green energy”. I must admit that it gets pretty frustrating arguing against those refrains: many people have been banging on the drum for quite a while now. Science is increasingly rearing its head and showing that our current management is hurting wildlife populations and making the climate crisis worse. Foresters, one hopes, will listen. Here’s to a revolution in our thinking. Its not that we don’t understand what foresters do: we know what they’re doing and it needs to change.

Jay R. Malcolm is Professor Emeritus at the Institute of Forestry and Conservation at Daniels, University of Toronto. His publications include “Forest harvesting and the carbon debt in boreal east-central Canada.“