Atlantic Forestry March 2019

Science and the beast

Glyphosate gets the all-clear from Health Canada

by David Palmer

“Enjoy your deli sandwich – it is riskier than glyphosate.” With those words, Dr. Len Ritter, professor of toxicology at the University of Guelph, wrapped up a 30-minute pre-lunchtime lecture summarizing the dozen or so studies conducted by national regulatory agencies since 2010 on a herbicide that is widely used in agriculture and forestry (and also in home and garden applications) to control unwanted competitive growth.

Glyphosate, developed by Monsanto but now owned by Bayer, is the active ingredient in Roundup. It was first registered for use in Canada in 1976. Its usage, particularly in agriculture, is growing by leaps and bounds, and currently exceeds one billion pounds a year globally. It is extremely effective at killing unwanted vegetation. In agriculture and home use, it is used to kill weeds in fields and lawns; in conservation, it is used to kill invasive species like Glossy buckthorn and Japanese knotweed; in forestry, it is used to kill hardwoods and shrubs that choke out planted seedlings. With 40 years of field and forest application, there has been lots of time for problems to show up.

All was fine and dandy until a 2015 report from the World Health Organization (WHO) International Agency for Research on Cancer, which touched off a regulatory firestorm by declaring glyphosate to be a “probable carcinogen” (see AFR, March 2016, pg. 25). That study gave rise to a campaign called “Stop Spraying New Brunswick,” which garnered an unprecedented 35,607 signatures (one in 20 New Brunswickers). The petition was presented in the legislature by Green Party MLA David Coon, who took advantage of the opportunity to cite a litany of concerns about glyphosate.

Opinions about spraying are polarized, and have less to do with science than with values. You could spray lemon juice on the forest and people would still be opposed. There are three parts to the opposition: one is concern about the inherent safety of the product; another has to do with the idea of killing young hardwoods to allow softwoods to grow better; finally, there is the question of who should pay for the spray.


Speaking at a vegetation management workshop presented in January by the Association of Registered Professional Foresters of New Brunswick, Dr. Ritter said warnings from the WHO study still pepper the internet, despite numerous exhaustive reviews conducted by a number of health and regulatory authorities. In the most recent review, completed this January, Health Canada said its scientists “left no stone unturned” and “had access to all relevant data and information from federal and provincial governments, international regulatory agencies, published scientific papers and multiple pesticide manufacturers.” Health Canada concluded that “the levels of glyphosate to which Canadians are exposed do not have any harmful effects, including cancer.”

If we trust Health Canada’s scientists (and why shouldn’t we?), that should settle the question once and for all. But does anybody really think that Health Canada’s clean bill of health for glyphosate will change the mind of even one of those 35,607 people who signed the anti-spraying petition in New Brunswick? It certainly hasn’t changed the position of campaign chairperson Caroline Lubbe-D’Arcy. She still has concerns over the impacts on wildlife and the environment. It also hasn’t affected the provincial government, whose throne speech pledged “to develop a model for a proper scientific review of the use of glyphosate,” albeit as part of a larger review of the Crown Lands and Forests Act.


Even if spray opponents accepted the preponderance of evidence that glyphosate is safe, they still don’t like the idea that it’s being used to kill hardwoods so that softwood plantations will grow better. The practice of clearcutting and re-planting with genetically-improved stock on the best tree-growing sites, followed by “weeding” using herbicides, and later thinning, is known as intensive forestry. Some might call it “tree farming,” as it mimics agricultural practices. In theory, if practiced on a portion of the landscape, enabling more wood to be grown on a smaller area, it will free up forest that has higher conservation value, allowing more land area to be protected.

For example, in an unexpected turnaround following a review of New Brunswick’s 2014 Forestry Plan, the previous Liberal government restored the area of conservation forest from 23 percent to 28 percent, and committed to doubling protected areas on Crown land – a move that was credited to better-than-expected growth rates on forest plantations. The increase will add 150,000 hectares to the province’s Crown land protected areas network (more than the combined area of four National Parks: Fundy, Kouchibouguac, Prince Edward Island, and Cape Breton Highlands), moving the provincial total up to 10 percent – still below Nova Scotia’s current 12 percent, but a big leap forward for New Brunswick.


In Nova Scotia, the Lahey report, now accepted by the provincial government, recommended a three-pronged approach to forestry on Crown land – a model commonly known as “triad” forestry. At one end of the spectrum, with minimal or no harvesting, is the conservation or protected forest; at the other end is the intensively managed industrial forest; and in the middle is the rest of the forest, where – according to Nova Scotia’s plan – clearcutting will be reduced, and harvesting will be carried out following ecological principles. In the intensive forest, herbicide spraying will be allowed, but the province won’t be paying for that treatment.

Under New Brunswick’s current Crown silviculture model – whether it’s thinning, planting, or applying herbicide – the government pays. The annual bill is a whopping $25 million, of which the herbicide portion is $2.5 million. The reasoning behind this government investment is that the land belongs to the government, and the government is therefore the primary beneficiary of the silviculture. It’s like owning an apartment; improvements to rental units are usually paid for by the landlord, not the tenant.

Moreover, the forestry deal that New Brunswick signed with J.D. Irving in 2014 binds the government to ensuring that funding for silviculture is adequate to support the increased wood supply that was guaranteed at that time – though there may be some wiggle room to negotiate changes to that deal, as industry has not fulfilled all commitments on their side.


While the triad model is an attractive concept, in practice it is up against some formidable obstacles, not least of which is agreeing on the proportions of protected and intensive forest. Intensive forestry is expensive and requires a long-term commitment; neither governments nor industry can afford to apply it to a large area, and in order to get the best bang for the buck, it must be limited to highly productive, operationally suitable sites. While spruce plantations blanket nearly 50 percent of JDI’s 200,000-hectare Black Brook District in northwestern New Brunswick, most industry wonks believe 20 percent is a more realistic proportion of any given forested land base. Andrew Kekacs, executive director of the Nova Scotia Woodlot Owners and Operators Association, is an enthusiastic proponent of the triad concept, and he thinks the area under intensive management should roughly equal the area of protected forest – say, about 15 percent.

A second challenge, and by far the largest one, is switching from current practices – which are primarily clearcutting or high-grading – to the new ecological forestry model of harvesting, where multi-age management prevails, and light-touch logging is the rule. While it is true that a high-value forest is the eventual outcome of this type of harvesting, it will take decades to get to that point. In the meantime, the products coming from these improvement harvests will be low-value and low-volume, probably necessitating substantial long-term subsidies to make it work. What government has the financial resources to support this on a large scale?

More importantly, without markets for those low-grade products, the whole exercise will grind to a halt. Nova Scotia is already down to two pulp mills, and the future of one of them is swinging in the breeze.

Finally, many sawmills, particularly hardwood mills, are already faced with log shortages. As implementation of the Lahey plan rolls out, and harvest practices refocus from taking all the products of the forest in one sweep (which generally yields a mixture of good and poor quality) to removing primarily the low-grade products, saw material shortages will become more acute, and an over-supply of pulpwood will develop.

It wasn’t so long ago that the New Brunswick government announced an initiative to retain and restore what remained of the Acadian Forest. The plan was scotched when it was calculated that the required changes in harvest practices would put an additional 100,000 cords/year of softwood pulp on the market, at a time when there was already a huge over-supply. The project never saw the light of day.

To offset the reduced supply of saw material coming from Crown operations during a prolonged period of quality-improvement efforts on this land base, harvest pressure on private land will increase. If industry can’t get the wood it needs from one source, it will go after that wood elsewhere.