James Steidle vividly remembers the slow death of aspen trees in the forest next to his family’s cattle ranch, nearly 15 years ago, after forestry planners in British Colombia sprayed glyphosate, an herbicide found in Roundup.

The trembling aspen wilted and took on a red hue. “The glyphosate killed all the leafy vegetation. The stuff that didn’t die became stunted,” says Steidle, a woodworker and forest activist living in Prince George. “They just started blasting. We had spray camps set up around our house. And helicopters. We told them we didn’t want them to do this but they did it anyway. They sprayed right up to our property line.”

Glyphosate, the most active ingredient in Roundup, is a widely used weedkiller in agriculture and forestry. It’s also a likely carcinogen. A recent study by US scientists showed that people exposed to glyphosate have biomarkers in their urine linked to the development of cancer and other fatal diseases.

Steidle has been campaigning for a glyphosate ban for years, but the Canadian government re-examined and re-authorized its use in 2017. Glyphosate spraying was forbidden in Québec more than 20 years ago but it is still the norm in most provinces, particularly in New Brunswick. Critics allege that government agencies and forestry experts have been captured by industry.

Glyphosate was first sprayed next to Steidle’s family home several years after the pine beetle infestation in BC, which prompted forestry planners to carry out extensive clearcut logging and plant more pine trees even though the beetles nest and feed on mature pine.

“It didn’t make any sense,” says Steidle, who spent part of his youth tree planting and was an active member of the Canadian Labour Congress. To make matters worse, he says, forest managers sprayed herbicide to prevent any plant species from competing with commercially valuable conifer plantations. Timber from evergreen tree farming is a major cash crop.

Across Canada and abroad, the commercial forest industry has created monoculture conifer plantations of lodgepole pine, spruce and Douglas fir. It’s common practice to use glyphosate and brush saws in forests to destroy broadleaf species—such as aspen, birch, cottonwood, willow and alder—which are crucial for biodiversity and sequestering carbon. Pine trees and spruce survive the spraying because they have a coat of wax on their needles that glyphosate doesn’t penetrate. But other plant species die, even symbiotic fungi and bacteria. Steidle says forests sprayed with glyphosate become sterile and quiet, often void of insects, birds and song.

Steidle believes that forest managers are trying to make the ecosystem fit their industrial model but their forestation policies are actually making forests more flammable.

“We wage chemical and mechanical warfare against the deciduous forest type to grow the most flammable forest type possible,” he stresses. “Climate change is making fire worse but forest management is gasoline on the fire.”

Steidle says conifers suck more water out of the ground and are more flammable, in part because of their architecture (the trees are needle-leaf from top to bottom). “They are a conduit for fire.” Aspen trees, on the other hand, moisten their environment. “They are basically like straws that suck in moisture. They are more fire resistant. If you have a ground fire it is harder for the fire to get into the canopy of an aspen tree.”

Research on the dynamics of fire has reinforced Steidle’s argument. A multi-decade study by Steve Cumming, a professor or forest ecology, showed in 2001 that pine forests are 8.4 times more likely to burn compared to deciduous aspen. The desiccated vegetation from glyphosate spraying is also more flammable.

Martin Alexander is a world expert on the behaviour of fires who worked as a research officer at Natural Resources Canada for more than three decades. He says he is unaware of any studies examining the impact of glyphosate spraying on fire behaviour, but he is acutely aware of the protective nature of aspen trees.

In 1979, a fire broke out in the forests at Willow River in the Northwest Territories on the traditional land of the Dene First Nation. The Dene had created an aspen-dominated forest around their community as a result of their trapping and fuel wood activities. The black spruce forest outside the settlement burned, but the aspens immediately surrounding their community acted as a fire break. “Their community did not burn. The outcome was pretty dramatic,” Alexander told me.

A 2019 study showed that 80 percent of First Nations communities in Canada are located in fire-prone regions that are often isolated. In the past, First Nations drew on their traditional knowledge to use controlled burns to manage and rejuvenate their lands. With the recent surge in severe, uncontrollable wildfires across Canada, there appears to be a slow, growing recognition that Indigenous knowledge must be incorporated into mainstream forest management strategies.

But the imperatives of eco-capitalism and the commodification of nature have long taken precedence over the traditional knowledge of Indigenous communities—to our collective peril.

First Nations in Ontario have observed the impact of glyphosate on their ecosystems for decades and call the herbicide the “rain of death.” They say glyphosate contaminates medicinal plants, kills birds and other animals, and poisons the waters on their territory. A group of elders from 21 bands on the North Shore of Huron, known as the Traditional Ecological Knowledge (TEK) elders have joined the Nishnawbe Aski Nation (representing 49 First Nations in Ontario), the Mushkegowuk Council, the North Shore Tribal Council, and Anishnaabe chiefs of the upper Great Lakes to voice their opposition to aerial spraying. Not surprisingly, they have been given the bureaucratic run-around by the federal government.

The TEK elders and other First Nations groups are also trying to persuade academics to question and update their scientific research on glyphosate, which was first introduced in 1974 by the agrochemical giant Monsanto. Monsanto was purchased by the German pharmaceutical company Bayer in 2018.

Perversely, the use of glyphosate and other herbicides is ensured by industrial monoculture plantations around the world. Under the pretext of climate change mitigation schemes, millions of trees are planted. The plantations do provide raw materials for biofuels and act as powerful carbon sinks. But when a natural forest is converted to a plantation, a natural ecosystem is destroyed. Biodiversity is lost and organic matter and nutrient levels are depleted. In a bid to manage reduced soil fertility, forestry planners use artificial fertilizers and herbicides. Each year, 10 million hectares of natural forest are lost to monoculture plantations. The policy is not addressing climate change. It’s compounding it.

Judi Rever is a journalist from Montréal and is the author of In Praise of Blood: The Crimes of the Rwandan Patriotic Front.