Herbicides should be kept out of forests: group

A group of residents in the central Interior are calling for an end to herbicide spraying of public forests.

  • Aug. 18, 2011 11:00 a.m.

A group of residents in the central Interior are calling for an end to herbicide spraying of public forests.

The group, Stop the Spray B.C., opposes the herbicide spraying of replanted areas on the grounds that it leaves stretches of newly reforested land largely devoid of broad-leaf plants diminishing diversity, limiting habitat and potentially damaging amphibian species that rely on it.

The herbicide commercially known as Vision Max that contains the chemical glyphosate is approved for spraying by timber licensees by the Ministry of Environment.

In an e-mail interview, the ministry describes glyphosate as a herbicide commonly used in the forest sector after replanting harvested areas to enhance the survival and growth of conifers  — that complies with Ministry of Forest, Lands and Natural Resource Operations directives stipulating species that are logged have to be the dominant species in a cutblock within 10 years. The ministry says the herbicide can aid in “preventing and reducing the impact of competing vegetation on new trees.”

However, James Steidle, Stop the Spray BC spokesperson, says the presence of broad-leaf species like aspen and birch that are targetted by the herbicide can be a benefit to maintaining a healthy soil that also benefits conifers.

“There are a whole range of concerns. In a nutshell it’s an unnecessary exposure of a known toxin to a number of different wildlife species,” Steidle said, noting that tadpoles and frogs are potentially at risk and that the long-term risk of spraying the herbicide in the forest has not been studied.

“It blows my mind that we go out there and kill whole classes of plant species — blueberries, raspberries and all the aspen. Aspen trees are huge cradles of biodiversity in the forest. … They perform all sorts of services to forest ecosystems.”

Regarding the herbicide’s impact on frogs, the ministry concedes that “over spraying could result in concentrations of glyphosate and associated attributes to be of concern to amphibian health.” And the ministry suggests pesticide management decisions should avoid negative effects to amphibians that may be present; it notes that Health Canada’s  Pesticide Management Regulatory Agency is re-evaluating glyphosate in herbicides and therefore, the ministry is taking “precautionary measures.”

From an environmental standpoint, the Sierra Club of Canada notes glyphosate has been shown to kill beneficial insects, as well as have negative impacts on birds and small insect-eating mammals. Effects on fish can include erratic swimming, gill damage, and changes in liver structure. Glyphosate   impacts non-target plant species in decreasing both the number of seeds germinating and the seedling weight.

The ministry requires forest licensees to use integrated pest management which includes prevention, considering alternatives to pesticides and monitoring pesticide activities. The application of Vision Max last year occurred  on 18,000 hectares of B.C.’s total forested area of 55 million hectares.

The herbicide is applied using aerial spot treatment from a helicopter or by workers on the ground. The herbicide is currently sprayed in the Lower Mainland, Omineca, Peace, Cariboo and Skeena areas of the province.

In a bid to halt the spraying in the Prince George Forest District, Stop the Spray B.C. has acquired funding from West Coast Environmental Law to challenge the Prince George Pest Management Plan. Steidle says this has occurred elsewhere in the province through the years and has resulted in a decline in areas that are sprayed.