A recent CBC news story about the use of glyphosate in BC to remove deciduous trees has generated considerable discussion about the practice. Below, I reproduce two letters relevant to this issue. The first is a letter submitted by the president of BC Nature to the Honourable Doug Donaldson and the Honourable George Heyman on October 9, 2019. The second is the reply to this letter from Shawn Hedges, RPF, Acting Executive Director/Deputy Chief Forester, Office of the Chief Forester.
October 9, 2019
Honourable Doug Donaldson
Minister of Forests, Lands, Natural Resource Operations and Rural Development
Honourable George Heyman
Minister of Environment and Climate Change Strategy
Dear Ministers Donaldson and Heyman:
I write to you on behalf of BC Nature (the Federation of BC Naturalists), which represents more than 50 naturalists’ clubs and 6000 members province-wide. Our membership consists of dedicated naturalists, including scientists, who are connected to, have expertise in and concern for the preservation of British Columbia’s landscapes and the diversity of organisms that inhabit them. We support any effort to promote the integrity of our natural ecosystems, not only to protect their biodiversity, but also our lives and the lives of our progeny in British Columbia.
BC Nature expresses dismay about the aerial spraying of glyphosates as an herbicidal tool to promote conifer crop species growth by killing aspen. We are well aware of the ongoing controversy about the use of glyphosate and its accompanying additives, including different opinions within your ministries. We oppose the spraying.
BC Nature questions silviculture plans mandated to convert mixed conifer broadleaf forest to conifer-only forest, thereby greatly reducing not only habitat and species diversity and the complexity of the soil ecosystem, but also fire resistance and climate change resilience. Many of our members worry about the impact of diminished deciduous forest on the number and variety of Neotropical migrants, already in steep decline. Most of these birds help control insect populations and require this mixed forest habitat for breeding and the production of their food. Consumptive users of broadleaf forest, such as trappers, report a decline in furbearers after aerial spraying. Fire danger, temperature increase and carbon dioxide sequestration decrease without an aspen mix. If regeneration hasn’t failed in the absence of herbicide application, perhaps herbicides were never required. While the possibility exists that aspen will slow the growth of conifers, we feel that, in general, the effects of conifer/broadleaf competition are exaggerated, at least in the BC Interior. Can those making the prescriptions show that the use of herbicide is necessary by providing evidence of what happens if they don’t use it while using the best regeneration practices?
We are highly suspicious of claims that Bayer-Monsanto uses to defend glyphosate safety and ask you to examine the mounting evidence that the chemical is a carcinogen, likely to all mammals. Germany has banned glyphosates. The EU may follow suit. A recent lab study found epigenetic transfer of diseases and other abnormalities in descendants of rats exposed to glyphosate (Kubsad et al. 2019). We wonder if the known threat to frogs, insects and other invertebrates extends to other animal taxa and microbes. Glyphosate can be stored in roots of perennial plants during dormancy and then move up to shoots and fruits in years following application (Wood 2019). We don’t know the long-term effects.
Perhaps further research will reveal symbiotic relationships between aspens and conifers, in parallel to UBC’s Suzanne Simard’s work (Simard et al. 1997) on the facilitation of young Douglas-fir forest growth and soil pathogen control by paper birch in the Southern Interior. And could the currently doomed aspen become more valuable as a crop tree?
At the landscape level (10,000 ha plus), BC Nature is seriously concerned with the prospect of shifts from broadleaf and mixed forest conditions to conifer-dominated landscapes and associated shifts in bird populations. We demand assurances that where spraying is taking place, in the Peace or Omineca, such shifts are not occurring. Independent data sources and analyses, (e.g. Forest Practices Board) could resolve this issue.
We claim that along with many obvious environmental and health costs of intensive herbicide application others remain hidden…for now. At a time when the agricultural model of herbicide use is being revisited, it seems ironic that glyphosates are applied increasingly to our natural ecosystems. While not a major practice in forestry in our province, we remain concerned and implore you to revisit the issue and carefully re-examine aerial spraying of glyphosates as an herbicide tool to more quickly grow marketable timber.
Cornelis (Kees) Visser, Ph.D., P. Geol.
References (further references upon request):
Deepika Kubsad, Eric E. Nilsson, Stephanie E. King, Ingrid Sadler-Riggleman, Daniel Beck, Michael K. Skinner. 2019. Assessment of Glyphosate Induced Epigenetic Transgenerational Inheritance of Pathologies and Sperm Epimutations: Generational Toxicology. Scientific Reports 9 (1): 6372
Simard, SW, Durall, DM, Jones MD. 1997. Carbon allocation and carbon transfer between Betula papyrifera and Pseudotsuga menziesii seedlings using a 13 C pulse-labeling method. Plant and Soil 191 (1): 41-55
Wood, L. 2019. The presence of glyphosate in forest plants with different life strategies one year after application. Canadian Journal of Forest Research, 2019, 49(6): 586-594
Letter in reply from Shawn Hedges, RPF
Cornelis Visser, Ph.D., P. Geol., BC Nature
Federation of BC Naturalists
Dear Doctor Visser:
Thank you for your email of October 9, 2019, advising Ministers Donaldson and Heyman regarding glyphosate use in British Columbia’s forests. I am pleased to respond on behalf of both Ministers.
Achieving diversity and ecosystem resilience is a key objective of this government and is considered across all treatments. Hence the government agrees that aspen, willow and other deciduous trees and plants provide a wide range of important values that need to be managed across the landscape. To that end, reforestation policy has steadily evolved with respect to incorporating broadleaves into reforestation prescriptions to meet a variety of objectives, including biodiversity, ecosystem integrity and resilience and more recently fire resistance.
Our researchers have conducted and reported on numerous brushing trials in reforested areas over the past several decades across the province, comparing untreated controls to a full range of options for managing competing vegetation. Based on this ongoing research into the impacts of competing vegetation, the ministry now allows significantly increased levels of broadleaves in managed stands on appropriate sites. Licensees have indicated that the changes made in the Cariboo region have reduced annual brushing programs there by an average of 17 percent.
The use of glyphosate is sometimes necessary on high brush prone productive sites to temporarily set back competing vegetation so that the desired crop of new trees can reach a free growing and productive state. Glyphosate is applied on a relatively small area of the provincial timber harvesting land base and has declined from an average of 13,802 hectares for the last five years and higher historical levels. Roughly 11,000 hectares of crown land were treated with glyphosate for silviculture in 2018 representing 0.04 percent of the 25 million hectares available for harvesting in BC and 0.44 percent of the tenured area on crown land that has an outstanding reforestation obligation.
The BC Ministry of Environment and Climate Change Strategy (ENV) administers the Integrated Pest Management Act and Regulation, the primary regulatory tools governing the use of pesticides in the province. The Integrated Pest Management (IPM) Program of ENV promotes IPM and environmental stewardship and ensures compliance with the Integrated Pest Management Act and Regulation.
Staff in ENV rely on Health Canada’s Pest Management Regulatory Agency (PMRA) to identify risks from the use of approved pesticides. Based on their 2019 decision, the PMRA indicated that they believe there is no new information that alters their most recent re-evaluation of glyphosate and stated there are no significant risks to human health or to the environment when used according to the label and the Integrated Pest Management Regulation (IPMR). The levels experienced by the public both directly and indirectly are not expected to result in any health concerns.
One of the primary public concerns regarding the use of glyphosate in forestry is the perception that by using it to control competition of broadleaf species such as trembling aspen, broadleaves are being eliminated from the landscape. These claims however are not supported when analyzing the level of deciduous components at free-growing, or the increase in mixed deciduous stands over time as a result of forest management.
A 2008 Forest and Range Evaluation Program review of species diversity pre and post-harvest in BC found that the amount of deciduous mixed stands at free growing increased from 2,811 hectares before harvest to 55,614 hectares in the Northern Interior Forest Region for all reporting periods. In the Northeast and Omineca Regions, where most herbicide treatments take place, the average number of deciduous stems/ha remaining at free growing following earlier aerial herbicide treatments was 864 and 445 stems per hectare, or 27 percent and 15 percent of the total stand species composition.
On a final note, I am pleased to advise that earlier this year the Office of the Chief Forester initiated an independent assessment of peer-reviewed forest science and best practices related to glyphosate use as a vegetation management tool in BC’s forests. The assessment is being conducted by FPInnovations in the context of the current array of forest values and objectives, such as biodiversity, carbon sequestration, wildfire, natural range in variation of species, and wildlife. The goal of the review, which should be completed shortly, is to help inform the development of future policy and research needs to promote the establishment of healthy and diverse forests.
Thank you for your interest in the management of BC’s forests.
Shawn Hedges, RPF
Acting Executive Director/Deputy Chief Forester
Office of the Chief Forester
pc: Honourable Doug Donaldson, Minister of Forests, Lands, Natural Resource
Operations and Rural Development
Honourable George Heyman, Minister of Environment and Climate Change Strategy