Glyphosate Wildfire Risk in Nova Scotia: Evidence and Approvals

An ongoing wildfire season in Nova Scotia has focused attention on forestry practices linked to landscape flammability—most notably, the provincial approvals for aerial glyphosate spraying on drought-stressed forest land. This article summarizes facts about glyphosate wildfire risk and key uncertainties based on recent information and scientific context.

What Has Been Approved and Why

• Area and approvals: In 2025 the province approved aerial glyphosate spraying covering roughly 3,577 acres (about 1,447 hectares) of forest described as drought-stricken and fire-prone. Exact parcel locations have not been widely disclosed to the public.
• Purpose: Forestry operators use glyphosate to remove competing deciduous trees and shrubs so that commercially preferred conifer seedlings can establish more quickly and meet silvicultural targets. Supporters argue this improves timber yield and stand uniformity.

Why Critics About the Risk of Glyphosate Wildfire

• Dead biomass and short-term fuel loading: When herbicide kills vegetation, that material dies and can dry out. In hot, dry conditions this dead material can become additional surface fuel, potentially increasing short-term ignition risk and fire intensity.
• Loss of mixed-wood resilience: Mixed stands with deciduous species such as aspen can reduce crown fire spread because deciduous foliage usually has higher moisture and lower resin content than conifers. Removing these species can make stands more homogeneous and, in some circumstances, more susceptible to rapid fire spread.
• Timing during drought and active wildfire season: Approvals issued or implemented during drought conditions raise additional concerns because drying conditions accelerate the transition of recently killed plant material into highly flammable fuel.

Scientific Uncertainties and Evidence

Several technical questions remain unresolved or depend on site-specific conditions:

• How quickly sprayed vegetation increases fire hazard: Drying time for killed stems varies by species, season, and weather, making short-term fire risk difficult to generalize without local monitoring.
• Residues and ecosystem effects: Glyphosate residues can persist in plant tissues and soils for variable periods; ecological impacts depend on application rate, vegetation type, and site conditions. These factors influence how stands recover and how fuels change over years.
• Tradeoffs: While glyphosate can speed conifer establishment, it can also reduce biodiversity and natural fire-resistant structures. The balance of economic benefit versus ecological and fire safety risk is not universally settled.

Alternatives and Risk-Reduction Measures

Forest managers and fire safety experts point to a suite of alternatives or complementary actions that can reduce fuel risk while achieving silvicultural goals:

• Mechanical competition control such as mowing or targeted cutting instead of aerial spraying.
• Selective thinning to maintain mixed species and create structural breaks.
• Prescribed burning where safe and feasible to reduce fuels under controlled conditions.
• Timing spray approvals for seasons with lower fire risk, and publishing detailed maps and buffer zones to increase transparency.

Adding Fuel to the Fire?

Glyphosate is a widely used silvicultural tool; however, its application in drought-stressed, fire-prone landscapes raises concerns about short-term increases in fuel and longer-term impacts on forest resilience. The tradeoffs—economic, ecological, and public safety—underscore the need for site-specific risk assessment, careful timing relative to fire conditions, and consideration of non-chemical alternatives. Ongoing monitoring and clear information remain essential for effective wildfire risk management.