When wildfire escapes into the wildlands-urban interface, homes, industrial facilities, and other urban values can be threatened or destroyed. As recommended by the FireSmart Canada program, vegetation management is a key principle in mitigating the risk of wildfire affecting urban values. In 2007, at a forested test site in the Northwest Territories, Canada, FPInnovations evaluated the effectiveness of using vegetation management- i.e., removal and reduction of forest fuels from the vicinity of a small building- as a strategy for protecting the building from wildfire.
Forest fuels engineering is one of the primary wildfire mitigation strategies advocated by FireSmart™ Canada and applied by partnering wildfire management agencies and industry operators. Fuel treatments have been extensively applied in and around communities in the wildland-urban interface, through a broad range of fuel modification techniques. A primary objective of fuel treatments is to modify fire behaviour to a ‘less difficult, disruptive, and destructive’ state (Reinhardt et al. 2008) which can allow for safer, more effective fire suppression operations (Moghaddas and Craggs 2007).
Black spruce is one of the most prevalent fuel types surrounding communities in central and northern Alberta, as well as other parts of boreal Canada. The densely stocked black spruce forest stands in the Red Earth Creek FireSmart research area exhibit typical crown fuel properties of black spruce: high crown bulk density and low crown base height, which contribute to crown fire initiation (Van Wagner 1977). These fuel characteristics, combined with low fuel moisture contents and strong winds, create ideal conditions for high-intensity, rapidly-spreading catastrophic wildfire (Flat Top Complex Wildfire Review Committee 2012).
Mulch fuel treatments use various types of equipment to masticate forest vegetation resulting in a reduction in crown bulk density and the conversion of canopy and ladder fuels to a more compacted and less available fuel source in the surface layer (Battaglia et al. 2010). Mulch thinning and strip mulch treatments create a more open surface fuel environment with both negative and positive impacts. Due to increased exposure to sun and wind flow, the chipped debris and other surface fuels in the open areas of the treatments dry more quickly than fine fuels in enclosed stands (Schiks and Wotton 2015). From a control perspective, the open thinned areas of the treatments allow more effective penetration of water/suppressant through canopy fuels to surface fuels (Hsieh in progress). Additionally, fine fuels at the surface of openings respond more quickly to water and suppressant application. Open areas of the treatments that have been wetted by sprinkler systems or aerial water delivery should reduce the potential for ignition and sustained burning, providing a potential barrier to fire spread.
Experimental crown fires have been conducted to challenge fuels treatments in other forest fuel types (Schroeder 2010, Mooney 2013) to evaluate the efficacy of these treatments in moderating fire behaviour. Mechanical (shearblading) fuel treatments in black spruce fuels (Butler et al. 2013) have been shown to reduce fire intensity. However, documentation of crown fire challenging mulch fuel treatments in black spruce fuels is limited. Fire and fuels managers would like to evaluate the effectiveness of mulch fuel treatments in reducing fire intensity and rate of spread and, ultimately, their ability to mitigate wildfire risk to communities surrounding these hazardous fuels.
Alberta Agriculture and Forestry (AAF) Wildfire Management Branch fuels managers designed the Red Earth Creek FireSmart research area with the objective of conducting research that will lead to a better understanding of mulch fuel treatments and how these changes in the black spruce fuel environment affect fire behaviour. On May 14, 2015, Slave Lake Forest Area personnel conducted an experimental fire at this site; FPInnovations and research partners collected data to document changes in fire behaviour.
The Canadian Boreal Community FireSmart project has been the site of several research projects designed to evaluate the efficacy of fuel treatments in mitigating wildfire. In June 2016, FPInnovations conducted an experimental crown fire which challenged a mulch fuel treatment.
Northwestern Alberta has been a focal point for agricultural expansion for many years. More recently, accelerated lands sales have led to the clearing of large tracks of land and significant burning projects aimed at preparing the land for agricultural use. Given the requirement for land owners to have burning permits during “Fire Season” (March 1st – October 31st) and the risks involved in large scale burning during fire season, sites are often differed to time frames outside the established fire season. Although windrow burning outside of fire season often poses less fire escape risk, other issues can arise and result in public safety concerns e.g. smoke, which can increase the potential for health issues and traffic accidents. Given these concerns local forestry and municipal authorities have engaged in discussions aimed at identifying potential burning options.
Class A foam “lowers water’s surface tension making it more effective in suppressing fire in Class A combustibles (wood, vegetation, paper and cotton products and rubber)” (ICL Performance Products LP, n.d.). Alberta Agriculture and Forestry has used class A liquid foam and liquid foam inductor kits in wildfire suppression since the 1980s. Although class A liquid foam has proven to be an effective tool, promoting the consistent use of it in Alberta has been a challenge since its introduction. Firefighter reluctance to use class A foam is often linked to reasons such as set-up time, working with the foam solution, system awkwardness, and anecdotal comparisons to straight water.
Alberta’s Provincial Warehouse and Service Centre (PWSC) was approached by ICL Performance Products LP (ICL) regarding a new class A foam system, the Phos-Chek SOLID Foam Stick and Scotty Foam-Fast Applicator. The foam stick and applicator were promoted by ICL as a simple and effective way of producing low-expansion class A foam using minimal equipment. Following an ICL presentation to Alberta’s PWSC and Fireline Equipment Working Group (FEWG), a decision was made to pursue field trials before considering a large-scale purchase.
To facilitate field trials, the PWSC purchased several applicators and a supply of foam sticks with the intent of having their firefighters assess the system. Further discussion by the group identified a lack of consistent evaluation criteria and a need for documented, fact-based test results. In follow-up, the PWSC requested assistance from Alberta’s Wildfire Management Science and Technology (WMST) program to engage a research provider, and in March of 2015, they asked FPInnovations to conduct an evaluation of the Phos-Chek SOLID Foam Stick (formulation ID #049-019F) and the Scotty Foam-Fast Applicator (model 4010-50).
FPInnovations worked with the WMST program working group, PWSC manager, and designated FEWG members to review research questions, project needs and develop the following project objectives.
Forest fuels engineering is one of the primary wildfire mitigation strategies advocated by FireSmart™ Canada (Partners in Protection, 2003) and applied by partnering wildfire management agencies and industry operators. Over the past two decades, mechanical forest fuel treatments (including mulching) have been extensively applied in and around communities in the wildland-urban interface to mitigate the risk of wildfire. Fuel managers and fire operations managers would like to better understand how manual and mechanical fuel treatments modify fire behaviour.
Fuel treatment efficacy has been evaluated through post-wildfire case studies (Mooney, 2014; Pritchard et al., 2011), fire behaviour modelling (Fernandes, 2009; Stephens et al., 2009) and subjective expert opinion based approaches (Hayes et al., 2008). The use of experimental fire to evaluate the effectiveness of fuel treatments is limited.
In late June and early July of 2015, many large fires burned in Saskatchewan (Figure 1). Two of these fires threatened pre-existing community protection fuel treatments established to protect their villages. This report documents the treatments completed and the influence that the treatments had on fire behaviour as fire moved into them. The two communities that had their fuel treatments challenged were the hamlets of Weyakwin and Wadin Bay. Weyakwin had built a fuelbreak on the east side of town and thinned 4.6 ha of forest on the west side of the fuelbreak. Wadin Bay had also completed a thinning project to protect the hamlet from fire moving in from the west and south. Two trips were made to observe and document the fuel treatments and how fire behaved within them. Stand density data was collected within and beside the treatments to describe the fuel environment. Other data sources included fuel treatment plans, fire weather data, fire chronology information and personal communication with those who were involved in the projects and firefighting efforts.
Current forest management policy in many jurisdictions in North America manages excess woody debris by piling and burning it, mainly as a post-harvest fire hazard abatement obligation. This study highlights three key points to consider regarding utilization and disposal of waste wood piles:
1) Allocate most woody debris waste to the biofuels sector in a cost-effective manner;
2) Allocate a small portion of woody debris (e.g. 10-15%) to implement windrow habitats where necessary to maintain mammalian biodiversity on clearcuts;
3) Limit burning of waste wood to those sites near human activity (potential fire hazard) that do not have an opportunity for biofuels or windrow purposes.