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.