An alternative fire regime zonation for Canada

Abstract

The ability of national and multipurpose ecological classification systems to provide an optimal zonation for a fire regime is questionable. Using wildfire (.1 ha) point data for the 1980-99 period, we defined zones with a homogeneous fire regime (HFR) across Canada and we assessed how these differ from the National Ecological Framework for Canada (NEFC) units of corresponding scale, i.e. ecoprovinces. Two HFR zonations were produced through spatially constrained clustering of (i) 1600-km 2 cells and (ii) the smallest units of the NEFC system, i.e. ecodistricts, using attributes for natural and anthropogenic fires. Thirty-three HFR zones were identified. HFR zonations showed smaller differences among each other than with NEFC ecoprovinces. Comparisons with ecoprovinces suggested general agreement of generalised fire regime values with HFR zones but with poor zone boundary correspondence. Ecoprovince zonation led to an overgeneralisation of fire regime estimates with less variation captured than by the HFR zonations, especially that using gridded fixed-area cells. Estimates of fire-return interval strongly differed between a priori and HFR zonations. The use of large-scale NEFC units or a zonation using its smallest units may constrain our ability to accurately quantify and portray fire regime variability across the country. The alternative empirical HFR zonation using gridded cells refines the location and nature of fire risk.

Resistance of the boreal forest to high burn rates

“…S4). Assuming that burn rates higher than 1% are constrained to some degree through a stand-age feedback, then about 700,000 km 2 of boreal forest would be fuel-limited, mostly in the northernmost, unmanaged part of the biome (39). Although the commercial boreal forest is more productive, and potentially less fuel-limited, than its unmanaged counterpart, it is also less exposed to high burn rates because fires are by far more frequent in the unmanaged sector (Fig.…”

The pyrogeography of eastern boreal Canada from 1901 to 2012 simulated with the LPJ-LMfire model

“…Within the study area, high-intensity crown fires are the most common type of fire events (Flannigan et al, 2016). Fire regimes are heterogeneous, but generally follow a declining trend along a southwest-northeast gradient (Boulanger et al, 2012). During the period of , the highest burn rates occurred in the western part of the BS ecozone (> 1 % yr −1 ), while they were the lowest in the TSE ecozone (< 0.2 % yr −1 ) (Boulanger et al, 2014).…”

Attributing extreme fire risk in Western Canada to human emissions

“…We use the homogeneous fire regime (HFR) zones defined by Boulanger et al (2012), who used a cluster analysis of fire characteristics and climatologies to refine the eco-classifications of the Ecological Stratification Working Group (ESWG) (1996) to regions more suited to wildfire analyses. The HFR zones in western Canada were numbered by the authors and the region containing Fort McMurray was selected (Fig.…”