A refinement of models projecting future Canadian fire regimes using homogeneous fire regime zones

Abstract

Broad-scale fire regime modelling is frequently based on large ecological and (or) administrative units. However, these units may not capture spatial heterogeneity in fire regimes and may thus lead to spatially inaccurate estimates of future fire activity. In this study, we defined homogeneous fire regime (HFR) zones for Canada based on annual area burned (AAB) and fire occurrence (FireOcc), and we used them to model future (2011-2040, 2041-2070, and 2071-2100) fire activity using multivariate adaptive regression splines (MARS). We identified a total of 16 HFR zones explaining 47.7% of the heterogeneity in AAB and FireOcc for the 1959-1999 period. MARS models based on HFR zones projected a 3.7-fold increase in AAB and a 3.0-fold increase in FireOcc by 2100 when compared with 1961-1990, with great interzone heterogeneity. The greatest increases would occur in zones located in central and northwestern Canada. Much of the increase in AAB would result from a sharp increase in fire activity during July and August. Ecozone-and HFR-based models projected relatively similar nationwide FireOcc and AAB. However, very high spatial discrepancies were noted between zonations over extensive areas. The proposed HFR zonation should help providing more spatially accurate estimates of future ecological patterns largely driven by fire in the boreal forest such as biodiversity patterns, energy flows, and carbon storage than those obtained from large-scale multipurpose classification units.

Human-caused fire occurrence modelling in perspective: a review

“…Accordingly, the temporal dimensions for fire observations may be daily (Crosby 1954;Haines et al 1983;Alonso-Betanzos et al 2003;Lozano et al 2007;Albertson et al 2009;Wotton et al 2010;Padilla and Vega-Garcia 2011;Sakr et al 2011), monthly (Preisler et al 2004;Boulanger et al 2014) or yearly (Todd and Kourtz 1991;Prestemon and Butry 2005;Hu and Zhou 2014;Karouni et al 2014). However, longer time-spans of several years are the most frequent (Pew and Larsen 2001;Chuvieco et al 2008;Avila-Flores et al 2010;GonzalezOlabarria et al 2011;West et al 2016).…”

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

“…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). Annual burn rates in the BP ecozone and in the eastern part of the BS ecozone varied from 0.2 to 0.5 % yr −1 , whereas they varied from 0.5 to 1.0 % yr −1 in the HP ecozone (Boulanger et al, 2014).…”

Regional Instability in the Abundance of Open Stands in the Boreal Forest of Eastern Canada

“…In fact, the burn rate varies according to the area being calculated and the periods of time selected being covered by the calculation [58]. This can lead to considerable variability of burn rate values or to their overestimation [59,60] that obscures the influence of fire regimes on the actual distribution of ecological patterns [61]. Landscape dynamics models often apply the assumption that fire regimes do not change for long periods of time, while significant variations in burn rates are observed from one year to the next, and from one decade to the next [58,62].…”