Fire suppression or exclusion is most likely the cause of several structural changes on the landscape, including an increase in tree density (Covington and Moore, 1994), changes in species composition (Weaver, 1943), shifts in grassland-forest ecotones (Arno and Gruell, 1983) and an increase in forest fuels and fire severity (Covington, 2000). Concerns have been raised about these unnatural changes especially in the light of recently large fire events and pest outbreaks (Filmon, 2004; Maclauchlan et al., 2006; Romme et al., 2006; Klenner et al., 2008) and it has been suggested that restoration is needed to return the landscape to a more natural condition (Gayton, 1996; Filmon, 2004).
Vaseux-Bighorn National Wildlife Area (NWA) is situated in the south Okanagan, BC (Figure 1). The NWA has seen large areas where the tree density has increased, and fire suppression is stated as one of the reasons that the NWA is currently in a poorer state as when in was established in 1979 (Environment Canada, 2011).
Using fire scars and forest demography data, Daniels and Pogue (2017) reconstructed the fire history on the west side of Vaseux-Bighorn NWA from 1714-2013. They determined that, until the mid-19th century, fires would burn through the area on average every seven years. These fires were driven by indigenous traditional burning, but lightning fires also occurred. These fires were of mixed severity. European colonization brought disease and indigenous people were moved onto reserves which caused a gap of almost 50 years before the next fire event occurred.
The reduction of fuel load to prevent catastrophic fires and re-introduction of low-intensity fires are two goals laid out in the Vaseux-Bighorn NWA management plan:
“Goal 1: Restoration and management of important habitats and ecosystems, particularly
for species at risk, migratory birds and other priority species
1.1. Sub-Goal: Forest habitats will be maintained to mimic an ecosystem driven by periodic low-intensity fires so that populations of species at risk, migratory birds and other priority species are sustained and/or residences and habitats are created, restored or maintained through active management.”
“Goal 4: Reduce risk of catastrophic fire in the NWA
4.1. Achieve sub-goal 1.1 so that fuel load is reduced through the removal of young trees and
downed woody material.” (Environment Canada, 2011).
It is therefore essential to take management actions to address goals 1 and 4 as stated above to ensure the fuel load is reduced and fire is reintroduced to improve habitat for species at risk and migratory birds, return the habitat to closer to historic habitats and meet the management objectives of the NWA.
