The Role of 'Natural' and Prescribed Fire

Fire suppression during the last century has had multiple effects on the park’s landscape and ecology, including a shift to more even-aged composition of forest vegetation (Shepherd et al. 2007). More recently, Parks Canada has recognized the important role that natural disturbances, such as fire, play in the long-term health of forests. As a result, Jasper National Park now aims to "achieve annual burning of an area that would eventually emulate 50% of the ... average long-term fire cycle"(Shepherd et al. 2007, 130). Other objectives are fulfilled when these aims are reached, including the restoration of ecological integrity, controlling mountain pine beetle outbreaks, and reducing risk of catastrophic fire events within and near the park (Robinson et al. 2010b)

 

Whitebark Pine and Fire

Whitebark Pine is increasingly recognized as a keystone species in high elevation forests. However, it is in decline throughout its range largely due to the effects of fire suppression, mountain pine beetle outbreaks, and White Pine blister rust (Parks Canada 2012). Prescribed burning is increasingly advocated as a management tool for the species since fire plays an important role in tree regeneration and overall health of the population (Gould 2011). As a pioneer species establishing first after a disturbance, Whitebark Pine benefits from small and large scale disturbances, such as fires, that create canopy gaps. As succession takes place and other vegetation grows in, Whitebark Pine can be out-competed by other species that grow well in its shade. Thus, fire suppression has been seen as one of the main factors contributing to the Pine’s decline. Further, the species has co-evolved with the Clark’s Nutcracker bird which has a unique seed dispersal method that benefits from fire. The regeneration of the trees relies on the birds opening the cones and stashing the seeds in suitable areas. Furthermore, approximately half the seeds are forgotten by the birds and these seeds ultimately form the basis of Whitebark Pine regeneration (Wilson and Stuart-Smith 2002). The Clark's Nutcracker has been found to prefer to stash seeds in open spaces with rich exposed mineral soil, such as those created by fire (Parks Canada 2012; Wilson and Stuart-Smith 2002). The knowledge of the process of Whitebark Pine regeneration contributes to the current approach used for the species’ management. The argument that "a prescribed burn program... must be an integral part of Parks Canada’s Whitebark Pine ecosystem conservation strategy" (Wilson and Stuart-Smith 2002, 19) is actively shaping policies for Whitebark Pine management.

 

Woodland Caribou and Fire

            Woodland Caribou are threatened by altered predator-prey dynamics, increased predator access, human disturbance, habitat loss, and small population threats within the park (Parks Canada 2011a). Caribou are a unique species that have generally been found to prefer older forested habitat, with stand ages ranging from 75 – 150, and 225 - 300 years at higher elevations with gentle slopes. Caribou are specialists, and this selection of habitat largely reflects their main source of food (lichens), which is a slow growing species most abundant in older forest (Shepherd et al. 2007). For these reasons, fires within caribou habitats have been found to be detrimental to the health of the species’ both directly by destroying their main source of food, and indirectly by increasing the overlap between caribou and wolves (Robinson et al. 2010a). In the past, fires within caribou habitats would not have had such profound consequences for the population, as they could relocate to another area. However, resource extraction and other threats contributing to habitat loss and fragmentation threaten the species livelihood outside the park. Therefore, relocation to avoid prescribed burn areas is an unlikely possibility for caribou today (personal correspondence with Layla Neufeld). However, there are some positive potential consequences of prescribed burning for caribou: burning small areas and reducing ladder fuel decreases the likelihood that a 'naturally set' high severity fire could wipe out larger portions of caribou habitat (personal correspondence, Layla Neufeld). Furthermore, there is evidence that fire increases the suitability of the forest for lichen cover in the long term; however, the habitat would be unsuitable by caribou for at least 75 years (Shepherd et al. 2007). Given the decline in caribou population and the number and magnitude of threats already faced, waiting 75 years for suitable habitat is not an ideal situation. The current Parks Canada conservation strategy reflects these conclusions by stating that, fire should be used only “in areas away from caribou habitat to maintain a safe distance between caribou and their predators” (Parks Canada 2011a). However, the Park also acknowledges that prescribed burns could be used "to guard against large fires within caribou habitat" (Parks Canada 2011a).