Photo Credit: Nick Parayko @nickparaykoimages
Controlled burns are a critical forest management tool and play a role in shaping the habitats of local animal and plant life in Northeastern British Columbia with up to 7,800 hectares burned each year. However, the effects of prescribed fires on ungulates (hooved animals) and their food supply are not yet thoroughly studied. In the Muskwa-Kechika Management Area of northeastern British Columbia, researchers from the Natural Resources and Environmental Studies Institute examined this widely used method for managing our forests and its effects on mountain dwelling grazing species, primarily elk and Stone’s sheep, as well as their food sources.
Researchers found that vegetation previously subjected to prescribed burns tended to have a significant short-term increase in their protein content and digestibility, making them more nutritious for grazing wildlife. The rate of growth of forage vegetation tended to be higher in the long run for burned areas, resulting in more food available. Furthermore, there were no invasive species introduced that could “out-compete native plants and have detrimental effects on forage quality in winter for ungulates.†Prescribed fires seem to have an overall positive effect on the quality and quantity of forage vegetation as opposed to unburned areas.
Using a variety of data collection methods such as radio collars, aerial observation, and examination of fecal pellets, researchers were able to form a comprehensive picture of the effects of controlled burns on local grazing species. They observed that both elk and Stone’s sheep strongly preferred areas previously subjected to burns. Elk preferred to use burned areas of varying ages with fast growing vegetation due to their large size and the amount of forage material required to sustain them whereas Stone’s sheep preferred younger burns with higher quality vegetation or rocky areas where they were more able to guard against predators.
Initially, there were concerns that prescribed burns would cause forage areas of different species to overlap, forcing them to compete for resources. However, “the two species partitioned the landscape through their differential use of elevation and topography†with Stone’s sheep preferring higher elevations and more rugged terrain and elk selecting lower elevations for grazing.
Based on their findings, researchers suggest that larger burns on south-facing slopes would benefit both species. South-facing slopes tended to have higher quantities of forage, and a larger burn would maximize the amount of food available to both species. Smaller burns on west-facing slopes with access to rugged terrain would benefit Stone’s sheep more by “reducing shrubs and increasing forage quality.†West-facing slopes tended to have more moisture and produce higher quality food sources. There is little risk of competition between the two species to their preference for different grazing areas.
Photo Credit: Stevin Tuchiwsky @stevint
While prescribed fire seems to enhance the quality of habitats for northern, mountain-dwelling ungulates in the short term, long term effects are not yet thoroughly understood. Furthermore, the effects of increasing numbers of grazing species on the predator population are not yet studied though it seems likely that “predator populations are likely to increase in response to the increasing elk prey base.†Careful monitoring of the longer term effects of prescribed fires is necessary to truly understand its effects.
In northeastern British Columbia, controlled burns are commonly used as a method to enhance the habitats of ungulates. This habitat management tool has a considerable impact on the ecosystem of mountainous and forested regions. While short-term effects are positive for local grazing species, the long-term effects are not yet thoroughly understood and warrant further study and monitoring to understand its impact on the mountain ecosystem.
This is a summary article written by Pierre Lin. For more information, please access the full document:
