Project Summary
Woodland caribou (Rangifer tarandus caribou) are a Threatened species in Canada. Their habitat in the boreal forests of Alberta is highly fragmented and disturbed by anthropogenic factors, such as oil and gas development and forestry. Additionally, the boreal forest is frequently disturbed by large, stand-replacing fires. Terricolous lichens of the Cladonia genus serve as a dominant food source for caribou populations, particularly during winter months. However, these lichens are very slow growing, and after a fire, they can take decades to reach a level of abundance that is suitable to sustain foraging caribou. As a result, caribou tend to avoid burns for many years after a fire. Additionally, caribou in Alberta spend much of their time in peatland habitats, to escape predation and to forage, but little is known of the forage availability in these refuge habitats.
Understanding the relationship between lichen cover and biomass in recovering stands in northeastern Alberta is important for accurately mapping available lichen forage. In this study, we look at the effects of fire on lichen regeneration in upland jack pine stands in the oil sands region of northeastern Alberta, and we also examine available lichen biomass in peatland habitats within known caribou ranges. I measured percent cover and height of five common reindeer lichen species in upland jack pine stands at various times since fire, and in mature peatland habitats. I also harvested a subsample of lichen in order to dry and weigh it. I compared this biomass to lichen cover relationship between fire ages to understand the effect of fire on lichen biomass recovery, as well as in peatlands, in order to quantify the available biomass in these habitats. I observed low lichen abundance after a recent fire, but total biomass increased rapidly between 20 and 40 years post-fire. Forests greater than 40 years post-fire maintained high levels of total biomass, but surprisingly, peatland habitats showed low total biomass. These findings may have implications for the identification and management of critical habitat for struggling woodland caribou populations, and may help guide wildfire management within caribou ranges.
Understanding the relationship between lichen cover and biomass in recovering stands in northeastern Alberta is important for accurately mapping available lichen forage. In this study, we look at the effects of fire on lichen regeneration in upland jack pine stands in the oil sands region of northeastern Alberta, and we also examine available lichen biomass in peatland habitats within known caribou ranges. I measured percent cover and height of five common reindeer lichen species in upland jack pine stands at various times since fire, and in mature peatland habitats. I also harvested a subsample of lichen in order to dry and weigh it. I compared this biomass to lichen cover relationship between fire ages to understand the effect of fire on lichen biomass recovery, as well as in peatlands, in order to quantify the available biomass in these habitats. I observed low lichen abundance after a recent fire, but total biomass increased rapidly between 20 and 40 years post-fire. Forests greater than 40 years post-fire maintained high levels of total biomass, but surprisingly, peatland habitats showed low total biomass. These findings may have implications for the identification and management of critical habitat for struggling woodland caribou populations, and may help guide wildfire management within caribou ranges.
Figure 1. Mat-forming lichens in a mature upland jack pine stand.
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Figure 2. Conducting lichen surveys in an upland pine stand.
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Figure 3. Cladonia stellaris, an important forage resource for woodland caribou.
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Disclaimer*. All or parts of this data may have been fabricated for the purposes of a RenR711 project.
About the Researcher
Ashley Hillman is a Research Assistant with the Applied Conservation Ecology Lab at the University of Alberta, led by Dr. Scott Nielsen. She has a broad background in field research, and has spent many summers working in the boreal forest, trudging through peatlands and swatting away insects. Her knowledge of lichen diversity and ecology led her to investigate how lichens can be used to aid in caribou management. |