Carissa Wasyliw

Dr. Carissa Brown

Research Group
Northern EDGE Lab

Previous Education
BSc Environmental and Conservation Sciences (bilingual), University of Alberta (2015)

Title of Project
Drivers of novel post-fire successional trajectories in the western Canadian subarctic

Project Description
Increased warming caused by climate change in the western subarctic has improved growing conditions for plant species at their northern extent. Under these conditions, it is expected that tree species would expand northward into the tundra. However, this has not always been observed and, in some cases, non-treed plant communities are emerging. A reason for this may be due to changes in fire patterns. Fires have recently grown in frequency, intensity, and size, causing a misalignment with forest reproductive cycles. This has decreased tree regeneration and caused an increase in shrub communities along the boreal-tundra edge ecosystem. Preliminary observations in the Eagle Plains area of northern Yukon have shown a shift in novel post-fire successional trajectories from boreal forest regeneration to two distinct ecosystem types, either dense tall-shrub or sparse low-shrub dominated plant communities. While we have some understanding of the initial processes driving ecosystem change in response to novel fire in the region, little is known about the specific mechanisms influencing the establishment of dominant vegetation communities in the absence of trees. The purpose of this research is to understand how novel disturbance regimes are changing the dominant vegetation species in the northwestern subarctic and to determine the driving abiotic factors behind these changes. Understanding the main factors influencing ecosystem change in the area will help predict future trends in ecosystem dominance, and the associated impacts on ecosystem services, food webs, and cultural wellbeing of those living in northern communities. A shift to shrub dominated sites may have future implications on culturally significant species such as caribou (Rangifer tarandus) and various plant species that are commonly harvested for berries. Results from this study will help to predict future northern plant communities and inform management of these biologically and culturally significant areas.

Research Interests

  • Northern ecology
  • Plant succession
  • Climate change