NWT RESEARCH DATABASE

Regions: Dehcho Region

Tags: physical sciences, permafrost, forestry, wildfire

Objective(s): To better understand the impact of disturbance on forest regeneration in the NWT.

Project Description: The primary objective is to better understand the impact of disturbance on forest regeneration in the NWT. To this end, the team aim to evaluate the direct impacts of both forest harvesting and wildfire on tree regeneration the interaction of these two disturbances with permafrost thaw. The research team will establish new monitoring sites in the proposed Forest Management Areas and adjacent unharvested catchments. Permafrost and vegetation sampling and hydrological characterization will be carried out in two areas in each catchment: upland sites (i.e. where harvesting will occur) and downslope sites (i.e. wetter, less productive areas underlain by permafrost unsuitable for harvesting). Sampling will be conducted prior to the proposed harvest date of Winter 2019/20 and in the years following harvest, thereby providing a powerful approach for understanding harvest impacts (Before-After-Control-Impact; BACI). The team will revisit sites with and without permafrost that were otherwise comparable to evaluate differences in regeneration outcomes associated with changing permafrost conditions. At each permafrost impacted site, the team will evaluate the permafrost conditions through maximum thaw depth measurements and existing emergency response team (ERT) surveys. The research team will also remeasure the vegetation composition and seedling counts at both permafrost and permafrost-free sites. Further, approximately 10% of sites experienced regeneration failure. To better understand what will replace forest in these sites where regeneration failed, the team will revisit the vegetation plots and measure the vegetation cover and composition.