Zachary Lefebvre
MSc Student
Département de géographie
Université Laval
zalef1@ulaval.ca
Research project description
Determining the distribution and formation conditions of Thufurs in the Parc national des Grands-Jardins sector
Introduction
The Parc national des Grands Jardins is a protected area located within the Charlevoix Biosphere Reserve. The exceptional natural heritage of the park, characterized by alpine plateaus, boreal forest and wetlands, is subject to a variety of pressures, particularly anthropogenic. The natural heritage includes frost basins, a lichen-covered environment where few summer days are frost-free. These environments are sometimes characterized by an abundance of thufurs, a type of periglacial soil that creates a repeating pattern. These forms are observed in a variety of northern environments, but their genesis and sensitivity is still poorly understood, hence the importance of studying them in this rich natural area to ensure their proper enhancement and protection.
Objectives
The aim of this research is to explain the genesis and context of the thufurs in the Parc des grands jardins. Specifically, it aims to (i) determine the spatial distribution of thufur fields in relation to surface deposits, topography and vegetation. (ii) elucidate the genesis conditions and activity history of the thufurs; and (iii) determine the sensitivity of thufurs and their regeneration potential.
Study Sites
The park is in the unorganized territory of Lac-Pikauba, within the Capitale Nationale region. Thufurs are found in frost bowls where local air masses and the ecological conditions of lichen spruce forests increase the likelihood of cold air masses forming on summer nights (Dy & Payette, 2007).
Five thufur fields will be selected as study sites in consultation with the Société des établissements de plein air du Québec (Sépaq), to avoid impacting sensitive areas and to include sites of particular interest.
Material and methods
Once the distribution of thufur fields has been determined using aerial photographs, common topographical, geomorphological and hydrological conditions will be determined using spatial analyses in ArcGIS.
At 5 selected sites, air and soil temperatures will be measured and the characteristics (height, width, number) of the thufurs will be determined. At each site, five thufurs will be sampled at their center using an Oakfield corer to characterize sediment granulometry and establish the presence or absence of fine sediments. If conditions permit, a thufur will be cut from each site to establish whether signs of involution are present in the sediment. Organic matter will be sampled at the interface between the mineral sediment and the organic layer to date the stabilization of the mineral surface.
References
Dy & Payette (2007). Frost hollows of the boreal forest as extreme environments for black spruce tree growth. Canadian Journal of Forest Research. 37(2): 492-504. https://doi.org/10.1139/X06-235
Research Site Coordinates
