Supervised by:

Christophe Kinnard (Regular Member (Co-researcher))

Co-supervised by:

Florent Domine (Regular Member (Co-researcher))

Research project description

Impacts of shrubs on snowpack thickness and thermal regime in the Arctic tundra

Introduction

Global warming is causing the expansion and growth of shrubs in the Arctic, a phenomenon known as Arctic "shrubification". Erect shrubs are known to intercept wind-blown snow, causing increased snow accumulation on the ground in shrub areas. This thicker snowpack insulates the ground, promoting winter soil warming and stimulating the decomposition of organic matter and the release of carbon dioxide to the atmosphere. On the other hand, shrub branches can act as thermal bridges and thus cause heat loss from the ground; the impact of shrubs on the thermal regime of the snowpack and the ground in winter is therefore still uncertain.

Objectives

The structuring effect of shrubs on snowpack requires a broader spatial view to better understand how the spatial organization of shrubs (e.g., isolated shrubs or groups of shrubs) alters snow redistribution across the landscape. In particular, the recent point-scale demonstration that shrub branches can act as heat bridges and cool the ground (Dominé et al., 2022), contradicts the commonly accepted notion that increased snow accumulation around shrubs warms permafrost. The proposed measurements aim to corroborate this phenomenon at the ecosystem scale, which would be a first.

Study Sites

The study site is located near Goose camp 1 of the CEN research station on Bylot Island, (73°N, -80°W) Nunavut. My study sites will be in the Qarlikturvik valley. The valley itself is relatively flat, and is characterized by artic tundra vegetation, with the presence of Salix Richardsonii and Salix Arctica.

Material and methods

In the spring of 2023, high-resolution (

Expected results

This study will enable us to better understand the dynamics between vegetation and snowpack thickness and temperature. Snow height maps will be produced using drone photogrammetry. These maps will enable us to detect where snow heights are highest. Shrub tales are areas where snow heights can be higher. Topographical depressions are also places where snow accumulates. Vertical temperature profiles in shrub vs. non-shrub sites can show whether the snow temperature is warmer in the shrub or non-shrub site.

Research Site Coordinates