Cassiope tetragona growth rate as a proxy of climate change on Ellesmere Island, Canada

The Arctic Tundra is an enigmatic biome. Its largely treeless plains feature low-lying sedges, grasses, mosses and shrubs adapted to permafrost, the permanently frozen subsoil that underpins what is, in fact, a surprisingly diverse northern ‘oasis’. As a region identified as particularly vulnerable to accelerated climate warming, a study of its flora can reveal much about the effects of such changes. A general study can give an overview of the ecological response to climate change in circumpolar regions, while individual species can be used as a proxy of long-term climate variations.

Open-top warming chambers at the Alexandra Fiord ITEX site. Photo: Professor Greg Henry,
University of British Columbia

My research will take me to Alexandra Fiord in the Canadian High Arctic, where I aim to analyse the growth and reproductive characteristics of the tundra shrub species Cassiope tetragona (Arctic bell-heather) and determine the link between these responses and climate change. My analysis will build on work established by the International Tundra Experiment (ITEX) in using dendrochronology – the study of tree rings. This is a common methodology within biogeography to infer environmental change, both spatial and temporal, within a specific locality. (Indeed, this tool has been used in each of the earth’s biomes for research into climate change, natural hazards such as forest fires and landslips, and even to identify and date the introduction of certain pollutants to a region.) While the Arctic tundra is a largely treeless environment, there exist some circumpolar species with growth characteristics that allow for similar applications – and Cassiope tetragona is one such species.

The tundra dwarf-shrub, Cassiope tetragona. Photo: Shaleen Humphreys, licensed under CC 3.0

This field site at Alexandra Fiord already consists of a long-term climate warming experiment in which a number of plots containing vascular tundra plant communities are contained within warming open-top ‘chambers’ (in which climate warming is simulated) alongside control plots (which are left without intervention). I will be able to calibrate the impact of the experimental climate warming on Cassiope tetragona by observing the annual changes in stem morphology from around 25 years since the beginning of the ITEX up until the present day. Ultimately, it is hoped that this will allow us to understand the effect of the experiment on the plants at the field site. Furthermore, the research will help to further develop the use of Cassiope tetragona as a relatively new climate proxy.

My Leverhulme Study Abroad Studentship will allow me to carry out this research as part of an MSc Geography degree at the University of British Columbia, a programme that enables me to cross-train in the disciplines of both biogeography and ecology. I also aim to pursue projects in science communication and outreach.

Ms Elise Gallois
University of British Columbia
Study Abroad Studentship