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Using paleolimnological methods to assess environmental change across Canada

Using paleolimnological methods to assess environmental change across Canada

Jennifer Korosi

The Canadian landscape has an abundance of lakes under pressure from multiple stressors. Lakes are sentinels of environmental change, as they archive changes occurring both within the lake, and in the surrounding terrestrial ecosystems within its watershed. Paleolimnology, that is, the study of lake sediment cores to reconstruct past climatic and environmental changes, helps us to understand threats to lake water quality by answering three simple questions: how we got here, where we are now and where we might be heading? 

These are the critical issues that Professor Jennifer Korosi’s research on lake ecosystem and climate change are seeking to address. Using paleolimnological methods, her research aims to answer a range of critical questions related to environmental change across Canada. To build her research program, Korosi devotes her time thinking about research questions and getting her students started on thesis projects that infer past environmental conditions and trajectories of lake ecosystem change with a geographical focus in southern Ontario and the Northwest Territories.    

Collecting sediment core from Lake Ontario

Korosi and her research team, including postdoctoral fellow Emily Stewart, are conducting a range of research studies on the role of climate warming and permafrost thaw as drivers of terrestrial and lake ecosystem change in high-latitude regions. They also are looking into the role of climate change in influencing the cycling and ecotoxicity of industrial contaminants. As well, they are examining regime shifts and ecosystem resilience in southern Ontario lakes impacted by multiple stressors like urbanization and land use activities, with a focus on the Kawartha Lakes watershed. 

In her NSERC Discovery project, Korosi studies permafrost as a dominant feature of the Canadian landscape with fellow EUC Professor Joshua Thienpont. Notably, rates of permafrost thaw have accelerated in recent decades -- a trend that is expected to continue with future climate warming. The thawing of permafrost represents a major stressor on northern lakes that may negatively impact the provision of essential lake ecosystem services. Considering that empirical evidence of long-term impacts to lake ecological and biogeochemical function is lacking, Korosi’s research is using paleoenvironmental techniques to track permafrost landscape change in the Northwest Territories, and the resulting lake ecosystem responses, over centennial to millennial timescales.

Drunken forest is a sign of permafrost thaw

The field sites are based in the Inuvik-Tuktoyaktuk region (ice-rich, continuous permafrost), and the Dehcho region (discontinuous permafrost). Her Dehcho-focused research is conducted as part of the Dehcho Collaborative on Permafrost, an initiative that aims to fuse scientific and Indigenous knowledge on permafrost to co-develop new predictive decision support tools and risk management strategies to manage permafrost and adapt to permafrost thaw. 

Korosi has received the Dean’s Award for Distinction in Research (Emerging Researcher) at the Faculty of Liberal Arts and Professional Studies; Julian M. Szeicz Award for Early Career Achievement by the Canadian Association of Geographers; Early Researcher Award by the International Paleolimnology Association; and Petro-Canada Young Innovator Award at York.